Re: [PATCH v3 5/6] s390/crash: Use note name macros

On 2025/01/08 22:50, Dave Martin wrote:

On Wed, Jan 08, 2025 at 01:53:51PM +0900, Akihiko Odaki wrote:

quoted

On 2025/01/08 1:17, Dave Martin wrote:

quoted

Hi,

On Tue, Jan 07, 2025 at 09:45:56PM +0900, Akihiko Odaki wrote:

quoted

Use note name macros to match with the userspace's expectation.

Signed-off-by: Akihiko Odaki <redacted>
---
   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

[...]

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+#define NT_INIT(buf, type, desc) \
+	(nt_init_name((buf), NT_ ## type, &(desc), sizeof(desc), NN_ ## type))

[...]

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(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.)

Well, being very pedantic, there are some cases where these parentheses 
have some effect.

If you omit the outer parentheses, the following code will have 
different consequences:
a->NT_INIT(buf, PRSTATUS, desc)

The parentheses around buf will make difference for the following code:
#define COMMA ,
NT_INIT(NULL COMMA buf, PRSTATUS, desc)

But nobody will write such code.

Regards,
Akihiko Odaki