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@chromium.org
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jessica Yu <jeyu@kernel.org>
Cc: Evan Green <evgreen@chromium.org>
Cc: Hsin-Yi Wang <hsinyi@chromium.org>
Cc: Dave Young <dyoung@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Sasha Levin <sashal@kernel.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/include/linux/buildid.h b/include/linux/buildid.h
index 3e8d77a93ec4a362b49d1719c957febcbab4f395..3b7a0ff4642fd96cdca4996f240c63acaa44f426 100644 (file)
--- a/include/linux/buildid.h
+++ b/include/linux/buildid.h
@@ -10,7 +10,7 @@ int build_id_parse(struct vm_area_struct *vma, unsigned char *build_id,
                   __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

diff --git a/include/linux/crash_core.h b/include/linux/crash_core.h
index 206bde8308b2ddee9a620cbecb8af35e3cfe5865..de62a722431e7dbcb3b4ec2af0d932601ff1d302 100644 (file)
--- a/include/linux/crash_core.h
+++ b/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);

diff --git a/kernel/crash_core.c b/kernel/crash_core.c
index da449c1cdca758f56fcccc0e1b5f276b489ac3b6..eb53f5ec62c900ff488532c67865cd79c377b35d 100644 (file)
--- a/kernel/crash_core.c
+++ b/kernel/crash_core.c
@@ -4,6 +4,7 @@
  * Copyright (C) 2002-2004 Eric Biederman  <ebiederm@xmission.com>
  */
 
+#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(void)
 }
 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 *)&note_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 = &note_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_init(void)
        }
 
        VMCOREINFO_OSRELEASE(init_uts_ns.name.release);
-       add_build_id_vmcoreinfo();
+       VMCOREINFO_BUILD_ID();
        VMCOREINFO_PAGESIZE(PAGE_SIZE);
 
        VMCOREINFO_SYMBOL(init_uts_ns);

diff --git a/lib/buildid.c b/lib/buildid.c
index 180a1a9b3b761d90b075c63b7fdc466e9c18d187..dfc62625cae4e3839696f3efe68eb6dfc8659bad 100644 (file)
--- a/lib/buildid.c
+++ b/lib/buildid.c
@@ -174,7 +174,7 @@ int build_id_parse_buf(const void *buf, unsigned char *build_id, u32 buf_size)
        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;
 
 /**