Commit-ID: 9f15b9120f562ae0bf0a836c96f4dafb33ae426a Gitweb: https://git.kernel.org/tip/9f15b9120f562ae0bf0a836c96f4dafb33ae426a Author: Kirill A. Shutemov <[email protected]> AuthorDate: Fri, 12 Jan 2018 19:25:32 +0300 Committer: Ingo Molnar <[email protected]> CommitDate: Sat, 13 Jan 2018 11:48:06 +0100
kdump: Write the correct address of mem_section into vmcoreinfo Depending on configuration mem_section can now be an array or a pointer to an array allocated dynamically. In most cases, we can continue to refer to it as 'mem_section' regardless of what it is. But there's one exception: '&mem_section' means "address of the array" if mem_section is an array, but if mem_section is a pointer, it would mean "address of the pointer". We've stepped onto this in the kdump code: VMCOREINFO_SYMBOL(mem_section) writes down the address of pointer into vmcoreinfo, not the array as we wanted, breaking kdump. Let's introduce VMCOREINFO_SYMBOL_ARRAY() that would handle the situation correctly for both cases. Mike Galbraith <[email protected]> Signed-off-by: Kirill A. Shutemov <[email protected]> Acked-by: Baoquan He <[email protected]> Acked-by: Dave Young <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Greg Kroah-Hartman <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Vivek Goyal <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Fixes: 83e3c48729d9 ("mm/sparsemem: Allocate mem_section at runtime for CONFIG_SPARSEMEM_EXTREME=y") Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]> --- include/linux/crash_core.h | 2 ++ kernel/crash_core.c | 2 +- 2 files changed, 3 insertions(+), 1 deletion(-) diff --git a/include/linux/crash_core.h b/include/linux/crash_core.h index 06097ef..b511f6d 100644 --- a/include/linux/crash_core.h +++ b/include/linux/crash_core.h @@ -42,6 +42,8 @@ phys_addr_t paddr_vmcoreinfo_note(void); vmcoreinfo_append_str("PAGESIZE=%ld\n", value) #define VMCOREINFO_SYMBOL(name) \ vmcoreinfo_append_str("SYMBOL(%s)=%lx\n", #name, (unsigned long)&name) +#define VMCOREINFO_SYMBOL_ARRAY(name) \ + vmcoreinfo_append_str("SYMBOL(%s)=%lx\n", #name, (unsigned long)name) #define VMCOREINFO_SIZE(name) \ vmcoreinfo_append_str("SIZE(%s)=%lu\n", #name, \ (unsigned long)sizeof(name)) diff --git a/kernel/crash_core.c b/kernel/crash_core.c index b366389..4f63597 100644 --- a/kernel/crash_core.c +++ b/kernel/crash_core.c @@ -410,7 +410,7 @@ static int __init crash_save_vmcoreinfo_init(void) VMCOREINFO_SYMBOL(contig_page_data); #endif #ifdef CONFIG_SPARSEMEM - VMCOREINFO_SYMBOL(mem_section); + VMCOREINFO_SYMBOL_ARRAY(mem_section); VMCOREINFO_LENGTH(mem_section, NR_SECTION_ROOTS); VMCOREINFO_STRUCT_SIZE(mem_section); VMCOREINFO_OFFSET(mem_section, section_mem_map);
