diff options
| author | Ard Biesheuvel <ardb@kernel.org> | 2023-04-12 09:50:20 +0100 |
|---|---|---|
| committer | Russell King (Oracle) <rmk+kernel@armlinux.org.uk> | 2023-04-12 10:04:56 +0100 |
| commit | c76c6c4ecbec0deb56a4f9e932b26866024a508f (patch) | |
| tree | e6da7ee937a9e9ee7b29dcab602a24d2ee974714 /arch/arm/vfp/entry.S | |
| parent | 3a2bdad0b46649cc73fb3b3f9e2b91ef97a7fa63 (diff) | |
ARM: 9294/2: vfp: Fix broken softirq handling with instrumentation enabled
Commit 62b95a7b44d1 ("ARM: 9282/1: vfp: Manipulate task VFP state with
softirqs disabled") replaced the en/disable preemption calls inside the
VFP state handling code with en/disabling of soft IRQs, which is
necessary to allow kernel use of the VFP/SIMD unit when handling a soft
IRQ.
Unfortunately, when lockdep is enabled (or other instrumentation that
enables TRACE_IRQFLAGS), the disable path implemented in asm fails to
perform the lockdep and RCU related bookkeeping, resulting in spurious
warnings and other badness.
Set let's rework the VFP entry code a little bit so we can make the
local_bh_disable() call from C, with all the instrumentations that
happen to have been configured. Calling local_bh_enable() can be done
from asm, as it is a simple wrapper around __local_bh_enable_ip(), which
is always a callable function.
Link: https://lore.kernel.org/all/ZBBYCSZUJOWBg1s8@localhost.localdomain/
Fixes: 62b95a7b44d1 ("ARM: 9282/1: vfp: Manipulate task VFP state with softirqs disabled")
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Diffstat (limited to 'arch/arm/vfp/entry.S')
| -rw-r--r-- | arch/arm/vfp/entry.S | 11 |
1 files changed, 1 insertions, 10 deletions
diff --git a/arch/arm/vfp/entry.S b/arch/arm/vfp/entry.S index 6dabb4761778..7483ef8bccda 100644 --- a/arch/arm/vfp/entry.S +++ b/arch/arm/vfp/entry.S @@ -24,14 +24,5 @@ ENTRY(do_vfp) mov r1, r10 mov r3, r9 - ldr r4, .LCvfp - ldr pc, [r4] @ call VFP entry point + b vfp_entry ENDPROC(do_vfp) - -ENTRY(vfp_null_entry) - ret lr -ENDPROC(vfp_null_entry) - - .align 2 -.LCvfp: - .word vfp_vector |