From: Bruno Haible Date: Thu, 2 Nov 2023 19:19:44 +0000 (-0300) Subject: hppa: Fix undefined behaviour in feclearexcept (BZ 30983) X-Git-Tag: glibc-2.39~181 X-Git-Url: https://sourceware.org/git/?a=commitdiff_plain;h=d0829302728954e0abacfc01551c17daf4d61c87;p=glibc.git hppa: Fix undefined behaviour in feclearexcept (BZ 30983) The expression (excepts & FE_ALL_EXCEPT) << 27 produces a signed integer overflow when 'excepts' is specified as FE_INVALID (= 0x10), because - excepts is of type 'int', - FE_ALL_EXCEPT is of type 'int', - thus (excepts & FE_ALL_EXCEPT) is (int) 0x10, - 'int' is 32 bits wide. The patched code produces the same instruction sequence as previosuly. Reviewed-by: Carlos O'Donell --- diff --git a/sysdeps/hppa/fpu/fclrexcpt.c b/sysdeps/hppa/fpu/fclrexcpt.c index 055fb04ccc..46caf39ec1 100644 --- a/sysdeps/hppa/fpu/fclrexcpt.c +++ b/sysdeps/hppa/fpu/fclrexcpt.c @@ -26,7 +26,7 @@ feclearexcept (int excepts) /* Get the current status word. */ __asm__ ("fstd %%fr0,0(%1)" : "=m" (s.l) : "r" (&s.l) : "%r0"); /* Clear all the relevant bits. */ - s.sw[0] &= ~((excepts & FE_ALL_EXCEPT) << 27); + s.sw[0] &= ~(((unsigned int) excepts & FE_ALL_EXCEPT) << 27); __asm__ ("fldd 0(%0),%%fr0" : : "r" (&s.l), "m" (s.l) : "%r0"); /* Success. */