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| author | Stefan Liebler <stli@linux.ibm.com> | 2019-10-23 14:51:53 +0200 |
|---|---|---|
| committer | Stefan Liebler <stli@linux.ibm.com> | 2019-10-23 14:51:53 +0200 |
| commit | 76aaa13d5d654a2ba0d59cd328b3f5425809aa7e (patch) | |
| tree | b5b75d556ff8b14586dc818dd2e3dfa21c317460 /sysdeps/unix/sysv/linux | |
| parent | 7db1fe38de21831d53ceab9ae83493d8d1aec601 (diff) | |
| download | glibc-76aaa13d5d654a2ba0d59cd328b3f5425809aa7e.tar.gz glibc-76aaa13d5d654a2ba0d59cd328b3f5425809aa7e.tar.xz glibc-76aaa13d5d654a2ba0d59cd328b3f5425809aa7e.zip | |
S390: Remove not needed stack frame in syscall function.
As an svc invocation does not clobber any user space registers despite of the return value r2 and it does not need a special stack frame. This patch gets rid of the extra frame. We just have to save and restore r6 and r7 as those are preserved across function calls.
Diffstat (limited to 'sysdeps/unix/sysv/linux')
| -rw-r--r-- | sysdeps/unix/sysv/linux/s390/s390-32/syscall.S | 26 | ||||
| -rw-r--r-- | sysdeps/unix/sysv/linux/s390/s390-64/syscall.S | 26 |
2 files changed, 8 insertions, 44 deletions
diff --git a/sysdeps/unix/sysv/linux/s390/s390-32/syscall.S b/sysdeps/unix/sysv/linux/s390/s390-32/syscall.S index 69561d0b76..06280992ab 100644 --- a/sysdeps/unix/sysv/linux/s390/s390-32/syscall.S +++ b/sysdeps/unix/sysv/linux/s390/s390-32/syscall.S @@ -22,37 +22,19 @@ more information about the value -4095 used below.*/ ENTRY (syscall) - /* Save registers and setup stack. */ - stm %r6,%r15,24(%r15) /* save registers */ - cfi_offset (%r15, -36) - cfi_offset (%r14, -40) - cfi_offset (%r13, -44) - cfi_offset (%r12, -48) - cfi_offset (%r11, -52) - cfi_offset (%r10, -56) - cfi_offset (%r9, -60) - cfi_offset (%r8, -64) + stm %r6,%r7,24(%r15) /* save registers */ cfi_offset (%r7, -68) cfi_offset (%r6, -72) - lr %r1,%r15 - l %r0,4(0,%r15) /* load eos */ - ahi %r15,-96 /* buy stack space */ - cfi_adjust_cfa_offset (96) - st %r1,0(0,%r15) /* store back chain */ - st %r0,4(0,%r15) /* store eos */ lr %r1,%r2 /* move syscall number */ lr %r2,%r3 /* first parameter */ lr %r3,%r4 /* second parameter */ lr %r4,%r5 /* third parameter */ lr %r5,%r6 /* fourth parameter */ - l %r6,192(%r15) /* fifth parameter */ - l %r7,196(%r15) /* sixth parameter */ - + lm %r6,%r7,96(%r15) /* fifth / sixth parameter */ svc 0 - l %r15,0(%r15) /* load back chain. */ - cfi_adjust_cfa_offset (-96) - lm %r6,%r15,24(%r15) /* load registers. */ + + lm %r6,%r7,24(%r15) /* load registers. */ lhi %r0,-4095 clr %r2,%r0 /* check R2 for error */ diff --git a/sysdeps/unix/sysv/linux/s390/s390-64/syscall.S b/sysdeps/unix/sysv/linux/s390/s390-64/syscall.S index bbe4d79848..bcffab6f4e 100644 --- a/sysdeps/unix/sysv/linux/s390/s390-64/syscall.S +++ b/sysdeps/unix/sysv/linux/s390/s390-64/syscall.S @@ -22,37 +22,19 @@ more information about the value -4095 used below.*/ ENTRY (syscall) - /* Save registers and setup stack. */ - stmg %r6,%r15,48(%r15) /* Save registers. */ - cfi_offset (%r15,-40) - cfi_offset (%r14,-48) - cfi_offset (%r13,-56) - cfi_offset (%r12,-64) - cfi_offset (%r11,-72) - cfi_offset (%r10,-80) - cfi_offset (%r9,-88) - cfi_offset (%r8,-96) + stmg %r6,%r7,48(%r15) /* Save registers. */ cfi_offset (%r7,-104) cfi_offset (%r6,-112) - lgr %r1,%r15 - lg %r0,8(%r15) /* Load eos. */ - aghi %r15,-160 /* Buy stack space. */ - cfi_adjust_cfa_offset (160) - stg %r1,0(%r15) /* Store back chain. */ - stg %r0,8(%r15) /* Store eos. */ lgr %r1,%r2 /* Move syscall number. */ lgr %r2,%r3 /* First parameter. */ lgr %r3,%r4 /* Second parameter. */ lgr %r4,%r5 /* Third parameter. */ lgr %r5,%r6 /* Fourth parameter. */ - lg %r6,320(%r15) /* Fifth parameter. */ - lg %r7,328(%r15) /* Sixth parameter. */ - + lmg %r6,%r7,160(%r15) /* Fifth / Sixth parameter. */ svc 0 - lg %r15,0(%r15) /* Load back chain. */ - cfi_adjust_cfa_offset (-160) - lmg %r6,%r15,48(%r15) /* Load registers. */ + + lmg %r6,%r7,48(%r15) /* Load registers. */ lghi %r0,-4095 clgr %r2,%r0 /* Check R2 for error. */ |