diff options
| author | Russell King <rmk+kernel@armlinux.org.uk> | 2017-11-27 11:22:42 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-12-16 10:33:50 +0100 |
| commit | dd8c78e2501eae30d27de93e6f17caf1504a3174 (patch) | |
| tree | c245a5255349b5b0332ee9bddf50720a668b4b3b /arch | |
| parent | af1d17239682cb019916195c3e9cdb7a5793cea3 (diff) | |
ARM: avoid faulting on qemu
commit 3aaf33bebda8d4ffcc0fc8ef39e6c1ac68823b11 upstream.
When qemu starts a kernel in a bare environment, the default SCR has
the AW and FW bits clear, which means that the kernel can't modify
the PSR A or PSR F bits, and means that FIQs and imprecise aborts are
always masked.
When running uboot under qemu, the AW and FW SCR bits are set, and the
kernel functions normally - and this is how real hardware behaves.
Fix this for qemu by ignoring the FIQ bit.
Fixes: 8bafae202c82 ("ARM: BUG if jumping to usermode address in kernel mode")
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Cc: Alex Shi <alex.shi@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm/kernel/entry-header.S | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/arm/kernel/entry-header.S b/arch/arm/kernel/entry-header.S index 3fd24e22036b..6d243e830516 100644 --- a/arch/arm/kernel/entry-header.S +++ b/arch/arm/kernel/entry-header.S @@ -295,7 +295,7 @@ mov r2, sp ldr r1, [r2, #\offset + S_PSR] @ get calling cpsr ldr lr, [r2, #\offset + S_PC]! @ get pc - tst r1, #0xcf + tst r1, #PSR_I_BIT | 0x0f bne 1f msr spsr_cxsf, r1 @ save in spsr_svc #if defined(CONFIG_CPU_V6) || defined(CONFIG_CPU_32v6K) @@ -327,7 +327,7 @@ ldr r1, [sp, #\offset + S_PSR] @ get calling cpsr ldr lr, [sp, #\offset + S_PC] @ get pc add sp, sp, #\offset + S_SP - tst r1, #0xcf + tst r1, #PSR_I_BIT | 0x0f bne 1f msr spsr_cxsf, r1 @ save in spsr_svc |