2020-05-27 10:02:25

by YuanJunQing

Subject: [PATCH] MIPS: Fix IRQ tracing when call handle_fpe() and handle_msa_fpe()

Register "a1" is unsaved in this function,
when CONFIG_TRACE_IRQFLAGS is enabled,
the TRACE_IRQS_OFF macro will call trace_hardirqs_off(),
and this may change register "a1".
The changed register "a1" as argument will be send
to do_fpe() and do_msa_fpe().

Signed-off-by: YuanJunQing <[email protected]>
---
arch/mips/kernel/genex.S | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/mips/kernel/genex.S b/arch/mips/kernel/genex.S
index 8236fb291e3f..a1b966f3578e 100644
--- a/arch/mips/kernel/genex.S
+++ b/arch/mips/kernel/genex.S
@@ -476,20 +476,20 @@ NESTED(nmi_handler, PT_SIZE, sp)
.endm

.macro __build_clear_fpe
+ CLI
+ TRACE_IRQS_OFF
.set push
/* gas fails to assemble cfc1 for some archs (octeon).*/ \
.set mips1
SET_HARDFLOAT
cfc1 a1, fcr31
.set pop
- CLI
- TRACE_IRQS_OFF
.endm

.macro __build_clear_msa_fpe
- _cfcmsa a1, MSA_CSR
CLI
TRACE_IRQS_OFF
+ _cfcmsa a1, MSA_CSR
.endm

.macro __build_clear_ade
--
2.17.1

2020-05-27 17:24:18

by Thomas Bogendoerfer

Subject: Re: [PATCH] MIPS: Fix IRQ tracing when call handle_fpe() and handle_msa_fpe()

On Wed, May 27, 2020 at 02:11:30PM +0800, YuanJunQing wrote:
> Register "a1" is unsaved in this function,
> when CONFIG_TRACE_IRQFLAGS is enabled,
> the TRACE_IRQS_OFF macro will call trace_hardirqs_off(),
> and this may change register "a1".
> The changed register "a1" as argument will be send
> to do_fpe() and do_msa_fpe().
>
> Signed-off-by: YuanJunQing <[email protected]>
> ---
> arch/mips/kernel/genex.S | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)

applied to mips-next.

Thomas.

--
Crap can work. Given enough thrust pigs will fly, but it's not necessarily a
good idea. [ RFC1925, 2.3 ]