[PATCH 2/4] kselftest/arm64: Fix printf() warning in the arm64 MTE prctl() test
Catalin Marinas
catalin.marinas at arm.com
Fri Nov 8 07:25:46 PST 2024
On Fri, Nov 08, 2024 at 03:10:59PM +0000, Mark Brown wrote:
> On Fri, Nov 08, 2024 at 01:49:18PM +0000, Catalin Marinas wrote:
> > While prctl() returns an 'int', the PR_MTE_TCF_MASK is defined as
> > unsigned long which results in the larger type following a bitwise 'and'
> > operation. Cast the printf() argument to 'int'.
>
> > } else {
> > ksft_print_msg("Got %x, expected %x\n",
> > - (ret & PR_MTE_TCF_MASK), mask);
> > + (int)(ret & PR_MTE_TCF_MASK), mask);
>
> Shouldn't we just use a %lx here? Casts tend to be suspicious...
It's more like the ret is actually 32-bit and should stay like that when
bits are masked out. But the bitwise op 'upgrades' it to a long (in
hindsight, we should not have used UL for the TCF bits and mask).
--
Catalin
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