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authorMax Filippov <jcmvbkbc@gmail.com>2014-07-27 07:23:41 +0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-10-05 13:40:56 -0700
commit2ca6012df2209959481cdafae17bd78b4f8a2a00 (patch)
tree0b143a8a647508855b573e79da95de91c99554d2 /arch
parente6eb4fdf8e624fe7f7d037fee6c3363f18cb184b (diff)
xtensa: fix access to THREAD_RA/THREAD_SP/THREAD_DS
commit 52247123749cc3cbc30168b33ad8c69515c96d23 upstream. With SMP and a lot of debug options enabled task_struct::thread gets out of reach of s32i/l32i instructions with base pointing at task_struct, breaking build with the following messages: arch/xtensa/kernel/entry.S: Assembler messages: arch/xtensa/kernel/entry.S:1002: Error: operand 3 of 'l32i.n' has invalid value '1048' arch/xtensa/kernel/entry.S:1831: Error: operand 3 of 's32i.n' has invalid value '1040' arch/xtensa/kernel/entry.S:1832: Error: operand 3 of 's32i.n' has invalid value '1044' Change base to point to task_struct::thread in such cases. Don't use a10 in _switch_to to save/restore prev pointer as a2 is not clobbered. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/xtensa/include/asm/uaccess.h5
-rw-r--r--arch/xtensa/kernel/entry.S12
2 files changed, 13 insertions, 4 deletions
diff --git a/arch/xtensa/include/asm/uaccess.h b/arch/xtensa/include/asm/uaccess.h
index fd686dc45d1..c7211e7e182 100644
--- a/arch/xtensa/include/asm/uaccess.h
+++ b/arch/xtensa/include/asm/uaccess.h
@@ -52,7 +52,12 @@
*/
.macro get_fs ad, sp
GET_CURRENT(\ad,\sp)
+#if THREAD_CURRENT_DS > 1020
+ addi \ad, \ad, TASK_THREAD
+ l32i \ad, \ad, THREAD_CURRENT_DS - TASK_THREAD
+#else
l32i \ad, \ad, THREAD_CURRENT_DS
+#endif
.endm
/*
diff --git a/arch/xtensa/kernel/entry.S b/arch/xtensa/kernel/entry.S
index ef7f4990722..db96acb1362 100644
--- a/arch/xtensa/kernel/entry.S
+++ b/arch/xtensa/kernel/entry.S
@@ -1820,7 +1820,6 @@ ENTRY(_switch_to)
entry a1, 16
- mov a10, a2 # preserve 'prev' (a2)
mov a11, a3 # and 'next' (a3)
l32i a4, a2, TASK_THREAD_INFO
@@ -1828,8 +1827,14 @@ ENTRY(_switch_to)
save_xtregs_user a4 a6 a8 a9 a12 a13 THREAD_XTREGS_USER
- s32i a0, a10, THREAD_RA # save return address
- s32i a1, a10, THREAD_SP # save stack pointer
+#if THREAD_RA > 1020 || THREAD_SP > 1020
+ addi a10, a2, TASK_THREAD
+ s32i a0, a10, THREAD_RA - TASK_THREAD # save return address
+ s32i a1, a10, THREAD_SP - TASK_THREAD # save stack pointer
+#else
+ s32i a0, a2, THREAD_RA # save return address
+ s32i a1, a2, THREAD_SP # save stack pointer
+#endif
/* Disable ints while we manipulate the stack pointer. */
@@ -1870,7 +1875,6 @@ ENTRY(_switch_to)
load_xtregs_user a5 a6 a8 a9 a12 a13 THREAD_XTREGS_USER
wsr a14, ps
- mov a2, a10 # return 'prev'
rsync
retw