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-rw-r--r--arch/arm/Kconfig9
-rw-r--r--arch/arm/mm/abort-ev6.S17
2 files changed, 20 insertions, 6 deletions
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index cf006d4..36586dba 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1186,6 +1186,15 @@ if !MMU
source "arch/arm/Kconfig-nommu"
endif
+config ARM_ERRATA_326103
+ bool "ARM errata: FSR write bit incorrect on a SWP to read-only memory"
+ depends on CPU_V6
+ help
+ Executing a SWP instruction to read-only memory does not set bit 11
+ of the FSR on the ARM 1136 prior to r1p0. This causes the kernel to
+ treat the access as a read, preventing a COW from occurring and
+ causing the faulting task to livelock.
+
config ARM_ERRATA_411920
bool "ARM errata: Invalidation of the Instruction Cache operation can fail"
depends on CPU_V6 || CPU_V6K
diff --git a/arch/arm/mm/abort-ev6.S b/arch/arm/mm/abort-ev6.S
index ff1f7cc..8074199 100644
--- a/arch/arm/mm/abort-ev6.S
+++ b/arch/arm/mm/abort-ev6.S
@@ -26,18 +26,23 @@ ENTRY(v6_early_abort)
mrc p15, 0, r1, c5, c0, 0 @ get FSR
mrc p15, 0, r0, c6, c0, 0 @ get FAR
/*
- * Faulty SWP instruction on 1136 doesn't set bit 11 in DFSR (erratum 326103).
- * The test below covers all the write situations, including Java bytecodes
+ * Faulty SWP instruction on 1136 doesn't set bit 11 in DFSR.
*/
- bic r1, r1, #1 << 11 @ clear bit 11 of FSR
+#ifdef CONFIG_ARM_ERRATA_326103
+ ldr ip, =0x4107b36
+ mrc p15, 0, r3, c0, c0, 0 @ get processor id
+ teq ip, r3, lsr #4 @ r0 ARM1136?
+ bne do_DataAbort
tst r5, #PSR_J_BIT @ Java?
+ tsteq r5, #PSR_T_BIT @ Thumb?
bne do_DataAbort
- do_thumb_abort fsr=r1, pc=r4, psr=r5, tmp=r3
- ldreq r3, [r4] @ read aborted ARM instruction
+ bic r1, r1, #1 << 11 @ clear bit 11 of FSR
+ ldr r3, [r4] @ read aborted ARM instruction
#ifdef CONFIG_CPU_ENDIAN_BE8
- reveq r3, r3
+ rev r3, r3
#endif
do_ldrd_abort tmp=ip, insn=r3
tst r3, #1 << 20 @ L = 0 -> write
orreq r1, r1, #1 << 11 @ yes.
+#endif
b do_DataAbort
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