summaryrefslogtreecommitdiff
path: root/include/linux/kexec.h
AgeCommit message (Collapse)AuthorFilesLines
2023-12-21kexec_file: add kexec_file flag to control debug printingBaoquan He1-1/+8
Patch series "kexec_file: print out debugging message if required", v4. Currently, specifying '-d' on kexec command will print a lot of debugging informationabout kexec/kdump loading with kexec_load interface. However, kexec_file_load prints nothing even though '-d' is specified. It's very inconvenient to debug or analyze the kexec/kdump loading when something wrong happened with kexec/kdump itself or develper want to check the kexec/kdump loading. In this patchset, a kexec_file flag is KEXEC_FILE_DEBUG added and checked in code. If it's passed in, debugging message of kexec_file code will be printed out and can be seen from console and dmesg. Otherwise, the debugging message is printed like beofre when pr_debug() is taken. Note: **** ===== 1) The code in kexec-tools utility also need be changed to support passing KEXEC_FILE_DEBUG to kernel when 'kexec -s -d' is specified. The patch link is here: ========= [PATCH] kexec_file: add kexec_file flag to support debug printing http://lists.infradead.org/pipermail/kexec/2023-November/028505.html 2) s390 also has kexec_file code, while I am not sure what debugging information is necessary. So leave it to s390 developer. Test: **** ==== Testing was done in v1 on x86_64 and arm64. For v4, tested on x86_64 again. And on x86_64, the printed messages look like below: -------------------------------------------------------------- kexec measurement buffer for the loaded kernel at 0x207fffe000. Loaded purgatory at 0x207fff9000 Loaded boot_param, command line and misc at 0x207fff3000 bufsz=0x1180 memsz=0x1180 Loaded 64bit kernel at 0x207c000000 bufsz=0xc88200 memsz=0x3c4a000 Loaded initrd at 0x2079e79000 bufsz=0x2186280 memsz=0x2186280 Final command line is: root=/dev/mapper/fedora_intel--knightslanding--lb--02-root ro rd.lvm.lv=fedora_intel-knightslanding-lb-02/root console=ttyS0,115200N81 crashkernel=256M E820 memmap: 0000000000000000-000000000009a3ff (1) 000000000009a400-000000000009ffff (2) 00000000000e0000-00000000000fffff (2) 0000000000100000-000000006ff83fff (1) 000000006ff84000-000000007ac50fff (2) ...... 000000207fff6150-000000207fff615f (128) 000000207fff6160-000000207fff714f (1) 000000207fff7150-000000207fff715f (128) 000000207fff7160-000000207fff814f (1) 000000207fff8150-000000207fff815f (128) 000000207fff8160-000000207fffffff (1) nr_segments = 5 segment[0]: buf=0x000000004e5ece74 bufsz=0x211 mem=0x207fffe000 memsz=0x1000 segment[1]: buf=0x000000009e871498 bufsz=0x4000 mem=0x207fff9000 memsz=0x5000 segment[2]: buf=0x00000000d879f1fe bufsz=0x1180 mem=0x207fff3000 memsz=0x2000 segment[3]: buf=0x000000001101cd86 bufsz=0xc88200 mem=0x207c000000 memsz=0x3c4a000 segment[4]: buf=0x00000000c6e38ac7 bufsz=0x2186280 mem=0x2079e79000 memsz=0x2187000 kexec_file_load: type:0, start:0x207fff91a0 head:0x109e004002 flags:0x8 --------------------------------------------------------------------------- This patch (of 7): When specifying 'kexec -c -d', kexec_load interface will print loading information, e.g the regions where kernel/initrd/purgatory/cmdline are put, the memmap passed to 2nd kernel taken as system RAM ranges, and printing all contents of struct kexec_segment, etc. These are very helpful for analyzing or positioning what's happening when kexec/kdump itself failed. The debugging printing for kexec_load interface is made in user space utility kexec-tools. Whereas, with kexec_file_load interface, 'kexec -s -d' print nothing. Because kexec_file code is mostly implemented in kernel space, and the debugging printing functionality is missed. It's not convenient when debugging kexec/kdump loading and jumping with kexec_file_load interface. Now add KEXEC_FILE_DEBUG to kexec_file flag to control the debugging message printing. And add global variable kexec_file_dbg_print and macro kexec_dprintk() to facilitate the printing. This is a preparation, later kexec_dprintk() will be used to replace the existing pr_debug(). Once 'kexec -s -d' is specified, it will print out kexec/kdump loading information. If '-d' is not specified, it regresses to pr_debug(). Link: https://lkml.kernel.org/r/20231213055747.61826-1-bhe@redhat.com Link: https://lkml.kernel.org/r/20231213055747.61826-2-bhe@redhat.com Signed-off-by: Baoquan He <bhe@redhat.com> Cc: Conor Dooley <conor@kernel.org> Cc: Joe Perches <joe@perches.com> Cc: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-04crash_core: move crashk_*res definition into crash_core.cBaoquan He1-4/+0
Both crashk_res and crashk_low_res are used to mark the reserved crashkernel regions in iomem_resource tree. And later the generic crashkernel resrvation will be added into crash_core.c. So move crashk_res and crashk_low_res definition into crash_core.c to avoid compiling error if CONFIG_CRASH_CORE=on while CONFIG_KEXEC_CORE is unset. Meanwhile include <asm/crash_core.h> in <linux/crash_core.h> if generic reservation is needed. In that case, <asm/crash_core.h> need be added by ARCH. In asm/crash_core.h, ARCH can provide its own macro definitions to override macros in <linux/crash_core.h> if needed. Wrap the including into CONFIG_ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION ifdeffery scope to avoid compiling error in other ARCH-es which don't take the generic reservation way yet. Link: https://lkml.kernel.org/r/20230914033142.676708-6-bhe@redhat.com Signed-off-by: Baoquan He <bhe@redhat.com> Reviewed-by: Zhen Lei <thunder.leizhen@huawei.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chen Jiahao <chenjiahao16@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-25crash: hotplug support for kexec_load()Eric DeVolder1-2/+12
The hotplug support for kexec_load() requires changes to the userspace kexec-tools and a little extra help from the kernel. Given a kdump capture kernel loaded via kexec_load(), and a subsequent hotplug event, the crash hotplug handler finds the elfcorehdr and rewrites it to reflect the hotplug change. That is the desired outcome, however, at kernel panic time, the purgatory integrity check fails (because the elfcorehdr changed), and the capture kernel does not boot and no vmcore is generated. Therefore, the userspace kexec-tools/kexec must indicate to the kernel that the elfcorehdr can be modified (because the kexec excluded the elfcorehdr from the digest, and sized the elfcorehdr memory buffer appropriately). To facilitate hotplug support with kexec_load(): - a new kexec flag KEXEC_UPATE_ELFCOREHDR indicates that it is safe for the kernel to modify the kexec_load()'d elfcorehdr - the /sys/kernel/crash_elfcorehdr_size node communicates the preferred size of the elfcorehdr memory buffer - The sysfs crash_hotplug nodes (ie. /sys/devices/system/[cpu|memory]/crash_hotplug) dynamically take into account kexec_file_load() vs kexec_load() and KEXEC_UPDATE_ELFCOREHDR. This is critical so that the udev rule processing of crash_hotplug is all that is needed to determine if the userspace unload-then-load of the kdump image is to be skipped, or not. The proposed udev rule change looks like: # The kernel updates the crash elfcorehdr for CPU and memory changes SUBSYSTEM=="cpu", ATTRS{crash_hotplug}=="1", GOTO="kdump_reload_end" SUBSYSTEM=="memory", ATTRS{crash_hotplug}=="1", GOTO="kdump_reload_end" The table below indicates the behavior of kexec_load()'d kdump image updates (with the new udev crash_hotplug rule in place): Kernel |Kexec -------+-----+---- Old |Old |New | a | a -------+-----+---- New | a | b -------+-----+---- where kexec 'old' and 'new' delineate kexec-tools has the needed modifications for the crash hotplug feature, and kernel 'old' and 'new' delineate the kernel supports this crash hotplug feature. Behavior 'a' indicates the unload-then-reload of the entire kdump image. For the kexec 'old' column, the unload-then-reload occurs due to the missing flag KEXEC_UPDATE_ELFCOREHDR. An 'old' kernel (with 'new' kexec) does not present the crash_hotplug sysfs node, which leads to the unload-then-reload of the kdump image. Behavior 'b' indicates the desired optimized behavior of the kernel directly modifying the elfcorehdr and avoiding the unload-then-reload of the kdump image. If the udev rule is not updated with crash_hotplug node check, then no matter any combination of kernel or kexec is new or old, the kdump image continues to be unload-then-reload on hotplug changes. To fully support crash hotplug feature, there needs to be a rollout of kernel, kexec-tools and udev rule changes. However, the order of the rollout of these pieces does not matter; kexec_load()'d kdump images still function for hotplug as-is. Link: https://lkml.kernel.org/r/20230814214446.6659-7-eric.devolder@oracle.com Signed-off-by: Eric DeVolder <eric.devolder@oracle.com> Suggested-by: Hari Bathini <hbathini@linux.ibm.com> Acked-by: Hari Bathini <hbathini@linux.ibm.com> Acked-by: Baoquan He <bhe@redhat.com> Cc: Akhil Raj <lf32.dev@gmail.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Borislav Petkov (AMD) <bp@alien8.de> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Dave Young <dyoung@redhat.com> Cc: David Hildenbrand <david@redhat.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Mimi Zohar <zohar@linux.ibm.com> Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Sean Christopherson <seanjc@google.com> Cc: Sourabh Jain <sourabhjain@linux.ibm.com> Cc: Takashi Iwai <tiwai@suse.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Thomas Weißschuh <linux@weissschuh.net> Cc: Valentin Schneider <vschneid@redhat.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-25crash: memory and CPU hotplug sysfs attributesEric DeVolder1-0/+8
Introduce the crash_hotplug attribute for memory and CPUs for use by userspace. These attributes directly facilitate the udev rule for managing userspace re-loading of the crash kernel upon hot un/plug changes. For memory, expose the crash_hotplug attribute to the /sys/devices/system/memory directory. For example: # udevadm info --attribute-walk /sys/devices/system/memory/memory81 looking at device '/devices/system/memory/memory81': KERNEL=="memory81" SUBSYSTEM=="memory" DRIVER=="" ATTR{online}=="1" ATTR{phys_device}=="0" ATTR{phys_index}=="00000051" ATTR{removable}=="1" ATTR{state}=="online" ATTR{valid_zones}=="Movable" looking at parent device '/devices/system/memory': KERNELS=="memory" SUBSYSTEMS=="" DRIVERS=="" ATTRS{auto_online_blocks}=="offline" ATTRS{block_size_bytes}=="8000000" ATTRS{crash_hotplug}=="1" For CPUs, expose the crash_hotplug attribute to the /sys/devices/system/cpu directory. For example: # udevadm info --attribute-walk /sys/devices/system/cpu/cpu0 looking at device '/devices/system/cpu/cpu0': KERNEL=="cpu0" SUBSYSTEM=="cpu" DRIVER=="processor" ATTR{crash_notes}=="277c38600" ATTR{crash_notes_size}=="368" ATTR{online}=="1" looking at parent device '/devices/system/cpu': KERNELS=="cpu" SUBSYSTEMS=="" DRIVERS=="" ATTRS{crash_hotplug}=="1" ATTRS{isolated}=="" ATTRS{kernel_max}=="8191" ATTRS{nohz_full}==" (null)" ATTRS{offline}=="4-7" ATTRS{online}=="0-3" ATTRS{possible}=="0-7" ATTRS{present}=="0-3" With these sysfs attributes in place, it is possible to efficiently instruct the udev rule to skip crash kernel reloading for kernels configured with crash hotplug support. For example, the following is the proposed udev rule change for RHEL system 98-kexec.rules (as the first lines of the rule file): # The kernel updates the crash elfcorehdr for CPU and memory changes SUBSYSTEM=="cpu", ATTRS{crash_hotplug}=="1", GOTO="kdump_reload_end" SUBSYSTEM=="memory", ATTRS{crash_hotplug}=="1", GOTO="kdump_reload_end" When examined in the context of 98-kexec.rules, the above rules test if crash_hotplug is set, and if so, the userspace initiated unload-then-reload of the crash kernel is skipped. CPU and memory checks are separated in accordance with CONFIG_HOTPLUG_CPU and CONFIG_MEMORY_HOTPLUG kernel config options. If an architecture supports, for example, memory hotplug but not CPU hotplug, then the /sys/devices/system/memory/crash_hotplug attribute file is present, but the /sys/devices/system/cpu/crash_hotplug attribute file will NOT be present. Thus the udev rule skips userspace processing of memory hot un/plug events, but the udev rule will evaluate false for CPU events, thus allowing userspace to process CPU hot un/plug events (ie the unload-then-reload of the kdump capture kernel). Link: https://lkml.kernel.org/r/20230814214446.6659-5-eric.devolder@oracle.com Signed-off-by: Eric DeVolder <eric.devolder@oracle.com> Reviewed-by: Sourabh Jain <sourabhjain@linux.ibm.com> Acked-by: Hari Bathini <hbathini@linux.ibm.com> Acked-by: Baoquan He <bhe@redhat.com> Cc: Akhil Raj <lf32.dev@gmail.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Borislav Petkov (AMD) <bp@alien8.de> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Dave Young <dyoung@redhat.com> Cc: David Hildenbrand <david@redhat.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Mimi Zohar <zohar@linux.ibm.com> Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Sean Christopherson <seanjc@google.com> Cc: Takashi Iwai <tiwai@suse.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Thomas Weißschuh <linux@weissschuh.net> Cc: Valentin Schneider <vschneid@redhat.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-25crash: add generic infrastructure for crash hotplug supportEric DeVolder1-0/+11
To support crash hotplug, a mechanism is needed to update the crash elfcorehdr upon CPU or memory changes (eg. hot un/plug or off/ onlining). The crash elfcorehdr describes the CPUs and memory to be written into the vmcore. To track CPU changes, callbacks are registered with the cpuhp mechanism via cpuhp_setup_state_nocalls(CPUHP_BP_PREPARE_DYN). The crash hotplug elfcorehdr update has no explicit ordering requirement (relative to other cpuhp states), so meets the criteria for utilizing CPUHP_BP_PREPARE_DYN. CPUHP_BP_PREPARE_DYN is a dynamic state and avoids the need to introduce a new state for crash hotplug. Also, CPUHP_BP_PREPARE_DYN is the last state in the PREPARE group, just prior to the STARTING group, which is very close to the CPU starting up in a plug/online situation, or stopping in a unplug/ offline situation. This minimizes the window of time during an actual plug/online or unplug/offline situation in which the elfcorehdr would be inaccurate. Note that for a CPU being unplugged or offlined, the CPU will still be present in the list of CPUs generated by crash_prepare_elf64_headers(). However, there is no need to explicitly omit the CPU, see justification in 'crash: change crash_prepare_elf64_headers() to for_each_possible_cpu()'. To track memory changes, a notifier is registered to capture the memblock MEM_ONLINE and MEM_OFFLINE events via register_memory_notifier(). The CPU callbacks and memory notifiers invoke crash_handle_hotplug_event() which performs needed tasks and then dispatches the event to the architecture specific arch_crash_handle_hotplug_event() to update the elfcorehdr with the current state of CPUs and memory. During the process, the kexec_lock is held. Link: https://lkml.kernel.org/r/20230814214446.6659-3-eric.devolder@oracle.com Signed-off-by: Eric DeVolder <eric.devolder@oracle.com> Reviewed-by: Sourabh Jain <sourabhjain@linux.ibm.com> Acked-by: Hari Bathini <hbathini@linux.ibm.com> Acked-by: Baoquan He <bhe@redhat.com> Cc: Akhil Raj <lf32.dev@gmail.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Borislav Petkov (AMD) <bp@alien8.de> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Dave Young <dyoung@redhat.com> Cc: David Hildenbrand <david@redhat.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Mimi Zohar <zohar@linux.ibm.com> Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Sean Christopherson <seanjc@google.com> Cc: Takashi Iwai <tiwai@suse.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Thomas Weißschuh <linux@weissschuh.net> Cc: Valentin Schneider <vschneid@redhat.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-25crash: move a few code bits to setup support of crash hotplugEric DeVolder1-15/+0
Patch series "crash: Kernel handling of CPU and memory hot un/plug", v28. Once the kdump service is loaded, if changes to CPUs or memory occur, either by hot un/plug or off/onlining, the crash elfcorehdr must also be updated. The elfcorehdr describes to kdump the CPUs and memory in the system, and any inaccuracies can result in a vmcore with missing CPU context or memory regions. The current solution utilizes udev to initiate an unload-then-reload of the kdump image (eg. kernel, initrd, boot_params, purgatory and elfcorehdr) by the userspace kexec utility. In the original post I outlined the significant performance problems related to offloading this activity to userspace. This patchset introduces a generic crash handler that registers with the CPU and memory notifiers. Upon CPU or memory changes, from either hot un/plug or off/onlining, this generic handler is invoked and performs important housekeeping, for example obtaining the appropriate lock, and then invokes an architecture specific handler to do the appropriate elfcorehdr update. Note the description in patch 'crash: change crash_prepare_elf64_headers() to for_each_possible_cpu()' and 'x86/crash: optimize CPU changes' that enables further optimizations related to CPU plug/unplug/online/offline performance of elfcorehdr updates. In the case of x86_64, the arch specific handler generates a new elfcorehdr, and overwrites the old one in memory; thus no involvement with userspace needed. To realize the benefits/test this patchset, one must make a couple of minor changes to userspace: - Prevent udev from updating kdump crash kernel on hot un/plug changes. Add the following as the first lines to the RHEL udev rule file /usr/lib/udev/rules.d/98-kexec.rules: # The kernel updates the crash elfcorehdr for CPU and memory changes SUBSYSTEM=="cpu", ATTRS{crash_hotplug}=="1", GOTO="kdump_reload_end" SUBSYSTEM=="memory", ATTRS{crash_hotplug}=="1", GOTO="kdump_reload_end" With this changeset applied, the two rules evaluate to false for CPU and memory change events and thus skip the userspace unload-then-reload of kdump. - Change to the kexec_file_load for loading the kdump kernel: Eg. on RHEL: in /usr/bin/kdumpctl, change to: standard_kexec_args="-p -d -s" which adds the -s to select kexec_file_load() syscall. This kernel patchset also supports kexec_load() with a modified kexec userspace utility. A working changeset to the kexec userspace utility is posted to the kexec-tools mailing list here: http://lists.infradead.org/pipermail/kexec/2023-May/027049.html To use the kexec-tools patch, apply, build and install kexec-tools, then change the kdumpctl's standard_kexec_args to replace the -s with --hotplug. The removal of -s reverts to the kexec_load syscall and the addition of --hotplug invokes the changes put forth in the kexec-tools patch. This patch (of 8): The crash hotplug support leans on the work for the kexec_file_load() syscall. To also support the kexec_load() syscall, a few bits of code need to be move outside of CONFIG_KEXEC_FILE. As such, these bits are moved out of kexec_file.c and into a common location crash_core.c. In addition, struct crash_mem and crash_notes were moved to new locales so that PROC_KCORE, which sets CRASH_CORE alone, builds correctly. No functionality change intended. Link: https://lkml.kernel.org/r/20230814214446.6659-1-eric.devolder@oracle.com Link: https://lkml.kernel.org/r/20230814214446.6659-2-eric.devolder@oracle.com Signed-off-by: Eric DeVolder <eric.devolder@oracle.com> Reviewed-by: Sourabh Jain <sourabhjain@linux.ibm.com> Acked-by: Hari Bathini <hbathini@linux.ibm.com> Acked-by: Baoquan He <bhe@redhat.com> Cc: Akhil Raj <lf32.dev@gmail.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Borislav Petkov (AMD) <bp@alien8.de> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Dave Young <dyoung@redhat.com> Cc: David Hildenbrand <david@redhat.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Mimi Zohar <zohar@linux.ibm.com> Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Sean Christopherson <seanjc@google.com> Cc: Takashi Iwai <tiwai@suse.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Thomas Weißschuh <linux@weissschuh.net> Cc: Valentin Schneider <vschneid@redhat.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-08kexec: remove unnecessary arch_kexec_kernel_image_load()Bjorn Helgaas1-6/+0
arch_kexec_kernel_image_load() only calls kexec_image_load_default(), and there are no arch-specific implementations. Remove the unnecessary arch_kexec_kernel_image_load() and make kexec_image_load_default() static. No functional change intended. Link: https://lkml.kernel.org/r/20230307224416.907040-3-helgaas@kernel.org Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Simon Horman <horms@kernel.org> Acked-by: Baoquan He <bhe@redhat.com> Cc: Borislav Petkov (AMD) <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-08x86/kexec: remove unnecessary arch_kexec_kernel_image_load()Bjorn Helgaas1-2/+0
Patch series "kexec: Remove unnecessary arch hook", v2. There are no arch-specific things in arch_kexec_kernel_image_load(), so remove it and just use the generic version. This patch (of 2): The x86 implementation of arch_kexec_kernel_image_load() is functionally identical to the generic arch_kexec_kernel_image_load(): arch_kexec_kernel_image_load # x86 if (!image->fops || !image->fops->load) return ERR_PTR(-ENOEXEC); return image->fops->load(image, image->kernel_buf, ...) arch_kexec_kernel_image_load # generic kexec_image_load_default if (!image->fops || !image->fops->load) return ERR_PTR(-ENOEXEC); return image->fops->load(image, image->kernel_buf, ...) Remove the x86-specific version and use the generic arch_kexec_kernel_image_load(). No functional change intended. Link: https://lkml.kernel.org/r/20230307224416.907040-1-helgaas@kernel.org Link: https://lkml.kernel.org/r/20230307224416.907040-2-helgaas@kernel.org Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Simon Horman <horms@kernel.org> Acked-by: Baoquan He <bhe@redhat.com> Cc: Borislav Petkov (AMD) <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-03kexec: introduce sysctl parameters kexec_load_limit_*Ricardo Ribalda1-1/+1
kexec allows replacing the current kernel with a different one. This is usually a source of concerns for sysadmins that want to harden a system. Linux already provides a way to disable loading new kexec kernel via kexec_load_disabled, but that control is very coard, it is all or nothing and does not make distinction between a panic kexec and a normal kexec. This patch introduces new sysctl parameters, with finer tuning to specify how many times a kexec kernel can be loaded. The sysadmin can set different limits for kexec panic and kexec reboot kernels. The value can be modified at runtime via sysctl, but only with a stricter value. With these new parameters on place, a system with loadpin and verity enabled, using the following kernel parameters: sysctl.kexec_load_limit_reboot=0 sysct.kexec_load_limit_panic=1 can have a good warranty that if initrd tries to load a panic kernel, a malitious user will have small chances to replace that kernel with a different one, even if they can trigger timeouts on the disk where the panic kernel lives. Link: https://lkml.kernel.org/r/20221114-disable-kexec-reset-v6-3-6a8531a09b9a@chromium.org Signed-off-by: Ricardo Ribalda <ribalda@chromium.org> Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org> Acked-by: Baoquan He <bhe@redhat.com> Cc: Bagas Sanjaya <bagasdotme@gmail.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Guilherme G. Piccoli <gpiccoli@igalia.com> # Steam Deck Cc: Joel Fernandes (Google) <joel@joelfernandes.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Philipp Rudo <prudo@redhat.com> Cc: Ross Zwisler <zwisler@kernel.org> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-03kexec: factor out kexec_load_permittedRicardo Ribalda1-1/+2
Both syscalls (kexec and kexec_file) do the same check, let's factor it out. Link: https://lkml.kernel.org/r/20221114-disable-kexec-reset-v6-2-6a8531a09b9a@chromium.org Signed-off-by: Ricardo Ribalda <ribalda@chromium.org> Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org> Acked-by: Baoquan He <bhe@redhat.com> Cc: Bagas Sanjaya <bagasdotme@gmail.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Guilherme G. Piccoli <gpiccoli@igalia.com> Cc: Joel Fernandes (Google) <joel@joelfernandes.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Philipp Rudo <prudo@redhat.com> Cc: Ross Zwisler <zwisler@kernel.org> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-11-19kexec: replace crash_mem_range with rangeLi Chen1-5/+2
We already have struct range, so just use it. Link: https://lkml.kernel.org/r/20220929042936.22012-4-bhe@redhat.com Signed-off-by: Li Chen <lchen@ambarella.com> Signed-off-by: Baoquan He <bhe@redhat.com> Acked-by: Baoquan He <bhe@redhat.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Chen Lifu <chenlifu@huawei.com> Cc: "Eric W . Biederman" <ebiederm@xmission.com> Cc: Jianglei Nie <niejianglei2021@163.com> Cc: Petr Mladek <pmladek@suse.com> Cc: Russell King <linux@armlinux.org.uk> Cc: ye xingchen <ye.xingchen@zte.com.cn> Cc: Zeal Robot <zealci@zte.com.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-12kexec: turn all kexec_mutex acquisitions into trylocksValentin Schneider1-1/+1
Patch series "kexec, panic: Making crash_kexec() NMI safe", v4. This patch (of 2): Most acquistions of kexec_mutex are done via mutex_trylock() - those were a direct "translation" from: 8c5a1cf0ad3a ("kexec: use a mutex for locking rather than xchg()") there have however been two additions since then that use mutex_lock(): crash_get_memory_size() and crash_shrink_memory(). A later commit will replace said mutex with an atomic variable, and locking operations will become atomic_cmpxchg(). Rather than having those mutex_lock() become while (atomic_cmpxchg(&lock, 0, 1)), turn them into trylocks that can return -EBUSY on acquisition failure. This does halve the printable size of the crash kernel, but that's still neighbouring 2G for 32bit kernels which should be ample enough. Link: https://lkml.kernel.org/r/20220630223258.4144112-1-vschneid@redhat.com Link: https://lkml.kernel.org/r/20220630223258.4144112-2-vschneid@redhat.com Signed-off-by: Valentin Schneider <vschneid@redhat.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: "Eric W . Biederman" <ebiederm@xmission.com> Cc: Juri Lelli <jlelli@redhat.com> Cc: Luis Claudio R. Goncalves <lgoncalv@redhat.com> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Petr Mladek <pmladek@suse.com> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Baoquan He <bhe@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-15kexec, KEYS: make the code in bzImage64_verify_sig genericCoiby Xu1-0/+7
commit 278311e417be ("kexec, KEYS: Make use of platform keyring for signature verify") adds platform keyring support on x86 kexec but not arm64. The code in bzImage64_verify_sig uses the keys on the .builtin_trusted_keys, .machine, if configured and enabled, .secondary_trusted_keys, also if configured, and .platform keyrings to verify the signed kernel image as PE file. Cc: kexec@lists.infradead.org Cc: keyrings@vger.kernel.org Cc: linux-security-module@vger.kernel.org Reviewed-by: Michal Suchanek <msuchanek@suse.de> Signed-off-by: Coiby Xu <coxu@redhat.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2022-07-15kexec: clean up arch_kexec_kernel_verify_sigCoiby Xu1-5/+0
Before commit 105e10e2cf1c ("kexec_file: drop weak attribute from functions"), there was already no arch-specific implementation of arch_kexec_kernel_verify_sig. With weak attribute dropped by that commit, arch_kexec_kernel_verify_sig is completely useless. So clean it up. Note later patches are dependent on this patch so it should be backported to the stable tree as well. Cc: stable@vger.kernel.org Suggested-by: Eric W. Biederman <ebiederm@xmission.com> Reviewed-by: Michal Suchanek <msuchanek@suse.de> Acked-by: Baoquan He <bhe@redhat.com> Signed-off-by: Coiby Xu <coxu@redhat.com> [zohar@linux.ibm.com: reworded patch description "Note"] Link: https://lore.kernel.org/linux-integrity/20220714134027.394370-1-coxu@redhat.com/ Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2022-07-15kexec: drop weak attribute from functionsNaveen N. Rao1-4/+28
Drop __weak attribute from functions in kexec_core.c: - machine_kexec_post_load() - arch_kexec_protect_crashkres() - arch_kexec_unprotect_crashkres() - crash_free_reserved_phys_range() Link: https://lkml.kernel.org/r/c0f6219e03cb399d166d518ab505095218a902dd.1656659357.git.naveen.n.rao@linux.vnet.ibm.com Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Suggested-by: Eric Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2022-07-15kexec_file: drop weak attribute from functionsNaveen N. Rao1-6/+38
As requested (http://lkml.kernel.org/r/87ee0q7b92.fsf@email.froward.int.ebiederm.org), this series converts weak functions in kexec to use the #ifdef approach. Quoting the 3e35142ef99fe ("kexec_file: drop weak attribute from arch_kexec_apply_relocations[_add]") changelog: : Since commit d1bcae833b32f1 ("ELF: Don't generate unused section symbols") : [1], binutils (v2.36+) started dropping section symbols that it thought : were unused. This isn't an issue in general, but with kexec_file.c, gcc : is placing kexec_arch_apply_relocations[_add] into a separate : .text.unlikely section and the section symbol ".text.unlikely" is being : dropped. Due to this, recordmcount is unable to find a non-weak symbol in : .text.unlikely to generate a relocation record against. This patch (of 2); Drop __weak attribute from functions in kexec_file.c: - arch_kexec_kernel_image_probe() - arch_kimage_file_post_load_cleanup() - arch_kexec_kernel_image_load() - arch_kexec_locate_mem_hole() - arch_kexec_kernel_verify_sig() arch_kexec_kernel_image_load() calls into kexec_image_load_default(), so drop the static attribute for the latter. arch_kexec_kernel_verify_sig() is not overridden by any architecture, so drop the __weak attribute. Link: https://lkml.kernel.org/r/cover.1656659357.git.naveen.n.rao@linux.vnet.ibm.com Link: https://lkml.kernel.org/r/2cd7ca1fe4d6bb6ca38e3283c717878388ed6788.1656659357.git.naveen.n.rao@linux.vnet.ibm.com Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Suggested-by: Eric Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2022-07-13ima: force signature verification when CONFIG_KEXEC_SIG is configuredCoiby Xu1-0/+6
Currently, an unsigned kernel could be kexec'ed when IMA arch specific policy is configured unless lockdown is enabled. Enforce kernel signature verification check in the kexec_file_load syscall when IMA arch specific policy is configured. Fixes: 99d5cadfde2b ("kexec_file: split KEXEC_VERIFY_SIG into KEXEC_SIG and KEXEC_SIG_FORCE") Reported-and-suggested-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Coiby Xu <coxu@redhat.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2022-06-01Merge tag 'riscv-for-linus-5.19-mw0' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux Pull RISC-V updates from Palmer Dabbelt: - Support for the Svpbmt extension, which allows memory attributes to be encoded in pages - Support for the Allwinner D1's implementation of page-based memory attributes - Support for running rv32 binaries on rv64 systems, via the compat subsystem - Support for kexec_file() - Support for the new generic ticket-based spinlocks, which allows us to also move to qrwlock. These should have already gone in through the asm-geneic tree as well - A handful of cleanups and fixes, include some larger ones around atomics and XIP * tag 'riscv-for-linus-5.19-mw0' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (51 commits) RISC-V: Prepare dropping week attribute from arch_kexec_apply_relocations[_add] riscv: compat: Using seperated vdso_maps for compat_vdso_info RISC-V: Fix the XIP build RISC-V: Split out the XIP fixups into their own file RISC-V: ignore xipImage RISC-V: Avoid empty create_*_mapping definitions riscv: Don't output a bogus mmu-type on a no MMU kernel riscv: atomic: Add custom conditional atomic operation implementation riscv: atomic: Optimize dec_if_positive functions riscv: atomic: Cleanup unnecessary definition RISC-V: Load purgatory in kexec_file RISC-V: Add purgatory RISC-V: Support for kexec_file on panic RISC-V: Add kexec_file support RISC-V: use memcpy for kexec_file mode kexec_file: Fix kexec_file.c build error for riscv platform riscv: compat: Add COMPAT Kbuild skeletal support riscv: compat: ptrace: Add compat_arch_ptrace implement riscv: compat: signal: Add rt_frame implementation riscv: add memory-type errata for T-Head ...
2022-05-27kexec_file: drop weak attribute from arch_kexec_apply_relocations[_add]Naveen N. Rao1-8/+38
Since commit d1bcae833b32f1 ("ELF: Don't generate unused section symbols") [1], binutils (v2.36+) started dropping section symbols that it thought were unused. This isn't an issue in general, but with kexec_file.c, gcc is placing kexec_arch_apply_relocations[_add] into a separate .text.unlikely section and the section symbol ".text.unlikely" is being dropped. Due to this, recordmcount is unable to find a non-weak symbol in .text.unlikely to generate a relocation record against. Address this by dropping the weak attribute from these functions. Instead, follow the existing pattern of having architectures #define the name of the function they want to override in their headers. [1] https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=d1bcae833b32f1 [akpm@linux-foundation.org: arch/s390/include/asm/kexec.h needs linux/module.h] Link: https://lkml.kernel.org/r/20220519091237.676736-1-naveen.n.rao@linux.vnet.ibm.com Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-19kexec_file: Fix kexec_file.c build error for riscv platformLiao Chang1-1/+1
When CONFIG_KEXEC_FILE is set for riscv platform, the compilation of kernel/kexec_file.c generate build error: kernel/kexec_file.c: In function 'crash_prepare_elf64_headers': ./arch/riscv/include/asm/page.h:110:71: error: request for member 'virt_addr' in something not a structure or union 110 | ((x) >= PAGE_OFFSET && (!IS_ENABLED(CONFIG_64BIT) || (x) < kernel_map.virt_addr)) | ^ ./arch/riscv/include/asm/page.h:131:2: note: in expansion of macro 'is_linear_mapping' 131 | is_linear_mapping(_x) ? \ | ^~~~~~~~~~~~~~~~~ ./arch/riscv/include/asm/page.h:140:31: note: in expansion of macro '__va_to_pa_nodebug' 140 | #define __phys_addr_symbol(x) __va_to_pa_nodebug(x) | ^~~~~~~~~~~~~~~~~~ ./arch/riscv/include/asm/page.h:143:24: note: in expansion of macro '__phys_addr_symbol' 143 | #define __pa_symbol(x) __phys_addr_symbol(RELOC_HIDE((unsigned long)(x), 0)) | ^~~~~~~~~~~~~~~~~~ kernel/kexec_file.c:1327:36: note: in expansion of macro '__pa_symbol' 1327 | phdr->p_offset = phdr->p_paddr = __pa_symbol(_text); This occurs is because the "kernel_map" referenced in macro is_linear_mapping() is suppose to be the one of struct kernel_mapping defined in arch/riscv/mm/init.c, but the 2nd argument of crash_prepare_elf64_header() has same symbol name, in expansion of macro is_linear_mapping in function crash_prepare_elf64_header(), "kernel_map" actually is the local variable. Signed-off-by: Liao Chang <liaochang1@huawei.com> Link: https://lore.kernel.org/r/20220408100914.150110-2-lizhengyu3@huawei.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-03-24kexec: make crashk_res, crashk_low_res and crash_notes symbols always visibleJisheng Zhang1-6/+6
Patch series "kexec: use IS_ENABLED(CONFIG_KEXEC_CORE) instead of #ifdef", v2. Replace the conditional compilation using "#ifdef CONFIG_KEXEC_CORE" by a check for "IS_ENABLED(CONFIG_KEXEC_CORE)", to simplify the code and increase compile coverage. I only modified x86, arm, arm64 and riscv, other architectures such as sh, powerpc and s390 are better to be kept kexec code as-is so they are not touched. This patch (of 5): Make the forward declarations of crashk_res, crashk_low_res and crash_notes always visible. Code referring to these symbols can then just check for IS_ENABLED(CONFIG_KEXEC_CORE), instead of requiring conditional compilation using an #ifdef, thus preparing to increase compile coverage and simplify the code. Link: https://lkml.kernel.org/r/20211206160514.2000-1-jszhang@kernel.org Link: https://lkml.kernel.org/r/20211206160514.2000-2-jszhang@kernel.org Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Acked-by: Baoquan He <bhe@redhat.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Palmer Dabbelt <palmer@rivosinc.com> Cc: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-03-08powerpc: Move ima buffer fields to struct kimageLakshmi Ramasubramanian1-0/+3
The fields ima_buffer_addr and ima_buffer_size in "struct kimage_arch" for powerpc are used to carry forward the IMA measurement list across kexec system call. These fields are not architecture specific, but are currently limited to powerpc. arch_ima_add_kexec_buffer() defined in "arch/powerpc/kexec/ima.c" sets ima_buffer_addr and ima_buffer_size for the kexec system call. This function does not have architecture specific code, but is currently limited to powerpc. Move ima_buffer_addr and ima_buffer_size to "struct kimage". Set ima_buffer_addr and ima_buffer_size in ima_add_kexec_buffer() in security/integrity/ima/ima_kexec.c. Co-developed-by: Prakhar Srivastava <prsriva@linux.microsoft.com> Signed-off-by: Prakhar Srivastava <prsriva@linux.microsoft.com> Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com> Suggested-by: Will Deacon <will@kernel.org> Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com> Signed-off-by: Rob Herring <robh@kernel.org> Link: https://lore.kernel.org/r/20210221174930.27324-9-nramas@linux.microsoft.com
2021-03-08kexec: Move ELF fields to struct kimageLakshmi Ramasubramanian1-0/+5
ELF related fields elf_headers, elf_headers_sz, and elf_load_addr are defined in architecture specific 'struct kimage_arch' for x86, powerpc, and arm64. The name of these fields are different in these architectures that makes it hard to have a common code for setting up the device tree for kexec system call. Move the ELF fields to 'struct kimage' defined in include/linux/kexec.h so common code can use it. Suggested-by: Rob Herring <robh@kernel.org> Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com> Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com> Signed-off-by: Rob Herring <robh@kernel.org> Link: https://lore.kernel.org/r/20210221174930.27324-2-nramas@linux.microsoft.com
2021-02-26Merge tag 'arm64-fixes' of ↵Linus Torvalds1-0/+2
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 fixes from Will Deacon: "The big one is a fix for the VHE enabling path during early boot, where the code enabling the MMU wasn't necessarily in the identity map of the new page-tables, resulting in a consistent crash with 64k pages. In fixing that, we noticed some missing barriers too, so we added those for the sake of architectural compliance. Other than that, just the usual merge window trickle. There'll be more to come, too. Summary: - Fix lockdep false alarm on resume-from-cpuidle path - Fix memory leak in kexec_file - Fix module linker script to work with GDB - Fix error code when trying to use uprobes with AArch32 instructions - Fix late VHE enabling with 64k pages - Add missing ISBs after TLB invalidation - Fix seccomp when tracing syscall -1 - Fix stacktrace return code at end of stack - Fix inconsistent whitespace for pointer return values - Fix compiler warnings when building with W=1" * tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: arm64: stacktrace: Report when we reach the end of the stack arm64: ptrace: Fix seccomp of traced syscall -1 (NO_SYSCALL) arm64: Add missing ISB after invalidating TLB in enter_vhe arm64: Add missing ISB after invalidating TLB in __primary_switch arm64: VHE: Enable EL2 MMU from the idmap KVM: arm64: make the hyp vector table entries local arm64/mm: Fixed some coding style issues arm64: uprobe: Return EOPNOTSUPP for AARCH32 instruction probing kexec: move machine_kexec_post_load() to public interface arm64 module: set plt* section addresses to 0x0 arm64: kexec_file: fix memory leakage in create_dtb() when fdt_open_into() fails arm64: spectre: Prevent lockdep splat on v4 mitigation enable path
2021-02-22kexec: move machine_kexec_post_load() to public interfacePavel Tatashin1-0/+2
The kernel test robot reports the following compiler warning: | arch/arm64/kernel/machine_kexec.c:62:5: warning: no previous prototype for | function 'machine_kexec_post_load' [-Wmissing-prototypes] | int machine_kexec_post_load(struct kimage *kimage) Fix it by moving the declaration of machine_kexec_post_load() from kexec_internal.h to the public header instead. Reported-by: kernel test robot <lkp@intel.com> Link: https://lore.kernel.org/linux-arm-kernel/202102030727.gqTokACH-lkp@intel.com Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com> Link: https://lore.kernel.org/r/20210219195142.13571-1-pasha.tatashin@soleen.com Fixes: 4c3c31230c91 ("arm64: kexec: move relocation function setup") Signed-off-by: Will Deacon <will@kernel.org>
2021-02-10ima: Free IMA measurement buffer after kexec syscallLakshmi Ramasubramanian1-0/+5
IMA allocates kernel virtual memory to carry forward the measurement list, from the current kernel to the next kernel on kexec system call, in ima_add_kexec_buffer() function. This buffer is not freed before completing the kexec system call resulting in memory leak. Add ima_buffer field in "struct kimage" to store the virtual address of the buffer allocated for the IMA measurement list. Free the memory allocated for the IMA measurement list in kimage_file_post_load_cleanup() function. Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com> Suggested-by: Tyler Hicks <tyhicks@linux.microsoft.com> Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com> Reviewed-by: Tyler Hicks <tyhicks@linux.microsoft.com> Fixes: 7b8589cc29e7 ("ima: on soft reboot, save the measurement list") Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2020-07-29kexec_file: Allow archs to handle special regions while locating memory holeHari Bathini1-11/+18
Some architectures may have special memory regions, within the given memory range, which can't be used for the buffer in a kexec segment. Implement weak arch_kexec_locate_mem_hole() definition which arch code may override, to take care of special regions, while trying to locate a memory hole. Also, add the missing declarations for arch overridable functions and and drop the __weak descriptors in the declarations to avoid non-weak definitions from becoming weak. Signed-off-by: Hari Bathini <hbathini@linux.ibm.com> Tested-by: Pingfan Liu <piliu@redhat.com> Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com> Acked-by: Dave Young <dyoung@redhat.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/159602273603.575379.17665852963340380839.stgit@hbathini
2020-06-16kexec: Replace zero-length array with flexible-arrayGustavo A. R. Silva1-1/+1
There is a regular need in the kernel to provide a way to declare having a dynamically sized set of trailing elements in a structure. Kernel code should always use “flexible array members”[1] for these cases. The older style of one-element or zero-length arrays should no longer be used[2]. [1] https://en.wikipedia.org/wiki/Flexible_array_member [2] https://github.com/KSPP/linux/issues/21 Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2019-09-28Merge branch 'next-lockdown' of ↵Linus Torvalds1-2/+2
git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security Pull kernel lockdown mode from James Morris: "This is the latest iteration of the kernel lockdown patchset, from Matthew Garrett, David Howells and others. From the original description: This patchset introduces an optional kernel lockdown feature, intended to strengthen the boundary between UID 0 and the kernel. When enabled, various pieces of kernel functionality are restricted. Applications that rely on low-level access to either hardware or the kernel may cease working as a result - therefore this should not be enabled without appropriate evaluation beforehand. The majority of mainstream distributions have been carrying variants of this patchset for many years now, so there's value in providing a doesn't meet every distribution requirement, but gets us much closer to not requiring external patches. There are two major changes since this was last proposed for mainline: - Separating lockdown from EFI secure boot. Background discussion is covered here: https://lwn.net/Articles/751061/ - Implementation as an LSM, with a default stackable lockdown LSM module. This allows the lockdown feature to be policy-driven, rather than encoding an implicit policy within the mechanism. The new locked_down LSM hook is provided to allow LSMs to make a policy decision around whether kernel functionality that would allow tampering with or examining the runtime state of the kernel should be permitted. The included lockdown LSM provides an implementation with a simple policy intended for general purpose use. This policy provides a coarse level of granularity, controllable via the kernel command line: lockdown={integrity|confidentiality} Enable the kernel lockdown feature. If set to integrity, kernel features that allow userland to modify the running kernel are disabled. If set to confidentiality, kernel features that allow userland to extract confidential information from the kernel are also disabled. This may also be controlled via /sys/kernel/security/lockdown and overriden by kernel configuration. New or existing LSMs may implement finer-grained controls of the lockdown features. Refer to the lockdown_reason documentation in include/linux/security.h for details. The lockdown feature has had signficant design feedback and review across many subsystems. This code has been in linux-next for some weeks, with a few fixes applied along the way. Stephen Rothwell noted that commit 9d1f8be5cf42 ("bpf: Restrict bpf when kernel lockdown is in confidentiality mode") is missing a Signed-off-by from its author. Matthew responded that he is providing this under category (c) of the DCO" * 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (31 commits) kexec: Fix file verification on S390 security: constify some arrays in lockdown LSM lockdown: Print current->comm in restriction messages efi: Restrict efivar_ssdt_load when the kernel is locked down tracefs: Restrict tracefs when the kernel is locked down debugfs: Restrict debugfs when the kernel is locked down kexec: Allow kexec_file() with appropriate IMA policy when locked down lockdown: Lock down perf when in confidentiality mode bpf: Restrict bpf when kernel lockdown is in confidentiality mode lockdown: Lock down tracing and perf kprobes when in confidentiality mode lockdown: Lock down /proc/kcore x86/mmiotrace: Lock down the testmmiotrace module lockdown: Lock down module params that specify hardware parameters (eg. ioport) lockdown: Lock down TIOCSSERIAL lockdown: Prohibit PCMCIA CIS storage when the kernel is locked down acpi: Disable ACPI table override if the kernel is locked down acpi: Ignore acpi_rsdp kernel param when the kernel has been locked down ACPI: Limit access to custom_method when the kernel is locked down x86/msr: Restrict MSR access when the kernel is locked down x86: Lock down IO port access when the kernel is locked down ...
2019-09-26kexec: restore arch_kexec_kernel_image_probe declarationVasily Gorbik1-0/+2
arch_kexec_kernel_image_probe function declaration has been removed by commit 9ec4ecef0af7 ("kexec_file,x86,powerpc: factor out kexec_file_ops functions"). Still this function is overridden by couple of architectures and proper prototype declaration is therefore important, so bring it back. This fixes the following sparse warning on s390: arch/s390/kernel/machine_kexec_file.c:333:5: warning: symbol 'arch_kexec_kernel_image_probe' was not declared. Should it be static? Link: http://lkml.kernel.org/r/patch.git-ff1c9045ebdc.your-ad-here.call-01564402297-ext-5690@work.hours Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Acked-by: Dave Young <dyoung@redhat.com> Reviewed-by: Bhupesh Sharma <bhsharma@redhat.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: AKASHI Takahiro <takahiro.akashi@linaro.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-07kexec_elf: remove parsing of section headersSven Schnelle1-1/+0
We're not using them, so we can drop the parsing. Signed-off-by: Sven Schnelle <svens@stackframe.org> Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com> Signed-off-by: Helge Deller <deller@gmx.de>
2019-09-07kexec: add KEXEC_ELFSven Schnelle1-0/+24
Right now powerpc provides an implementation to read elf files with the kexec_file_load() syscall. Make that available as a public kexec interface so it can be re-used on other architectures. Signed-off-by: Sven Schnelle <svens@stackframe.org> Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com> Signed-off-by: Helge Deller <deller@gmx.de>
2019-08-20kexec_file: split KEXEC_VERIFY_SIG into KEXEC_SIG and KEXEC_SIG_FORCEJiri Bohac1-2/+2
This is a preparatory patch for kexec_file_load() lockdown. A locked down kernel needs to prevent unsigned kernel images from being loaded with kexec_file_load(). Currently, the only way to force the signature verification is compiling with KEXEC_VERIFY_SIG. This prevents loading usigned images even when the kernel is not locked down at runtime. This patch splits KEXEC_VERIFY_SIG into KEXEC_SIG and KEXEC_SIG_FORCE. Analogous to the MODULE_SIG and MODULE_SIG_FORCE for modules, KEXEC_SIG turns on the signature verification but allows unsigned images to be loaded. KEXEC_SIG_FORCE disallows images without a valid signature. Signed-off-by: Jiri Bohac <jbohac@suse.cz> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Matthew Garrett <mjg59@google.com> cc: kexec@lists.infradead.org Signed-off-by: James Morris <jmorris@namei.org>
2018-12-27Merge branch 'x86-cleanups-for-linus' of ↵Linus Torvalds1-0/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 cleanups from Ingo Molnar: "Misc cleanups" * 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/kprobes: Remove trampoline_handler() prototype x86/kernel: Fix more -Wmissing-prototypes warnings x86: Fix various typos in comments x86/headers: Fix -Wmissing-prototypes warning x86/process: Avoid unnecessary NULL check in get_wchan() x86/traps: Complete prototype declarations x86/mce: Fix -Wmissing-prototypes warnings x86/gart: Rewrite early_gart_iommu_check() comment
2018-12-06powerpc, kexec_file: factor out memblock-based arch_kexec_walk_mem()AKASHI Takahiro1-2/+0
Memblock list is another source for usable system memory layout. So move powerpc's arch_kexec_walk_mem() to common code so that other memblock-based architectures, particularly arm64, can also utilise it. A moved function is now renamed to kexec_walk_memblock() and integrated into kexec_locate_mem_hole(), which will now be usable for all architectures with no need for overriding arch_kexec_walk_mem(). With this change, arch_kexec_walk_mem() need no longer be a weak function, and was now renamed to kexec_walk_resources(). Since powerpc doesn't support kdump in its kexec_file_load(), the current kexec_walk_memblock() won't work for kdump either in this form, this will be fixed in the next patch. Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Acked-by: Dave Young <dyoung@redhat.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Baoquan He <bhe@redhat.com> Acked-by: James Morse <james.morse@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-12-06s390, kexec_file: drop arch_kexec_mem_walk()AKASHI Takahiro1-0/+8
Since s390 already knows where to locate buffers, calling arch_kexec_mem_walk() has no sense. So we can just drop it as kbuf->mem indicates this while all other architectures sets it to 0 initially. This change is a preparatory work for the next patch, where all the variant memory walks, either on system resource or memblock, will be put in one common place so that it will satisfy all the architectures' need. Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org> Reviewed-by: Philipp Rudo <prudo@linux.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Dave Young <dyoung@redhat.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Baoquan He <bhe@redhat.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-12-06kexec_file: make kexec_image_post_load_cleanup_default() globalAKASHI Takahiro1-0/+1
Change this function from static to global so that arm64 can implement its own arch_kimage_file_post_load_cleanup() later using kexec_image_post_load_cleanup_default(). Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org> Acked-by: Dave Young <dyoung@redhat.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Baoquan He <bhe@redhat.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-11-23x86/headers: Fix -Wmissing-prototypes warningYi Wang1-0/+1
When building the kernel with W=1 we get a lot of -Wmissing-prototypes warnings, which are trivial in nature and easy to fix - and which may mask some real future bugs if the prototypes get out of sync with the function definition. This patch fixes most of -Wmissing-prototypes warnings which are in the root directory of arch/x86/kernel, not including the subdirectories. These are the warnings fixed in this patch: arch/x86/kernel/signal.c:865:17: warning: no previous prototype for ‘sys32_x32_rt_sigreturn’ [-Wmissing-prototypes] arch/x86/kernel/signal_compat.c:164:6: warning: no previous prototype for ‘sigaction_compat_abi’ [-Wmissing-prototypes] arch/x86/kernel/traps.c:625:46: warning: no previous prototype for ‘sync_regs’ [-Wmissing-prototypes] arch/x86/kernel/traps.c:640:24: warning: no previous prototype for ‘fixup_bad_iret’ [-Wmissing-prototypes] arch/x86/kernel/traps.c:929:13: warning: no previous prototype for ‘trap_init’ [-Wmissing-prototypes] arch/x86/kernel/irq.c:270:28: warning: no previous prototype for ‘smp_x86_platform_ipi’ [-Wmissing-prototypes] arch/x86/kernel/irq.c:301:16: warning: no previous prototype for ‘smp_kvm_posted_intr_ipi’ [-Wmissing-prototypes] arch/x86/kernel/irq.c:314:16: warning: no previous prototype for ‘smp_kvm_posted_intr_wakeup_ipi’ [-Wmissing-prototypes] arch/x86/kernel/irq.c:328:16: warning: no previous prototype for ‘smp_kvm_posted_intr_nested_ipi’ [-Wmissing-prototypes] arch/x86/kernel/irq_work.c:16:28: warning: no previous prototype for ‘smp_irq_work_interrupt’ [-Wmissing-prototypes] arch/x86/kernel/irqinit.c:79:13: warning: no previous prototype for ‘init_IRQ’ [-Wmissing-prototypes] arch/x86/kernel/quirks.c:672:13: warning: no previous prototype for ‘early_platform_quirks’ [-Wmissing-prototypes] arch/x86/kernel/tsc.c:1499:15: warning: no previous prototype for ‘calibrate_delay_is_known’ [-Wmissing-prototypes] arch/x86/kernel/process.c:653:13: warning: no previous prototype for ‘arch_post_acpi_subsys_init’ [-Wmissing-prototypes] arch/x86/kernel/process.c:717:15: warning: no previous prototype for ‘arch_randomize_brk’ [-Wmissing-prototypes] arch/x86/kernel/process.c:784:6: warning: no previous prototype for ‘do_arch_prctl_common’ [-Wmissing-prototypes] arch/x86/kernel/reboot.c:869:6: warning: no previous prototype for ‘nmi_panic_self_stop’ [-Wmissing-prototypes] arch/x86/kernel/smp.c:176:27: warning: no previous prototype for ‘smp_reboot_interrupt’ [-Wmissing-prototypes] arch/x86/kernel/smp.c:260:28: warning: no previous prototype for ‘smp_reschedule_interrupt’ [-Wmissing-prototypes] arch/x86/kernel/smp.c:281:28: warning: no previous prototype for ‘smp_call_function_interrupt’ [-Wmissing-prototypes] arch/x86/kernel/smp.c:291:28: warning: no previous prototype for ‘smp_call_function_single_interrupt’ [-Wmissing-prototypes] arch/x86/kernel/ftrace.c:840:6: warning: no previous prototype for ‘arch_ftrace_update_trampoline’ [-Wmissing-prototypes] arch/x86/kernel/ftrace.c:934:7: warning: no previous prototype for ‘arch_ftrace_trampoline_func’ [-Wmissing-prototypes] arch/x86/kernel/ftrace.c:946:6: warning: no previous prototype for ‘arch_ftrace_trampoline_free’ [-Wmissing-prototypes] arch/x86/kernel/crash.c:114:6: warning: no previous prototype for ‘crash_smp_send_stop’ [-Wmissing-prototypes] arch/x86/kernel/crash.c:351:5: warning: no previous prototype for ‘crash_setup_memmap_entries’ [-Wmissing-prototypes] arch/x86/kernel/crash.c:424:5: warning: no previous prototype for ‘crash_load_segments’ [-Wmissing-prototypes] arch/x86/kernel/machine_kexec_64.c:372:7: warning: no previous prototype for ‘arch_kexec_kernel_image_load’ [-Wmissing-prototypes] arch/x86/kernel/paravirt-spinlocks.c:12:16: warning: no previous prototype for ‘__native_queued_spin_unlock’ [-Wmissing-prototypes] arch/x86/kernel/paravirt-spinlocks.c:18:6: warning: no previous prototype for ‘pv_is_native_spin_unlock’ [-Wmissing-prototypes] arch/x86/kernel/paravirt-spinlocks.c:24:16: warning: no previous prototype for ‘__native_vcpu_is_preempted’ [-Wmissing-prototypes] arch/x86/kernel/paravirt-spinlocks.c:30:6: warning: no previous prototype for ‘pv_is_native_vcpu_is_preempted’ [-Wmissing-prototypes] arch/x86/kernel/kvm.c:258:1: warning: no previous prototype for ‘do_async_page_fault’ [-Wmissing-prototypes] arch/x86/kernel/jailhouse.c:200:6: warning: no previous prototype for ‘jailhouse_paravirt’ [-Wmissing-prototypes] arch/x86/kernel/check.c:91:13: warning: no previous prototype for ‘setup_bios_corruption_check’ [-Wmissing-prototypes] arch/x86/kernel/check.c:139:6: warning: no previous prototype for ‘check_for_bios_corruption’ [-Wmissing-prototypes] arch/x86/kernel/devicetree.c:32:13: warning: no previous prototype for ‘early_init_dt_scan_chosen_arch’ [-Wmissing-prototypes] arch/x86/kernel/devicetree.c:42:13: warning: no previous prototype for ‘add_dtb’ [-Wmissing-prototypes] arch/x86/kernel/devicetree.c:108:6: warning: no previous prototype for ‘x86_of_pci_init’ [-Wmissing-prototypes] arch/x86/kernel/devicetree.c:314:13: warning: no previous prototype for ‘x86_dtb_init’ [-Wmissing-prototypes] arch/x86/kernel/tracepoint.c:16:5: warning: no previous prototype for ‘trace_pagefault_reg’ [-Wmissing-prototypes] arch/x86/kernel/tracepoint.c:22:6: warning: no previous prototype for ‘trace_pagefault_unreg’ [-Wmissing-prototypes] arch/x86/kernel/head64.c:113:22: warning: no previous prototype for ‘__startup_64’ [-Wmissing-prototypes] arch/x86/kernel/head64.c:262:15: warning: no previous prototype for ‘__startup_secondary_64’ [-Wmissing-prototypes] arch/x86/kernel/head64.c:350:12: warning: no previous prototype for ‘early_make_pgtable’ [-Wmissing-prototypes] [ mingo: rewrote the changelog, fixed build errors. ] Signed-off-by: Yi Wang <wang.yi59@zte.com.cn> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: akataria@vmware.com Cc: akpm@linux-foundation.org Cc: andy.shevchenko@gmail.com Cc: anton@enomsg.org Cc: ard.biesheuvel@linaro.org Cc: bhe@redhat.com Cc: bhelgaas@google.com Cc: bp@alien8.de Cc: ccross@android.com Cc: devicetree@vger.kernel.org Cc: douly.fnst@cn.fujitsu.com Cc: dwmw@amazon.co.uk Cc: dyoung@redhat.com Cc: ebiederm@xmission.com Cc: frank.rowand@sony.com Cc: frowand.list@gmail.com Cc: ivan.gorinov@intel.com Cc: jailhouse-dev@googlegroups.com Cc: jan.kiszka@siemens.com Cc: jgross@suse.com Cc: jroedel@suse.de Cc: keescook@chromium.org Cc: kexec@lists.infradead.org Cc: konrad.wilk@oracle.com Cc: kvm@vger.kernel.org Cc: linux-efi@vger.kernel.org Cc: linux-pci@vger.kernel.org Cc: luto@kernel.org Cc: m.mizuma@jp.fujitsu.com Cc: namit@vmware.com Cc: oleg@redhat.com Cc: pasha.tatashin@oracle.com Cc: pbonzini@redhat.com Cc: prarit@redhat.com Cc: pravin.shedge4linux@gmail.com Cc: rajvi.jingar@intel.com Cc: rkrcmar@redhat.com Cc: robh+dt@kernel.org Cc: robh@kernel.org Cc: rostedt@goodmis.org Cc: takahiro.akashi@linaro.org Cc: thomas.lendacky@amd.com Cc: tony.luck@intel.com Cc: up2wing@gmail.com Cc: virtualization@lists.linux-foundation.org Cc: zhe.he@windriver.com Cc: zhong.weidong@zte.com.cn Link: http://lkml.kernel.org/r/1542852249-19820-1-git-send-email-wang.yi59@zte.com.cn Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-04-14kernel/kexec_file.c: allow archs to set purgatory load addressPhilipp Rudo1-11/+6
For s390 new kernels are loaded to fixed addresses in memory before they are booted. With the current code this is a problem as it assumes the kernel will be loaded to an 'arbitrary' address. In particular, kexec_locate_mem_hole searches for a large enough memory region and sets the load address (kexec_bufer->mem) to it. Luckily there is a simple workaround for this problem. By returning 1 in arch_kexec_walk_mem, kexec_locate_mem_hole is turned off. This allows the architecture to set kbuf->mem by hand. While the trick works fine for the kernel it does not for the purgatory as here the architectures don't have access to its kexec_buffer. Give architectures access to the purgatories kexec_buffer by changing kexec_load_purgatory to take a pointer to it. With this change architectures have access to the buffer and can edit it as they need. A nice side effect of this change is that we can get rid of the purgatory_info->purgatory_load_address field. As now the information stored there can directly be accessed from kbuf->mem. Link: http://lkml.kernel.org/r/20180321112751.22196-11-prudo@linux.vnet.ibm.com Signed-off-by: Philipp Rudo <prudo@linux.vnet.ibm.com> Reviewed-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Acked-by: Dave Young <dyoung@redhat.com> Cc: AKASHI Takahiro <takahiro.akashi@linaro.org> Cc: Eric Biederman <ebiederm@xmission.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com> Cc: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-04-14kernel/kexec_file.c: use read-only sections in arch_kexec_apply_relocations*Philipp Rudo1-4/+9
When the relocations are applied to the purgatory only the section the relocations are applied to is writable. The other sections, i.e. the symtab and .rel/.rela, are in read-only kexec_purgatory. Highlight this by marking the corresponding variables as 'const'. While at it also change the signatures of arch_kexec_apply_relocations* to take section pointers instead of just the index of the relocation section. This removes the second lookup and sanity check of the sections in arch code. Link: http://lkml.kernel.org/r/20180321112751.22196-6-prudo@linux.vnet.ibm.com Signed-off-by: Philipp Rudo <prudo@linux.vnet.ibm.com> Acked-by: Dave Young <dyoung@redhat.com> Cc: AKASHI Takahiro <takahiro.akashi@linaro.org> Cc: Eric Biederman <ebiederm@xmission.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com> Cc: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-04-14kernel/kexec_file.c: make purgatory_info->ehdr constPhilipp Rudo1-6/+11
The kexec_purgatory buffer is read-only. Thus all pointers into kexec_purgatory are read-only, too. Point this out by explicitly marking purgatory_info->ehdr as 'const' and update the comments in purgatory_info. Link: http://lkml.kernel.org/r/20180321112751.22196-4-prudo@linux.vnet.ibm.com Signed-off-by: Philipp Rudo <prudo@linux.vnet.ibm.com> Acked-by: Dave Young <dyoung@redhat.com> Cc: AKASHI Takahiro <takahiro.akashi@linaro.org> Cc: Eric Biederman <ebiederm@xmission.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com> Cc: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-04-14include/linux/kexec.h: silence compile warningsPhilipp Rudo1-0/+2
Patch series "kexec_file: Clean up purgatory load", v2. Following the discussion with Dave and AKASHI, here are the common code patches extracted from my recent patch set (Add kexec_file_load support to s390) [1]. The patches were extracted to allow upstream integration together with AKASHI's common code patches before the arch code gets adjusted to the new base. The reason for this series is to prepare common code for adding kexec_file_load to s390 as well as cleaning up the mis-use of the sh_offset field during purgatory load. In detail this series contains: Patch #1&2: Minor cleanups/fixes. Patch #3-9: Clean up the purgatory load/relocation code. Especially remove the mis-use of the purgatory_info->sechdrs->sh_offset field, currently holding a pointer into either kexec_purgatory (ro) or purgatory_buf (rw) depending on the section. With these patches the section address will be calculated verbosely and sh_offset will contain the offset of the section in the stripped purgatory binary (purgatory_buf). Patch #10: Allows architectures to set the purgatory load address. This patch is important for s390 as the kernel and purgatory have to be loaded to fixed addresses. In current code this is impossible as the purgatory load is opaque to the architecture. Patch #11: Moves x86 purgatories sha implementation to common lib/ directory to allow reuse in other architectures. This patch (of 11) When building the kernel with CONFIG_KEXEC_FILE enabled gcc prints a compile warning multiple times. In file included from <path>/linux/init/initramfs.c:526:0: <path>/include/linux/kexec.h:120:9: warning: `struct kimage' declared inside parameter list [enabled by default] unsigned long cmdline_len); ^ This is because the typedefs for kexec_file_load uses struct kimage before it is declared. Fix this by simply forward declaring struct kimage. Link: http://lkml.kernel.org/r/20180321112751.22196-2-prudo@linux.vnet.ibm.com Signed-off-by: Philipp Rudo <prudo@linux.vnet.ibm.com> Acked-by: Dave Young <dyoung@redhat.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: AKASHI Takahiro <takahiro.akashi@linaro.org> Cc: Ingo Molnar <mingo@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-04-14kexec_file, x86: move re-factored code to generic sideAKASHI Takahiro1-0/+19
In the previous patches, commonly-used routines, exclude_mem_range() and prepare_elf64_headers(), were carved out. Now place them in kexec common code. A prefix "crash_" is given to each of their names to avoid possible name collisions. Link: http://lkml.kernel.org/r/20180306102303.9063-8-takahiro.akashi@linaro.org Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org> Acked-by: Dave Young <dyoung@redhat.com> Tested-by: Dave Young <dyoung@redhat.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Baoquan He <bhe@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-04-14kexec_file,x86,powerpc: factor out kexec_file_ops functionsAKASHI Takahiro1-7/+6
As arch_kexec_kernel_image_{probe,load}(), arch_kimage_file_post_load_cleanup() and arch_kexec_kernel_verify_sig() are almost duplicated among architectures, they can be commonalized with an architecture-defined kexec_file_ops array. So let's factor them out. Link: http://lkml.kernel.org/r/20180306102303.9063-3-takahiro.akashi@linaro.org Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org> Acked-by: Dave Young <dyoung@redhat.com> Tested-by: Dave Young <dyoung@redhat.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Baoquan He <bhe@redhat.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-04-02kexec: move sys_kexec_load() prototype to syscalls.hDominik Brodowski1-4/+0
As the syscall function should only be called from the system call table but not from elsewhere in the kernel, move the prototype for sys_kexec_load() to include/syscall.h. Cc: Eric Biederman <ebiederm@xmission.com> Cc: kexec@lists.infradead.org Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2017-11-07resource: Provide resource struct in resource walk callbackTom Lendacky1-1/+1
In preperation for a new function that will need additional resource information during the resource walk, update the resource walk callback to pass the resource structure. Since the current callback start and end arguments are pulled from the resource structure, the callback functions can obtain them from the resource structure directly. Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Borislav Petkov <bp@suse.de> Tested-by: Borislav Petkov <bp@suse.de> Cc: kvm@vger.kernel.org Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Borislav Petkov <bp@alien8.de> Cc: linuxppc-dev@lists.ozlabs.org Link: https://lkml.kernel.org/r/20171020143059.3291-10-brijesh.singh@amd.com
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman1-0/+1
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-18x86/mm, kexec: Allow kexec to be used with SMETom Lendacky1-0/+8
Provide support so that kexec can be used to boot a kernel when SME is enabled. Support is needed to allocate pages for kexec without encryption. This is needed in order to be able to reboot in the kernel in the same manner as originally booted. Additionally, when shutting down all of the CPUs we need to be sure to flush the caches and then halt. This is needed when booting from a state where SME was not active into a state where SME is active (or vice-versa). Without these steps, it is possible for cache lines to exist for the same physical location but tagged both with and without the encryption bit. This can cause random memory corruption when caches are flushed depending on which cacheline is written last. Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Borislav Petkov <bp@suse.de> Cc: <kexec@lists.infradead.org> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Brijesh Singh <brijesh.singh@amd.com> Cc: Dave Young <dyoung@redhat.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Larry Woodman <lwoodman@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Toshimitsu Kani <toshi.kani@hpe.com> Cc: kasan-dev@googlegroups.com Cc: kvm@vger.kernel.org Cc: linux-arch@vger.kernel.org Cc: linux-doc@vger.kernel.org Cc: linux-efi@vger.kernel.org Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/b95ff075db3e7cd545313f2fb609a49619a09625.1500319216.git.thomas.lendacky@amd.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-07-13kdump: protect vmcoreinfo data under the crash memoryXunlei Pang1-0/+2
Currently vmcoreinfo data is updated at boot time subsys_initcall(), it has the risk of being modified by some wrong code during system is running. As a result, vmcore dumped may contain the wrong vmcoreinfo. Later on, when using "crash", "makedumpfile", etc utility to parse this vmcore, we probably will get "Segmentation fault" or other unexpected errors. E.g. 1) wrong code overwrites vmcoreinfo_data; 2) further crashes the system; 3) trigger kdump, then we obviously will fail to recognize the crash context correctly due to the corrupted vmcoreinfo. Now except for vmcoreinfo, all the crash data is well protected(including the cpu note which is fully updated in the crash path, thus its correctness is guaranteed). Given that vmcoreinfo data is a large chunk prepared for kdump, we better protect it as well. To solve this, we relocate and copy vmcoreinfo_data to the crash memory when kdump is loading via kexec syscalls. Because the whole crash memory will be protected by existing arch_kexec_protect_crashkres() mechanism, we naturally protect vmcoreinfo_data from write(even read) access under kernel direct mapping after kdump is loaded. Since kdump is usually loaded at the very early stage after boot, we can trust the correctness of the vmcoreinfo data copied. On the other hand, we still need to operate the vmcoreinfo safe copy when crash happens to generate vmcoreinfo_note again, we rely on vmap() to map out a new kernel virtual address and update to use this new one instead in the following crash_save_vmcoreinfo(). BTW, we do not touch vmcoreinfo_note, because it will be fully updated using the protected vmcoreinfo_data after crash which is surely correct just like the cpu crash note. Link: http://lkml.kernel.org/r/1493281021-20737-3-git-send-email-xlpang@redhat.com Signed-off-by: Xunlei Pang <xlpang@redhat.com> Tested-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Dave Young <dyoung@redhat.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: Hari Bathini <hbathini@linux.vnet.ibm.com> Cc: Juergen Gross <jgross@suse.com> Cc: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-05s390/crash: Remove unused KEXEC_NOTE_BYTESMichael Holzheu1-9/+0
After commmit 692f66f26a4c19 ("crash: move crashkernel parsing and vmcore related code under CONFIG_CRASH_CORE") the KEXEC_NOTE_BYTES macro is not used anymore and for s390 we create the ELF header in the new kernel anyway. Therefore remove the macro. Reported-by: Xunlei Pang <xpang@redhat.com> Reviewed-by: Mikhail Zaslonko <zaslonko@linux.vnet.ibm.com> Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>