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@xxxxxxxxxx>
---
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
