| Message ID | 20250107-elf-v3-5-99cb505b1ab2@daynix.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | elf: Define note name macros | expand |
Hi, On Tue, Jan 07, 2025 at 09:45:56PM +0900, Akihiko Odaki wrote: > Use note name macros to match with the userspace's expectation. > > Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com> > --- > 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 [...] > @@ -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)) Nit: this macro name clashes with the naming scheme in elf.h. I think that there is a (weak) convention that macros with upper-case names don't expand to a C function call; thus, a macro with an upper- case name can be invoked in places where a C function call would not be allowed. (This convention is not followed everywhere, though -- it's up to the maintainer what they prefer here.) (Note also, the outer parentheses and the parentheses around (buf) appear redundant -- although harmless?) > > /* > * 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)) Nit: name prefix clash (again); possibly redundant parentheses. [...] > @@ -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); It might be worth fixing the funny spacing on these lines, since all the affected lines are being replaced. > 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 */ Otherwise, this looks sensible to me. Cheers ---Dave
On 2025/01/08 1:17, Dave Martin wrote: > Hi, > > On Tue, Jan 07, 2025 at 09:45:56PM +0900, Akihiko Odaki wrote: >> Use note name macros to match with the userspace's expectation. >> >> Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com> >> --- >> 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 > > [...] > >> @@ -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)) > > Nit: this macro name clashes with the naming scheme in elf.h. > > I think that there is a (weak) convention that macros with upper-case > names don't expand to a C function call; thus, a macro with an upper- > case name can be invoked in places where a C function call would not be > allowed. (This convention is not followed everywhere, though -- it's > up to the maintainer what they prefer here.) I wanted to clarify it is a macro as it concatenates tokens with ##, but I also find there are many macros that are named lower-case and performs token concatenation. S390 maintainers, please tell usr your opinion. > > (Note also, the outer parentheses and the parentheses around (buf) > appear redundant -- although harmless?) They only make a difference in trivial corner cases and may look needlessly verbose. > >> >> /* >> * 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)) > > Nit: name prefix clash (again); possibly redundant parentheses. > > [...] > >> @@ -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); > > It might be worth fixing the funny spacing on these lines, since all > the affected lines are being replaced. > >> 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 */ > > Otherwise, this looks sensible to me. > > Cheers > ---Dave
On Wed, Jan 08, 2025 at 01:53:51PM +0900, Akihiko Odaki wrote: > On 2025/01/08 1:17, Dave Martin wrote: > > > +#define NT_INIT(buf, type, desc) \ > > > + (nt_init_name((buf), NT_ ## type, &(desc), sizeof(desc), NN_ ## type)) > > > > Nit: this macro name clashes with the naming scheme in elf.h. > > > > I think that there is a (weak) convention that macros with upper-case > > names don't expand to a C function call; thus, a macro with an upper- > > case name can be invoked in places where a C function call would not be > > allowed. (This convention is not followed everywhere, though -- it's > > up to the maintainer what they prefer here.) > > I wanted to clarify it is a macro as it concatenates tokens with ##, but I > also find there are many macros that are named lower-case and performs token > concatenation. > > S390 maintainers, please tell usr your opinion. Just make the new macros lower case to avoid the naming scheme clashes, please. Otherwise it doesn't matter too much. > > > +#define NT_SIZE(type, desc) (nt_size_name(sizeof(desc), NN_ ## type)) > > > > Nit: name prefix clash (again); possibly redundant parentheses. Same here. > > > - 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); > > > > It might be worth fixing the funny spacing on these lines, since all > > the affected lines are being replaced. Yes, please! Besides that this looks good: Acked-by: Heiko Carstens <hca@linux.ibm.com>
On Wed, Jan 08, 2025 at 01:53:51PM +0900, Akihiko Odaki wrote: > On 2025/01/08 1:17, Dave Martin wrote: > > Hi, > > > > On Tue, Jan 07, 2025 at 09:45:56PM +0900, Akihiko Odaki wrote: > > > Use note name macros to match with the userspace's expectation. > > > > > > Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com> > > > --- > > > 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 > > > > [...] > > > +#define NT_INIT(buf, type, desc) \ > > > + (nt_init_name((buf), NT_ ## type, &(desc), sizeof(desc), NN_ ## type)) [...] > > (Note also, the outer parentheses and the parentheses around (buf) > > appear redundant -- although harmless?) > > They only make a difference in trivial corner cases and may look needlessly > verbose. (In case there was a misunderstanding here, I meant that some parentheses can be removed without affecting correctness: #define NT_INIT(buf, type, desc) \ nt_init_name(buf, NT_ ## type, &(desc), sizeof(desc), NN_ ## type)) It still doesn't matter though -- and some people do prefer to be defensive anyway and err on the side of having too many parentheses rather than too few.) [...] Cheers ---Dave
diff --git a/arch/s390/kernel/crash_dump.c b/arch/s390/kernel/crash_dump.c index cd0c93a8fb8b..6359ce645756 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 */
Use note name macros to match with the userspace's expectation. Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com> --- arch/s390/kernel/crash_dump.c | 62 ++++++++++++++++--------------------------- 1 file changed, 23 insertions(+), 39 deletions(-)