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 <[email protected]>
Cc: Maciej Rozycki <[email protected]>
Cc: [email protected]
[1] 35938a00ba86 ("MIPS: Fix ISA I FP sigcontext access violation handling")
[2] f92722dc4545 ("MIPS: Correct MIPS I FP sigcontext layout")
Cc: [email protected]
Fixes: f92722dc4545 ("MIPS: Correct MIPS I FP sigcontext layout")
Acked-by: Maciej W. Rozycki <[email protected]>
Acked-by: Thomas Bogendoerfer <[email protected]>
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Eric W. Biederman <[email protected]>

0 files changed, 0 insertions, 0 deletions