Re: [PATCH] x86/hweight: Fix and improve __arch_hweight{32,64}() assembly
From: Borislav Petkov
Date: Mon Mar 10 2025 - 17:09:10 EST
On Mon, Mar 10, 2025 at 09:54:25PM +0100, Uros Bizjak wrote:
> Ok, so let it be your way and let's just sweep the issue under the carpet.
Can you please read my mails more carefilly? Where did I say we should sweep
the issue under the carpet?
The commit message should be *perfectly* clear what it is fixing. This
"a) Use ASM_CALL_CONSTRAINT to prevent inline asm that includes call
instruction from being scheduled before the frame pointer gets set
up by the containing function, causing objtool to print a "call
without frame pointer save/setup" warning."
says that objool is printing a warning. When I ask, it is not really printing
a warning but it can potentially do so because the compiler is allowed to
schedule things wrongly.
Do you notice the difference?
Dammit, it is very important *why* a commit message is there - it is not
write-only and people look at it. So *again* *please* be precise when
explaining why your patch exists!
All that stuff has been documented at length:
https://kernel.org/doc/html/latest/process/submitting-patches.html#describe-your-changes
Thanks.
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette