On 5/13/26 11:56, Hongfu Li wrote: > mmap() returns MAP_FAILED, which is defined as (void *)-1, on error, > not NULL. Several selftests incorrectly check the return value of > mmap() using !ptr or ptr == NULL, which would erroneously treat > MAP_FAILED as a valid pointer since MAP_FAILED is non-zero and > non-NULL. This can lead to segfaults when mmap() actually fails > under memory pressure.
Well, your patch also adds more checks where we previously didn't have any checks? > > Signed-off-by: Hongfu Li <[email protected]> > Reviewed-by: Dev Jain <[email protected]> > --- > v2: > - Add missing mmap() return value checks in pkey_sighandler_tests.c > and protection_keys.c > --- [...] > diff --git a/tools/testing/selftests/mm/protection_keys.c > b/tools/testing/selftests/mm/protection_keys.c > index 2085982dba69..580bf1668c71 100644 > --- a/tools/testing/selftests/mm/protection_keys.c > +++ b/tools/testing/selftests/mm/protection_keys.c > @@ -1217,6 +1217,7 @@ static void arch_force_pkey_reg_init(void) > * doing the XSAVE size enumeration dance. > */ > buf = mmap(NULL, 1*MB, PROT_READ|PROT_WRITE, MAP_ANONYMOUS|MAP_PRIVATE, > -1, 0); > + pkey_assert(buf != (void *)-1); What's the reason for not using MAP_FAILED? -- Cheers, David
