blob: f64808cfe3e3c0c183cd0fb7b4fd278e7b7177b0 [file] [log] [blame]
From 54a20ce80ef496482d694b2096311549ff6bc87a Mon Sep 17 00:00:00 2001
From: Vladimir Murzin <vladimir.murzin@arm.com>
Date: Thu, 10 Oct 2019 10:12:20 +0100
Subject: [PATCH] ARM: 8914/1: NOMMU: Fix exc_ret for XIP
commit 4c0742f65b4ee466546fd24b71b56516cacd4613 upstream.
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>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
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
--
2.7.4