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author | Xunlei Pang <xlpang@redhat.com> | 2017-07-12 14:33:14 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-07-12 16:25:59 -0700 |
commit | 203e9e41219b4e7357104e525e91ac609fba2c6c (patch) | |
tree | f7b0b4235857f20c11bf15d2e582d57f9f29a872 /arch/x86 | |
parent | 112166f88cf83dd11486cf1818672d42b540865b (diff) | |
download | linux-203e9e41219b4e7357104e525e91ac609fba2c6c.tar.bz2 |
kexec: move vmcoreinfo out of the kernel's .bss section
As Eric said,
"what we need to do is move the variable vmcoreinfo_note out of the
kernel's .bss section. And modify the code to regenerate and keep this
information in something like the control page.
Definitely something like this needs a page all to itself, and ideally
far away from any other kernel data structures. I clearly was not
watching closely the data someone decided to keep this silly thing in
the kernel's .bss section."
This patch allocates extra pages for these vmcoreinfo_XXX variables, one
advantage is that it enhances some safety of vmcoreinfo, because
vmcoreinfo now is kept far away from other kernel data structures.
Link: http://lkml.kernel.org/r/1493281021-20737-1-git-send-email-xlpang@redhat.com
Signed-off-by: Xunlei Pang <xlpang@redhat.com>
Tested-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Suggested-by: Eric Biederman <ebiederm@xmission.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Dave Young <dyoung@redhat.com>
Cc: Hari Bathini <hbathini@linux.vnet.ibm.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>
Diffstat (limited to 'arch/x86')
-rw-r--r-- | arch/x86/kernel/crash.c | 2 | ||||
-rw-r--r-- | arch/x86/xen/mmu_pv.c | 4 |
2 files changed, 3 insertions, 3 deletions
diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c index 22217ece26c8..44404e2307bb 100644 --- a/arch/x86/kernel/crash.c +++ b/arch/x86/kernel/crash.c @@ -457,7 +457,7 @@ static int prepare_elf64_headers(struct crash_elf_data *ced, bufp += sizeof(Elf64_Phdr); phdr->p_type = PT_NOTE; phdr->p_offset = phdr->p_paddr = paddr_vmcoreinfo_note(); - phdr->p_filesz = phdr->p_memsz = sizeof(vmcoreinfo_note); + phdr->p_filesz = phdr->p_memsz = VMCOREINFO_NOTE_SIZE; (ehdr->e_phnum)++; #ifdef CONFIG_X86_64 diff --git a/arch/x86/xen/mmu_pv.c b/arch/x86/xen/mmu_pv.c index 1d7a7213a310..cab28cf2cffb 100644 --- a/arch/x86/xen/mmu_pv.c +++ b/arch/x86/xen/mmu_pv.c @@ -2693,8 +2693,8 @@ EXPORT_SYMBOL_GPL(xen_destroy_contiguous_region); phys_addr_t paddr_vmcoreinfo_note(void) { if (xen_pv_domain()) - return virt_to_machine(&vmcoreinfo_note).maddr; + return virt_to_machine(vmcoreinfo_note).maddr; else - return __pa_symbol(&vmcoreinfo_note); + return __pa(vmcoreinfo_note); } #endif /* CONFIG_KEXEC_CORE */ |