Messages in this thread | | | From | Jane Chu <> | Subject | Re: [PATCH v5] x86/mce: retrieve poison range from hardware | Date | Mon, 1 Aug 2022 20:31:19 +0000 |
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On 8/1/2022 8:58 AM, Luck, Tony wrote: >> struct mce m; >> + int lsb = PAGE_SHIFT; > > Some maintainers like to order local declaration lines from longest to shortest > >> + /* >> + * Even if the ->validation_bits are set for address mask, >> + * to be extra safe, check and reject an error radius '0', >> + * and fallback to the default page size. >> + */ >> + if (mem_err->validation_bits & CPER_MEM_VALID_PA_MASK) { >> + lsb = __ffs64(mem_err->physical_addr_mask); >> + if (lsb == 1) >> + lsb = PAGE_SHIFT; >> + } > > > The comment above __ffs64() says: > > * The result is not defined if no bits are set, so check that @word > * is non-zero before calling this. > > So if the intent is "extra safe" should check for that: > > if (mem_err->validation_bits & CPER_MEM_VALID_PA_MASK && > mem_err->physical_addr_mask) { > lsb = __ffs64(mem_err->physical_addr_mask); > if (lsb == 1) > lsb = PAGE_SHIFT; > }
Indeed, thanks a lot!
-jane
> > -Tony > > >
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