On 2020-03-25 20:34:03 Wed, Nicholas Piggin wrote: > 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 <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.
Acked-by: Mahesh Salgaonkar <mah...@linux.ibm.com> Thanks, -Mahesh. > */ > #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) > { > -- > 2.23.0 > -- Mahesh J Salgaonkar