[PATCH AUTOSEL 4.19 057/191] s390/vdso: correct CFI annotations of vDSO functions

From: Sasha Levin
Date: Sat Nov 09 2019 - 21:42:18 EST

From: Vasily Gorbik <gor@xxxxxxxxxxxxx>

[ Upstream commit 26f4414a45b808f83d42d6fd2fbf4a59ef25e84b ]

Correct stack frame overhead for 31-bit vdso, which should be 96 rather
then 160. This is done by reusing STACK_FRAME_OVERHEAD definition which
contains correct value based on build flags. This fixes stack unwinding
within vdso code for 31-bit processes. While at it replace all hard coded
stack frame overhead values with the same definition in vdso64 as well.

Reviewed-by: Hendrik Brueckner <brueckner@xxxxxxxxxxxxx>
Signed-off-by: Vasily Gorbik <gor@xxxxxxxxxxxxx>
Signed-off-by: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
arch/s390/kernel/vdso32/clock_gettime.S | 19 ++++++++++---------
arch/s390/kernel/vdso32/gettimeofday.S | 3 ++-
arch/s390/kernel/vdso64/clock_gettime.S | 25 +++++++++++++------------
arch/s390/kernel/vdso64/gettimeofday.S | 3 ++-
4 files changed, 27 insertions(+), 23 deletions(-)

diff --git a/arch/s390/kernel/vdso32/clock_gettime.S b/arch/s390/kernel/vdso32/clock_gettime.S
index a9418bf975db5..ada5c11a16e5a 100644
--- a/arch/s390/kernel/vdso32/clock_gettime.S
+++ b/arch/s390/kernel/vdso32/clock_gettime.S
@@ -10,6 +10,7 @@
#include <asm/asm-offsets.h>
#include <asm/unistd.h>
#include <asm/dwarf.h>
+#include <asm/ptrace.h>

.text
.align 4
@@ -18,8 +19,8 @@
__kernel_clock_gettime:
CFI_STARTPROC
ahi %r15,-16
- CFI_DEF_CFA_OFFSET 176
- CFI_VAL_OFFSET 15, -160
+ CFI_DEF_CFA_OFFSET STACK_FRAME_OVERHEAD+16
+ CFI_VAL_OFFSET 15, -STACK_FRAME_OVERHEAD
basr %r5,0
0: al %r5,21f-0b(%r5) /* get &_vdso_data */
chi %r2,__CLOCK_REALTIME_COARSE
@@ -72,13 +73,13 @@ __kernel_clock_gettime:
st %r1,4(%r3) /* store tp->tv_nsec */
lhi %r2,0
ahi %r15,16
- CFI_DEF_CFA_OFFSET 160
+ CFI_DEF_CFA_OFFSET STACK_FRAME_OVERHEAD
CFI_RESTORE 15
br %r14

/* CLOCK_MONOTONIC_COARSE */
- CFI_DEF_CFA_OFFSET 176
- CFI_VAL_OFFSET 15, -160
+ CFI_DEF_CFA_OFFSET STACK_FRAME_OVERHEAD+16
+ CFI_VAL_OFFSET 15, -STACK_FRAME_OVERHEAD
9: l %r4,__VDSO_UPD_COUNT+4(%r5) /* load update counter */
tml %r4,0x0001 /* pending update ? loop */
jnz 9b
@@ -158,17 +159,17 @@ __kernel_clock_gettime:
st %r1,4(%r3) /* store tp->tv_nsec */
lhi %r2,0
ahi %r15,16
- CFI_DEF_CFA_OFFSET 160
+ CFI_DEF_CFA_OFFSET STACK_FRAME_OVERHEAD
CFI_RESTORE 15
br %r14

/* Fallback to system call */
- CFI_DEF_CFA_OFFSET 176
- CFI_VAL_OFFSET 15, -160
+ CFI_DEF_CFA_OFFSET STACK_FRAME_OVERHEAD+16
+ CFI_VAL_OFFSET 15, -STACK_FRAME_OVERHEAD
19: lhi %r1,__NR_clock_gettime
svc 0
ahi %r15,16
- CFI_DEF_CFA_OFFSET 160
+ CFI_DEF_CFA_OFFSET STACK_FRAME_OVERHEAD
CFI_RESTORE 15
br %r14
CFI_ENDPROC
diff --git a/arch/s390/kernel/vdso32/gettimeofday.S b/arch/s390/kernel/vdso32/gettimeofday.S
index 3c0db0fa6ad90..b23063fbc892c 100644
--- a/arch/s390/kernel/vdso32/gettimeofday.S
+++ b/arch/s390/kernel/vdso32/gettimeofday.S
@@ -10,6 +10,7 @@
#include <asm/asm-offsets.h>
#include <asm/unistd.h>
#include <asm/dwarf.h>
+#include <asm/ptrace.h>

.text
.align 4
@@ -19,7 +20,7 @@ __kernel_gettimeofday:
CFI_STARTPROC
ahi %r15,-16
CFI_ADJUST_CFA_OFFSET 16
- CFI_VAL_OFFSET 15, -160
+ CFI_VAL_OFFSET 15, -STACK_FRAME_OVERHEAD
basr %r5,0
0: al %r5,13f-0b(%r5) /* get &_vdso_data */
1: ltr %r3,%r3 /* check if tz is NULL */
diff --git a/arch/s390/kernel/vdso64/clock_gettime.S b/arch/s390/kernel/vdso64/clock_gettime.S
index fac3ab5ec83a9..9d2ee79b90f25 100644
--- a/arch/s390/kernel/vdso64/clock_gettime.S
+++ b/arch/s390/kernel/vdso64/clock_gettime.S
@@ -10,6 +10,7 @@
#include <asm/asm-offsets.h>
#include <asm/unistd.h>
#include <asm/dwarf.h>
+#include <asm/ptrace.h>

.text
.align 4
@@ -18,8 +19,8 @@
__kernel_clock_gettime:
CFI_STARTPROC
aghi %r15,-16
- CFI_DEF_CFA_OFFSET 176
- CFI_VAL_OFFSET 15, -160
+ CFI_DEF_CFA_OFFSET STACK_FRAME_OVERHEAD+16
+ CFI_VAL_OFFSET 15, -STACK_FRAME_OVERHEAD
larl %r5,_vdso_data
cghi %r2,__CLOCK_REALTIME_COARSE
je 4f
@@ -56,13 +57,13 @@ __kernel_clock_gettime:
stg %r1,8(%r3) /* store tp->tv_nsec */
lghi %r2,0
aghi %r15,16
- CFI_DEF_CFA_OFFSET 160
+ CFI_DEF_CFA_OFFSET STACK_FRAME_OVERHEAD
CFI_RESTORE 15
br %r14

/* CLOCK_MONOTONIC_COARSE */
- CFI_DEF_CFA_OFFSET 176
- CFI_VAL_OFFSET 15, -160
+ CFI_DEF_CFA_OFFSET STACK_FRAME_OVERHEAD+16
+ CFI_VAL_OFFSET 15, -STACK_FRAME_OVERHEAD
3: lg %r4,__VDSO_UPD_COUNT(%r5) /* load update counter */
tmll %r4,0x0001 /* pending update ? loop */
jnz 3b
@@ -115,13 +116,13 @@ __kernel_clock_gettime:
stg %r1,8(%r3) /* store tp->tv_nsec */
lghi %r2,0
aghi %r15,16
- CFI_DEF_CFA_OFFSET 160
+ CFI_DEF_CFA_OFFSET STACK_FRAME_OVERHEAD
CFI_RESTORE 15
br %r14

/* CPUCLOCK_VIRT for this thread */
- CFI_DEF_CFA_OFFSET 176
- CFI_VAL_OFFSET 15, -160
+ CFI_DEF_CFA_OFFSET STACK_FRAME_OVERHEAD+16
+ CFI_VAL_OFFSET 15, -STACK_FRAME_OVERHEAD
9: lghi %r4,0
icm %r0,15,__VDSO_ECTG_OK(%r5)
jz 12f
@@ -142,17 +143,17 @@ __kernel_clock_gettime:
stg %r4,8(%r3)
lghi %r2,0
aghi %r15,16
- CFI_DEF_CFA_OFFSET 160
+ CFI_DEF_CFA_OFFSET STACK_FRAME_OVERHEAD
CFI_RESTORE 15
br %r14

/* Fallback to system call */
- CFI_DEF_CFA_OFFSET 176
- CFI_VAL_OFFSET 15, -160
+ CFI_DEF_CFA_OFFSET STACK_FRAME_OVERHEAD+16
+ CFI_VAL_OFFSET 15, -STACK_FRAME_OVERHEAD
12: lghi %r1,__NR_clock_gettime
svc 0
aghi %r15,16
- CFI_DEF_CFA_OFFSET 160
+ CFI_DEF_CFA_OFFSET STACK_FRAME_OVERHEAD
CFI_RESTORE 15
br %r14
CFI_ENDPROC
diff --git a/arch/s390/kernel/vdso64/gettimeofday.S b/arch/s390/kernel/vdso64/gettimeofday.S
index 6e1f0b421695a..aebe10dc7c99a 100644
--- a/arch/s390/kernel/vdso64/gettimeofday.S
+++ b/arch/s390/kernel/vdso64/gettimeofday.S
@@ -10,6 +10,7 @@
#include <asm/asm-offsets.h>
#include <asm/unistd.h>
#include <asm/dwarf.h>
+#include <asm/ptrace.h>

.text
.align 4
@@ -19,7 +20,7 @@ __kernel_gettimeofday:
CFI_STARTPROC
aghi %r15,-16
CFI_ADJUST_CFA_OFFSET 16
- CFI_VAL_OFFSET 15, -160
+ CFI_VAL_OFFSET 15, -STACK_FRAME_OVERHEAD
larl %r5,_vdso_data
0: ltgr %r3,%r3 /* check if tz is NULL */
je 1f
--
2.20.1