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authorHeiko Carstens <heiko.carstens@de.ibm.com>2014-10-27 08:28:08 +0100
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2014-10-27 13:27:02 +0100
commit9b2efe035eafb1a29ff3dfe21ed0e755aac09130 (patch)
tree37f0a0c357aaf7305ca9acf2850c78da576c4f93
parent1f759bb3a2a0d75ceeeec729b1c66a7f443631ba (diff)
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s390/vdso: fix stack corruption
The kernel provided vdso functions do not get a stack frame from the calling function and therefore may not change the stack contents, unless they allocate space on their own. This problem was exposed with 070b7be633dc "s390/vdso: replace stck with stcke" which writes 16 bytes instead of 8 bytes into the stack frame. These additional 8 bytes however were indeed used by the caller (glibc) to save data and therefore this data was corrupted by the vdso code. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat
-rw-r--r--arch/s390/kernel/vdso32/clock_gettime.S12
-rw-r--r--arch/s390/kernel/vdso32/gettimeofday.S14
-rw-r--r--arch/s390/kernel/vdso64/clock_gettime.S13
-rw-r--r--arch/s390/kernel/vdso64/gettimeofday.S6
4 files changed, 29 insertions, 16 deletions
diff --git a/arch/s390/kernel/vdso32/clock_gettime.S b/arch/s390/kernel/vdso32/clock_gettime.S
index 48c2206a3956..5eec9afbb5b5 100644
--- a/arch/s390/kernel/vdso32/clock_gettime.S
+++ b/arch/s390/kernel/vdso32/clock_gettime.S
@@ -19,6 +19,7 @@
.type __kernel_clock_gettime,@function
__kernel_clock_gettime:
.cfi_startproc
+ ahi %r15,-16
basr %r5,0
0: al %r5,21f-0b(%r5) /* get &_vdso_data */
chi %r2,__CLOCK_REALTIME_COARSE
@@ -34,8 +35,8 @@ __kernel_clock_gettime:
1: l %r4,__VDSO_UPD_COUNT+4(%r5) /* load update counter */
tml %r4,0x0001 /* pending update ? loop */
jnz 1b
- stcke 24(%r15) /* Store TOD clock */
- lm %r0,%r1,25(%r15)
+ stcke 0(%r15) /* Store TOD clock */
+ lm %r0,%r1,1(%r15)
s %r0,__VDSO_XTIME_STAMP(%r5) /* TOD - cycle_last */
sl %r1,__VDSO_XTIME_STAMP+4(%r5)
brc 3,2f
@@ -70,6 +71,7 @@ __kernel_clock_gettime:
8: st %r2,0(%r3) /* store tp->tv_sec */
st %r1,4(%r3) /* store tp->tv_nsec */
lhi %r2,0
+ ahi %r15,16
br %r14
/* CLOCK_MONOTONIC_COARSE */
@@ -96,8 +98,8 @@ __kernel_clock_gettime:
11: l %r4,__VDSO_UPD_COUNT+4(%r5) /* load update counter */
tml %r4,0x0001 /* pending update ? loop */
jnz 11b
- stcke 24(%r15) /* Store TOD clock */
- lm %r0,%r1,25(%r15)
+ stcke 0(%r15) /* Store TOD clock */
+ lm %r0,%r1,1(%r15)
s %r0,__VDSO_XTIME_STAMP(%r5) /* TOD - cycle_last */
sl %r1,__VDSO_XTIME_STAMP+4(%r5)
brc 3,12f
@@ -132,11 +134,13 @@ __kernel_clock_gettime:
17: st %r2,0(%r3) /* store tp->tv_sec */
st %r1,4(%r3) /* store tp->tv_nsec */
lhi %r2,0
+ ahi %r15,16
br %r14
/* Fallback to system call */
19: lhi %r1,__NR_clock_gettime
svc 0
+ ahi %r15,16
br %r14
20: .long 1000000000
diff --git a/arch/s390/kernel/vdso32/gettimeofday.S b/arch/s390/kernel/vdso32/gettimeofday.S
index 60def5f562db..719de6186b20 100644
--- a/arch/s390/kernel/vdso32/gettimeofday.S
+++ b/arch/s390/kernel/vdso32/gettimeofday.S
@@ -19,6 +19,7 @@
.type __kernel_gettimeofday,@function
__kernel_gettimeofday:
.cfi_startproc
+ ahi %r15,-16
basr %r5,0
0: al %r5,13f-0b(%r5) /* get &_vdso_data */
1: ltr %r3,%r3 /* check if tz is NULL */
@@ -29,30 +30,30 @@ __kernel_gettimeofday:
l %r4,__VDSO_UPD_COUNT+4(%r5) /* load update counter */
tml %r4,0x0001 /* pending update ? loop */
jnz 1b
- stcke 24(%r15) /* Store TOD clock */
- lm %r0,%r1,25(%r15)
+ stcke 0(%r15) /* Store TOD clock */
+ lm %r0,%r1,1(%r15)
s %r0,__VDSO_XTIME_STAMP(%r5) /* TOD - cycle_last */
sl %r1,__VDSO_XTIME_STAMP+4(%r5)
brc 3,3f
ahi %r0,-1
3: ms %r0,__VDSO_TK_MULT(%r5) /* * tk->mult */
- st %r0,24(%r15)
+ st %r0,0(%r15)
l %r0,__VDSO_TK_MULT(%r5)
ltr %r1,%r1
mr %r0,%r0
jnm 4f
a %r0,__VDSO_TK_MULT(%r5)
-4: al %r0,24(%r15)
+4: al %r0,0(%r15)
al %r0,__VDSO_XTIME_NSEC(%r5) /* + xtime */
al %r1,__VDSO_XTIME_NSEC+4(%r5)
brc 12,5f
ahi %r0,1
-5: mvc 24(4,%r15),__VDSO_XTIME_SEC+4(%r5)
+5: mvc 0(4,%r15),__VDSO_XTIME_SEC+4(%r5)
cl %r4,__VDSO_UPD_COUNT+4(%r5) /* check update counter */
jne 1b
l %r4,__VDSO_TK_SHIFT(%r5) /* Timekeeper shift */
srdl %r0,0(%r4) /* >> tk->shift */
- l %r4,24(%r15) /* get tv_sec from stack */
+ l %r4,0(%r15) /* get tv_sec from stack */
basr %r5,0
6: ltr %r0,%r0
jnz 7f
@@ -71,6 +72,7 @@ __kernel_gettimeofday:
9: srl %r0,6
st %r0,4(%r2) /* store tv->tv_usec */
10: slr %r2,%r2
+ ahi %r15,16
br %r14
11: .long 1000000000
12: .long 274877907
diff --git a/arch/s390/kernel/vdso64/clock_gettime.S b/arch/s390/kernel/vdso64/clock_gettime.S
index 9d9761f8e110..7699e735ae28 100644
--- a/arch/s390/kernel/vdso64/clock_gettime.S
+++ b/arch/s390/kernel/vdso64/clock_gettime.S
@@ -19,6 +19,7 @@
.type __kernel_clock_gettime,@function
__kernel_clock_gettime:
.cfi_startproc
+ aghi %r15,-16
larl %r5,_vdso_data
cghi %r2,__CLOCK_REALTIME_COARSE
je 4f
@@ -37,10 +38,10 @@ __kernel_clock_gettime:
0: lg %r4,__VDSO_UPD_COUNT(%r5) /* load update counter */
tmll %r4,0x0001 /* pending update ? loop */
jnz 0b
- stcke 48(%r15) /* Store TOD clock */
+ stcke 0(%r15) /* Store TOD clock */
lgf %r2,__VDSO_TK_SHIFT(%r5) /* Timekeeper shift */
lg %r0,__VDSO_WTOM_SEC(%r5)
- lg %r1,49(%r15)
+ lg %r1,1(%r15)
sg %r1,__VDSO_XTIME_STAMP(%r5) /* TOD - cycle_last */
msgf %r1,__VDSO_TK_MULT(%r5) /* * tk->mult */
alg %r1,__VDSO_WTOM_NSEC(%r5)
@@ -56,6 +57,7 @@ __kernel_clock_gettime:
2: stg %r0,0(%r3) /* store tp->tv_sec */
stg %r1,8(%r3) /* store tp->tv_nsec */
lghi %r2,0
+ aghi %r15,16
br %r14
/* CLOCK_MONOTONIC_COARSE */
@@ -82,9 +84,9 @@ __kernel_clock_gettime:
5: lg %r4,__VDSO_UPD_COUNT(%r5) /* load update counter */
tmll %r4,0x0001 /* pending update ? loop */
jnz 5b
- stcke 48(%r15) /* Store TOD clock */
+ stcke 0(%r15) /* Store TOD clock */
lgf %r2,__VDSO_TK_SHIFT(%r5) /* Timekeeper shift */
- lg %r1,49(%r15)
+ lg %r1,1(%r15)
sg %r1,__VDSO_XTIME_STAMP(%r5) /* TOD - cycle_last */
msgf %r1,__VDSO_TK_MULT(%r5) /* * tk->mult */
alg %r1,__VDSO_XTIME_NSEC(%r5) /* + tk->xtime_nsec */
@@ -101,6 +103,7 @@ __kernel_clock_gettime:
7: stg %r0,0(%r3) /* store tp->tv_sec */
stg %r1,8(%r3) /* store tp->tv_nsec */
lghi %r2,0
+ aghi %r15,16
br %r14
/* CLOCK_THREAD_CPUTIME_ID for this thread */
@@ -134,11 +137,13 @@ __kernel_clock_gettime:
slgr %r4,%r0 /* r4 = tv_nsec */
stg %r4,8(%r3)
lghi %r2,0
+ aghi %r15,16
br %r14
/* Fallback to system call */
12: lghi %r1,__NR_clock_gettime
svc 0
+ aghi %r15,16
br %r14
13: .quad 1000000000
diff --git a/arch/s390/kernel/vdso64/gettimeofday.S b/arch/s390/kernel/vdso64/gettimeofday.S
index 7a344995a97f..6ce46707663c 100644
--- a/arch/s390/kernel/vdso64/gettimeofday.S
+++ b/arch/s390/kernel/vdso64/gettimeofday.S
@@ -19,6 +19,7 @@
.type __kernel_gettimeofday,@function
__kernel_gettimeofday:
.cfi_startproc
+ aghi %r15,-16
larl %r5,_vdso_data
0: ltgr %r3,%r3 /* check if tz is NULL */
je 1f
@@ -28,8 +29,8 @@ __kernel_gettimeofday:
lg %r4,__VDSO_UPD_COUNT(%r5) /* load update counter */
tmll %r4,0x0001 /* pending update ? loop */
jnz 0b
- stcke 48(%r15) /* Store TOD clock */
- lg %r1,49(%r15)
+ stcke 0(%r15) /* Store TOD clock */
+ lg %r1,1(%r15)
sg %r1,__VDSO_XTIME_STAMP(%r5) /* TOD - cycle_last */
msgf %r1,__VDSO_TK_MULT(%r5) /* * tk->mult */
alg %r1,__VDSO_XTIME_NSEC(%r5) /* + tk->xtime_nsec */
@@ -50,6 +51,7 @@ __kernel_gettimeofday:
srlg %r0,%r0,6
stg %r0,8(%r2) /* store tv->tv_usec */
4: lghi %r2,0
+ aghi %r15,16
br %r14
5: .quad 1000000000
.long 274877907
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-30 00:11:34 +0000