mirror/glibc
2
0
Fork 0
mirror of git://sourceware.org/git/glibc.git synced 2025-02-17 13:00:43 +08:00
Code Issues Packages Projects Releases Wiki Activity

S390: Remove not needed stack frame in syscall function.

Browse Source 
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.
This commit is contained in:
Stefan Liebler 2019-10-23 14:51:53 +02:00
parent 7db1fe38de
commit 76aaa13d5d
2 changed files with 8 additions and 44 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

26
sysdeps/unix/sysv/linux/s390/s390-32/syscall.S
View File

@ -22,37 +22,19 @@
more information about the value -4095 used below.*/ more information about the value -4095 used below.*/
ENTRY (syscall) ENTRY (syscall)
/* Save registers and setup stack. */ stm %r6,%r7,24(%r15) /* save registers */
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)
cfi_offset (%r7, -68) cfi_offset (%r7, -68)
cfi_offset (%r6, -72) 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 %r1,%r2 /* move syscall number */
lr %r2,%r3 /* first parameter */ lr %r2,%r3 /* first parameter */
lr %r3,%r4 /* second parameter */ lr %r3,%r4 /* second parameter */
lr %r4,%r5 /* third parameter */ lr %r4,%r5 /* third parameter */
lr %r5,%r6 /* fourth parameter */ lr %r5,%r6 /* fourth parameter */
l %r6,192(%r15) /* fifth parameter */ lm %r6,%r7,96(%r15) /* fifth / sixth parameter */
l %r7,196(%r15) /* sixth parameter */
svc 0 svc 0
l %r15,0(%r15) /* load back chain. */
cfi_adjust_cfa_offset (-96) lm %r6,%r7,24(%r15) /* load registers. */
lm %r6,%r15,24(%r15) /* load registers. */
lhi %r0,-4095 lhi %r0,-4095
clr %r2,%r0 /* check R2 for error */ clr %r2,%r0 /* check R2 for error */

26
sysdeps/unix/sysv/linux/s390/s390-64/syscall.S
View File

@ -22,37 +22,19 @@
more information about the value -4095 used below.*/ more information about the value -4095 used below.*/
ENTRY (syscall) ENTRY (syscall)
/* Save registers and setup stack. */ stmg %r6,%r7,48(%r15) /* Save registers. */
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)
cfi_offset (%r7,-104) cfi_offset (%r7,-104)
cfi_offset (%r6,-112) 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 %r1,%r2 /* Move syscall number. */
lgr %r2,%r3 /* First parameter. */ lgr %r2,%r3 /* First parameter. */
lgr %r3,%r4 /* Second parameter. */ lgr %r3,%r4 /* Second parameter. */
lgr %r4,%r5 /* Third parameter. */ lgr %r4,%r5 /* Third parameter. */
lgr %r5,%r6 /* Fourth parameter. */ lgr %r5,%r6 /* Fourth parameter. */
lg %r6,320(%r15) /* Fifth parameter. */ lmg %r6,%r7,160(%r15) /* Fifth / Sixth parameter. */
lg %r7,328(%r15) /* Sixth parameter. */
svc 0 svc 0
lg %r15,0(%r15) /* Load back chain. */
cfi_adjust_cfa_offset (-160) lmg %r6,%r7,48(%r15) /* Load registers. */
lmg %r6,%r15,48(%r15) /* Load registers. */
lghi %r0,-4095 lghi %r0,-4095
clgr %r2,%r0 /* Check R2 for error. */ clgr %r2,%r0 /* Check R2 for error. */