Re: [PATCH v4 5/6] s390/crash: Use note name macros

Dave Martin
2025-01-14T12:23:31Z

Hi,

On Sat, Jan 11, 2025 at 02:48:48PM +0900, Akihiko Odaki wrote:
> Use note name macros to match with the userspace's expectation.
>
> Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
> Acked-by: Heiko Carstens <hca@linux.ibm.com>

Reviewed-by: Dave Martin <Dave.Martin@arm.com>

(I'm not in a position to test this, though.)

> ---
> arch/s390/kernel/crash_dump.c | 62 ++++++++++++++++---------------------------
> 1 file changed, 23 insertions(+), 39 deletions(-)
>
> diff --git a/arch/s390/kernel/crash_dump.c b/arch/s390/kernel/crash_dump.c
> index cd0c93a8fb8b..022f4f198edf 100644
> --- a/arch/s390/kernel/crash_dump.c
> +++ b/arch/s390/kernel/crash_dump.c
> @@ -248,15 +248,6 @@ bool is_kdump_kernel(void)
> }
> EXPORT_SYMBOL_GPL(is_kdump_kernel);
>
> -static const char *nt_name(Elf64_Word type)
> -{
> - const char *name = "LINUX";
> -
> - if (type == NT_PRPSINFO || type == NT_PRSTATUS || type == NT_PRFPREG)
> - name = KEXEC_CORE_NOTE_NAME;
> - return name;
> -}
> -
> /*
> * Initialize ELF note
> */
> @@ -281,10 +272,8 @@ static void *nt_init_name(void *buf, Elf64_Word type, void *desc, int d_len,
> return PTR_ADD(buf, len);
> }
>
> -static inline void *nt_init(void *buf, Elf64_Word type, void *desc, int d_len)
> -{
> - return nt_init_name(buf, type, desc, d_len, nt_name(type));
> -}
> +#define nt_init(buf, type, desc) \
> + nt_init_name(buf, NT_ ## type, &(desc), sizeof(desc), NN_ ## type)
>
> /*
> * Calculate the size of ELF note
> @@ -300,10 +289,7 @@ static size_t nt_size_name(int d_len, const char *name)
> return size;
> }
>
> -static inline size_t nt_size(Elf64_Word type, int d_len)
> -{
> - return nt_size_name(d_len, nt_name(type));
> -}
> +#define nt_size(type, desc) nt_size_name(sizeof(desc), NN_ ## type)
>
> /*
> * Fill ELF notes for one CPU with save area registers
> @@ -324,18 +310,16 @@ static void *fill_cpu_elf_notes(void *ptr, int cpu, struct save_area *sa)
> memcpy(&nt_fpregset.fpc, &sa->fpc, sizeof(sa->fpc));
> memcpy(&nt_fpregset.fprs, &sa->fprs, sizeof(sa->fprs));
> /* Create ELF notes for the CPU */
> - ptr = nt_init(ptr, NT_PRSTATUS, &nt_prstatus, sizeof(nt_prstatus));
> - ptr = nt_init(ptr, NT_PRFPREG, &nt_fpregset, sizeof(nt_fpregset));
> - ptr = nt_init(ptr, NT_S390_TIMER, &sa->timer, sizeof(sa->timer));
> - ptr = nt_init(ptr, NT_S390_TODCMP, &sa->todcmp, sizeof(sa->todcmp));
> - ptr = nt_init(ptr, NT_S390_TODPREG, &sa->todpreg, sizeof(sa->todpreg));
> - ptr = nt_init(ptr, NT_S390_CTRS, &sa->ctrs, sizeof(sa->ctrs));
> - ptr = nt_init(ptr, NT_S390_PREFIX, &sa->prefix, sizeof(sa->prefix));
> + ptr = nt_init(ptr, PRSTATUS, nt_prstatus);
> + ptr = nt_init(ptr, PRFPREG, nt_fpregset);
> + ptr = nt_init(ptr, S390_TIMER, sa->timer);
> + ptr = nt_init(ptr, S390_TODCMP, sa->todcmp);
> + ptr = nt_init(ptr, S390_TODPREG, sa->todpreg);
> + ptr = nt_init(ptr, S390_CTRS, sa->ctrs);
> + ptr = nt_init(ptr, S390_PREFIX, sa->prefix);
> if (cpu_has_vx()) {
> - ptr = nt_init(ptr, NT_S390_VXRS_HIGH,
> - &sa->vxrs_high, sizeof(sa->vxrs_high));
> - ptr = nt_init(ptr, NT_S390_VXRS_LOW,
> - &sa->vxrs_low, sizeof(sa->vxrs_low));
> + ptr = nt_init(ptr, S390_VXRS_HIGH, sa->vxrs_high);
> + ptr = nt_init(ptr, S390_VXRS_LOW, sa->vxrs_low);
> }
> return ptr;
> }
> @@ -348,16 +332,16 @@ static size_t get_cpu_elf_notes_size(void)
> struct save_area *sa = NULL;
> size_t size;
>
> - size = nt_size(NT_PRSTATUS, sizeof(struct elf_prstatus));
> - size += nt_size(NT_PRFPREG, sizeof(elf_fpregset_t));
> - size += nt_size(NT_S390_TIMER, sizeof(sa->timer));
> - size += nt_size(NT_S390_TODCMP, sizeof(sa->todcmp));
> - size += nt_size(NT_S390_TODPREG, sizeof(sa->todpreg));
> - size += nt_size(NT_S390_CTRS, sizeof(sa->ctrs));
> - size += nt_size(NT_S390_PREFIX, sizeof(sa->prefix));
> + size = nt_size(PRSTATUS, struct elf_prstatus);
> + size += nt_size(PRFPREG, elf_fpregset_t);
> + size += nt_size(S390_TIMER, sa->timer);
> + size += nt_size(S390_TODCMP, sa->todcmp);
> + size += nt_size(S390_TODPREG, sa->todpreg);
> + size += nt_size(S390_CTRS, sa->ctrs);
> + size += nt_size(S390_PREFIX, sa->prefix);
> if (cpu_has_vx()) {
> - size += nt_size(NT_S390_VXRS_HIGH, sizeof(sa->vxrs_high));
> - size += nt_size(NT_S390_VXRS_LOW, sizeof(sa->vxrs_low));
> + size += nt_size(S390_VXRS_HIGH, sa->vxrs_high);
> + size += nt_size(S390_VXRS_LOW, sa->vxrs_low);
> }
>
> return size;
> @@ -373,7 +357,7 @@ static void *nt_prpsinfo(void *ptr)
> memset(&prpsinfo, 0, sizeof(prpsinfo));
> prpsinfo.pr_sname = 'R';
> strcpy(prpsinfo.pr_fname, "vmlinux");
> - return nt_init(ptr, NT_PRPSINFO, &prpsinfo, sizeof(prpsinfo));
> + return nt_init(ptr, PRPSINFO, prpsinfo);
> }
>
> /*
> @@ -589,7 +573,7 @@ static size_t get_elfcorehdr_size(int phdr_count)
> /* PT_NOTES */
> size += sizeof(Elf64_Phdr);
> /* nt_prpsinfo */
> - size += nt_size(NT_PRPSINFO, sizeof(struct elf_prpsinfo));
> + size += nt_size(PRPSINFO, struct elf_prpsinfo);
> /* regsets */
> size += get_cpu_cnt() * get_cpu_elf_notes_size();
> /* nt_vmcoreinfo */
>
> --
> 2.47.1
>
>