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" <redacted>
---
 arch/mips/kernel/r2300_fpu.S | 4 ++--
 arch/mips/kernel/syscall.c   | 9 ---------
 2 files changed, 2 insertions(+), 11 deletions(-)

Acked-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

-- 
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