On 04/20/21 at 02:50pm, Stephen Boyd wrote:
> We can use the vmlinux_build_id array here now instead of open coding
> it. This mostly consolidates code.
>
> 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: <kexec@xxxxxxxxxxxxxxxxxxx>
> Signed-off-by: Stephen Boyd <swboyd@xxxxxxxxxxxx>
> ---
> include/linux/crash_core.h | 12 ++++-----
> kernel/crash_core.c | 50 ++------------------------------------
> 2 files changed, 8 insertions(+), 54 deletions(-)
>
> diff --git a/include/linux/crash_core.h b/include/linux/crash_core.h
> index 206bde8308b2..de62a722431e 100644
> --- 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); \
Since there has been static_assert at above, can we remove the magic
number '20'?
And I checked format_decode(), didn't find which type corresponds to
'N', could you tell?
Other than these, this patch looks good to me, thanks for the effort.
Thanks
Baoquan
> + })
> +
> #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 825284baaf46..29cc15398ee4 100644
> --- a/kernel/crash_core.c
> +++ b/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(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 *)¬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_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);
> --
> https://chromeos.dev
>
>
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>
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