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| author | Nicholas Piggin <npiggin@gmail.com> | 2021-10-26 22:25:31 +1000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-11-17 11:04:50 +0100 |
| commit | baf19ea102c3f3712fa9c5fef8a6ca3d37a90c1a (patch) | |
| tree | 106e0654b8c4928413f149a4102d2981d9e0e768 | |
| parent | 251959e47018b4696ccbef32f5502f0f810603f4 (diff) | |
| download | linux-baf19ea102c3f3712fa9c5fef8a6ca3d37a90c1a.tar.gz linux-baf19ea102c3f3712fa9c5fef8a6ca3d37a90c1a.zip | |
powerpc/64s/interrupt: Fix check_return_regs_valid() false positive
commit 4a5cb51f3db4be547225a4bce7a43d41b231382b upstream.
The check_return_regs_valid() can cause a false positive if the return
regs are marked as norestart and they are an HSRR type interrupt,
because the low bit in the bottom of regs->trap causes interrupt type
matching to fail.
This can occcur for example on bare metal with a HV privileged doorbell
interrupt that causes a signal, but do_signal returns early because
get_signal() fails, and takes the "No signal to deliver" path. In this
case no signal was delivered so the return location is not changed so
return SRRs are not invalidated, yet set_trap_norestart is called, which
messes up the match. Building go-1.16.6 is known to reproduce this.
Fix it by using the TRAP() accessor which masks out the low bit.
Fixes: 6eaaf9de3599 ("powerpc/64s/interrupt: Check and fix srr_valid without crashing")
Cc: stable@vger.kernel.org # v5.14+
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211026122531.3599918-1-npiggin@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | arch/powerpc/kernel/interrupt.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/powerpc/kernel/interrupt.c b/arch/powerpc/kernel/interrupt.c index ec4e2d363507..795bf682ec71 100644 --- a/arch/powerpc/kernel/interrupt.c +++ b/arch/powerpc/kernel/interrupt.c @@ -268,7 +268,7 @@ static void check_return_regs_valid(struct pt_regs *regs) if (trap_is_scv(regs)) return; - trap = regs->trap; + trap = TRAP(regs); // EE in HV mode sets HSRRs like 0xea0 if (cpu_has_feature(CPU_FTR_HVMODE) && trap == INTERRUPT_EXTERNAL) trap = 0xea0; |