| Date | Thu, 21 Oct 2021 09:06:50 -0700 | From | Kees Cook <> | Subject | Re: [PATCH 05/20] signal/mips: Update (_save|_restore)_fp_context to fail with -EFAULT |
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On Wed, Oct 20, 2021 at 12:43:51PM -0500, Eric W. Biederman wrote: > When an instruction to save or restore a register from the stack fails > in _save_fp_context or _restore_fp_context return with -EFAULT. This > change was made to r2300_fpu.S[1] but it looks like it got lost with > the introduction of EX2[2]. This is also what the other implementation > of _save_fp_context and _restore_fp_context in r4k_fpu.S does, and > what is needed for the callers to be able to handle the error. > > Furthermore calling do_exit(SIGSEGV) from bad_stack is wrong because > it does not terminate the entire process it just terminates a single > thread. > > As the changed code was the only caller of arch/mips/kernel/syscall.c:bad_stack > remove the problematic and now unused helper function. > > Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> > Cc: Maciej Rozycki <macro@orcam.me.uk> > Cc: linux-mips@vger.kernel.org > [1] 35938a00ba86 ("MIPS: Fix ISA I FP sigcontext access violation handling") > [2] f92722dc4545 ("MIPS: Correct MIPS I FP sigcontext layout") > Fixes: f92722dc4545 ("MIPS: Correct MIPS I FP sigcontext layout") > Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
-- Kees Cook
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