Commit 44e8a5e9 authored by Stephen Boyd's avatar Stephen Boyd Committed by Linus Torvalds
Browse files

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: default avatarStephen 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: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 3f14d029

include/linux/buildid.h

+1 −1
Original line number Diff line number Diff line
@@ -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

include/linux/crash_core.h

+6 −6
Original line number Diff line number Diff line
@@ -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);

kernel/crash_core.c

+2 −48
Original line number Diff line number Diff line
@@ -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);

lib/buildid.c

+1 −1
Original line number Diff line number Diff line
@@ -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;



/**