| Message ID | 1498221450-8381-1-git-send-email-adhemerval.zanella@linaro.org |
|---|---|
| State | New |
| Headers | show |
On 06/23/2017 08:37 AM, Adhemerval Zanella wrote: > On aarch64, alpha, arm, hppa, mips, nios2, powerpc, s390, sh, > sparch, 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, microblaze, ia64, i386, and m68k > differs by calling exit syscall directly. > > This patch changes all architectures to call the exit syscall > directly, as for 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. How is it that this doesn't break threading completely on the existing architectures that call _exit? Is it because NPTL calls the clone syscall directly instead of calling the clone() function and nobody uses clone() because of all the other problems it has? I admit that only an explicit call to _exit() or exit() should terminate every thread in the thread group, *and* looking at the kernel side code I see it does try to terminate every thread in the group (zap_other_threads()). The patch looks good to me, but I just want some clarification about my question "Why haven't we noticed?" :-) > [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/s390/s390-32/clone.S (__clone): Likewise. > * sysdeps/unix/sysv/linux/s390/s390-64/clone.S (__clone): 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. > --- > sysdeps/unix/sysv/linux/Makefile | 4 +- > sysdeps/unix/sysv/linux/aarch64/clone.S | 9 +-- > sysdeps/unix/sysv/linux/alpha/clone.S | 11 +-- > sysdeps/unix/sysv/linux/arm/clone.S | 6 +- > sysdeps/unix/sysv/linux/hppa/clone.S | 6 +- > sysdeps/unix/sysv/linux/i386/clone.S | 2 - > sysdeps/unix/sysv/linux/ia64/clone2.S | 8 +- > sysdeps/unix/sysv/linux/m68k/clone.S | 2 - > sysdeps/unix/sysv/linux/mips/clone.S | 12 +-- > sysdeps/unix/sysv/linux/nios2/clone.S | 17 +--- > sysdeps/unix/sysv/linux/powerpc/powerpc32/clone.S | 7 +- > sysdeps/unix/sysv/linux/powerpc/powerpc64/clone.S | 11 +-- > sysdeps/unix/sysv/linux/s390/s390-32/clone.S | 2 +- > sysdeps/unix/sysv/linux/s390/s390-64/clone.S | 2 +- > sysdeps/unix/sysv/linux/sh/clone.S | 21 +---- > sysdeps/unix/sysv/linux/sparc/sparc32/clone.S | 5 +- > sysdeps/unix/sysv/linux/sparc/sparc64/clone.S | 5 +- > sysdeps/unix/sysv/linux/tile/clone.S | 6 +- > sysdeps/unix/sysv/linux/tst-clone3.c | 95 +++++++++++++++++++++++ > sysdeps/unix/sysv/linux/x86_64/clone.S | 5 +- > 20 files changed, 130 insertions(+), 106 deletions(-) > create mode 100644 sysdeps/unix/sysv/linux/tst-clone3.c > > diff --git a/sysdeps/unix/sysv/linux/Makefile b/sysdeps/unix/sysv/linux/Makefile > index 8b340d4..9d6a2de 100644 > --- a/sysdeps/unix/sysv/linux/Makefile > +++ b/sysdeps/unix/sysv/linux/Makefile > @@ -49,8 +49,8 @@ sysdep_headers += sys/mount.h sys/acct.h sys/sysctl.h \ > bits/mman-linux.h \ > bits/siginfo-arch.h bits/siginfo-consts-arch.h > > -tests += tst-clone tst-clone2 tst-fanotify tst-personality tst-quota \ > - tst-sync_file_range test-errno-linux > +tests += tst-clone tst-clone2 tst-clone3 tst-fanotify tst-personality \ > + tst-quota tst-sync_file_range test-errno-linux > > # Generate the list of SYS_* macros for the system calls (__NR_* macros). > > diff --git a/sysdeps/unix/sysv/linux/aarch64/clone.S b/sysdeps/unix/sysv/linux/aarch64/clone.S > index 259ec07..905915a 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 <bits/errno.h> > > -#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 > > diff --git a/sysdeps/unix/sysv/linux/alpha/clone.S b/sysdeps/unix/sysv/linux/alpha/clone.S > index 20ae361..550461f 100644 > --- a/sysdeps/unix/sysv/linux/alpha/clone.S > +++ b/sysdeps/unix/sysv/linux/alpha/clone.S > @@ -23,8 +23,6 @@ > #define _ERRNO_H 1 > #include <bits/errno.h> > > -#define CLONE_VM 0x00000100 > - > /* int clone(int (*fn)(void *arg), void *child_stack, int flags, > void *arg, pid_t *ptid, void *tls, pid_t *ctid); > > @@ -100,13 +98,8 @@ thread_start: > jsr ra, (pv) > ldgp gp, 0(ra) > > - /* Call _exit rather than doing it inline for breakpoint purposes. */ > - mov v0, a0 > -#ifdef PIC > - bsr ra, HIDDEN_JUMPTARGET(_exit) !samegp > -#else > - jsr ra, HIDDEN_JUMPTARGET(_exit) > -#endif > + ldiq v0, __NR_exit > + call_pal PAL_callsys > > /* Die horribly. */ > .align 4 > diff --git a/sysdeps/unix/sysv/linux/arm/clone.S b/sysdeps/unix/sysv/linux/arm/clone.S > index a309add..f01968a 100644 > --- a/sysdeps/unix/sysv/linux/arm/clone.S > +++ b/sysdeps/unix/sysv/linux/arm/clone.S > @@ -24,9 +24,6 @@ > #define _ERRNO_H 1 > #include <bits/errno.h> > > -#define CLONE_VM 0x00000100 > -#define CLONE_THREAD 0x00010000 > - > /* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg, > pid_t *ptid, struct user_desc *tls, pid_t *ctid); */ > > @@ -76,7 +73,8 @@ PSEUDO_END (__clone) > BLX (ip) > > @ and we are done, passing the return value through r0 > - b PLTJMP(HIDDEN_JUMPTARGET(_exit)) > + ldr r7, =SYS_ify(clone) > + swi 0x0 > > .fnend > > diff --git a/sysdeps/unix/sysv/linux/hppa/clone.S b/sysdeps/unix/sysv/linux/hppa/clone.S > index d36b302..8c43944 100644 > --- a/sysdeps/unix/sysv/linux/hppa/clone.S > +++ b/sysdeps/unix/sysv/linux/hppa/clone.S > @@ -148,10 +148,10 @@ ENTRY(__clone) > copy %r4, %r19 > #endif > /* The call to _exit needs saved r19. */ > - bl _exit, %rp > - copy %ret0, %arg0 > + ble 0x100(%sr2, %r0) > + ldi __NR_exit, %r20 > > - /* We should not return from _exit. > + /* We should not return from exit. > We do not restore r4, or the stack state. */ > iitlbp %r0, (%sr0, %r0) > > diff --git a/sysdeps/unix/sysv/linux/i386/clone.S b/sysdeps/unix/sysv/linux/i386/clone.S > index a4ba3e2..49c82d9 100644 > --- a/sysdeps/unix/sysv/linux/i386/clone.S > +++ b/sysdeps/unix/sysv/linux/i386/clone.S > @@ -39,8 +39,6 @@ > #define __NR_clone 120 > #define SYS_clone 120 > > -#define CLONE_VM 0x00000100 > - > .text > ENTRY (__clone) > /* Sanity check arguments. */ > diff --git a/sysdeps/unix/sysv/linux/ia64/clone2.S b/sysdeps/unix/sysv/linux/ia64/clone2.S > index 9b59473..3157ce9 100644 > --- a/sysdeps/unix/sysv/linux/ia64/clone2.S > +++ b/sysdeps/unix/sysv/linux/ia64/clone2.S > @@ -74,11 +74,11 @@ ENTRY(__clone2) > mov b6=out1 > br.call.dptk.many rp=b6 /* Call fn(arg) in the child */ > ;; > - mov out0=r8 /* Argument to _exit */ > + mov out0=r8 /* Argument to exit */ > mov gp=loc0 > - .globl HIDDEN_JUMPTARGET(_exit) > - br.call.dpnt.many rp=HIDDEN_JUMPTARGET(_exit) > - /* call _exit with result from fn. */ > + mov r15=SYS_ify (exit) > + .save rp, r0 > + break __BREAK_SYSCALL > ret /* Not reached. */ > PSEUDO_END(__clone2) > > diff --git a/sysdeps/unix/sysv/linux/m68k/clone.S b/sysdeps/unix/sysv/linux/m68k/clone.S > index a680191..0894b2a 100644 > --- a/sysdeps/unix/sysv/linux/m68k/clone.S > +++ b/sysdeps/unix/sysv/linux/m68k/clone.S > @@ -24,8 +24,6 @@ > #include <bits/errno.h> > #include <tls.h> > > -#define CLONE_VM 0x00000100 > - > /* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg, > void *parent_tidptr, void *tls, void *child_tidptr) */ > > diff --git a/sysdeps/unix/sysv/linux/mips/clone.S b/sysdeps/unix/sysv/linux/mips/clone.S > index 8b79457..855f972 100644 > --- a/sysdeps/unix/sysv/linux/mips/clone.S > +++ b/sysdeps/unix/sysv/linux/mips/clone.S > @@ -25,9 +25,6 @@ > #include <bits/errno.h> > #include <tls.h> > > -#define CLONE_VM 0x00000100 > -#define CLONE_THREAD 0x00010000 > - > /* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg, > void *parent_tidptr, void *tls, void *child_tidptr) */ > > @@ -137,14 +134,9 @@ L(thread_start): > /* Call the user's function. */ > jal t9 > > - /* Call _exit rather than doing it inline for breakpoint purposes. */ > move a0,v0 > -#ifdef __PIC__ > - PTR_LA t9,_exit > - jalr t9 > -#else > - jal _exit > -#endif > + li v0,__NR_clone > + syscall > > END(__thread_start) > > diff --git a/sysdeps/unix/sysv/linux/nios2/clone.S b/sysdeps/unix/sysv/linux/nios2/clone.S > index 7929dfa..2ba8258 100644 > --- a/sysdeps/unix/sysv/linux/nios2/clone.S > +++ b/sysdeps/unix/sysv/linux/nios2/clone.S > @@ -25,8 +25,6 @@ > #include <bits/errno.h> > #include <tcb-offsets.h> > > -#define CLONE_VM 0x00000100 > - > /* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg, > void *parent_tidptr, void *tls, void *child_tidptr) */ > > @@ -75,18 +73,9 @@ thread_start: > /* Call the user's function. */ > callr r5 > > - /* _exit with the result. */ > - mov r4, r2 > -#ifdef PIC > - nextpc r22 > -1: movhi r8, %hiadj(_gp_got - 1b) > - addi r8, r8, %lo(_gp_got - 1b) > - add r22, r22, r8 > - ldw r8, %call(HIDDEN_JUMPTARGET(_exit))(r22) > - jmp r8 > -#else > - jmpi _exit > -#endif > + /* exit with the result. */ > + movi r2, SYS_ify (exit) > + trap > cfi_endproc > > cfi_startproc > diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/clone.S b/sysdeps/unix/sysv/linux/powerpc/powerpc32/clone.S > index a07b7d3..e48cc5f 100644 > --- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/clone.S > +++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/clone.S > @@ -20,10 +20,6 @@ > #define _ERRNO_H 1 > #include <bits/errno.h> > > -#define CLONE_VM 0x00000100 > -#define CLONE_THREAD 0x00010000 > - > - > /* This is the only really unusual system call in PPC linux, but not > because of any weirdness in the system call itself; because of > all the freaky stuff we have to do to make the call useful. */ > @@ -80,8 +76,7 @@ ENTRY (__clone) > mtctr r30 > mr r3,r31 > bctrl > - /* Call _exit with result from procedure. */ > - b HIDDEN_JUMPTARGET(_exit) > + DO_CALL(SYS_ify(exit)) > > L(parent): > /* Parent. Restore registers & return. */ > diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/clone.S b/sysdeps/unix/sysv/linux/powerpc/powerpc64/clone.S > index 9e5bfd2..78c353a 100644 > --- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/clone.S > +++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/clone.S > @@ -20,9 +20,6 @@ > #define _ERRNO_H 1 > #include <bits/errno.h> > > -#define CLONE_VM 0x00000100 > -#define CLONE_THREAD 0x00010000 > - > /* This is the only really unusual system call in PPC linux, but not > because of any weirdness in the system call itself; because of > all the freaky stuff we have to do to make the call useful. */ > @@ -84,15 +81,11 @@ ENTRY (__clone) > mr r3,r31 > bctrl > ld r2,FRAME_TOC_SAVE(r1) > - /* Call _exit with result from procedure. */ > -#ifdef SHARED > - b JUMPTARGET(__GI__exit) > -#else > - bl JUMPTARGET(_exit) > + > + DO_CALL(SYS_ify(exit)) > /* We won't ever get here but provide a nop so that the linker > will insert a toc adjusting stub if necessary. */ > nop > -#endif > > L(badargs): > cfi_startproc > diff --git a/sysdeps/unix/sysv/linux/s390/s390-32/clone.S b/sysdeps/unix/sysv/linux/s390/s390-32/clone.S > index a8b4dbc..1588e5f 100644 > --- a/sysdeps/unix/sysv/linux/s390/s390-32/clone.S > +++ b/sysdeps/unix/sysv/linux/s390/s390-32/clone.S > @@ -59,7 +59,7 @@ thread_start: > ahi %r15,-96 /* make room on the stack for the save area */ > xc 0(4,%r15),0(%r15) > basr %r14,%r1 /* jump to fn */ > - DO_CALL (exit, 1) > + svc SYS_ify(exit) > > libc_hidden_def (__clone) > weak_alias (__clone, clone) > diff --git a/sysdeps/unix/sysv/linux/s390/s390-64/clone.S b/sysdeps/unix/sysv/linux/s390/s390-64/clone.S > index daf8a58..5843188 100644 > --- a/sysdeps/unix/sysv/linux/s390/s390-64/clone.S > +++ b/sysdeps/unix/sysv/linux/s390/s390-64/clone.S > @@ -60,7 +60,7 @@ thread_start: > aghi %r15,-160 /* make room on the stack for the save area */ > xc 0(8,%r15),0(%r15) > basr %r14,%r1 /* jump to fn */ > - DO_CALL (exit, 1) > + svc SYS_ify(exit) > > libc_hidden_def (__clone) > weak_alias (__clone, clone) > diff --git a/sysdeps/unix/sysv/linux/sh/clone.S b/sysdeps/unix/sysv/linux/sh/clone.S > index 9063b21..b13a64b 100644 > --- a/sysdeps/unix/sysv/linux/sh/clone.S > +++ b/sysdeps/unix/sysv/linux/sh/clone.S > @@ -73,25 +73,8 @@ ENTRY(__clone) > mov.l @(4,r15), r4 > > /* we are done, passing the return value through r0 */ > - mov.l .L3, r1 > -#ifdef SHARED > - mov.l r12, @-r15 > - sts.l pr, @-r15 > - mov r0, r4 > - mova .LG, r0 > - mov.l .LG, r12 > - add r0, r12 > - mova .L3, r0 > - add r0, r1 > - jsr @r1 > - nop > - lds.l @r15+, pr > - rts > - mov.l @r15+, r12 > -#else > - jmp @r1 > - mov r0, r4 > -#endif > + mov #+SYS_ify(exit), r3 > + trapa #0x15 > .align 2 > .LG: > .long _GLOBAL_OFFSET_TABLE_ > diff --git a/sysdeps/unix/sysv/linux/sparc/sparc32/clone.S b/sysdeps/unix/sysv/linux/sparc/sparc32/clone.S > index 6d2f5bd..1afa26e 100644 > --- a/sysdeps/unix/sysv/linux/sparc/sparc32/clone.S > +++ b/sysdeps/unix/sysv/linux/sparc/sparc32/clone.S > @@ -24,8 +24,6 @@ > #include <tcb-offsets.h> > #include <sysdep.h> > > -#define CLONE_VM 0x00000100 > - > /* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg, > pid_t *ptid, void *tls, pid_t *ctid); */ > > @@ -81,7 +79,8 @@ __thread_start: > mov %g0, %fp /* terminate backtrace */ > call %g2 > mov %g3,%o0 > - call HIDDEN_JUMPTARGET(_exit),0 > + set __NR_exit, %g1 > + ta 0x10 > nop > > .size __thread_start, .-__thread_start > diff --git a/sysdeps/unix/sysv/linux/sparc/sparc64/clone.S b/sysdeps/unix/sysv/linux/sparc/sparc64/clone.S > index fc28539..785ccd1 100644 > --- a/sysdeps/unix/sysv/linux/sparc/sparc64/clone.S > +++ b/sysdeps/unix/sysv/linux/sparc/sparc64/clone.S > @@ -24,8 +24,6 @@ > #include <tcb-offsets.h> > #include <sysdep.h> > > -#define CLONE_VM 0x00000100 > - > /* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg, > pid_t *ptid, void *tls, pid_t *ctid); */ > > @@ -78,7 +76,8 @@ __thread_start: > mov %g0, %fp /* terminate backtrace */ > call %g2 > mov %g3,%o0 > - call HIDDEN_JUMPTARGET(_exit),0 > + set __NR_exit, %g1 > + ta 0x6d > nop > > .size __thread_start, .-__thread_start > diff --git a/sysdeps/unix/sysv/linux/tile/clone.S b/sysdeps/unix/sysv/linux/tile/clone.S > index d7d2a3b..9610acd 100644 > --- a/sysdeps/unix/sysv/linux/tile/clone.S > +++ b/sysdeps/unix/sysv/linux/tile/clone.S > @@ -168,10 +168,8 @@ ENTRY (__clone) > move r0, r31 > jalr r32 > } > - { > - j HIDDEN_JUMPTARGET(_exit) > - info INFO_OP_CANNOT_BACKTRACE /* Notify backtracer to stop. */ > - } > + moveli TREG_SYSCALL_NR_NAME, __NR_exit > + swint1 > PSEUDO_END (__clone) > > libc_hidden_def (__clone) > diff --git a/sysdeps/unix/sysv/linux/tst-clone3.c b/sysdeps/unix/sysv/linux/tst-clone3.c > new file mode 100644 > index 0000000..e893e4d > --- /dev/null > +++ b/sysdeps/unix/sysv/linux/tst-clone3.c > @@ -0,0 +1,95 @@ > +/* Check if clone (CLONE_THREAD) does not call exit_group (BZ #21512) > + Copyright (C) 2017 Free Software Foundation, Inc. > + This file is part of the GNU C Library. > + > + 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/>. */ > + > +#include <string.h> > +#include <sched.h> > +#include <signal.h> > +#include <unistd.h> > +#include <sys/syscall.h> > +#include <sys/wait.h> > +#include <sys/types.h> > +#include <linux/futex.h> > + > +#include <stackinfo.h> /* For _STACK_GROWS_{UP,DOWN}. */ > +#include <support/check.h> > + > +/* Test if clone call with CLONE_THREAD does not call exit_group. The 'f' > + function returns '1', which will be used by clone thread to call the > + 'exit' syscall directly. If _exit is used instead, exit_group will be > + used and thus the thread group will finish with return value of '1' > + (where '2' from main thread is expected. */ s/(where/where/g > + > +static int > +f (void *a) > +{ > + return 1; > +} > + > +/* Futex wait for TID argument, similar to pthread_join internal > + implementation. */ > +#define wait_tid(tid) \ > + do { \ > + __typeof (tid) __tid; \ > + while ((__tid = (tid)) != 0) \ > + futex_wait (&(tid), __tid); \ > + } while (0) > + > +static inline int > +futex_wait (int *futexp, int val) > +{ > + return syscall (__NR_futex, futexp, FUTEX_WAIT, val); > +} > + > +static int > +do_test (void) > +{ > + char st[1024] __attribute__ ((aligned)); > + int clone_flags = CLONE_THREAD; > + /* Minimum required flags to used along with CLONE_THREAD. */ > + clone_flags |= CLONE_VM | CLONE_SIGHAND; > + /* We will used ctid to call on futex to wait for thread exit. */ > + clone_flags |= CLONE_CHILD_CLEARTID; > + pid_t ctid, tid; > + > +#ifdef __ia64__ > + extern int __clone2 (int (*__fn) (void *__arg), void *__child_stack_base, > + size_t __child_stack_size, int __flags, > + void *__arg, ...); > + tid = __clone2 (f, st, sizeof (st), clone_flags, NULL, /* ptid */ NULL, > + /* tls */ NULL, &ctid); > +#else > +#if _STACK_GROWS_DOWN > + tid = clone (f, st + sizeof (st), clone_flags, NULL, /* ptid */ NULL, > + /* tls */ NULL, &ctid); > +#elif _STACK_GROWS_UP > + tid = clone (f, st, clone_flags, NULL, /* ptid */ NULL, /* tls */ NULL, > + &ctid); > +#else > +#error "Define either _STACK_GROWS_DOWN or _STACK_GROWS_UP" > +#endif > +#endif > + if (tid == -1) > + FAIL_EXIT1 ("clone failed: %m"); > + > + wait_tid (ctid); > + > + return 2; > +} > + > +#define EXPECTED_STATUS 2 > +#include <support/test-driver.c> > diff --git a/sysdeps/unix/sysv/linux/x86_64/clone.S b/sysdeps/unix/sysv/linux/x86_64/clone.S > index d5c2d07..b10fc29 100644 > --- a/sysdeps/unix/sysv/linux/x86_64/clone.S > +++ b/sysdeps/unix/sysv/linux/x86_64/clone.S > @@ -23,8 +23,6 @@ > #include <bits/errno.h> > #include <asm-syntax.h> > > -#define CLONE_VM 0x00000100 > - > /* The userland implementation is: > int clone (int (*fn)(void *arg), void *child_stack, int flags, void *arg), > the kernel entry is: > @@ -97,7 +95,8 @@ L(thread_start): > call *%rax > /* Call exit with return value from function call. */ > movq %rax, %rdi > - call HIDDEN_JUMPTARGET (_exit) > + movl $SYS_ify(exit), %eax > + syscall > cfi_endproc; > > cfi_startproc; >
On Fri, 23 Jun 2017, Adhemerval Zanella wrote: > diff --git a/sysdeps/unix/sysv/linux/arm/clone.S b/sysdeps/unix/sysv/linux/arm/clone.S > @@ -76,7 +73,8 @@ PSEUDO_END (__clone) > BLX (ip) > > @ and we are done, passing the return value through r0 > - b PLTJMP(HIDDEN_JUMPTARGET(_exit)) > + ldr r7, =SYS_ify(clone) > + swi 0x0 This looks like it would call the clone syscall, not exit. > diff --git a/sysdeps/unix/sysv/linux/mips/clone.S b/sysdeps/unix/sysv/linux/mips/clone.S > @@ -137,14 +134,9 @@ L(thread_start): > /* Call the user's function. */ > jal t9 > > - /* Call _exit rather than doing it inline for breakpoint purposes. */ > move a0,v0 > -#ifdef __PIC__ > - PTR_LA t9,_exit > - jalr t9 > -#else > - jal _exit > -#endif > + li v0,__NR_clone > + syscall Likewise.
> On 23 Jun 2017, at 10:14, Joseph Myers <joseph@codesourcery.com> wrote: > >> On Fri, 23 Jun 2017, Adhemerval Zanella wrote: >> >> diff --git a/sysdeps/unix/sysv/linux/arm/clone.S b/sysdeps/unix/sysv/linux/arm/clone.S > >> @@ -76,7 +73,8 @@ PSEUDO_END (__clone) >> BLX (ip) >> >> @ and we are done, passing the return value through r0 >> - b PLTJMP(HIDDEN_JUMPTARGET(_exit)) >> + ldr r7, =SYS_ify(clone) >> + swi 0x0 > > This looks like it would call the clone syscall, not exit. > Ugh... I will fix it. >> diff --git a/sysdeps/unix/sysv/linux/mips/clone.S b/sysdeps/unix/sysv/linux/mips/clone.S > >> @@ -137,14 +134,9 @@ L(thread_start): >> /* Call the user's function. */ >> jal t9 >> >> - /* Call _exit rather than doing it inline for breakpoint purposes. */ >> move a0,v0 >> -#ifdef __PIC__ >> - PTR_LA t9,_exit >> - jalr t9 >> -#else >> - jal _exit >> -#endif >> + li v0,__NR_clone >> + syscall > > Likewise. > Same. > -- > Joseph S. Myers > joseph@codesourcery.com
> On 23 Jun 2017, at 09:55, Carlos O'Donell <carlos@redhat.com> wrote: > >> On 06/23/2017 08:37 AM, Adhemerval Zanella wrote: >> On aarch64, alpha, arm, hppa, mips, nios2, powerpc, s390, sh, >> sparch, 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, microblaze, ia64, i386, and m68k >> differs by calling exit syscall directly. >> >> This patch changes all architectures to call the exit syscall >> directly, as for 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. > > How is it that this doesn't break threading completely on the existing > architectures that call _exit? Is it because NPTL calls the clone syscall > directly instead of calling the clone() function and nobody uses clone() > because of all the other problems it has? For thread creation within GLIBC the clone is called using the ARCH_FORK macro which issues a direct syscall. Sometime ago I tried to see if it were worth a cleanup to use clone symbol instead, but I got stuck with an issue I don't quite remind the details. > > I admit that only an explicit call to _exit() or exit() should terminate > every thread in the thread group, *and* looking at the kernel side code > I see it does try to terminate every thread in the group (zap_other_threads()). > > The patch looks good to me, but I just want some clarification about my > question "Why haven't we noticed?" :-) Basically because we never used the clone symbol internally and when we did (new posix_spawn implementation) we call an explicit _exit (spawni). I also think no one really tried to use clone along with CLONE_THREAD. > >> [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/s390/s390-32/clone.S (__clone): Likewise. >> * sysdeps/unix/sysv/linux/s390/s390-64/clone.S (__clone): 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. >> --- >> sysdeps/unix/sysv/linux/Makefile | 4 +- >> sysdeps/unix/sysv/linux/aarch64/clone.S | 9 +-- >> sysdeps/unix/sysv/linux/alpha/clone.S | 11 +-- >> sysdeps/unix/sysv/linux/arm/clone.S | 6 +- >> sysdeps/unix/sysv/linux/hppa/clone.S | 6 +- >> sysdeps/unix/sysv/linux/i386/clone.S | 2 - >> sysdeps/unix/sysv/linux/ia64/clone2.S | 8 +- >> sysdeps/unix/sysv/linux/m68k/clone.S | 2 - >> sysdeps/unix/sysv/linux/mips/clone.S | 12 +-- >> sysdeps/unix/sysv/linux/nios2/clone.S | 17 +--- >> sysdeps/unix/sysv/linux/powerpc/powerpc32/clone.S | 7 +- >> sysdeps/unix/sysv/linux/powerpc/powerpc64/clone.S | 11 +-- >> sysdeps/unix/sysv/linux/s390/s390-32/clone.S | 2 +- >> sysdeps/unix/sysv/linux/s390/s390-64/clone.S | 2 +- >> sysdeps/unix/sysv/linux/sh/clone.S | 21 +---- >> sysdeps/unix/sysv/linux/sparc/sparc32/clone.S | 5 +- >> sysdeps/unix/sysv/linux/sparc/sparc64/clone.S | 5 +- >> sysdeps/unix/sysv/linux/tile/clone.S | 6 +- >> sysdeps/unix/sysv/linux/tst-clone3.c | 95 +++++++++++++++++++++++ >> sysdeps/unix/sysv/linux/x86_64/clone.S | 5 +- >> 20 files changed, 130 insertions(+), 106 deletions(-) >> create mode 100644 sysdeps/unix/sysv/linux/tst-clone3.c >> >> diff --git a/sysdeps/unix/sysv/linux/Makefile b/sysdeps/unix/sysv/linux/Makefile >> index 8b340d4..9d6a2de 100644 >> --- a/sysdeps/unix/sysv/linux/Makefile >> +++ b/sysdeps/unix/sysv/linux/Makefile >> @@ -49,8 +49,8 @@ sysdep_headers += sys/mount.h sys/acct.h sys/sysctl.h \ >> bits/mman-linux.h \ >> bits/siginfo-arch.h bits/siginfo-consts-arch.h >> >> -tests += tst-clone tst-clone2 tst-fanotify tst-personality tst-quota \ >> - tst-sync_file_range test-errno-linux >> +tests += tst-clone tst-clone2 tst-clone3 tst-fanotify tst-personality \ >> + tst-quota tst-sync_file_range test-errno-linux >> >> # Generate the list of SYS_* macros for the system calls (__NR_* macros). >> >> diff --git a/sysdeps/unix/sysv/linux/aarch64/clone.S b/sysdeps/unix/sysv/linux/aarch64/clone.S >> index 259ec07..905915a 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 <bits/errno.h> >> >> -#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 >> >> diff --git a/sysdeps/unix/sysv/linux/alpha/clone.S b/sysdeps/unix/sysv/linux/alpha/clone.S >> index 20ae361..550461f 100644 >> --- a/sysdeps/unix/sysv/linux/alpha/clone.S >> +++ b/sysdeps/unix/sysv/linux/alpha/clone.S >> @@ -23,8 +23,6 @@ >> #define _ERRNO_H 1 >> #include <bits/errno.h> >> >> -#define CLONE_VM 0x00000100 >> - >> /* int clone(int (*fn)(void *arg), void *child_stack, int flags, >> void *arg, pid_t *ptid, void *tls, pid_t *ctid); >> >> @@ -100,13 +98,8 @@ thread_start: >> jsr ra, (pv) >> ldgp gp, 0(ra) >> >> - /* Call _exit rather than doing it inline for breakpoint purposes. */ >> - mov v0, a0 >> -#ifdef PIC >> - bsr ra, HIDDEN_JUMPTARGET(_exit) !samegp >> -#else >> - jsr ra, HIDDEN_JUMPTARGET(_exit) >> -#endif >> + ldiq v0, __NR_exit >> + call_pal PAL_callsys >> >> /* Die horribly. */ >> .align 4 >> diff --git a/sysdeps/unix/sysv/linux/arm/clone.S b/sysdeps/unix/sysv/linux/arm/clone.S >> index a309add..f01968a 100644 >> --- a/sysdeps/unix/sysv/linux/arm/clone.S >> +++ b/sysdeps/unix/sysv/linux/arm/clone.S >> @@ -24,9 +24,6 @@ >> #define _ERRNO_H 1 >> #include <bits/errno.h> >> >> -#define CLONE_VM 0x00000100 >> -#define CLONE_THREAD 0x00010000 >> - >> /* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg, >> pid_t *ptid, struct user_desc *tls, pid_t *ctid); */ >> >> @@ -76,7 +73,8 @@ PSEUDO_END (__clone) >> BLX (ip) >> >> @ and we are done, passing the return value through r0 >> - b PLTJMP(HIDDEN_JUMPTARGET(_exit)) >> + ldr r7, =SYS_ify(clone) >> + swi 0x0 >> >> .fnend >> >> diff --git a/sysdeps/unix/sysv/linux/hppa/clone.S b/sysdeps/unix/sysv/linux/hppa/clone.S >> index d36b302..8c43944 100644 >> --- a/sysdeps/unix/sysv/linux/hppa/clone.S >> +++ b/sysdeps/unix/sysv/linux/hppa/clone.S >> @@ -148,10 +148,10 @@ ENTRY(__clone) >> copy %r4, %r19 >> #endif >> /* The call to _exit needs saved r19. */ >> - bl _exit, %rp >> - copy %ret0, %arg0 >> + ble 0x100(%sr2, %r0) >> + ldi __NR_exit, %r20 >> >> - /* We should not return from _exit. >> + /* We should not return from exit. >> We do not restore r4, or the stack state. */ >> iitlbp %r0, (%sr0, %r0) >> >> diff --git a/sysdeps/unix/sysv/linux/i386/clone.S b/sysdeps/unix/sysv/linux/i386/clone.S >> index a4ba3e2..49c82d9 100644 >> --- a/sysdeps/unix/sysv/linux/i386/clone.S >> +++ b/sysdeps/unix/sysv/linux/i386/clone.S >> @@ -39,8 +39,6 @@ >> #define __NR_clone 120 >> #define SYS_clone 120 >> >> -#define CLONE_VM 0x00000100 >> - >> .text >> ENTRY (__clone) >> /* Sanity check arguments. */ >> diff --git a/sysdeps/unix/sysv/linux/ia64/clone2.S b/sysdeps/unix/sysv/linux/ia64/clone2.S >> index 9b59473..3157ce9 100644 >> --- a/sysdeps/unix/sysv/linux/ia64/clone2.S >> +++ b/sysdeps/unix/sysv/linux/ia64/clone2.S >> @@ -74,11 +74,11 @@ ENTRY(__clone2) >> mov b6=out1 >> br.call.dptk.many rp=b6 /* Call fn(arg) in the child */ >> ;; >> - mov out0=r8 /* Argument to _exit */ >> + mov out0=r8 /* Argument to exit */ >> mov gp=loc0 >> - .globl HIDDEN_JUMPTARGET(_exit) >> - br.call.dpnt.many rp=HIDDEN_JUMPTARGET(_exit) >> - /* call _exit with result from fn. */ >> + mov r15=SYS_ify (exit) >> + .save rp, r0 >> + break __BREAK_SYSCALL >> ret /* Not reached. */ >> PSEUDO_END(__clone2) >> >> diff --git a/sysdeps/unix/sysv/linux/m68k/clone.S b/sysdeps/unix/sysv/linux/m68k/clone.S >> index a680191..0894b2a 100644 >> --- a/sysdeps/unix/sysv/linux/m68k/clone.S >> +++ b/sysdeps/unix/sysv/linux/m68k/clone.S >> @@ -24,8 +24,6 @@ >> #include <bits/errno.h> >> #include <tls.h> >> >> -#define CLONE_VM 0x00000100 >> - >> /* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg, >> void *parent_tidptr, void *tls, void *child_tidptr) */ >> >> diff --git a/sysdeps/unix/sysv/linux/mips/clone.S b/sysdeps/unix/sysv/linux/mips/clone.S >> index 8b79457..855f972 100644 >> --- a/sysdeps/unix/sysv/linux/mips/clone.S >> +++ b/sysdeps/unix/sysv/linux/mips/clone.S >> @@ -25,9 +25,6 @@ >> #include <bits/errno.h> >> #include <tls.h> >> >> -#define CLONE_VM 0x00000100 >> -#define CLONE_THREAD 0x00010000 >> - >> /* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg, >> void *parent_tidptr, void *tls, void *child_tidptr) */ >> >> @@ -137,14 +134,9 @@ L(thread_start): >> /* Call the user's function. */ >> jal t9 >> >> - /* Call _exit rather than doing it inline for breakpoint purposes. */ >> move a0,v0 >> -#ifdef __PIC__ >> - PTR_LA t9,_exit >> - jalr t9 >> -#else >> - jal _exit >> -#endif >> + li v0,__NR_clone >> + syscall >> >> END(__thread_start) >> >> diff --git a/sysdeps/unix/sysv/linux/nios2/clone.S b/sysdeps/unix/sysv/linux/nios2/clone.S >> index 7929dfa..2ba8258 100644 >> --- a/sysdeps/unix/sysv/linux/nios2/clone.S >> +++ b/sysdeps/unix/sysv/linux/nios2/clone.S >> @@ -25,8 +25,6 @@ >> #include <bits/errno.h> >> #include <tcb-offsets.h> >> >> -#define CLONE_VM 0x00000100 >> - >> /* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg, >> void *parent_tidptr, void *tls, void *child_tidptr) */ >> >> @@ -75,18 +73,9 @@ thread_start: >> /* Call the user's function. */ >> callr r5 >> >> - /* _exit with the result. */ >> - mov r4, r2 >> -#ifdef PIC >> - nextpc r22 >> -1: movhi r8, %hiadj(_gp_got - 1b) >> - addi r8, r8, %lo(_gp_got - 1b) >> - add r22, r22, r8 >> - ldw r8, %call(HIDDEN_JUMPTARGET(_exit))(r22) >> - jmp r8 >> -#else >> - jmpi _exit >> -#endif >> + /* exit with the result. */ >> + movi r2, SYS_ify (exit) >> + trap >> cfi_endproc >> >> cfi_startproc >> diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/clone.S b/sysdeps/unix/sysv/linux/powerpc/powerpc32/clone.S >> index a07b7d3..e48cc5f 100644 >> --- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/clone.S >> +++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/clone.S >> @@ -20,10 +20,6 @@ >> #define _ERRNO_H 1 >> #include <bits/errno.h> >> >> -#define CLONE_VM 0x00000100 >> -#define CLONE_THREAD 0x00010000 >> - >> - >> /* This is the only really unusual system call in PPC linux, but not >> because of any weirdness in the system call itself; because of >> all the freaky stuff we have to do to make the call useful. */ >> @@ -80,8 +76,7 @@ ENTRY (__clone) >> mtctr r30 >> mr r3,r31 >> bctrl >> - /* Call _exit with result from procedure. */ >> - b HIDDEN_JUMPTARGET(_exit) >> + DO_CALL(SYS_ify(exit)) >> >> L(parent): >> /* Parent. Restore registers & return. */ >> diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/clone.S b/sysdeps/unix/sysv/linux/powerpc/powerpc64/clone.S >> index 9e5bfd2..78c353a 100644 >> --- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/clone.S >> +++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/clone.S >> @@ -20,9 +20,6 @@ >> #define _ERRNO_H 1 >> #include <bits/errno.h> >> >> -#define CLONE_VM 0x00000100 >> -#define CLONE_THREAD 0x00010000 >> - >> /* This is the only really unusual system call in PPC linux, but not >> because of any weirdness in the system call itself; because of >> all the freaky stuff we have to do to make the call useful. */ >> @@ -84,15 +81,11 @@ ENTRY (__clone) >> mr r3,r31 >> bctrl >> ld r2,FRAME_TOC_SAVE(r1) >> - /* Call _exit with result from procedure. */ >> -#ifdef SHARED >> - b JUMPTARGET(__GI__exit) >> -#else >> - bl JUMPTARGET(_exit) >> + >> + DO_CALL(SYS_ify(exit)) >> /* We won't ever get here but provide a nop so that the linker >> will insert a toc adjusting stub if necessary. */ >> nop >> -#endif >> >> L(badargs): >> cfi_startproc >> diff --git a/sysdeps/unix/sysv/linux/s390/s390-32/clone.S b/sysdeps/unix/sysv/linux/s390/s390-32/clone.S >> index a8b4dbc..1588e5f 100644 >> --- a/sysdeps/unix/sysv/linux/s390/s390-32/clone.S >> +++ b/sysdeps/unix/sysv/linux/s390/s390-32/clone.S >> @@ -59,7 +59,7 @@ thread_start: >> ahi %r15,-96 /* make room on the stack for the save area */ >> xc 0(4,%r15),0(%r15) >> basr %r14,%r1 /* jump to fn */ >> - DO_CALL (exit, 1) >> + svc SYS_ify(exit) >> >> libc_hidden_def (__clone) >> weak_alias (__clone, clone) >> diff --git a/sysdeps/unix/sysv/linux/s390/s390-64/clone.S b/sysdeps/unix/sysv/linux/s390/s390-64/clone.S >> index daf8a58..5843188 100644 >> --- a/sysdeps/unix/sysv/linux/s390/s390-64/clone.S >> +++ b/sysdeps/unix/sysv/linux/s390/s390-64/clone.S >> @@ -60,7 +60,7 @@ thread_start: >> aghi %r15,-160 /* make room on the stack for the save area */ >> xc 0(8,%r15),0(%r15) >> basr %r14,%r1 /* jump to fn */ >> - DO_CALL (exit, 1) >> + svc SYS_ify(exit) >> >> libc_hidden_def (__clone) >> weak_alias (__clone, clone) >> diff --git a/sysdeps/unix/sysv/linux/sh/clone.S b/sysdeps/unix/sysv/linux/sh/clone.S >> index 9063b21..b13a64b 100644 >> --- a/sysdeps/unix/sysv/linux/sh/clone.S >> +++ b/sysdeps/unix/sysv/linux/sh/clone.S >> @@ -73,25 +73,8 @@ ENTRY(__clone) >> mov.l @(4,r15), r4 >> >> /* we are done, passing the return value through r0 */ >> - mov.l .L3, r1 >> -#ifdef SHARED >> - mov.l r12, @-r15 >> - sts.l pr, @-r15 >> - mov r0, r4 >> - mova .LG, r0 >> - mov.l .LG, r12 >> - add r0, r12 >> - mova .L3, r0 >> - add r0, r1 >> - jsr @r1 >> - nop >> - lds.l @r15+, pr >> - rts >> - mov.l @r15+, r12 >> -#else >> - jmp @r1 >> - mov r0, r4 >> -#endif >> + mov #+SYS_ify(exit), r3 >> + trapa #0x15 >> .align 2 >> .LG: >> .long _GLOBAL_OFFSET_TABLE_ >> diff --git a/sysdeps/unix/sysv/linux/sparc/sparc32/clone.S b/sysdeps/unix/sysv/linux/sparc/sparc32/clone.S >> index 6d2f5bd..1afa26e 100644 >> --- a/sysdeps/unix/sysv/linux/sparc/sparc32/clone.S >> +++ b/sysdeps/unix/sysv/linux/sparc/sparc32/clone.S >> @@ -24,8 +24,6 @@ >> #include <tcb-offsets.h> >> #include <sysdep.h> >> >> -#define CLONE_VM 0x00000100 >> - >> /* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg, >> pid_t *ptid, void *tls, pid_t *ctid); */ >> >> @@ -81,7 +79,8 @@ __thread_start: >> mov %g0, %fp /* terminate backtrace */ >> call %g2 >> mov %g3,%o0 >> - call HIDDEN_JUMPTARGET(_exit),0 >> + set __NR_exit, %g1 >> + ta 0x10 >> nop >> >> .size __thread_start, .-__thread_start >> diff --git a/sysdeps/unix/sysv/linux/sparc/sparc64/clone.S b/sysdeps/unix/sysv/linux/sparc/sparc64/clone.S >> index fc28539..785ccd1 100644 >> --- a/sysdeps/unix/sysv/linux/sparc/sparc64/clone.S >> +++ b/sysdeps/unix/sysv/linux/sparc/sparc64/clone.S >> @@ -24,8 +24,6 @@ >> #include <tcb-offsets.h> >> #include <sysdep.h> >> >> -#define CLONE_VM 0x00000100 >> - >> /* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg, >> pid_t *ptid, void *tls, pid_t *ctid); */ >> >> @@ -78,7 +76,8 @@ __thread_start: >> mov %g0, %fp /* terminate backtrace */ >> call %g2 >> mov %g3,%o0 >> - call HIDDEN_JUMPTARGET(_exit),0 >> + set __NR_exit, %g1 >> + ta 0x6d >> nop >> >> .size __thread_start, .-__thread_start >> diff --git a/sysdeps/unix/sysv/linux/tile/clone.S b/sysdeps/unix/sysv/linux/tile/clone.S >> index d7d2a3b..9610acd 100644 >> --- a/sysdeps/unix/sysv/linux/tile/clone.S >> +++ b/sysdeps/unix/sysv/linux/tile/clone.S >> @@ -168,10 +168,8 @@ ENTRY (__clone) >> move r0, r31 >> jalr r32 >> } >> - { >> - j HIDDEN_JUMPTARGET(_exit) >> - info INFO_OP_CANNOT_BACKTRACE /* Notify backtracer to stop. */ >> - } >> + moveli TREG_SYSCALL_NR_NAME, __NR_exit >> + swint1 >> PSEUDO_END (__clone) >> >> libc_hidden_def (__clone) >> diff --git a/sysdeps/unix/sysv/linux/tst-clone3.c b/sysdeps/unix/sysv/linux/tst-clone3.c >> new file mode 100644 >> index 0000000..e893e4d >> --- /dev/null >> +++ b/sysdeps/unix/sysv/linux/tst-clone3.c >> @@ -0,0 +1,95 @@ >> +/* Check if clone (CLONE_THREAD) does not call exit_group (BZ #21512) >> + Copyright (C) 2017 Free Software Foundation, Inc. >> + This file is part of the GNU C Library. >> + >> + 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/>. */ >> + >> +#include <string.h> >> +#include <sched.h> >> +#include <signal.h> >> +#include <unistd.h> >> +#include <sys/syscall.h> >> +#include <sys/wait.h> >> +#include <sys/types.h> >> +#include <linux/futex.h> >> + >> +#include <stackinfo.h> /* For _STACK_GROWS_{UP,DOWN}. */ >> +#include <support/check.h> >> + >> +/* Test if clone call with CLONE_THREAD does not call exit_group. The 'f' >> + function returns '1', which will be used by clone thread to call the >> + 'exit' syscall directly. If _exit is used instead, exit_group will be >> + used and thus the thread group will finish with return value of '1' >> + (where '2' from main thread is expected. */ > > s/(where/where/g > >> + >> +static int >> +f (void *a) >> +{ >> + return 1; >> +} >> + >> +/* Futex wait for TID argument, similar to pthread_join internal >> + implementation. */ >> +#define wait_tid(tid) \ >> + do { \ >> + __typeof (tid) __tid; \ >> + while ((__tid = (tid)) != 0) \ >> + futex_wait (&(tid), __tid); \ >> + } while (0) >> + >> +static inline int >> +futex_wait (int *futexp, int val) >> +{ >> + return syscall (__NR_futex, futexp, FUTEX_WAIT, val); >> +} >> + >> +static int >> +do_test (void) >> +{ >> + char st[1024] __attribute__ ((aligned)); >> + int clone_flags = CLONE_THREAD; >> + /* Minimum required flags to used along with CLONE_THREAD. */ >> + clone_flags |= CLONE_VM | CLONE_SIGHAND; >> + /* We will used ctid to call on futex to wait for thread exit. */ >> + clone_flags |= CLONE_CHILD_CLEARTID; >> + pid_t ctid, tid; >> + >> +#ifdef __ia64__ >> + extern int __clone2 (int (*__fn) (void *__arg), void *__child_stack_base, >> + size_t __child_stack_size, int __flags, >> + void *__arg, ...); >> + tid = __clone2 (f, st, sizeof (st), clone_flags, NULL, /* ptid */ NULL, >> + /* tls */ NULL, &ctid); >> +#else >> +#if _STACK_GROWS_DOWN >> + tid = clone (f, st + sizeof (st), clone_flags, NULL, /* ptid */ NULL, >> + /* tls */ NULL, &ctid); >> +#elif _STACK_GROWS_UP >> + tid = clone (f, st, clone_flags, NULL, /* ptid */ NULL, /* tls */ NULL, >> + &ctid); >> +#else >> +#error "Define either _STACK_GROWS_DOWN or _STACK_GROWS_UP" >> +#endif >> +#endif >> + if (tid == -1) >> + FAIL_EXIT1 ("clone failed: %m"); >> + >> + wait_tid (ctid); >> + >> + return 2; >> +} >> + >> +#define EXPECTED_STATUS 2 >> +#include <support/test-driver.c> >> diff --git a/sysdeps/unix/sysv/linux/x86_64/clone.S b/sysdeps/unix/sysv/linux/x86_64/clone.S >> index d5c2d07..b10fc29 100644 >> --- a/sysdeps/unix/sysv/linux/x86_64/clone.S >> +++ b/sysdeps/unix/sysv/linux/x86_64/clone.S >> @@ -23,8 +23,6 @@ >> #include <bits/errno.h> >> #include <asm-syntax.h> >> >> -#define CLONE_VM 0x00000100 >> - >> /* The userland implementation is: >> int clone (int (*fn)(void *arg), void *child_stack, int flags, void *arg), >> the kernel entry is: >> @@ -97,7 +95,8 @@ L(thread_start): >> call *%rax >> /* Call exit with return value from function call. */ >> movq %rax, %rdi >> - call HIDDEN_JUMPTARGET (_exit) >> + movl $SYS_ify(exit), %eax >> + syscall >> cfi_endproc; >> >> cfi_startproc; >> > > > -- > Cheers, > Carlos.
diff --git a/sysdeps/unix/sysv/linux/Makefile b/sysdeps/unix/sysv/linux/Makefile index 8b340d4..9d6a2de 100644 --- a/sysdeps/unix/sysv/linux/Makefile +++ b/sysdeps/unix/sysv/linux/Makefile @@ -49,8 +49,8 @@ sysdep_headers += sys/mount.h sys/acct.h sys/sysctl.h \ bits/mman-linux.h \ bits/siginfo-arch.h bits/siginfo-consts-arch.h -tests += tst-clone tst-clone2 tst-fanotify tst-personality tst-quota \ - tst-sync_file_range test-errno-linux +tests += tst-clone tst-clone2 tst-clone3 tst-fanotify tst-personality \ + tst-quota tst-sync_file_range test-errno-linux # Generate the list of SYS_* macros for the system calls (__NR_* macros). diff --git a/sysdeps/unix/sysv/linux/aarch64/clone.S b/sysdeps/unix/sysv/linux/aarch64/clone.S index 259ec07..905915a 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 <bits/errno.h> -#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 diff --git a/sysdeps/unix/sysv/linux/alpha/clone.S b/sysdeps/unix/sysv/linux/alpha/clone.S index 20ae361..550461f 100644 --- a/sysdeps/unix/sysv/linux/alpha/clone.S +++ b/sysdeps/unix/sysv/linux/alpha/clone.S @@ -23,8 +23,6 @@ #define _ERRNO_H 1 #include <bits/errno.h> -#define CLONE_VM 0x00000100 - /* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg, pid_t *ptid, void *tls, pid_t *ctid); @@ -100,13 +98,8 @@ thread_start: jsr ra, (pv) ldgp gp, 0(ra) - /* Call _exit rather than doing it inline for breakpoint purposes. */ - mov v0, a0 -#ifdef PIC - bsr ra, HIDDEN_JUMPTARGET(_exit) !samegp -#else - jsr ra, HIDDEN_JUMPTARGET(_exit) -#endif + ldiq v0, __NR_exit + call_pal PAL_callsys /* Die horribly. */ .align 4 diff --git a/sysdeps/unix/sysv/linux/arm/clone.S b/sysdeps/unix/sysv/linux/arm/clone.S index a309add..f01968a 100644 --- a/sysdeps/unix/sysv/linux/arm/clone.S +++ b/sysdeps/unix/sysv/linux/arm/clone.S @@ -24,9 +24,6 @@ #define _ERRNO_H 1 #include <bits/errno.h> -#define CLONE_VM 0x00000100 -#define CLONE_THREAD 0x00010000 - /* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg, pid_t *ptid, struct user_desc *tls, pid_t *ctid); */ @@ -76,7 +73,8 @@ PSEUDO_END (__clone) BLX (ip) @ and we are done, passing the return value through r0 - b PLTJMP(HIDDEN_JUMPTARGET(_exit)) + ldr r7, =SYS_ify(clone) + swi 0x0 .fnend diff --git a/sysdeps/unix/sysv/linux/hppa/clone.S b/sysdeps/unix/sysv/linux/hppa/clone.S index d36b302..8c43944 100644 --- a/sysdeps/unix/sysv/linux/hppa/clone.S +++ b/sysdeps/unix/sysv/linux/hppa/clone.S @@ -148,10 +148,10 @@ ENTRY(__clone) copy %r4, %r19 #endif /* The call to _exit needs saved r19. */ - bl _exit, %rp - copy %ret0, %arg0 + ble 0x100(%sr2, %r0) + ldi __NR_exit, %r20 - /* We should not return from _exit. + /* We should not return from exit. We do not restore r4, or the stack state. */ iitlbp %r0, (%sr0, %r0) diff --git a/sysdeps/unix/sysv/linux/i386/clone.S b/sysdeps/unix/sysv/linux/i386/clone.S index a4ba3e2..49c82d9 100644 --- a/sysdeps/unix/sysv/linux/i386/clone.S +++ b/sysdeps/unix/sysv/linux/i386/clone.S @@ -39,8 +39,6 @@ #define __NR_clone 120 #define SYS_clone 120 -#define CLONE_VM 0x00000100 - .text ENTRY (__clone) /* Sanity check arguments. */ diff --git a/sysdeps/unix/sysv/linux/ia64/clone2.S b/sysdeps/unix/sysv/linux/ia64/clone2.S index 9b59473..3157ce9 100644 --- a/sysdeps/unix/sysv/linux/ia64/clone2.S +++ b/sysdeps/unix/sysv/linux/ia64/clone2.S @@ -74,11 +74,11 @@ ENTRY(__clone2) mov b6=out1 br.call.dptk.many rp=b6 /* Call fn(arg) in the child */ ;; - mov out0=r8 /* Argument to _exit */ + mov out0=r8 /* Argument to exit */ mov gp=loc0 - .globl HIDDEN_JUMPTARGET(_exit) - br.call.dpnt.many rp=HIDDEN_JUMPTARGET(_exit) - /* call _exit with result from fn. */ + mov r15=SYS_ify (exit) + .save rp, r0 + break __BREAK_SYSCALL ret /* Not reached. */ PSEUDO_END(__clone2) diff --git a/sysdeps/unix/sysv/linux/m68k/clone.S b/sysdeps/unix/sysv/linux/m68k/clone.S index a680191..0894b2a 100644 --- a/sysdeps/unix/sysv/linux/m68k/clone.S +++ b/sysdeps/unix/sysv/linux/m68k/clone.S @@ -24,8 +24,6 @@ #include <bits/errno.h> #include <tls.h> -#define CLONE_VM 0x00000100 - /* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg, void *parent_tidptr, void *tls, void *child_tidptr) */ diff --git a/sysdeps/unix/sysv/linux/mips/clone.S b/sysdeps/unix/sysv/linux/mips/clone.S index 8b79457..855f972 100644 --- a/sysdeps/unix/sysv/linux/mips/clone.S +++ b/sysdeps/unix/sysv/linux/mips/clone.S @@ -25,9 +25,6 @@ #include <bits/errno.h> #include <tls.h> -#define CLONE_VM 0x00000100 -#define CLONE_THREAD 0x00010000 - /* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg, void *parent_tidptr, void *tls, void *child_tidptr) */ @@ -137,14 +134,9 @@ L(thread_start): /* Call the user's function. */ jal t9 - /* Call _exit rather than doing it inline for breakpoint purposes. */ move a0,v0 -#ifdef __PIC__ - PTR_LA t9,_exit - jalr t9 -#else - jal _exit -#endif + li v0,__NR_clone + syscall END(__thread_start) diff --git a/sysdeps/unix/sysv/linux/nios2/clone.S b/sysdeps/unix/sysv/linux/nios2/clone.S index 7929dfa..2ba8258 100644 --- a/sysdeps/unix/sysv/linux/nios2/clone.S +++ b/sysdeps/unix/sysv/linux/nios2/clone.S @@ -25,8 +25,6 @@ #include <bits/errno.h> #include <tcb-offsets.h> -#define CLONE_VM 0x00000100 - /* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg, void *parent_tidptr, void *tls, void *child_tidptr) */ @@ -75,18 +73,9 @@ thread_start: /* Call the user's function. */ callr r5 - /* _exit with the result. */ - mov r4, r2 -#ifdef PIC - nextpc r22 -1: movhi r8, %hiadj(_gp_got - 1b) - addi r8, r8, %lo(_gp_got - 1b) - add r22, r22, r8 - ldw r8, %call(HIDDEN_JUMPTARGET(_exit))(r22) - jmp r8 -#else - jmpi _exit -#endif + /* exit with the result. */ + movi r2, SYS_ify (exit) + trap cfi_endproc cfi_startproc diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/clone.S b/sysdeps/unix/sysv/linux/powerpc/powerpc32/clone.S index a07b7d3..e48cc5f 100644 --- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/clone.S +++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/clone.S @@ -20,10 +20,6 @@ #define _ERRNO_H 1 #include <bits/errno.h> -#define CLONE_VM 0x00000100 -#define CLONE_THREAD 0x00010000 - - /* This is the only really unusual system call in PPC linux, but not because of any weirdness in the system call itself; because of all the freaky stuff we have to do to make the call useful. */ @@ -80,8 +76,7 @@ ENTRY (__clone) mtctr r30 mr r3,r31 bctrl - /* Call _exit with result from procedure. */ - b HIDDEN_JUMPTARGET(_exit) + DO_CALL(SYS_ify(exit)) L(parent): /* Parent. Restore registers & return. */ diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/clone.S b/sysdeps/unix/sysv/linux/powerpc/powerpc64/clone.S index 9e5bfd2..78c353a 100644 --- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/clone.S +++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/clone.S @@ -20,9 +20,6 @@ #define _ERRNO_H 1 #include <bits/errno.h> -#define CLONE_VM 0x00000100 -#define CLONE_THREAD 0x00010000 - /* This is the only really unusual system call in PPC linux, but not because of any weirdness in the system call itself; because of all the freaky stuff we have to do to make the call useful. */ @@ -84,15 +81,11 @@ ENTRY (__clone) mr r3,r31 bctrl ld r2,FRAME_TOC_SAVE(r1) - /* Call _exit with result from procedure. */ -#ifdef SHARED - b JUMPTARGET(__GI__exit) -#else - bl JUMPTARGET(_exit) + + DO_CALL(SYS_ify(exit)) /* We won't ever get here but provide a nop so that the linker will insert a toc adjusting stub if necessary. */ nop -#endif L(badargs): cfi_startproc diff --git a/sysdeps/unix/sysv/linux/s390/s390-32/clone.S b/sysdeps/unix/sysv/linux/s390/s390-32/clone.S index a8b4dbc..1588e5f 100644 --- a/sysdeps/unix/sysv/linux/s390/s390-32/clone.S +++ b/sysdeps/unix/sysv/linux/s390/s390-32/clone.S @@ -59,7 +59,7 @@ thread_start: ahi %r15,-96 /* make room on the stack for the save area */ xc 0(4,%r15),0(%r15) basr %r14,%r1 /* jump to fn */ - DO_CALL (exit, 1) + svc SYS_ify(exit) libc_hidden_def (__clone) weak_alias (__clone, clone) diff --git a/sysdeps/unix/sysv/linux/s390/s390-64/clone.S b/sysdeps/unix/sysv/linux/s390/s390-64/clone.S index daf8a58..5843188 100644 --- a/sysdeps/unix/sysv/linux/s390/s390-64/clone.S +++ b/sysdeps/unix/sysv/linux/s390/s390-64/clone.S @@ -60,7 +60,7 @@ thread_start: aghi %r15,-160 /* make room on the stack for the save area */ xc 0(8,%r15),0(%r15) basr %r14,%r1 /* jump to fn */ - DO_CALL (exit, 1) + svc SYS_ify(exit) libc_hidden_def (__clone) weak_alias (__clone, clone) diff --git a/sysdeps/unix/sysv/linux/sh/clone.S b/sysdeps/unix/sysv/linux/sh/clone.S index 9063b21..b13a64b 100644 --- a/sysdeps/unix/sysv/linux/sh/clone.S +++ b/sysdeps/unix/sysv/linux/sh/clone.S @@ -73,25 +73,8 @@ ENTRY(__clone) mov.l @(4,r15), r4 /* we are done, passing the return value through r0 */ - mov.l .L3, r1 -#ifdef SHARED - mov.l r12, @-r15 - sts.l pr, @-r15 - mov r0, r4 - mova .LG, r0 - mov.l .LG, r12 - add r0, r12 - mova .L3, r0 - add r0, r1 - jsr @r1 - nop - lds.l @r15+, pr - rts - mov.l @r15+, r12 -#else - jmp @r1 - mov r0, r4 -#endif + mov #+SYS_ify(exit), r3 + trapa #0x15 .align 2 .LG: .long _GLOBAL_OFFSET_TABLE_ diff --git a/sysdeps/unix/sysv/linux/sparc/sparc32/clone.S b/sysdeps/unix/sysv/linux/sparc/sparc32/clone.S index 6d2f5bd..1afa26e 100644 --- a/sysdeps/unix/sysv/linux/sparc/sparc32/clone.S +++ b/sysdeps/unix/sysv/linux/sparc/sparc32/clone.S @@ -24,8 +24,6 @@ #include <tcb-offsets.h> #include <sysdep.h> -#define CLONE_VM 0x00000100 - /* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg, pid_t *ptid, void *tls, pid_t *ctid); */ @@ -81,7 +79,8 @@ __thread_start: mov %g0, %fp /* terminate backtrace */ call %g2 mov %g3,%o0 - call HIDDEN_JUMPTARGET(_exit),0 + set __NR_exit, %g1 + ta 0x10 nop .size __thread_start, .-__thread_start diff --git a/sysdeps/unix/sysv/linux/sparc/sparc64/clone.S b/sysdeps/unix/sysv/linux/sparc/sparc64/clone.S index fc28539..785ccd1 100644 --- a/sysdeps/unix/sysv/linux/sparc/sparc64/clone.S +++ b/sysdeps/unix/sysv/linux/sparc/sparc64/clone.S @@ -24,8 +24,6 @@ #include <tcb-offsets.h> #include <sysdep.h> -#define CLONE_VM 0x00000100 - /* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg, pid_t *ptid, void *tls, pid_t *ctid); */ @@ -78,7 +76,8 @@ __thread_start: mov %g0, %fp /* terminate backtrace */ call %g2 mov %g3,%o0 - call HIDDEN_JUMPTARGET(_exit),0 + set __NR_exit, %g1 + ta 0x6d nop .size __thread_start, .-__thread_start diff --git a/sysdeps/unix/sysv/linux/tile/clone.S b/sysdeps/unix/sysv/linux/tile/clone.S index d7d2a3b..9610acd 100644 --- a/sysdeps/unix/sysv/linux/tile/clone.S +++ b/sysdeps/unix/sysv/linux/tile/clone.S @@ -168,10 +168,8 @@ ENTRY (__clone) move r0, r31 jalr r32 } - { - j HIDDEN_JUMPTARGET(_exit) - info INFO_OP_CANNOT_BACKTRACE /* Notify backtracer to stop. */ - } + moveli TREG_SYSCALL_NR_NAME, __NR_exit + swint1 PSEUDO_END (__clone) libc_hidden_def (__clone) diff --git a/sysdeps/unix/sysv/linux/tst-clone3.c b/sysdeps/unix/sysv/linux/tst-clone3.c new file mode 100644 index 0000000..e893e4d --- /dev/null +++ b/sysdeps/unix/sysv/linux/tst-clone3.c @@ -0,0 +1,95 @@ +/* Check if clone (CLONE_THREAD) does not call exit_group (BZ #21512) + Copyright (C) 2017 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + 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/>. */ + +#include <string.h> +#include <sched.h> +#include <signal.h> +#include <unistd.h> +#include <sys/syscall.h> +#include <sys/wait.h> +#include <sys/types.h> +#include <linux/futex.h> + +#include <stackinfo.h> /* For _STACK_GROWS_{UP,DOWN}. */ +#include <support/check.h> + +/* Test if clone call with CLONE_THREAD does not call exit_group. The 'f' + function returns '1', which will be used by clone thread to call the + 'exit' syscall directly. If _exit is used instead, exit_group will be + used and thus the thread group will finish with return value of '1' + (where '2' from main thread is expected. */ + +static int +f (void *a) +{ + return 1; +} + +/* Futex wait for TID argument, similar to pthread_join internal + implementation. */ +#define wait_tid(tid) \ + do { \ + __typeof (tid) __tid; \ + while ((__tid = (tid)) != 0) \ + futex_wait (&(tid), __tid); \ + } while (0) + +static inline int +futex_wait (int *futexp, int val) +{ + return syscall (__NR_futex, futexp, FUTEX_WAIT, val); +} + +static int +do_test (void) +{ + char st[1024] __attribute__ ((aligned)); + int clone_flags = CLONE_THREAD; + /* Minimum required flags to used along with CLONE_THREAD. */ + clone_flags |= CLONE_VM | CLONE_SIGHAND; + /* We will used ctid to call on futex to wait for thread exit. */ + clone_flags |= CLONE_CHILD_CLEARTID; + pid_t ctid, tid; + +#ifdef __ia64__ + extern int __clone2 (int (*__fn) (void *__arg), void *__child_stack_base, + size_t __child_stack_size, int __flags, + void *__arg, ...); + tid = __clone2 (f, st, sizeof (st), clone_flags, NULL, /* ptid */ NULL, + /* tls */ NULL, &ctid); +#else +#if _STACK_GROWS_DOWN + tid = clone (f, st + sizeof (st), clone_flags, NULL, /* ptid */ NULL, + /* tls */ NULL, &ctid); +#elif _STACK_GROWS_UP + tid = clone (f, st, clone_flags, NULL, /* ptid */ NULL, /* tls */ NULL, + &ctid); +#else +#error "Define either _STACK_GROWS_DOWN or _STACK_GROWS_UP" +#endif +#endif + if (tid == -1) + FAIL_EXIT1 ("clone failed: %m"); + + wait_tid (ctid); + + return 2; +} + +#define EXPECTED_STATUS 2 +#include <support/test-driver.c> diff --git a/sysdeps/unix/sysv/linux/x86_64/clone.S b/sysdeps/unix/sysv/linux/x86_64/clone.S index d5c2d07..b10fc29 100644 --- a/sysdeps/unix/sysv/linux/x86_64/clone.S +++ b/sysdeps/unix/sysv/linux/x86_64/clone.S @@ -23,8 +23,6 @@ #include <bits/errno.h> #include <asm-syntax.h> -#define CLONE_VM 0x00000100 - /* The userland implementation is: int clone (int (*fn)(void *arg), void *child_stack, int flags, void *arg), the kernel entry is: @@ -97,7 +95,8 @@ L(thread_start): call *%rax /* Call exit with return value from function call. */ movq %rax, %rdi - call HIDDEN_JUMPTARGET (_exit) + movl $SYS_ify(exit), %eax + syscall cfi_endproc; cfi_startproc;