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2017-04-01kasan: do not sanitize kexec purgatoryMike Galbraith1-0/+1
Fixes this: kexec: Undefined symbol: __asan_load8_noabort kexec-bzImage64: Loading purgatory failed Link: http://lkml.kernel.org/r/1489672155.4458.7.camel@gmx.de Signed-off-by: Mike Galbraith <efault@gmx.de> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-03-10kexec, x86/purgatory: Unbreak it and clean it upThomas Gleixner4-28/+18
The purgatory code defines global variables which are referenced via a symbol lookup in the kexec code (core and arch). A recent commit addressing sparse warnings made these static and thereby broke kexec_file. Why did this happen? Simply because the whole machinery is undocumented and lacks any form of forward declarations. The variable names are unspecific and lack a prefix, so adding forward declarations creates shadow variables in the core code. Aside of that the code relies on magic constants and duplicate struct definitions with no way to ensure that these things stay in sync. The section placement of the purgatory variables happened by chance and not by design. Unbreak kexec and cleanup the mess: - Add proper forward declarations and document the usage - Use common struct definition - Use the proper common defines instead of magic constants - Add a purgatory_ prefix to have a proper name space - Use ARRAY_SIZE() instead of a homebrewn reimplementation - Add proper sections to the purgatory variables [ From Mike ] Fixes: 72042a8c7b01 ("x86/purgatory: Make functions and variables static") Reported-by: Mike Galbraith <<efault@gmx.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Nicholas Mc Guire <der.herr@hofr.at> Cc: Borislav Petkov <bp@alien8.de> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: "Tobin C. Harding" <me@tobin.cc> Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1703101315140.3681@nanos Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2017-03-01x86/purgatory: Fix sparse warning, symbol not declaredTobin C. Harding3-0/+10
Sparse emits warning, 'symbol not declared' for a function that has neither file scope nor a forward declaration. The functions only call site is an ASM file. Add a header file with the function declaration. Include the header file in the C source file defining the function in order to fix the sparse warning. Include the header file in ASM file containing the call site to document the usage. Signed-off-by: Tobin C. Harding <me@tobin.cc> Link: http://lkml.kernel.org/r/1487545956-2547-3-git-send-email-me@tobin.cc Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2017-03-01x86/purgatory: Make functions and variables staticTobin C. Harding1-5/+5
Sparse emits several 'symbol not declared' warnings for various functions and variables. Add static keyword to functions and variables which have file scope only. Signed-off-by: Tobin C. Harding <me@tobin.cc> Link: http://lkml.kernel.org/r/1487545956-2547-2-git-send-email-me@tobin.cc Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-11-10x86/kexec: add -fno-PIESebastian Andrzej Siewior1-0/+1
If the gcc is configured to do -fPIE by default then the build aborts later with: | Unsupported relocation type: unknown type rel type name (29) Tagging it stable so it is possible to compile recent stable kernels as well. Cc: stable@vger.kernel.org Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Michal Marek <mmarek@suse.com>
2016-06-07Add sancov pluginEmese Revfy1-0/+2
The sancov gcc plugin inserts a __sanitizer_cov_trace_pc() call at the start of basic blocks. This plugin is a helper plugin for the kcov feature. It supports all gcc versions with plugin support (from gcc-4.5 on). It is based on the gcc commit "Add fuzzing coverage support" by Dmitry Vyukov (https://gcc.gnu.org/viewcvs/gcc?limit_changes=0&view=revision&revision=231296). Signed-off-by: Emese Revfy <re.emese@gmail.com> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Michal Marek <mmarek@suse.com>
2016-04-20kbuild: delete unnecessary "@:"Masahiro Yamada1-2/+0
Since commit 2aedcd098a94 ('kbuild: suppress annoying "... is up to date." message'), $(call if_changed,...) is evaluated to "@:" when there is nothing to do. We no longer need to add "@:" after $(call if_changed,...) to suppress "... is up to date." message. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Michal Marek <mmarek@suse.com>
2016-03-24Merge branch 'x86-urgent-for-linus' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Ingo Molnar: "Misc fixes: - fix hotplug bugs - fix irq live lock - fix various topology handling bugs - fix APIC ACK ordering - fix PV iopl handling - fix speling - fix/tweak memcpy_mcsafe() return value - fix fbcon bug - remove stray prototypes" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/msr: Remove unused native_read_tscp() x86/apic: Remove declaration of unused hw_nmi_is_cpu_stuck x86/oprofile/nmi: Add missing hotplug FROZEN handling x86/hpet: Use proper mask to modify hotplug action x86/apic/uv: Fix the hotplug notifier x86/apb/timer: Use proper mask to modify hotplug action x86/topology: Use total_cpus not nr_cpu_ids for logical packages x86/topology: Fix Intel HT disable x86/topology: Fix logical package mapping x86/irq: Cure live lock in fixup_irqs() x86/tsc: Prevent NULL pointer deref in calibrate_delay_is_known() x86/apic: Fix suspicious RCU usage in smp_trace_call_function_interrupt() x86/iopl: Fix iopl capability check on Xen PV x86/iopl/64: Properly context-switch IOPL on Xen PV selftests/x86: Add an iopl test x86/mm, x86/mce: Fix return type/value for memcpy_mcsafe() x86/video: Don't assume all FB devices are PCI devices arch/x86/irq: Purge useless handler declarations from hw_irq.h x86: Fix misspellings in comments
2016-02-29objtool: Mark non-standard object files and directoriesJosh Poimboeuf1-0/+2
Code which runs outside the kernel's normal mode of operation often does unusual things which can cause a static analysis tool like objtool to emit false positive warnings: - boot image - vdso image - relocation - realmode - efi - head - purgatory - modpost Set OBJECT_FILES_NON_STANDARD for their related files and directories, which will tell objtool to skip checking them. It's ok to skip them because they don't affect runtime stack traces. Also skip the following code which does the right thing with respect to frame pointers, but is too "special" to be validated by a tool: - entry - mcount Also skip the test_nx module because it modifies its exception handling table at runtime, which objtool can't understand. Fortunately it's just a test module so it doesn't matter much. Currently objtool is the only user of OBJECT_FILES_NON_STANDARD, but it might eventually be useful for other tools. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Bernd Petrovitsch <bernd@petrovitsch.priv.at> Cc: Borislav Petkov <bp@alien8.de> Cc: Chris J Arges <chris.j.arges@canonical.com> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michal Marek <mmarek@suse.cz> Cc: Namhyung Kim <namhyung@gmail.com> Cc: Pedro Alves <palves@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: live-patching@vger.kernel.org Link: http://lkml.kernel.org/r/366c080e3844e8a5b6a0327dc7e8c2b90ca3baeb.1456719558.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-24x86: Fix misspellings in commentsAdam Buchbinder1-1/+1
Signed-off-by: Adam Buchbinder <adam.buchbinder@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: trivial@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-12-10Merge branches 'x86-build-for-linus', 'x86-cleanups-for-linus' and ↵Linus Torvalds1-0/+1
'x86-debug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 build, cleanup and defconfig updates from Ingo Molnar: "A single minor build change to suppress a repetitive build messages, misc cleanups and a defconfig update" * 'x86-build-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/purgatory, build: Suppress kexec-purgatory.c is up to date message * 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86, CPU, AMD: Move K8 TLB flush filter workaround to K8 code x86, espfix: Remove stale ptemask x86, msr: Use seek definitions instead of hard-coded values x86, msr: Convert printk to pr_foo() x86, msr: Use PTR_ERR_OR_ZERO x86/simplefb: Use PTR_ERR_OR_ZERO x86/sysfb: Use PTR_ERR_OR_ZERO x86, cpuid: Use PTR_ERR_OR_ZERO * 'x86-debug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/kconfig/defconfig: Enable CONFIG_FHANDLE=y
2014-10-15x86/purgatory, build: Suppress kexec-purgatory.c is up to date messageWANG Chao1-0/+1
Suppress this unnecessary message during kernel re-build (CONFIG_KEXEC_FILE=y): make[1]: `arch/x86/purgatory/kexec-purgatory.c' is up to date. Signed-off-by: WANG Chao <chaowang@redhat.com> Link: http://lkml.kernel.org/r/1413262019-3759-1-git-send-email-chaowang@redhat.com Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2014-10-14arch/x86/purgatory/Makefile: try to use automatic variable in kexec ↵Baoquan He1-1/+2
purgatory makefile Make the Makefile of kexec purgatory be consistent with others in linux src tree, and make it look generic and simple. Signed-off-by: Baoquan He <bhe@redhat.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-30x86/purgatory: use approprate -m64/-32 build flag for arch/x86/purgatoryVivek Goyal1-0/+1
Thomas reported that build of x86_64 kernel was failing for him. He is using 32bit tool chain. Problem is that while compiling purgatory, I have not specified -m64 flag. And 32bit tool chain must be assuming -m32 by default. Following is error message. (mini) [~/work/linux-2.6] make scripts/kconfig/conf --silentoldconfig Kconfig CHK include/config/kernel.release UPD include/config/kernel.release CHK include/generated/uapi/linux/version.h CHK include/generated/utsrelease.h UPD include/generated/utsrelease.h CC arch/x86/purgatory/purgatory.o arch/x86/purgatory/purgatory.c:1:0: error: code model 'large' not supported in the 32 bit mode Fix it by explicitly passing appropriate -m64/-m32 build flag for purgatory. Reported-by: Thomas Glanzmann <thomas@glanzmann.de> Tested-by: Thomas Glanzmann <thomas@glanzmann.de> Suggested-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-30kexec: create a new config option CONFIG_KEXEC_FILE for new syscallVivek Goyal1-4/+1
Currently new system call kexec_file_load() and all the associated code compiles if CONFIG_KEXEC=y. But new syscall also compiles purgatory code which currently uses gcc option -mcmodel=large. This option seems to be available only gcc 4.4 onwards. Hiding new functionality behind a new config option will not break existing users of old gcc. Those who wish to enable new functionality will require new gcc. Having said that, I am trying to figure out how can I move away from using -mcmodel=large but that can take a while. I think there are other advantages of introducing this new config option. As this option will be enabled only on x86_64, other arches don't have to compile generic kexec code which will never be used. This new code selects CRYPTO=y and CRYPTO_SHA256=y. And all other arches had to do this for CONFIG_KEXEC. Now with introduction of new config option, we can remove crypto dependency from other arches. Now CONFIG_KEXEC_FILE is available only on x86_64. So whereever I had CONFIG_X86_64 defined, I got rid of that. For CONFIG_KEXEC_FILE, instead of doing select CRYPTO=y, I changed it to "depends on CRYPTO=y". This should be safer as "select" is not recursive. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: H. Peter Anvin <hpa@zytor.com> Tested-by: Shaun Ruffell <sruffell@digium.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-09kexec: support for kexec on panic using new system callVivek Goyal1-3/+3
This patch adds support for loading a kexec on panic (kdump) kernel usning new system call. It prepares ELF headers for memory areas to be dumped and for saved cpu registers. Also prepares the memory map for second kernel and limits its boot to reserved areas only. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Cc: Borislav Petkov <bp@suse.de> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Eric Biederman <ebiederm@xmission.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Cc: Greg Kroah-Hartman <greg@kroah.com> Cc: Dave Young <dyoung@redhat.com> Cc: WANG Chao <chaowang@redhat.com> Cc: Baoquan He <bhe@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-09purgatory: core purgatory functionalityVivek Goyal6-0/+293
Create a stand alone relocatable object purgatory which runs between two kernels. This name, concept and some code has been taken from kexec-tools. Idea is that this code runs after a crash and it runs in minimal environment. So keep it separate from rest of the kernel and in long term we will have to practically do no maintenance of this code. This code also has the logic to do verify sha256 hashes of various segments which have been loaded into memory. So first we verify that the kernel we are jumping to is fine and has not been corrupted and make progress only if checsums are verified. This code also takes care of copying some memory contents to backup region. [sfr@canb.auug.org.au: run host built programs from objtree] Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Cc: Borislav Petkov <bp@suse.de> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Eric Biederman <ebiederm@xmission.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Cc: Greg Kroah-Hartman <greg@kroah.com> Cc: Dave Young <dyoung@redhat.com> Cc: WANG Chao <chaowang@redhat.com> Cc: Baoquan He <bhe@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-09purgatory/sha256: provide implementation of sha256 in purgaotory contextVivek Goyal2-0/+305
Next two patches provide code for purgatory. This is a code which does not link against the kernel and runs stand alone. This code runs between two kernels. One of the primary purpose of this code is to verify the digest of newly loaded kernel and making sure it matches the digest computed at kernel load time. We use sha256 for calculating digest of kexec segmetns. Purgatory can't use stanard crypto API as that API is not available in purgatory context. Hence, I have copied code from crypto/sha256_generic.c and compiled it with purgaotry code so that it could be used. I could not #include sha256_generic.c file here as some of the function signature requiered little tweaking. Original functions work with crypto API but these ones don't So instead of doing #include on sha256_generic.c I just copied relevant portions of code into arch/x86/purgatory/sha256.c. Now we shouldn't have to touch this code at all. Do let me know if there are better ways to handle it. This patch does not enable compiling of this code. That happens in next patch. I wanted to highlight this change in a separate patch for easy review. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Cc: Borislav Petkov <bp@suse.de> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Eric Biederman <ebiederm@xmission.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Cc: Greg Kroah-Hartman <greg@kroah.com> Cc: Dave Young <dyoung@redhat.com> Cc: WANG Chao <chaowang@redhat.com> Cc: Baoquan He <bhe@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>