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authorEric W. Biederman <ebiederm@xmission.com>2021-10-20 12:43:51 -0500
committerEric W. Biederman <ebiederm@xmission.com>2021-10-25 15:55:35 -0500
commit95bf9d646c3c3f95cb0be7e703b371db8da5be68 (patch)
tree803ea8fedd4f3acf211a73cf3981a61eddca7037 /arch/mips/kernel
parent97cae848270731e4224681368f2061c94a9fc588 (diff)
signal/mips: Update (_save|_restore)_fp_context to fail with -EFAULT
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") Cc: stable@vger.kernel.org Fixes: f92722dc4545 ("MIPS: Correct MIPS I FP sigcontext layout") Acked-by: Maciej W. Rozycki <macro@orcam.me.uk> Acked-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Link: https://lkml.kernel.org/r/20211020174406.17889-5-ebiederm@xmission.com Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Diffstat (limited to 'arch/mips/kernel')
-rw-r--r--arch/mips/kernel/r2300_fpu.S4
-rw-r--r--arch/mips/kernel/syscall.c9
2 files changed, 2 insertions, 11 deletions
diff --git a/arch/mips/kernel/r2300_fpu.S b/arch/mips/kernel/r2300_fpu.S
index 12e58053544f..cbf6db98cfb3 100644
--- a/arch/mips/kernel/r2300_fpu.S
+++ b/arch/mips/kernel/r2300_fpu.S
@@ -29,8 +29,8 @@
#define EX2(a,b) \
9: a,##b; \
.section __ex_table,"a"; \
- PTR 9b,bad_stack; \
- PTR 9b+4,bad_stack; \
+ PTR 9b,fault; \
+ PTR 9b+4,fault; \
.previous
.set mips1
diff --git a/arch/mips/kernel/syscall.c b/arch/mips/kernel/syscall.c
index 2afa3eef486a..5512cd586e6e 100644
--- a/arch/mips/kernel/syscall.c
+++ b/arch/mips/kernel/syscall.c
@@ -240,12 +240,3 @@ SYSCALL_DEFINE3(cachectl, char *, addr, int, nbytes, int, op)
{
return -ENOSYS;
}
-
-/*
- * If we ever come here the user sp is bad. Zap the process right away.
- * Due to the bad stack signaling wouldn't work.
- */
-asmlinkage void bad_stack(void)
-{
- do_exit(SIGSEGV);
-}