Le 03/04/2020 à 15:26, Nicholas Piggin a écrit :
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.
Acked-by: Mahesh Salgaonkar <mah...@linux.ibm.com>
Signed-off-by: Nicholas Piggin <npig...@gmail.com>
---
arch/powerpc/platforms/pseries/ras.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/platforms/pseries/ras.c
b/arch/powerpc/platforms/pseries/ras.c
index c74d5e740922..9a37bda47468 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))))
Why not just change < to <= and leave the 0x7ff0 ?
static inline struct rtas_error_log *fwnmi_get_errlog(void)
{
Christophe
