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authorPingfan Liu <kernelfans@gmail.com>2021-06-16 04:23:36 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2021-06-23 15:42:52 +0300
commitb842b568a584645cf9fcaf5b62fd875d1ef5d275 (patch)
tree0c45f5fa631c8b50aa3e78ea2a0daff11131e256
parent63ba83563e71d5785f642e7ed2dc503acf48a092 (diff)
downloadlinux-b842b568a584645cf9fcaf5b62fd875d1ef5d275.tar.xz
crash_core, vmcoreinfo: append 'SECTION_SIZE_BITS' to vmcoreinfo
commit 4f5aecdff25f59fb5ea456d5152a913906ecf287 upstream. As mentioned in kernel commit 1d50e5d0c505 ("crash_core, vmcoreinfo: Append 'MAX_PHYSMEM_BITS' to vmcoreinfo"), SECTION_SIZE_BITS in the formula: #define SECTIONS_SHIFT (MAX_PHYSMEM_BITS - SECTION_SIZE_BITS) Besides SECTIONS_SHIFT, SECTION_SIZE_BITS is also used to calculate PAGES_PER_SECTION in makedumpfile just like kernel. Unfortunately, this arch-dependent macro SECTION_SIZE_BITS changes, e.g. recently in kernel commit f0b13ee23241 ("arm64/sparsemem: reduce SECTION_SIZE_BITS"). But user space wants a stable interface to get this info. Such info is impossible to be deduced from a crashdump vmcore. Hence append SECTION_SIZE_BITS to vmcoreinfo. Link: https://lkml.kernel.org/r/20210608103359.84907-1-kernelfans@gmail.com Link: http://lists.infradead.org/pipermail/kexec/2021-June/022676.html Signed-off-by: Pingfan Liu <kernelfans@gmail.com> Acked-by: Baoquan He <bhe@redhat.com> Cc: Bhupesh Sharma <bhupesh.sharma@linaro.org> Cc: Kazuhito Hagio <k-hagio@ab.jp.nec.com> Cc: Dave Young <dyoung@redhat.com> Cc: Boris Petkov <bp@alien8.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: James Morse <james.morse@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Will Deacon <will@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Dave Anderson <anderson@redhat.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--kernel/crash_core.c1
1 files changed, 1 insertions, 0 deletions
diff --git a/kernel/crash_core.c b/kernel/crash_core.c
index 106e4500fd53..4a5fed2f497b 100644
--- a/kernel/crash_core.c
+++ b/kernel/crash_core.c
@@ -463,6 +463,7 @@ static int __init crash_save_vmcoreinfo_init(void)
VMCOREINFO_LENGTH(mem_section, NR_SECTION_ROOTS);
VMCOREINFO_STRUCT_SIZE(mem_section);
VMCOREINFO_OFFSET(mem_section, section_mem_map);
+ VMCOREINFO_NUMBER(SECTION_SIZE_BITS);
VMCOREINFO_NUMBER(MAX_PHYSMEM_BITS);
#endif
VMCOREINFO_STRUCT_SIZE(page);