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author | Zack Weinberg <zackw@panix.com> | 2017-06-08 15:39:03 -0400 |
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committer | Zack Weinberg <zackw@panix.com> | 2017-06-08 15:39:03 -0400 |
commit | 5046dbb4a7eba5eccfd258f92f4735c9ffc8d069 (patch) | |
tree | 4470480d904b65cf14ca524f96f79eca818c3eaf /REORG.TODO/sysdeps/unix/sysv/linux/i386/clone.S | |
parent | 199fc19d3aaaf57944ef036e15904febe877fc93 (diff) | |
download | glibc-zack/build-layout-experiment.tar.gz glibc-zack/build-layout-experiment.tar.xz glibc-zack/build-layout-experiment.zip |
Prepare for radical source tree reorganization. zack/build-layout-experiment
All top-level files and directories are moved into a temporary storage directory, REORG.TODO, except for files that will certainly still exist in their current form at top level when we're done (COPYING, COPYING.LIB, LICENSES, NEWS, README), all old ChangeLog files (which are moved to the new directory OldChangeLogs, instead), and the generated file INSTALL (which is just deleted; in the new order, there will be no generated files checked into version control).
Diffstat (limited to 'REORG.TODO/sysdeps/unix/sysv/linux/i386/clone.S')
-rw-r--r-- | REORG.TODO/sysdeps/unix/sysv/linux/i386/clone.S | 124 |
1 files changed, 124 insertions, 0 deletions
diff --git a/REORG.TODO/sysdeps/unix/sysv/linux/i386/clone.S b/REORG.TODO/sysdeps/unix/sysv/linux/i386/clone.S new file mode 100644 index 0000000000..a4ba3e20ff --- /dev/null +++ b/REORG.TODO/sysdeps/unix/sysv/linux/i386/clone.S @@ -0,0 +1,124 @@ +/* Copyright (C) 1996-2017 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Richard Henderson (rth@tamu.edu) + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +/* clone() is even more special than fork() as it mucks with stacks + and invokes a function in the right context after its all over. */ + +#include <sysdep.h> +#define _ERRNO_H 1 +#include <bits/errno.h> +#include <asm-syntax.h> + +/* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg, + pid_t *ptid, struct user_desc *tls, pid_t *ctid); */ + +#define PARMS 4 /* no space for saved regs */ +#define FUNC PARMS +#define STACK FUNC+4 +#define FLAGS STACK+4 +#define ARG FLAGS+4 +#define PTID ARG+4 +#define TLS PTID+4 +#define CTID TLS+4 + +#define __NR_clone 120 +#define SYS_clone 120 + +#define CLONE_VM 0x00000100 + + .text +ENTRY (__clone) + /* Sanity check arguments. */ + movl $-EINVAL,%eax + movl FUNC(%esp),%ecx /* no NULL function pointers */ + testl %ecx,%ecx + jz SYSCALL_ERROR_LABEL + movl STACK(%esp),%ecx /* no NULL stack pointers */ + testl %ecx,%ecx + jz SYSCALL_ERROR_LABEL + + /* Insert the argument onto the new stack. Make sure the new + thread is started with an alignment of (mod 16). */ + andl $0xfffffff0, %ecx + subl $28,%ecx + movl ARG(%esp),%eax /* no negative argument counts */ + movl %eax,12(%ecx) + + /* Save the function pointer as the zeroth argument. + It will be popped off in the child in the ebx frobbing below. */ + movl FUNC(%esp),%eax + movl %eax,8(%ecx) + /* Don't leak any information. */ + movl $0,4(%ecx) + + /* Do the system call */ + pushl %ebx + cfi_adjust_cfa_offset (4) + pushl %esi + cfi_adjust_cfa_offset (4) + pushl %edi + cfi_adjust_cfa_offset (4) + + movl TLS+12(%esp),%esi + cfi_rel_offset (esi, 4) + movl PTID+12(%esp),%edx + movl FLAGS+12(%esp),%ebx + cfi_rel_offset (ebx, 8) + movl CTID+12(%esp),%edi + cfi_rel_offset (edi, 0) + movl $SYS_ify(clone),%eax + + /* Remember the flag value. */ + movl %ebx, (%ecx) + + /* End FDE now, because in the child the unwind info will be + wrong. */ + cfi_endproc + + int $0x80 + popl %edi + popl %esi + popl %ebx + + test %eax,%eax + jl SYSCALL_ERROR_LABEL + jz L(thread_start) + + ret + +L(thread_start): + cfi_startproc; + /* Clearing frame pointer is insufficient, use CFI. */ + cfi_undefined (eip); + /* Note: %esi is zero. */ + movl %esi,%ebp /* terminate the stack frame */ + call *%ebx +#ifdef PIC + call L(here) +L(here): + popl %ebx + addl $_GLOBAL_OFFSET_TABLE_+[.-L(here)], %ebx +#endif + movl %eax, %ebx + movl $SYS_ify(exit), %eax + ENTER_KERNEL + +PSEUDO_END (__clone) + +libc_hidden_def (__clone) +weak_alias (__clone, clone) |