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e57d8fc97b
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
73 lines
2.6 KiB
ArmAsm
73 lines
2.6 KiB
ArmAsm
/* Wrapper around clone system call. 64 bit S/390 version.
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Copyright (C) 2001-2022 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<https://www.gnu.org/licenses/>. */
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/* clone is even more special than fork as it mucks with stacks
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and invokes a function in the right context after its all over. */
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#include <sysdep.h>
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#include <tls.h>
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#define _ERRNO_H 1
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#include <bits/errno.h>
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/* int __clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg,
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pid_t *parent_tid, void *tls, pid_t *child_tid); */
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/* sys_clone (void *child_stack, unsigned long flags,
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pid_t *parent_tid, pid_t *child_tid, void *tls); */
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.text
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ENTRY(__clone)
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stmg %r6,%r7,48(%r15) /* Save registers. */
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cfi_offset (%r7,-104)
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cfi_offset (%r6,-112)
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ltgr %r7,%r2 /* check fn and move to %r7 */
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jz error /* no NULL function pointers */
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lghi %r0,-16 /* Align the child_stack to a ... */
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ngr %r3,%r0 /* double word boundary and ... */
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jz error /* avoid NULL stack pointers. */
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lgr %r0,%r5 /* move *arg out of the way */
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lgr %r2,%r3 /* move child_stack to %r2 */
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lgr %r3,%r4 /* move flags to %r3 */
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lgr %r4,%r6 /* move parent_tid to %r4 */
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lg %r5,168(%r15) /* load child_tid from stack */
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lg %r6,160(%r15) /* load tls from stack */
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lghi %r1,SYS_ify (clone)
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svc 0
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ltgr %r2,%r2 /* check return code */
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jz thread_start
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lmg %r6,%r7,48(%r15) /* Restore registers. */
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jgm SYSCALL_ERROR_LABEL
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br %r14
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error:
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lghi %r2,-EINVAL
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jg SYSCALL_ERROR_LABEL
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PSEUDO_END (__clone)
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thread_start:
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cfi_startproc
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/* Mark r14 as undefined in order to stop unwinding here! */
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cfi_undefined (r14)
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/* fn is in gpr 7, arg in gpr 0 */
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lgr %r2,%r0 /* set first parameter to void *arg */
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aghi %r15,-160 /* make room on the stack for the save area */
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xc 0(8,%r15),0(%r15)
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basr %r14,%r7 /* jump to fn */
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DO_CALL (exit, 1)
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cfi_endproc
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libc_hidden_def (__clone)
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weak_alias (__clone, clone)
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