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| author | Nicholas Piggin <npiggin@gmail.com> | 2020-05-08 07:33:58 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-06-24 18:50:28 +0300 |
| commit | 1a588c7edcd08370eacc2ecafff5769e6e9907b0 (patch) | |
| tree | ac2d7d58907a147a00c3f0941576395e024b8f5b | |
| parent | 8240829fc38cc09ef13588d661e2b9cc887f6623 (diff) | |
| download | linux-1a588c7edcd08370eacc2ecafff5769e6e9907b0.tar.xz | |
powerpc/pseries/ras: Fix FWNMI_VALID off by one
[ Upstream commit deb70f7a35a22dffa55b2c3aac71bc6fb0f486ce ]
This was discovered developing qemu fwnmi sreset support. This
off-by-one bug means the last 16 bytes of the rtas area can not
be used for a 16 byte save area.
It's not a serious bug, and QEMU implementation has to retain a
workaround for old kernels, but it's good to tighten it.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Mahesh Salgaonkar <mahesh@linux.ibm.com>
Link: https://lore.kernel.org/r/20200508043408.886394-7-npiggin@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | arch/powerpc/platforms/pseries/ras.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/arch/powerpc/platforms/pseries/ras.c b/arch/powerpc/platforms/pseries/ras.c index 753adeb624f2..13ef77fd648f 100644 --- a/arch/powerpc/platforms/pseries/ras.c +++ b/arch/powerpc/platforms/pseries/ras.c @@ -395,10 +395,11 @@ static irqreturn_t ras_error_interrupt(int irq, void *dev_id) /* * Some versions of FWNMI place the buffer inside the 4kB page starting at * 0x7000. Other versions place it inside the rtas buffer. We check both. + * Minimum size of the buffer is 16 bytes. */ #define VALID_FWNMI_BUFFER(A) \ - ((((A) >= 0x7000) && ((A) < 0x7ff0)) || \ - (((A) >= rtas.base) && ((A) < (rtas.base + rtas.size - 16)))) + ((((A) >= 0x7000) && ((A) <= 0x8000 - 16)) || \ + (((A) >= rtas.base) && ((A) <= (rtas.base + rtas.size - 16)))) static inline struct rtas_error_log *fwnmi_get_errlog(void) { |