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| author | Stefan Liebler <stli@linux.ibm.com> | 2022-08-25 12:17:48 +0200 |
|---|---|---|
| committer | Stefan Liebler <stli@linux.ibm.com> | 2022-08-30 10:54:46 +0200 |
| commit | e57d8fc97b90127de4ed3e3a9cdf663667580935 (patch) | |
| tree | f6b33a78454ea861ddef36b3ed8eb28289094f28 /sysdeps/unix/sysv/linux/s390/s390-32/swapcontext.S | |
| parent | 1d495912a746e2a1ffb780c9a81fd234ec2464e8 (diff) | |
| download | glibc-e57d8fc97b90127de4ed3e3a9cdf663667580935.zip glibc-e57d8fc97b90127de4ed3e3a9cdf663667580935.tar.gz glibc-e57d8fc97b90127de4ed3e3a9cdf663667580935.tar.bz2 | |
S390: Always use svc 0
On s390x syscalls are triggered by svc instruction. One can
pass the syscall number encoded in the instruction "svc 123"
or by storing it in r1:
lghi r1,123
svc 0
If the syscall number is encoded in the instruction, this can
cause broken syscall restarts. Therefore this patch is now just
passing the syscall number in r1.
See also kernel-commit:
"s390/signal: switch to using vdso for sigreturn and syscall restart"
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/arch/s390/[%e2%80%a6]call.c?h=v6.0-rc1&id=df29a7440c4b5c65765c8f60396b3b13063e24e9
As information, the "svc 0" feature was introduced in kernel 2.5.62:
commit b5aad611393ef2e132e3648fa4c6e56a9cfa8708
Diffstat (limited to 'sysdeps/unix/sysv/linux/s390/s390-32/swapcontext.S')
| -rw-r--r-- | sysdeps/unix/sysv/linux/s390/s390-32/swapcontext.S | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/sysdeps/unix/sysv/linux/s390/s390-32/swapcontext.S b/sysdeps/unix/sysv/linux/s390/s390-32/swapcontext.S index def4e8b..b75bf75 100644 --- a/sysdeps/unix/sysv/linux/s390/s390-32/swapcontext.S +++ b/sysdeps/unix/sysv/linux/s390/s390-32/swapcontext.S @@ -73,7 +73,8 @@ ENTRY(__swapcontext) la %r3,SC_MASK(%r5) la %r4,SC_MASK(%r1) lhi %r5,_NSIG8 - svc SYS_ify(rt_sigprocmask) + lhi %r1,SYS_ify(rt_sigprocmask) + svc 0 /* Load fpu context. */ lr %r5,%r0 |