diff options
| author | Baoquan He <bhe@redhat.com> | 2016-12-15 02:04:20 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-12-15 03:04:07 +0300 |
| commit | 401721ecd1dcb0a428aa5d6832ee05ffbdbffbbe (patch) | |
| tree | d284ae75d3763fff031f1919e7f5a65c72cae946 /arch/x86/kernel/machine_kexec_64.c | |
| parent | 69f58384791ac6da4165ce8e6defd6f408f4afdf (diff) | |
| download | linux-401721ecd1dcb0a428aa5d6832ee05ffbdbffbbe.tar.xz | |
kexec: export the value of phys_base instead of symbol address
Currently in x86_64, the symbol address of phys_base is exported to
vmcoreinfo. Dave Anderson complained this is really useless for his
Crash implementation. Because in user-space utility Crash and
Makedumpfile which exported vmcore information is mainly used for, value
of phys_base is needed to covert virtual address of exported kernel
symbol to physical address. Especially init_level4_pgt, if we want to
access and go over the page table to look up a PA corresponding to VA,
firstly we need calculate
page_dir = SYMBOL(init_level4_pgt) - __START_KERNEL_map + phys_base;
Now in Crash and Makedumpfile, we have to analyze the vmcore elf program
header to get value of phys_base. As Dave said, it would be preferable
if it were readily availabl in vmcoreinfo rather than depending upon the
PT_LOAD semantics.
Hence in this patch change to export the value of phys_base instead of
its virtual address.
And people also complained that KERNEL_IMAGE_SIZE exporting is x86_64
only, should be moved into arch dependent function
arch_crash_save_vmcoreinfo. Do the moving in this patch.
Link: http://lkml.kernel.org/r/1478568596-30060-2-git-send-email-bhe@redhat.com
Signed-off-by: Baoquan He <bhe@redhat.com>
Cc: Thomas Garnier <thgarnie@google.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Xunlei Pang <xlpang@redhat.com>
Cc: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Eugene Surovegin <surovegin@google.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: AKASHI Takahiro <takahiro.akashi@linaro.org>
Cc: Atsushi Kumagai <ats-kumagai@wm.jp.nec.com>
Cc: Dave Anderson <anderson@redhat.com>
Cc: Pratyush Anand <panand@redhat.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>
Diffstat (limited to 'arch/x86/kernel/machine_kexec_64.c')
| -rw-r--r-- | arch/x86/kernel/machine_kexec_64.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/x86/kernel/machine_kexec_64.c b/arch/x86/kernel/machine_kexec_64.c index 5a294e48b185..307b1f4543de 100644 --- a/arch/x86/kernel/machine_kexec_64.c +++ b/arch/x86/kernel/machine_kexec_64.c @@ -328,7 +328,7 @@ void machine_kexec(struct kimage *image) void arch_crash_save_vmcoreinfo(void) { - VMCOREINFO_SYMBOL(phys_base); + VMCOREINFO_NUMBER(phys_base); VMCOREINFO_SYMBOL(init_level4_pgt); #ifdef CONFIG_NUMA @@ -337,6 +337,7 @@ void arch_crash_save_vmcoreinfo(void) #endif vmcoreinfo_append_str("KERNELOFFSET=%lx\n", kaslr_offset()); + VMCOREINFO_NUMBER(KERNEL_IMAGE_SIZE); } /* arch-dependent functionality related to kexec file-based syscall */ |