4.14-stable review patch. If anyone has any objections, please let me know.
------------------ From: Kirill A. Shutemov <kirill.shute...@linux.intel.com> commit a0b1280368d1e91ab72f849ef095b4f07a39bbf1 upstream. 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 kdump code. VMCOREINFO_SYMBOL(mem_section) writes down address of pointer into vmcoreinfo, not array as we wanted. Let's introduce VMCOREINFO_SYMBOL_ARRAY() that would handle the situation correctly for both cases. Link: http://lkml.kernel.org/r/20180112162532.35896-1-kirill.shute...@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shute...@linux.intel.com> Fixes: 83e3c48729d9 ("mm/sparsemem: Allocate mem_section at runtime for CONFIG_SPARSEMEM_EXTREME=y") Acked-by: Baoquan He <b...@redhat.com> Acked-by: Dave Young <dyo...@redhat.com> Cc: Ingo Molnar <mi...@redhat.com> Cc: Thomas Gleixner <t...@linutronix.de> Cc: "H. Peter Anvin" <h...@zytor.com> Cc: Greg Kroah-Hartman <gre...@linuxfoundation.org> Cc: Dave Young <dyo...@redhat.com> Cc: Baoquan He <b...@redhat.com> Cc: Vivek Goyal <vgo...@redhat.com> Signed-off-by: Andrew Morton <a...@linux-foundation.org> Signed-off-by: Linus Torvalds <torva...@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org> --- include/linux/crash_core.h | 2 ++ kernel/crash_core.c | 2 +- 2 files changed, 3 insertions(+), 1 deletion(-) --- 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)) --- a/kernel/crash_core.c +++ b/kernel/crash_core.c @@ -409,7 +409,7 @@ static int __init crash_save_vmcoreinfo_ 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);
