From: Stephen Boyd <swboyd@xxxxxxxxxxxx> Subject: kdump: use vmlinux_build_id to simplify We can use the vmlinux_build_id array here now instead of open coding it. This mostly consolidates code. Link: https://lkml.kernel.org/r/20210511003845.2429846-14-swboyd@xxxxxxxxxxxx Signed-off-by: Stephen Boyd <swboyd@xxxxxxxxxxxx> Cc: Jiri Olsa <jolsa@xxxxxxxxxx> Cc: Alexei Starovoitov <ast@xxxxxxxxxx> Cc: Jessica Yu <jeyu@xxxxxxxxxx> Cc: Evan Green <evgreen@xxxxxxxxxxxx> Cc: Hsin-Yi Wang <hsinyi@xxxxxxxxxxxx> Cc: Dave Young <dyoung@xxxxxxxxxx> Cc: Baoquan He <bhe@xxxxxxxxxx> Cc: Vivek Goyal <vgoyal@xxxxxxxxxx> Cc: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> Cc: Borislav Petkov <bp@xxxxxxxxx> Cc: Catalin Marinas <catalin.marinas@xxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Cc: Konstantin Khlebnikov <khlebnikov@xxxxxxxxxxxxxx> Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx> Cc: Petr Mladek <pmladek@xxxxxxxx> Cc: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx> Cc: Sasha Levin <sashal@xxxxxxxxxx> Cc: Sergey Senozhatsky <sergey.senozhatsky@xxxxxxxxx> Cc: Steven Rostedt <rostedt@xxxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: Will Deacon <will@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/buildid.h | 2 - include/linux/crash_core.h | 12 ++++---- kernel/crash_core.c | 50 +---------------------------------- lib/buildid.c | 2 - 4 files changed, 10 insertions(+), 56 deletions(-) --- a/include/linux/buildid.h~kdump-use-vmlinux_build_id-to-simplify +++ a/include/linux/buildid.h @@ -10,7 +10,7 @@ int build_id_parse(struct vm_area_struct __u32 *size); int build_id_parse_buf(const void *buf, unsigned char *build_id, u32 buf_size); -#if IS_ENABLED(CONFIG_STACKTRACE_BUILD_ID) +#if IS_ENABLED(CONFIG_STACKTRACE_BUILD_ID) || IS_ENABLED(CONFIG_CRASH_CORE) extern unsigned char vmlinux_build_id[BUILD_ID_SIZE_MAX]; void init_vmlinux_build_id(void); #else --- a/include/linux/crash_core.h~kdump-use-vmlinux_build_id-to-simplify +++ a/include/linux/crash_core.h @@ -38,8 +38,12 @@ phys_addr_t paddr_vmcoreinfo_note(void); #define VMCOREINFO_OSRELEASE(value) \ vmcoreinfo_append_str("OSRELEASE=%s\n", value) -#define VMCOREINFO_BUILD_ID(value) \ - vmcoreinfo_append_str("BUILD-ID=%s\n", value) +#define VMCOREINFO_BUILD_ID() \ + ({ \ + static_assert(sizeof(vmlinux_build_id) == 20); \ + vmcoreinfo_append_str("BUILD-ID=%20phN\n", vmlinux_build_id); \ + }) + #define VMCOREINFO_PAGESIZE(value) \ vmcoreinfo_append_str("PAGESIZE=%ld\n", value) #define VMCOREINFO_SYMBOL(name) \ @@ -69,10 +73,6 @@ extern unsigned char *vmcoreinfo_data; extern size_t vmcoreinfo_size; extern u32 *vmcoreinfo_note; -/* raw contents of kernel .notes section */ -extern const void __start_notes __weak; -extern const void __stop_notes __weak; - Elf_Word *append_elf_note(Elf_Word *buf, char *name, unsigned int type, void *data, size_t data_len); void final_note(Elf_Word *buf); --- a/kernel/crash_core.c~kdump-use-vmlinux_build_id-to-simplify +++ a/kernel/crash_core.c @@ -4,6 +4,7 @@ * Copyright (C) 2002-2004 Eric Biederman <ebiederm@xxxxxxxxxxxx> */ +#include <linux/buildid.h> #include <linux/crash_core.h> #include <linux/utsname.h> #include <linux/vmalloc.h> @@ -378,53 +379,6 @@ phys_addr_t __weak paddr_vmcoreinfo_note } EXPORT_SYMBOL(paddr_vmcoreinfo_note); -#define NOTES_SIZE (&__stop_notes - &__start_notes) -#define BUILD_ID_MAX SHA1_DIGEST_SIZE -#define NT_GNU_BUILD_ID 3 - -struct elf_note_section { - struct elf_note n_hdr; - u8 n_data[]; -}; - -/* - * Add build ID from .notes section as generated by the GNU ld(1) - * or LLVM lld(1) --build-id option. - */ -static void add_build_id_vmcoreinfo(void) -{ - char build_id[BUILD_ID_MAX * 2 + 1]; - int n_remain = NOTES_SIZE; - - while (n_remain >= sizeof(struct elf_note)) { - const struct elf_note_section *note_sec = - &__start_notes + NOTES_SIZE - n_remain; - const u32 n_namesz = note_sec->n_hdr.n_namesz; - - if (note_sec->n_hdr.n_type == NT_GNU_BUILD_ID && - n_namesz != 0 && - !strcmp((char *)¬e_sec->n_data[0], "GNU")) { - if (note_sec->n_hdr.n_descsz <= BUILD_ID_MAX) { - const u32 n_descsz = note_sec->n_hdr.n_descsz; - const u8 *s = ¬e_sec->n_data[n_namesz]; - - s = PTR_ALIGN(s, 4); - bin2hex(build_id, s, n_descsz); - build_id[2 * n_descsz] = '\0'; - VMCOREINFO_BUILD_ID(build_id); - return; - } - pr_warn("Build ID is too large to include in vmcoreinfo: %u > %u\n", - note_sec->n_hdr.n_descsz, - BUILD_ID_MAX); - return; - } - n_remain -= sizeof(struct elf_note) + - ALIGN(note_sec->n_hdr.n_namesz, 4) + - ALIGN(note_sec->n_hdr.n_descsz, 4); - } -} - static int __init crash_save_vmcoreinfo_init(void) { vmcoreinfo_data = (unsigned char *)get_zeroed_page(GFP_KERNEL); @@ -443,7 +397,7 @@ static int __init crash_save_vmcoreinfo_ } VMCOREINFO_OSRELEASE(init_uts_ns.name.release); - add_build_id_vmcoreinfo(); + VMCOREINFO_BUILD_ID(); VMCOREINFO_PAGESIZE(PAGE_SIZE); VMCOREINFO_SYMBOL(init_uts_ns); --- a/lib/buildid.c~kdump-use-vmlinux_build_id-to-simplify +++ a/lib/buildid.c @@ -174,7 +174,7 @@ int build_id_parse_buf(const void *buf, return parse_build_id_buf(build_id, NULL, buf, buf_size); } -#if IS_ENABLED(CONFIG_STACKTRACE_BUILD_ID) +#if IS_ENABLED(CONFIG_STACKTRACE_BUILD_ID) || IS_ENABLED(CONFIG_CRASH_CORE) unsigned char vmlinux_build_id[BUILD_ID_SIZE_MAX] __ro_after_init; /** _
