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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 | |
| 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.
| -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. */ |