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MIPS: Fix sigreturn via VDSO on microMIPS kernel

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commit 13eb192d10bcc9ac518d57356179071d603bcb4e upstream.

In microMIPS kernels, handle_signal() sets the isa16 mode bit in the
vdso address so that the sigreturn trampolines (which are offset from
the VDSO) get executed as microMIPS.

However commit ebb5e78cc634 ("MIPS: Initial implementation of a VDSO")
changed the offsets to come from the VDSO image, which already have the
isa16 mode bit set correctly since they're extracted from the VDSO
shared library symbol table.

Drop the isa16 mode bit handling from handle_signal() to fix sigreturn
for cores which support both microMIPS and normal MIPS. This doesn't fix
microMIPS only cores, since the VDSO is still built for normal MIPS, but
thats a separate problem.

Fixes: ebb5e78cc634 ("MIPS: Initial implementation of a VDSO")
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13348/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
James Hogan 2016-05-24 09:35:10 +01:00 committed by Greg Kroah-Hartman
parent 13defedff1
commit 1985bf8d71
1 changed files with 0 additions and 8 deletions
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8
arch/mips/kernel/signal.c
View File

@ -770,15 +770,7 @@ static void handle_signal(struct ksignal *ksig, struct pt_regs *regs)
sigset_t *oldset = sigmask_to_save();
int ret;
struct mips_abi *abi = current->thread.abi;
#ifdef CONFIG_CPU_MICROMIPS
void *vdso;
unsigned long tmp = (unsigned long)current->mm->context.vdso;
set_isa16_mode(tmp);
vdso = (void *)tmp;
#else
void *vdso = current->mm->context.vdso;
#endif
if (regs->regs[0]) {
switch(regs->regs[2]) {