MIPS: Save static registers before sysmips

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commit 49955d84cd upstream.

The MIPS sysmips system call handler may return directly from the
MIPS_ATOMIC_SET case (mips_atomic_set()) to syscall_exit. This path
restores the static (callee saved) registers, however they won't have
been saved on entry to the system call.

Use the save_static_function() macro to create a __sys_sysmips wrapper
function which saves the static registers before calling sys_sysmips, so
that the correct static register state is restored by syscall_exit.

Fixes: f1e39a4a61 ("MIPS: Rewrite sysmips(MIPS_ATOMIC_SET, ...) in C with inline assembler")
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16149/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

...

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James Hogan 2017-05-31 16:19:48 +01:00 • committed by Greg Kroah-Hartman

parent a9db2f4f88

commit f8c331cbc9

5 changed files with 10 additions and 4 deletions

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2

arch/mips/kernel/scall32-o32.S

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arch/mips/kernel/scall64-64.S

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arch/mips/kernel/scall64-n32.S

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arch/mips/kernel/scall64-o32.S

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arch/mips/kernel/syscall.c

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