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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 /kernel/ksysfs.c | |
parent | 112166f88cf83dd11486cf1818672d42b540865b (diff) | |
download | lwn-203e9e41219b4e7357104e525e91ac609fba2c6c.tar.gz lwn-203e9e41219b4e7357104e525e91ac609fba2c6c.zip |
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 'kernel/ksysfs.c')
-rw-r--r-- | kernel/ksysfs.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/ksysfs.c b/kernel/ksysfs.c index df1a9aa602a0..46ba853656f6 100644 --- a/kernel/ksysfs.c +++ b/kernel/ksysfs.c @@ -134,7 +134,7 @@ static ssize_t vmcoreinfo_show(struct kobject *kobj, { phys_addr_t vmcore_base = paddr_vmcoreinfo_note(); return sprintf(buf, "%pa %x\n", &vmcore_base, - (unsigned int)sizeof(vmcoreinfo_note)); + (unsigned int)VMCOREINFO_NOTE_SIZE); } KERNEL_ATTR_RO(vmcoreinfo); |