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authorMatheus Castanho <msc@linux.ibm.com>2021-10-26 10:44:59 -0300
committerMatheus Castanho <msc@linux.ibm.com>2021-11-30 15:18:52 -0300
commitd120fb9941be1fb1934f0b50c6ad64e4c5e404fb (patch)
treedba157bb45723e2b9d95fdb843d8c5d50d0dd0ae /sysdeps
parentefc6b2dbc47231dee7a7ac39beec808deb4e4d1f (diff)
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powerpc64[le]: Fix CFI and LR save address for asm syscalls [BZ #28532]
Syscalls based on the assembly templates are missing CFI for r31, which gets clobbered when scv is used, and info for LR is inaccurate, placed in the wrong LOC and not using the proper offset. LR was also being saved to the callee's frame, while the ABI mandates it to be saved to the caller's frame. These are fixed by this commit. After this change: $ readelf -wF libc.so.6 | grep 0004b9d4.. -A 7 && objdump --disassemble=kill libc.so.6 00004a48 0000000000000020 00004a4c FDE cie=00000000 pc=000000000004b9d4..000000000004ba3c LOC CFA r31 ra 000000000004b9d4 r1+0 u u 000000000004b9e4 r1+48 u u 000000000004b9e8 r1+48 c-16 u 000000000004b9fc r1+48 c-16 c+16 000000000004ba08 r1+48 c-16 000000000004ba18 r1+48 u 000000000004ba1c r1+0 u libc.so.6: file format elf64-powerpcle Disassembly of section .text: 000000000004b9d4 <kill>: 4b9d4: 1f 00 4c 3c addis r2,r12,31 4b9d8: 2c c3 42 38 addi r2,r2,-15572 4b9dc: 25 00 00 38 li r0,37 4b9e0: d1 ff 21 f8 stdu r1,-48(r1) 4b9e4: 20 00 e1 fb std r31,32(r1) 4b9e8: 98 8f ed eb ld r31,-28776(r13) 4b9ec: 10 00 ff 77 andis. r31,r31,16 4b9f0: 1c 00 82 41 beq 4ba0c <kill+0x38> 4b9f4: a6 02 28 7d mflr r9 4b9f8: 40 00 21 f9 std r9,64(r1) 4b9fc: 01 00 00 44 scv 0 4ba00: 40 00 21 e9 ld r9,64(r1) 4ba04: a6 03 28 7d mtlr r9 4ba08: 08 00 00 48 b 4ba10 <kill+0x3c> 4ba0c: 02 00 00 44 sc 4ba10: 00 00 bf 2e cmpdi cr5,r31,0 4ba14: 20 00 e1 eb ld r31,32(r1) 4ba18: 30 00 21 38 addi r1,r1,48 4ba1c: 18 00 96 41 beq cr5,4ba34 <kill+0x60> 4ba20: 01 f0 20 39 li r9,-4095 4ba24: 40 48 23 7c cmpld r3,r9 4ba28: 20 00 e0 4d bltlr+ 4ba2c: d0 00 63 7c neg r3,r3 4ba30: 08 00 00 48 b 4ba38 <kill+0x64> 4ba34: 20 00 e3 4c bnslr+ 4ba38: c8 32 fe 4b b 2ed00 <__syscall_error> ... 4ba44: 40 20 0c 00 .long 0xc2040 4ba48: 68 00 00 00 .long 0x68 4ba4c: 06 00 5f 5f rlwnm r31,r26,r0,0,3 4ba50: 6b 69 6c 6c xoris r12,r3,26987
Diffstat (limited to 'sysdeps')
-rw-r--r--sysdeps/powerpc/powerpc64/sysdep.h10
1 files changed, 6 insertions, 4 deletions
diff --git a/sysdeps/powerpc/powerpc64/sysdep.h b/sysdeps/powerpc/powerpc64/sysdep.h
index 589f7c8..cfcfa69 100644
--- a/sysdeps/powerpc/powerpc64/sysdep.h
+++ b/sysdeps/powerpc/powerpc64/sysdep.h
@@ -275,12 +275,14 @@ LT_LABELSUFFIX(name,_name_end): ; \
/* Allocate frame and save register */
#define NVOLREG_SAVE \
stdu r1,-SCV_FRAME_SIZE(r1); \
+ cfi_adjust_cfa_offset(SCV_FRAME_SIZE); \
std r31,SCV_FRAME_NVOLREG_SAVE(r1); \
- cfi_adjust_cfa_offset(SCV_FRAME_SIZE);
+ cfi_rel_offset(r31,SCV_FRAME_NVOLREG_SAVE);
/* Restore register and destroy frame */
#define NVOLREG_RESTORE \
ld r31,SCV_FRAME_NVOLREG_SAVE(r1); \
+ cfi_restore(r31); \
addi r1,r1,SCV_FRAME_SIZE; \
cfi_adjust_cfa_offset(-SCV_FRAME_SIZE);
@@ -331,13 +333,13 @@ LT_LABELSUFFIX(name,_name_end): ; \
#define DO_CALL_SCV \
mflr r9; \
- std r9,FRAME_LR_SAVE(r1); \
- cfi_offset(lr,FRAME_LR_SAVE); \
+ std r9,SCV_FRAME_SIZE+FRAME_LR_SAVE(r1); \
+ cfi_rel_offset(lr,SCV_FRAME_SIZE+FRAME_LR_SAVE); \
.machine "push"; \
.machine "power9"; \
scv 0; \
.machine "pop"; \
- ld r9,FRAME_LR_SAVE(r1); \
+ ld r9,SCV_FRAME_SIZE+FRAME_LR_SAVE(r1); \
mtlr r9; \
cfi_restore(lr);