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authorVladimir Murzin <vladimir.murzin@arm.com>2019-10-10 10:12:20 +0100
committerRussell King <rmk+kernel@armlinux.org.uk>2019-10-10 22:23:20 +0100
commit4c0742f65b4ee466546fd24b71b56516cacd4613 (patch)
tree729b8210efc070da68736b24e3cd28be45c71d84 /arch/arm
parent851140ab0d083c78e5723a8b1cbd258f567a7aff (diff)
downloadlinux-4c0742f65b4ee466546fd24b71b56516cacd4613.tar.bz2
ARM: 8914/1: NOMMU: Fix exc_ret for XIP
It was reported that 72cd4064fcca "NOMMU: Toggle only bits in EXC_RETURN we are really care of" breaks NOMMU+XIP combination. It happens because saved EXC_RETURN gets overwritten when data section is relocated. The fix is to propagate EXC_RETURN via register and let relocation code to commit that value into memory. Fixes: 72cd4064fcca ("ARM: 8830/1: NOMMU: Toggle only bits in EXC_RETURN we are really care of") Reported-by: afzal mohammed <afzal.mohd.ma@gmail.com> Tested-by: afzal mohammed <afzal.mohd.ma@gmail.com> Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Diffstat (limited to 'arch/arm')
-rw-r--r--arch/arm/kernel/head-common.S5
-rw-r--r--arch/arm/kernel/head-nommu.S2
-rw-r--r--arch/arm/mm/proc-v7m.S5
3 files changed, 7 insertions, 5 deletions
diff --git a/arch/arm/kernel/head-common.S b/arch/arm/kernel/head-common.S
index a7810be07da1..4a3982812a40 100644
--- a/arch/arm/kernel/head-common.S
+++ b/arch/arm/kernel/head-common.S
@@ -68,7 +68,7 @@ ENDPROC(__vet_atags)
* The following fragment of code is executed with the MMU on in MMU mode,
* and uses absolute addresses; this is not position independent.
*
- * r0 = cp#15 control register
+ * r0 = cp#15 control register (exc_ret for M-class)
* r1 = machine ID
* r2 = atags/dtb pointer
* r9 = processor ID
@@ -137,7 +137,8 @@ __mmap_switched_data:
#ifdef CONFIG_CPU_CP15
.long cr_alignment @ r3
#else
- .long 0 @ r3
+M_CLASS(.long exc_ret) @ r3
+AR_CLASS(.long 0) @ r3
#endif
.size __mmap_switched_data, . - __mmap_switched_data
diff --git a/arch/arm/kernel/head-nommu.S b/arch/arm/kernel/head-nommu.S
index afa350f44dea..0fc814bbc34b 100644
--- a/arch/arm/kernel/head-nommu.S
+++ b/arch/arm/kernel/head-nommu.S
@@ -201,6 +201,8 @@ M_CLASS(streq r3, [r12, #PMSAv8_MAIR1])
bic r0, r0, #V7M_SCB_CCR_IC
#endif
str r0, [r12, V7M_SCB_CCR]
+ /* Pass exc_ret to __mmap_switched */
+ mov r0, r10
#endif /* CONFIG_CPU_CP15 elif CONFIG_CPU_V7M */
ret lr
ENDPROC(__after_proc_init)
diff --git a/arch/arm/mm/proc-v7m.S b/arch/arm/mm/proc-v7m.S
index 1448f144e7fb..efebf4120a0c 100644
--- a/arch/arm/mm/proc-v7m.S
+++ b/arch/arm/mm/proc-v7m.S
@@ -136,9 +136,8 @@ __v7m_setup_cont:
cpsie i
svc #0
1: cpsid i
- ldr r0, =exc_ret
- orr lr, lr, #EXC_RET_THREADMODE_PROCESSSTACK
- str lr, [r0]
+ /* Calculate exc_ret */
+ orr r10, lr, #EXC_RET_THREADMODE_PROCESSSTACK
ldmia sp, {r0-r3, r12}
str r5, [r12, #11 * 4] @ restore the original SVC vector entry
mov lr, r6 @ restore LR