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authorMax Filippov <jcmvbkbc@gmail.com>2014-07-27 07:23:41 +0400
committerMax Filippov <jcmvbkbc@gmail.com>2014-08-14 11:59:16 +0400
commit52247123749cc3cbc30168b33ad8c69515c96d23 (patch)
tree2bdc9346c7ce61227d7d68e12aace9b130406bcb /arch/xtensa
parent89f77c6f5bb4b0058f40f510809ec07255e02a7e (diff)
downloadlinux-52247123749cc3cbc30168b33ad8c69515c96d23.tar.bz2
xtensa: fix access to THREAD_RA/THREAD_SP/THREAD_DS
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. Cc: stable@vger.kernel.org Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Diffstat (limited to 'arch/xtensa')
-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 fd686dc45d1a..c7211e7e182d 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 ef7f4990722b..db96acb1362b 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