From 3f823e87ccbf3723eb4eeb63b0619f1a0ceb174e Mon Sep 17 00:00:00 2001 From: Adhemerval Zanella Date: Thu, 22 Jun 2017 08:49:34 -0300 Subject: Call exit directly in clone (BZ #21512) On aarch64, alpha, arm, hppa, mips, nios2, powerpc, sh, sparc, tile, and x86_64 the clone syscall jumps to _exit after the child execution and the function ends the process execution by calling exit_group. This behavior have a small issue where threads created with CLONE_THREAD using clone syscall directly will eventually exit the whole group altogether instead of just the thread created. Also, s390, microblaze, ia64, i386, and m68k differs by calling exit syscall directly. This patch changes all architectures to call the exit syscall directly, as for s390, microblaze, ia64, i386, and m68k. This do not have change glibc internal behavior in any sort, since the only usage of clone implementation in posix_spawn calls _exit directly in the created child (fork uses a direct call to clone). Checked on x86_64-linux-gnu, i686-linux-gnu, aarch64-linux-gnu, powerpc-linux-gnu, powerpc64le-linux-gnu, sparc64-linux-gnu, and sparcv9-linux-gnu. [BZ #21512] * sysdeps/unix/sysv/linux/aarch64/clone.S (__clone): Call exit syscall instead of jump to _exit. (CLONE_VM_BIT): Remove unused define. (CLONE_VM): Likewise. (CLONE_THREAD_BIT): Likewise. (CLONE_THREAD): Likewise. * sysdeps/unix/sysv/linux/alpha/clone.S (__clone): Likewise. (CLONE_VM): Remove unused define. * sysdeps/unix/sysv/linux/arm/clone.S (__clone): Likewise. (CLONE_VM): Remove unused define. (CLONE_THREAD): Likewise. * sysdeps/unix/sysv/linux/i386/clone.S (CLONE_VM): Likewise. * sysdeps/unix/sysv/linux/ia64/clone2.S (__clone2): Call exit syscall instead of jump to _exit. * sysdeps/unix/sysv/linux/hppa/clone.S (__clone): Likewise. * sysdeps/unix/sysv/linux/mips/clone.S (__clone): Likewise. (CLONE_VM): Remove unused define. (CLONE_THREAD): Likewise. * sysdeps/unix/sysv/linux/nios2/clone.S (__clone): Likewise. (CLONE_VM): Remove unused define. * sysdeps/unix/sysv/linux/powerpc/powerpc32/clone.S (__clone): Likewise. (CLONE_VM): Remove unused define. (CLONE_THREAD): Likewise. * sysdeps/unix/sysv/linux/powerpc/powerpc64/clone.S (__clone): Likewise. (CLONE_VM): Remove unused define. (CLONE_THREAD): Likewise. * sysdeps/unix/sysv/linux/sh/clone.S (__clone): Likewise. * sysdeps/unix/sysv/linux/sparc/sparc32/clone.S (__clone): Likewise. (CLONE_VM): Remove unused define. * sysdeps/unix/sysv/linux/sparc/sparc64/clone.S (__clone): Likewise. (CLONE_VM): Remove unused define. * sysdeps/unix/sysv/linux/tile/clone.S (__clone): Likewise. * sysdeps/unix/sysv/linux/x86_64/clone.S (__clone): Likewise. (CLONE_VM): Remove unused define. * sysdeps/unix/sysv/linux/Makefile (tests): Add tst-clone3. * sysdeps/unix/sysv/linux/tst-clone3.c: New file. Fix --- sysdeps/unix/sysv/linux/aarch64/clone.S | 9 ++------- 1 file changed, 2 insertions(+), 7 deletions(-) (limited to 'sysdeps/unix/sysv/linux/aarch64') diff --git a/sysdeps/unix/sysv/linux/aarch64/clone.S b/sysdeps/unix/sysv/linux/aarch64/clone.S index 259ec073c5..905915a0f3 100644 --- a/sysdeps/unix/sysv/linux/aarch64/clone.S +++ b/sysdeps/unix/sysv/linux/aarch64/clone.S @@ -23,12 +23,6 @@ #define _ERRNO_H 1 #include -#define CLONE_VM_BIT 8 -#define CLONE_VM (1 << CLONE_VM_BIT) - -#define CLONE_THREAD_BIT 16 -#define CLONE_THREAD (1 << CLONE_THREAD_BIT) - /* int clone(int (*fn)(void *arg), x0 void *child_stack, x1 int flags, x2 @@ -84,7 +78,8 @@ thread_start: blr x10 /* We are done, pass the return value through x0. */ - b HIDDEN_JUMPTARGET(_exit) + mov x8, #SYS_ify(exit) + svc 0x0 cfi_endproc .size thread_start, .-thread_start -- cgit 1.4.1