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authorMichal Simek <monstr@monstr.eu>2012-03-30 08:21:38 +0200
committerMichal Simek <monstr@monstr.eu>2012-03-30 11:37:13 +0200
commitac64a9caa55bdfd8d24784f25c68cb7919ddabe3 (patch)
tree9832daebc0a5c4e97388ff37aae74bf32cbfabfd /arch/microblaze/lib
parenta28d73ca3ac7fffff317e62167ef26310b951ca0 (diff)
downloadlinux-ac64a9caa55bdfd8d24784f25c68cb7919ddabe3.tar.gz
microblaze: Fix stack usage in PAGE_SIZE copy_tofrom_user
If access to user space failed we need to reconstruct stack pointer and restore all register. This patch fixed problem introduces by: "microblaze: Add loop unrolling for PAGE in copy_tofrom_user" (sha1: ebe211254bfa6295f4ab0b33c7c881bdfabbab60) Signed-off-by: Michal Simek <monstr@monstr.eu>
Diffstat (limited to 'arch/microblaze/lib')
-rw-r--r--arch/microblaze/lib/uaccess_old.S98
1 files changed, 62 insertions, 36 deletions
diff --git a/arch/microblaze/lib/uaccess_old.S b/arch/microblaze/lib/uaccess_old.S
index f037266cdaf..f085995ee84 100644
--- a/arch/microblaze/lib/uaccess_old.S
+++ b/arch/microblaze/lib/uaccess_old.S
@@ -122,22 +122,22 @@ __strnlen_user:
15: swi r24, r5, 0x0018 + offset; \
16: swi r25, r5, 0x001C + offset; \
.section __ex_table,"a"; \
- .word 1b, 0f; \
- .word 2b, 0f; \
- .word 3b, 0f; \
- .word 4b, 0f; \
- .word 5b, 0f; \
- .word 6b, 0f; \
- .word 7b, 0f; \
- .word 8b, 0f; \
- .word 9b, 0f; \
- .word 10b, 0f; \
- .word 11b, 0f; \
- .word 12b, 0f; \
- .word 13b, 0f; \
- .word 14b, 0f; \
- .word 15b, 0f; \
- .word 16b, 0f; \
+ .word 1b, 33f; \
+ .word 2b, 33f; \
+ .word 3b, 33f; \
+ .word 4b, 33f; \
+ .word 5b, 33f; \
+ .word 6b, 33f; \
+ .word 7b, 33f; \
+ .word 8b, 33f; \
+ .word 9b, 33f; \
+ .word 10b, 33f; \
+ .word 11b, 33f; \
+ .word 12b, 33f; \
+ .word 13b, 33f; \
+ .word 14b, 33f; \
+ .word 15b, 33f; \
+ .word 16b, 33f; \
.text
#define COPY_80(offset) \
@@ -190,14 +190,17 @@ w2: sw r4, r5, r3
.align 4 /* Alignment is important to keep icache happy */
page: /* Create room on stack and save registers for storign values */
- addik r1, r1, -32
- swi r19, r1, 4
- swi r20, r1, 8
- swi r21, r1, 12
- swi r22, r1, 16
- swi r23, r1, 20
- swi r24, r1, 24
- swi r25, r1, 28
+ addik r1, r1, -40
+ swi r5, r1, 0
+ swi r6, r1, 4
+ swi r7, r1, 8
+ swi r19, r1, 12
+ swi r20, r1, 16
+ swi r21, r1, 20
+ swi r22, r1, 24
+ swi r23, r1, 28
+ swi r24, r1, 32
+ swi r25, r1, 36
loop: /* r4, r19, r20, r21, r22, r23, r24, r25 are used for storing values */
/* Loop unrolling to get performance boost */
COPY_80(0x000);
@@ -205,21 +208,44 @@ loop: /* r4, r19, r20, r21, r22, r23, r24, r25 are used for storing values */
COPY_80(0x100);
COPY_80(0x180);
/* copy loop */
- addik r6, r6, 0x200
- addik r7, r7, -0x200
- bneid r7, loop
- addik r5, r5, 0x200
+ addik r6, r6, 0x200
+ addik r7, r7, -0x200
+ bneid r7, loop
+ addik r5, r5, 0x200
+
/* Restore register content */
- lwi r19, r1, 4
- lwi r20, r1, 8
- lwi r21, r1, 12
- lwi r22, r1, 16
- lwi r23, r1, 20
- lwi r24, r1, 24
- lwi r25, r1, 28
- addik r1, r1, 32
+ lwi r5, r1, 0
+ lwi r6, r1, 4
+ lwi r7, r1, 8
+ lwi r19, r1, 12
+ lwi r20, r1, 16
+ lwi r21, r1, 20
+ lwi r22, r1, 24
+ lwi r23, r1, 28
+ lwi r24, r1, 32
+ lwi r25, r1, 36
+ addik r1, r1, 40
/* return back */
+ addik r3, r0, 0
+ rtsd r15, 8
+ nop
+
+/* Fault case - return temp count */
+33:
addik r3, r7, 0
+ /* Restore register content */
+ lwi r5, r1, 0
+ lwi r6, r1, 4
+ lwi r7, r1, 8
+ lwi r19, r1, 12
+ lwi r20, r1, 16
+ lwi r21, r1, 20
+ lwi r22, r1, 24
+ lwi r23, r1, 28
+ lwi r24, r1, 32
+ lwi r25, r1, 36
+ addik r1, r1, 40
+ /* return back */
rtsd r15, 8
nop