Commit 4c0742f6 authored by Vladimir Murzin's avatar Vladimir Murzin Committed by Russell King
Browse files

ARM: 8914/1: NOMMU: Fix exc_ret for XIP

It was reported that 72cd4064 "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: 72cd4064

 ("ARM: 8830/1: NOMMU: Toggle only bits in EXC_RETURN we are really care of")
Reported-by: default avatarafzal mohammed <afzal.mohd.ma@gmail.com>
Tested-by: default avatarafzal mohammed <afzal.mohd.ma@gmail.com>
Signed-off-by: default avatarVladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: default avatarRussell King <rmk+kernel@armlinux.org.uk>
parent 851140ab
......@@ -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
......
......@@ -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)
......
......@@ -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
......
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