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From: Adhemerval Zanella <azanella@sourceware.org> To: glibc-cvs@sourceware.org Subject: [glibc/azanella/bz12683] nptl: sparc: Fix Race conditions in pthread cancellation [BZ#12683] Date: Fri, 3 Apr 2020 20:24:21 +0000 (GMT) [thread overview] Message-ID: <20200403202421.42049385DC2D@sourceware.org> (raw) https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=2b1355ce27e6fca5bf0f80a3d6b02e78511c5b23 commit 2b1355ce27e6fca5bf0f80a3d6b02e78511c5b23 Author: Adhemerval Zanella <adhemerval.zanella@linaro.org> Date: Mon Jan 16 17:02:36 2017 -0200 nptl: sparc: Fix Race conditions in pthread cancellation [BZ#12683] This patch adds the sparc modifications required for the BZ#12683 fix. Different than other architectures, SPARC passes the sigcontext_t struct pointer as third argument in the signal handler set with SA_SIGINFO (some info at [1]) for 64 bits and the pt_regs in 32 bits. From Linux code: * arch/sparc/kernel/signal_64.c 428 /* 3. signal handler back-trampoline and parameters */ 429 regs->u_regs[UREG_FP] = ((unsigned long) sf) - STACK_BIAS; 430 regs->u_regs[UREG_I0] = ksig->sig; 431 regs->u_regs[UREG_I1] = (unsigned long) &sf->info; 432 433 /* The sigcontext is passed in this way because of how it 434 * is defined in GLIBC's /usr/include/bits/sigcontext.h 435 * for sparc64. It includes the 128 bytes of siginfo_t. 436 */ 437 regs->u_regs[UREG_I2] = (unsigned long) &sf->info; * arch/sparc/kernel/signal_32.c: 392 regs->u_regs[UREG_FP] = (unsigned long) sf; 393 regs->u_regs[UREG_I0] = ksig->sig; 394 regs->u_regs[UREG_I1] = (unsigned long) &sf->info; 395 regs->u_regs[UREG_I2] = (unsigned long) &sf->regs; 396 397 regs->pc = (unsigned long) ksig->ka.sa.sa_handler; 398 regs->npc = (regs->pc + 4); So it requires an arch-specific ucontext_add_cancel. Also on sparc interrupted pause syscall returns with a PC indicating a side-effect and this deviates from other architectures. The sparc64 pause fall back to ppool syscall. Checked on sparc64-linux-gnu and sparcv9-linux-gnu. [1] https://www.spinics.net/lists/sparclinux/msg05037.html Diff: --- sysdeps/sparc/nptl/tcb-offsets.sym | 3 + .../unix/sysv/linux/sparc/cancellation-sigmask.h | 39 ++++++++++++ .../unix/sysv/linux/sparc/sparc32/syscall_cancel.S | 71 +++++++++++++++++++++ sysdeps/unix/sysv/linux/sparc/sparc64/pause.c | 25 ++++++++ .../unix/sysv/linux/sparc/sparc64/syscall_cancel.S | 74 ++++++++++++++++++++++ 5 files changed, 212 insertions(+) diff --git a/sysdeps/sparc/nptl/tcb-offsets.sym b/sysdeps/sparc/nptl/tcb-offsets.sym index f75d02065e..8112290d88 100644 --- a/sysdeps/sparc/nptl/tcb-offsets.sym +++ b/sysdeps/sparc/nptl/tcb-offsets.sym @@ -4,3 +4,6 @@ MULTIPLE_THREADS_OFFSET offsetof (tcbhead_t, multiple_threads) POINTER_GUARD offsetof (tcbhead_t, pointer_guard) TID offsetof (struct pthread, tid) + +-- Not strictly offsets, used on syscall_cancel.S +TCB_CANCELED_BITMASK CANCELED_BITMASK diff --git a/sysdeps/unix/sysv/linux/sparc/cancellation-sigmask.h b/sysdeps/unix/sysv/linux/sparc/cancellation-sigmask.h new file mode 100644 index 0000000000..8086228828 --- /dev/null +++ b/sysdeps/unix/sysv/linux/sparc/cancellation-sigmask.h @@ -0,0 +1,39 @@ +/* Architecture specific bits for cancellation handling. + Copyright (C) 2020 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/>. */ + +#ifndef _NPTL_CANCELLATION_SIGMASK_H +#define _NPTL_CANCELLATION_SIGMASK_H 1 + +/* Add the SIGCANCEL signal on sigmask set at the ucontext CTX obtained from + the sigaction handler. */ +static void +ucontext_block_sigcancel (void *ctx) +{ + sigset_t *set; +#ifdef __arch64__ + struct pt_regs *regs = (struct pt_regs*) ((siginfo_t *)(ctx) + 1); + __siginfo_fpu_t *f = (__siginfo_fpu_t *)(regs + 1); + set = (sigset_t *) ((stack_t *)(f + 1) + 1); +#else + struct pt_regs32 *ptregs = (struct pt_regs32 *) (ctx); + set = (sigset_t *) (ptregs + 1); +#endif + __sigaddset (set, SIGCANCEL); +} + +#endif diff --git a/sysdeps/unix/sysv/linux/sparc/sparc32/syscall_cancel.S b/sysdeps/unix/sysv/linux/sparc/sparc32/syscall_cancel.S new file mode 100644 index 0000000000..2393bf9be0 --- /dev/null +++ b/sysdeps/unix/sysv/linux/sparc/sparc32/syscall_cancel.S @@ -0,0 +1,71 @@ +/* Cancellable syscall wrapper. Linux/sparc32 version. + Copyright (C) 2020 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 <sysdep.h> + +/* long int __syscall_cancel_arch (int *cancelhandling, + long int nr, + long int arg1, + long int arg2, + long int arg3, + long int arg4, + long int arg5, + long int arg6) */ + +ENTRY (__syscall_cancel_arch) + save %sp, -96, %sp + + cfi_window_save + cfi_register (%o7, %i7) + cfi_def_cfa_register (%fp) + + .globl __syscall_cancel_arch_start +__syscall_cancel_arch_start: + + /* if (*cancelhandling & CANCELED_BITMASK) + __syscall_do_cancel() */ + ld [%i0], %g2 + andcc %g2, TCB_CANCELED_BITMASK, %g0 + bne,pn %icc, 2f + /* Issue a 6 argument syscall. */ + mov %i1, %g1 + mov %i2, %o0 + mov %i3, %o1 + mov %i4, %o2 + mov %i5, %o3 + ld [%fp+92], %o4 + ld [%fp+96], %o5 + ta 0x10 + + .globl __syscall_cancel_arch_end +__syscall_cancel_arch_end: + bcc 1f + nop + sub %g0, %o0, %o0 +1: + mov %o0, %i0 + return %i7+8 + nop + +2: + call __syscall_do_cancel, 0 + nop + nop + +END (__syscall_cancel_arch) +libc_hidden_def (__syscall_cancel_arch) diff --git a/sysdeps/unix/sysv/linux/sparc/sparc64/pause.c b/sysdeps/unix/sysv/linux/sparc/sparc64/pause.c new file mode 100644 index 0000000000..4fae573091 --- /dev/null +++ b/sysdeps/unix/sysv/linux/sparc/sparc64/pause.c @@ -0,0 +1,25 @@ +/* Linux pause syscall implementation. Linux/sparc64. + Copyright (C) 2020 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 <sys/syscall.h> + +/* On sparc interrupted pause syscall returns with a PC indicating a + side-effect and this deviates from other architectures. Fall back to + ppool implementation. */ +#undef __NR_pause +#include <sysdeps/unix/sysv/linux/pause.c> diff --git a/sysdeps/unix/sysv/linux/sparc/sparc64/syscall_cancel.S b/sysdeps/unix/sysv/linux/sparc/sparc64/syscall_cancel.S new file mode 100644 index 0000000000..f9ecb4a851 --- /dev/null +++ b/sysdeps/unix/sysv/linux/sparc/sparc64/syscall_cancel.S @@ -0,0 +1,74 @@ +/* Cancellable syscall wrapper. Linux/sparc64 version. + Copyright (C) 2020 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 <sysdep.h> + + .register %g2, #scratch + +/* long int __syscall_cancel_arch (int *cancelhandling, + long int nr, + long int arg1, + long int arg2, + long int arg3, + long int arg4, + long int arg5, + long int arg6) */ + +ENTRY (__syscall_cancel_arch) + save %sp, -176, %sp + + cfi_window_save + cfi_register (%o7, %i7) + cfi_def_cfa_register (%fp) + + .globl __syscall_cancel_arch_start +__syscall_cancel_arch_start: + + /* if (*cancelhandling & CANCELED_BITMASK) + __syscall_do_cancel() */ + lduw [%i0], %g2 + andcc %g2, TCB_CANCELED_BITMASK, %g0 + bne,pn %xcc, 2f + /* Issue a 6 argument syscall. */ + mov %i1, %g1 + mov %i2, %o0 + mov %i3, %o1 + mov %i4, %o2 + mov %i5, %o3 + ldx [%fp + STACK_BIAS + 176], %o4 + ldx [%fp + STACK_BIAS + 184], %o5 + ta 0x6d + + .global __syscall_cancel_arch_end +__syscall_cancel_arch_end: + + bcc,pt %xcc, 1f + nop + sub %g0, %o0, %o0 +1: + mov %o0, %i0 + return %i7+8 + nop + +2: + call __syscall_do_cancel, 0 + nop + nop + +END (__syscall_cancel_arch) +libc_hidden_def (__syscall_cancel_arch)
next reply other threads:[~2020-04-03 20:24 UTC|newest] Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-04-03 20:24 Adhemerval Zanella [this message] -- strict thread matches above, loose matches on Subject: below -- 2020-04-07 14:04 Adhemerval Zanella 2019-10-17 13:57 [glibc/azanella/bz12683] nptl: sparc: Fix Race conditions in pthread cancellation (BZ#12683) Adhemerval Zanella 2019-08-19 20:36 Adhemerval Zanella
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