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https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
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![Linus Torvalds](/assets/img/avatar_default.png)
This set of changes removes tracehook.h, moves modification of all of the ptrace fields inside of siglock to remove races, adds a missing permission check to ptrace.c The removal of tracehook.h is quite significant as it has been a major source of confusion in recent years. Much of that confusion was around task_work and TIF_NOTIFY_SIGNAL (which I have now decoupled making the semantics clearer). For people who don't know tracehook.h is a vestiage of an attempt to implement uprobes like functionality that was never fully merged, and was later superseeded by uprobes when uprobes was merged. For many years now we have been removing what tracehook functionaly a little bit at a time. To the point where now anything left in tracehook.h is some weird strange thing that is difficult to understand. Eric W. Biederman (15): ptrace: Move ptrace_report_syscall into ptrace.h ptrace/arm: Rename tracehook_report_syscall report_syscall ptrace: Create ptrace_report_syscall_{entry,exit} in ptrace.h ptrace: Remove arch_syscall_{enter,exit}_tracehook ptrace: Remove tracehook_signal_handler task_work: Remove unnecessary include from posix_timers.h task_work: Introduce task_work_pending task_work: Call tracehook_notify_signal from get_signal on all architectures task_work: Decouple TIF_NOTIFY_SIGNAL and task_work signal: Move set_notify_signal and clear_notify_signal into sched/signal.h resume_user_mode: Remove #ifdef TIF_NOTIFY_RESUME in set_notify_resume resume_user_mode: Move to resume_user_mode.h tracehook: Remove tracehook.h ptrace: Move setting/clearing ptrace_message into ptrace_stop ptrace: Return the signal to continue with from ptrace_stop Jann Horn (1): ptrace: Check PTRACE_O_SUSPEND_SECCOMP permission on PTRACE_SEIZE Yang Li (1): ptrace: Remove duplicated include in ptrace.c MAINTAINERS | 1 - arch/Kconfig | 5 +- arch/alpha/kernel/ptrace.c | 5 +- arch/alpha/kernel/signal.c | 4 +- arch/arc/kernel/ptrace.c | 5 +- arch/arc/kernel/signal.c | 4 +- arch/arm/kernel/ptrace.c | 12 +- arch/arm/kernel/signal.c | 4 +- arch/arm64/kernel/ptrace.c | 14 +-- arch/arm64/kernel/signal.c | 4 +- arch/csky/kernel/ptrace.c | 5 +- arch/csky/kernel/signal.c | 4 +- arch/h8300/kernel/ptrace.c | 5 +- arch/h8300/kernel/signal.c | 4 +- arch/hexagon/kernel/process.c | 4 +- arch/hexagon/kernel/signal.c | 1 - arch/hexagon/kernel/traps.c | 6 +- arch/ia64/kernel/process.c | 4 +- arch/ia64/kernel/ptrace.c | 6 +- arch/ia64/kernel/signal.c | 1 - arch/m68k/kernel/ptrace.c | 5 +- arch/m68k/kernel/signal.c | 4 +- arch/microblaze/kernel/ptrace.c | 5 +- arch/microblaze/kernel/signal.c | 4 +- arch/mips/kernel/ptrace.c | 5 +- arch/mips/kernel/signal.c | 4 +- arch/nds32/include/asm/syscall.h | 2 +- arch/nds32/kernel/ptrace.c | 5 +- arch/nds32/kernel/signal.c | 4 +- arch/nios2/kernel/ptrace.c | 5 +- arch/nios2/kernel/signal.c | 4 +- arch/openrisc/kernel/ptrace.c | 5 +- arch/openrisc/kernel/signal.c | 4 +- arch/parisc/kernel/ptrace.c | 7 +- arch/parisc/kernel/signal.c | 4 +- arch/powerpc/kernel/ptrace/ptrace.c | 8 +- arch/powerpc/kernel/signal.c | 4 +- arch/riscv/kernel/ptrace.c | 5 +- arch/riscv/kernel/signal.c | 4 +- arch/s390/include/asm/entry-common.h | 1 - arch/s390/kernel/ptrace.c | 1 - arch/s390/kernel/signal.c | 5 +- arch/sh/kernel/ptrace_32.c | 5 +- arch/sh/kernel/signal_32.c | 4 +- arch/sparc/kernel/ptrace_32.c | 5 +- arch/sparc/kernel/ptrace_64.c | 5 +- arch/sparc/kernel/signal32.c | 1 - arch/sparc/kernel/signal_32.c | 4 +- arch/sparc/kernel/signal_64.c | 4 +- arch/um/kernel/process.c | 4 +- arch/um/kernel/ptrace.c | 5 +- arch/x86/kernel/ptrace.c | 1 - arch/x86/kernel/signal.c | 5 +- arch/x86/mm/tlb.c | 1 + arch/xtensa/kernel/ptrace.c | 5 +- arch/xtensa/kernel/signal.c | 4 +- block/blk-cgroup.c | 2 +- fs/coredump.c | 1 - fs/exec.c | 1 - fs/io-wq.c | 6 +- fs/io_uring.c | 11 +- fs/proc/array.c | 1 - fs/proc/base.c | 1 - include/asm-generic/syscall.h | 2 +- include/linux/entry-common.h | 47 +------- include/linux/entry-kvm.h | 2 +- include/linux/posix-timers.h | 1 - include/linux/ptrace.h | 81 ++++++++++++- include/linux/resume_user_mode.h | 64 ++++++++++ include/linux/sched/signal.h | 17 +++ include/linux/task_work.h | 5 + include/linux/tracehook.h | 226 ----------------------------------- include/uapi/linux/ptrace.h | 2 +- kernel/entry/common.c | 19 +-- kernel/entry/kvm.c | 9 +- kernel/exit.c | 3 +- kernel/livepatch/transition.c | 1 - kernel/ptrace.c | 47 +++++--- kernel/seccomp.c | 1 - kernel/signal.c | 62 +++++----- kernel/task_work.c | 4 +- kernel/time/posix-cpu-timers.c | 1 + mm/memcontrol.c | 2 +- security/apparmor/domain.c | 1 - security/selinux/hooks.c | 1 - 85 files changed, 372 insertions(+), 495 deletions(-) Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEgjlraLDcwBA2B+6cC/v6Eiajj0AFAmJCQkoACgkQC/v6Eiaj j0DCWQ/5AZVFU+hX32obUNCLackHTwgcCtSOs3JNBmNA/zL/htPiYYG0ghkvtlDR Dw5J5DnxC6P7PVAdAqrpvx2uX2FebHYU0bRlyLx8LYUEP5dhyNicxX9jA882Z+vw Ud0Ue9EojwGWS76dC9YoKUj3slThMATbhA2r4GVEoof8fSNJaBxQIqath44t0FwU DinWa+tIOvZANGBZr6CUUINNIgqBIZCH/R4h6ArBhMlJpuQ5Ufk2kAaiWFwZCkX4 0LuuAwbKsCKkF8eap5I2KrIg/7zZVgxAg9O3cHOzzm8OPbKzRnNnQClcDe8perqp S6e/f3MgpE+eavd1EiLxevZ660cJChnmikXVVh8ZYYoefaMKGqBaBSsB38bNcLjY 3+f2dB+TNBFRnZs1aCujK3tWBT9QyjZDKtCBfzxDNWBpXGLhHH6j6lA5Lj+Cef5K /HNHFb+FuqedlFZh5m1Y+piFQ70hTgCa2u8b+FSOubI2hW9Zd+WzINV0ANaZ2LvZ 4YGtcyDNk1q1+c87lxP9xMRl/xi6rNg+B9T2MCo4IUnHgpSVP6VEB3osgUmrrrN0 eQlUI154G/AaDlqXLgmn1xhRmlPGfmenkxpok1AuzxvNJsfLKnpEwQSc13g3oiZr disZQxNY0kBO2Nv3G323Z6PLinhbiIIFez6cJzK5v0YJ2WtO3pY= =uEro -----END PGP SIGNATURE----- Merge tag 'ptrace-cleanups-for-v5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull ptrace cleanups from Eric Biederman: "This set of changes removes tracehook.h, moves modification of all of the ptrace fields inside of siglock to remove races, adds a missing permission check to ptrace.c The removal of tracehook.h is quite significant as it has been a major source of confusion in recent years. Much of that confusion was around task_work and TIF_NOTIFY_SIGNAL (which I have now decoupled making the semantics clearer). For people who don't know tracehook.h is a vestiage of an attempt to implement uprobes like functionality that was never fully merged, and was later superseeded by uprobes when uprobes was merged. For many years now we have been removing what tracehook functionaly a little bit at a time. To the point where anything left in tracehook.h was some weird strange thing that was difficult to understand" * tag 'ptrace-cleanups-for-v5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: ptrace: Remove duplicated include in ptrace.c ptrace: Check PTRACE_O_SUSPEND_SECCOMP permission on PTRACE_SEIZE ptrace: Return the signal to continue with from ptrace_stop ptrace: Move setting/clearing ptrace_message into ptrace_stop tracehook: Remove tracehook.h resume_user_mode: Move to resume_user_mode.h resume_user_mode: Remove #ifdef TIF_NOTIFY_RESUME in set_notify_resume signal: Move set_notify_signal and clear_notify_signal into sched/signal.h task_work: Decouple TIF_NOTIFY_SIGNAL and task_work task_work: Call tracehook_notify_signal from get_signal on all architectures task_work: Introduce task_work_pending task_work: Remove unnecessary include from posix_timers.h ptrace: Remove tracehook_signal_handler ptrace: Remove arch_syscall_{enter,exit}_tracehook ptrace: Create ptrace_report_syscall_{entry,exit} in ptrace.h ptrace/arm: Rename tracehook_report_syscall report_syscall ptrace: Move ptrace_report_syscall into ptrace.h
534 lines
15 KiB
C
534 lines
15 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright IBM Corp. 1999, 2006
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* Author(s): Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com)
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*
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* Based on Intel version
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*
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* Copyright (C) 1991, 1992 Linus Torvalds
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*
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* 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
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*/
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#include <linux/sched.h>
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#include <linux/sched/task_stack.h>
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#include <linux/mm.h>
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#include <linux/smp.h>
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#include <linux/kernel.h>
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#include <linux/signal.h>
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#include <linux/entry-common.h>
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#include <linux/errno.h>
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#include <linux/wait.h>
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#include <linux/ptrace.h>
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#include <linux/unistd.h>
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#include <linux/stddef.h>
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#include <linux/tty.h>
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#include <linux/personality.h>
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#include <linux/binfmts.h>
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#include <linux/syscalls.h>
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#include <linux/compat.h>
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#include <asm/ucontext.h>
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#include <linux/uaccess.h>
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#include <asm/lowcore.h>
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#include <asm/switch_to.h>
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#include <asm/vdso.h>
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#include "entry.h"
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/*
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* Layout of an old-style signal-frame:
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* -----------------------------------------
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* | save area (_SIGNAL_FRAMESIZE) |
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* -----------------------------------------
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* | struct sigcontext |
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* | oldmask |
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* | _sigregs * |
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* -----------------------------------------
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* | _sigregs with |
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* | _s390_regs_common |
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* | _s390_fp_regs |
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* -----------------------------------------
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* | int signo |
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* -----------------------------------------
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* | _sigregs_ext with |
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* | gprs_high 64 byte (opt) |
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* | vxrs_low 128 byte (opt) |
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* | vxrs_high 256 byte (opt) |
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* | reserved 128 byte (opt) |
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* -----------------------------------------
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* | __u16 svc_insn |
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* -----------------------------------------
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* The svc_insn entry with the sigreturn system call opcode does not
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* have a fixed position and moves if gprs_high or vxrs exist.
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* Future extensions will be added to _sigregs_ext.
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*/
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struct sigframe
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{
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__u8 callee_used_stack[__SIGNAL_FRAMESIZE];
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struct sigcontext sc;
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_sigregs sregs;
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int signo;
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_sigregs_ext sregs_ext;
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__u16 svc_insn; /* Offset of svc_insn is NOT fixed! */
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};
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/*
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* Layout of an rt signal-frame:
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* -----------------------------------------
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* | save area (_SIGNAL_FRAMESIZE) |
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* -----------------------------------------
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* | svc __NR_rt_sigreturn 2 byte |
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* -----------------------------------------
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* | struct siginfo |
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* -----------------------------------------
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* | struct ucontext_extended with |
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* | unsigned long uc_flags |
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* | struct ucontext *uc_link |
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* | stack_t uc_stack |
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* | _sigregs uc_mcontext with |
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* | _s390_regs_common |
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* | _s390_fp_regs |
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* | sigset_t uc_sigmask |
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* | _sigregs_ext uc_mcontext_ext |
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* | gprs_high 64 byte (opt) |
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* | vxrs_low 128 byte (opt) |
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* | vxrs_high 256 byte (opt)|
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* | reserved 128 byte (opt) |
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* -----------------------------------------
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* Future extensions will be added to _sigregs_ext.
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*/
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struct rt_sigframe
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{
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__u8 callee_used_stack[__SIGNAL_FRAMESIZE];
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__u16 svc_insn;
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struct siginfo info;
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struct ucontext_extended uc;
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};
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/* Store registers needed to create the signal frame */
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static void store_sigregs(void)
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{
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save_access_regs(current->thread.acrs);
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save_fpu_regs();
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}
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/* Load registers after signal return */
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static void load_sigregs(void)
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{
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restore_access_regs(current->thread.acrs);
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}
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/* Returns non-zero on fault. */
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static int save_sigregs(struct pt_regs *regs, _sigregs __user *sregs)
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{
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_sigregs user_sregs;
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/* Copy a 'clean' PSW mask to the user to avoid leaking
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information about whether PER is currently on. */
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user_sregs.regs.psw.mask = PSW_USER_BITS |
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(regs->psw.mask & (PSW_MASK_USER | PSW_MASK_RI));
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user_sregs.regs.psw.addr = regs->psw.addr;
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memcpy(&user_sregs.regs.gprs, ®s->gprs, sizeof(sregs->regs.gprs));
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memcpy(&user_sregs.regs.acrs, current->thread.acrs,
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sizeof(user_sregs.regs.acrs));
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fpregs_store(&user_sregs.fpregs, ¤t->thread.fpu);
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if (__copy_to_user(sregs, &user_sregs, sizeof(_sigregs)))
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return -EFAULT;
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return 0;
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}
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static int restore_sigregs(struct pt_regs *regs, _sigregs __user *sregs)
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{
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_sigregs user_sregs;
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/* Always make any pending restarted system call return -EINTR */
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current->restart_block.fn = do_no_restart_syscall;
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if (__copy_from_user(&user_sregs, sregs, sizeof(user_sregs)))
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return -EFAULT;
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if (!is_ri_task(current) && (user_sregs.regs.psw.mask & PSW_MASK_RI))
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return -EINVAL;
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/* Test the floating-point-control word. */
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if (test_fp_ctl(user_sregs.fpregs.fpc))
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return -EINVAL;
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/* Use regs->psw.mask instead of PSW_USER_BITS to preserve PER bit. */
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regs->psw.mask = (regs->psw.mask & ~(PSW_MASK_USER | PSW_MASK_RI)) |
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(user_sregs.regs.psw.mask & (PSW_MASK_USER | PSW_MASK_RI));
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/* Check for invalid user address space control. */
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if ((regs->psw.mask & PSW_MASK_ASC) == PSW_ASC_HOME)
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regs->psw.mask = PSW_ASC_PRIMARY |
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(regs->psw.mask & ~PSW_MASK_ASC);
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/* Check for invalid amode */
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if (regs->psw.mask & PSW_MASK_EA)
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regs->psw.mask |= PSW_MASK_BA;
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regs->psw.addr = user_sregs.regs.psw.addr;
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memcpy(®s->gprs, &user_sregs.regs.gprs, sizeof(sregs->regs.gprs));
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memcpy(¤t->thread.acrs, &user_sregs.regs.acrs,
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sizeof(current->thread.acrs));
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fpregs_load(&user_sregs.fpregs, ¤t->thread.fpu);
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clear_pt_regs_flag(regs, PIF_SYSCALL); /* No longer in a system call */
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return 0;
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}
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/* Returns non-zero on fault. */
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static int save_sigregs_ext(struct pt_regs *regs,
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_sigregs_ext __user *sregs_ext)
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{
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__u64 vxrs[__NUM_VXRS_LOW];
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int i;
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/* Save vector registers to signal stack */
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if (MACHINE_HAS_VX) {
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for (i = 0; i < __NUM_VXRS_LOW; i++)
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vxrs[i] = *((__u64 *)(current->thread.fpu.vxrs + i) + 1);
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if (__copy_to_user(&sregs_ext->vxrs_low, vxrs,
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sizeof(sregs_ext->vxrs_low)) ||
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__copy_to_user(&sregs_ext->vxrs_high,
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current->thread.fpu.vxrs + __NUM_VXRS_LOW,
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sizeof(sregs_ext->vxrs_high)))
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return -EFAULT;
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}
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return 0;
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}
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static int restore_sigregs_ext(struct pt_regs *regs,
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_sigregs_ext __user *sregs_ext)
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{
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__u64 vxrs[__NUM_VXRS_LOW];
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int i;
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/* Restore vector registers from signal stack */
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if (MACHINE_HAS_VX) {
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if (__copy_from_user(vxrs, &sregs_ext->vxrs_low,
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sizeof(sregs_ext->vxrs_low)) ||
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__copy_from_user(current->thread.fpu.vxrs + __NUM_VXRS_LOW,
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&sregs_ext->vxrs_high,
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sizeof(sregs_ext->vxrs_high)))
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return -EFAULT;
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for (i = 0; i < __NUM_VXRS_LOW; i++)
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*((__u64 *)(current->thread.fpu.vxrs + i) + 1) = vxrs[i];
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}
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return 0;
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}
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SYSCALL_DEFINE0(sigreturn)
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{
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struct pt_regs *regs = task_pt_regs(current);
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struct sigframe __user *frame =
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(struct sigframe __user *) regs->gprs[15];
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sigset_t set;
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if (__copy_from_user(&set.sig, &frame->sc.oldmask, _SIGMASK_COPY_SIZE))
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goto badframe;
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set_current_blocked(&set);
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save_fpu_regs();
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if (restore_sigregs(regs, &frame->sregs))
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goto badframe;
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if (restore_sigregs_ext(regs, &frame->sregs_ext))
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goto badframe;
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load_sigregs();
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return regs->gprs[2];
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badframe:
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force_sig(SIGSEGV);
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return 0;
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}
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SYSCALL_DEFINE0(rt_sigreturn)
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{
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struct pt_regs *regs = task_pt_regs(current);
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struct rt_sigframe __user *frame =
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(struct rt_sigframe __user *)regs->gprs[15];
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sigset_t set;
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if (__copy_from_user(&set.sig, &frame->uc.uc_sigmask, sizeof(set)))
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goto badframe;
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set_current_blocked(&set);
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if (restore_altstack(&frame->uc.uc_stack))
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goto badframe;
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save_fpu_regs();
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if (restore_sigregs(regs, &frame->uc.uc_mcontext))
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goto badframe;
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if (restore_sigregs_ext(regs, &frame->uc.uc_mcontext_ext))
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goto badframe;
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load_sigregs();
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return regs->gprs[2];
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badframe:
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force_sig(SIGSEGV);
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return 0;
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}
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/*
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* Determine which stack to use..
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*/
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static inline void __user *
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get_sigframe(struct k_sigaction *ka, struct pt_regs * regs, size_t frame_size)
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{
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unsigned long sp;
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/* Default to using normal stack */
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sp = regs->gprs[15];
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/* Overflow on alternate signal stack gives SIGSEGV. */
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if (on_sig_stack(sp) && !on_sig_stack((sp - frame_size) & -8UL))
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return (void __user *) -1UL;
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/* This is the X/Open sanctioned signal stack switching. */
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if (ka->sa.sa_flags & SA_ONSTACK) {
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if (! sas_ss_flags(sp))
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sp = current->sas_ss_sp + current->sas_ss_size;
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}
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return (void __user *)((sp - frame_size) & -8ul);
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}
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static int setup_frame(int sig, struct k_sigaction *ka,
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sigset_t *set, struct pt_regs * regs)
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{
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struct sigframe __user *frame;
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struct sigcontext sc;
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unsigned long restorer;
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size_t frame_size;
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/*
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* gprs_high are only present for a 31-bit task running on
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* a 64-bit kernel (see compat_signal.c) but the space for
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* gprs_high need to be allocated if vector registers are
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* included in the signal frame on a 31-bit system.
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*/
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frame_size = sizeof(*frame) - sizeof(frame->sregs_ext);
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if (MACHINE_HAS_VX)
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frame_size += sizeof(frame->sregs_ext);
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frame = get_sigframe(ka, regs, frame_size);
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if (frame == (void __user *) -1UL)
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return -EFAULT;
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/* Set up backchain. */
|
|
if (__put_user(regs->gprs[15], (addr_t __user *) frame))
|
|
return -EFAULT;
|
|
|
|
/* Create struct sigcontext on the signal stack */
|
|
memcpy(&sc.oldmask, &set->sig, _SIGMASK_COPY_SIZE);
|
|
sc.sregs = (_sigregs __user __force *) &frame->sregs;
|
|
if (__copy_to_user(&frame->sc, &sc, sizeof(frame->sc)))
|
|
return -EFAULT;
|
|
|
|
/* Store registers needed to create the signal frame */
|
|
store_sigregs();
|
|
|
|
/* Create _sigregs on the signal stack */
|
|
if (save_sigregs(regs, &frame->sregs))
|
|
return -EFAULT;
|
|
|
|
/* Place signal number on stack to allow backtrace from handler. */
|
|
if (__put_user(regs->gprs[2], (int __user *) &frame->signo))
|
|
return -EFAULT;
|
|
|
|
/* Create _sigregs_ext on the signal stack */
|
|
if (save_sigregs_ext(regs, &frame->sregs_ext))
|
|
return -EFAULT;
|
|
|
|
/* Set up to return from userspace. If provided, use a stub
|
|
already in userspace. */
|
|
if (ka->sa.sa_flags & SA_RESTORER)
|
|
restorer = (unsigned long) ka->sa.sa_restorer;
|
|
else
|
|
restorer = VDSO64_SYMBOL(current, sigreturn);
|
|
|
|
/* Set up registers for signal handler */
|
|
regs->gprs[14] = restorer;
|
|
regs->gprs[15] = (unsigned long) frame;
|
|
/* Force default amode and default user address space control. */
|
|
regs->psw.mask = PSW_MASK_EA | PSW_MASK_BA |
|
|
(PSW_USER_BITS & PSW_MASK_ASC) |
|
|
(regs->psw.mask & ~PSW_MASK_ASC);
|
|
regs->psw.addr = (unsigned long) ka->sa.sa_handler;
|
|
|
|
regs->gprs[2] = sig;
|
|
regs->gprs[3] = (unsigned long) &frame->sc;
|
|
|
|
/* We forgot to include these in the sigcontext.
|
|
To avoid breaking binary compatibility, they are passed as args. */
|
|
if (sig == SIGSEGV || sig == SIGBUS || sig == SIGILL ||
|
|
sig == SIGTRAP || sig == SIGFPE) {
|
|
/* set extra registers only for synchronous signals */
|
|
regs->gprs[4] = regs->int_code & 127;
|
|
regs->gprs[5] = regs->int_parm_long;
|
|
regs->gprs[6] = current->thread.last_break;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int setup_rt_frame(struct ksignal *ksig, sigset_t *set,
|
|
struct pt_regs *regs)
|
|
{
|
|
struct rt_sigframe __user *frame;
|
|
unsigned long uc_flags, restorer;
|
|
size_t frame_size;
|
|
|
|
frame_size = sizeof(struct rt_sigframe) - sizeof(_sigregs_ext);
|
|
/*
|
|
* gprs_high are only present for a 31-bit task running on
|
|
* a 64-bit kernel (see compat_signal.c) but the space for
|
|
* gprs_high need to be allocated if vector registers are
|
|
* included in the signal frame on a 31-bit system.
|
|
*/
|
|
uc_flags = 0;
|
|
if (MACHINE_HAS_VX) {
|
|
frame_size += sizeof(_sigregs_ext);
|
|
uc_flags |= UC_VXRS;
|
|
}
|
|
frame = get_sigframe(&ksig->ka, regs, frame_size);
|
|
if (frame == (void __user *) -1UL)
|
|
return -EFAULT;
|
|
|
|
/* Set up backchain. */
|
|
if (__put_user(regs->gprs[15], (addr_t __user *) frame))
|
|
return -EFAULT;
|
|
|
|
/* Set up to return from userspace. If provided, use a stub
|
|
already in userspace. */
|
|
if (ksig->ka.sa.sa_flags & SA_RESTORER)
|
|
restorer = (unsigned long) ksig->ka.sa.sa_restorer;
|
|
else
|
|
restorer = VDSO64_SYMBOL(current, rt_sigreturn);
|
|
|
|
/* Create siginfo on the signal stack */
|
|
if (copy_siginfo_to_user(&frame->info, &ksig->info))
|
|
return -EFAULT;
|
|
|
|
/* Store registers needed to create the signal frame */
|
|
store_sigregs();
|
|
|
|
/* Create ucontext on the signal stack. */
|
|
if (__put_user(uc_flags, &frame->uc.uc_flags) ||
|
|
__put_user(NULL, &frame->uc.uc_link) ||
|
|
__save_altstack(&frame->uc.uc_stack, regs->gprs[15]) ||
|
|
save_sigregs(regs, &frame->uc.uc_mcontext) ||
|
|
__copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)) ||
|
|
save_sigregs_ext(regs, &frame->uc.uc_mcontext_ext))
|
|
return -EFAULT;
|
|
|
|
/* Set up registers for signal handler */
|
|
regs->gprs[14] = restorer;
|
|
regs->gprs[15] = (unsigned long) frame;
|
|
/* Force default amode and default user address space control. */
|
|
regs->psw.mask = PSW_MASK_EA | PSW_MASK_BA |
|
|
(PSW_USER_BITS & PSW_MASK_ASC) |
|
|
(regs->psw.mask & ~PSW_MASK_ASC);
|
|
regs->psw.addr = (unsigned long) ksig->ka.sa.sa_handler;
|
|
|
|
regs->gprs[2] = ksig->sig;
|
|
regs->gprs[3] = (unsigned long) &frame->info;
|
|
regs->gprs[4] = (unsigned long) &frame->uc;
|
|
regs->gprs[5] = current->thread.last_break;
|
|
return 0;
|
|
}
|
|
|
|
static void handle_signal(struct ksignal *ksig, sigset_t *oldset,
|
|
struct pt_regs *regs)
|
|
{
|
|
int ret;
|
|
|
|
/* Set up the stack frame */
|
|
if (ksig->ka.sa.sa_flags & SA_SIGINFO)
|
|
ret = setup_rt_frame(ksig, oldset, regs);
|
|
else
|
|
ret = setup_frame(ksig->sig, &ksig->ka, oldset, regs);
|
|
|
|
signal_setup_done(ret, ksig, test_thread_flag(TIF_SINGLE_STEP));
|
|
}
|
|
|
|
/*
|
|
* Note that 'init' is a special process: it doesn't get signals it doesn't
|
|
* want to handle. Thus you cannot kill init even with a SIGKILL even by
|
|
* mistake.
|
|
*
|
|
* Note that we go through the signals twice: once to check the signals that
|
|
* the kernel can handle, and then we build all the user-level signal handling
|
|
* stack-frames in one go after that.
|
|
*/
|
|
|
|
void arch_do_signal_or_restart(struct pt_regs *regs)
|
|
{
|
|
struct ksignal ksig;
|
|
sigset_t *oldset = sigmask_to_save();
|
|
|
|
/*
|
|
* Get signal to deliver. When running under ptrace, at this point
|
|
* the debugger may change all our registers, including the system
|
|
* call information.
|
|
*/
|
|
current->thread.system_call =
|
|
test_pt_regs_flag(regs, PIF_SYSCALL) ? regs->int_code : 0;
|
|
|
|
if (get_signal(&ksig)) {
|
|
/* Whee! Actually deliver the signal. */
|
|
if (current->thread.system_call) {
|
|
regs->int_code = current->thread.system_call;
|
|
/* Check for system call restarting. */
|
|
switch (regs->gprs[2]) {
|
|
case -ERESTART_RESTARTBLOCK:
|
|
case -ERESTARTNOHAND:
|
|
regs->gprs[2] = -EINTR;
|
|
break;
|
|
case -ERESTARTSYS:
|
|
if (!(ksig.ka.sa.sa_flags & SA_RESTART)) {
|
|
regs->gprs[2] = -EINTR;
|
|
break;
|
|
}
|
|
fallthrough;
|
|
case -ERESTARTNOINTR:
|
|
regs->gprs[2] = regs->orig_gpr2;
|
|
regs->psw.addr =
|
|
__rewind_psw(regs->psw,
|
|
regs->int_code >> 16);
|
|
break;
|
|
}
|
|
}
|
|
/* No longer in a system call */
|
|
clear_pt_regs_flag(regs, PIF_SYSCALL);
|
|
|
|
rseq_signal_deliver(&ksig, regs);
|
|
if (is_compat_task())
|
|
handle_signal32(&ksig, oldset, regs);
|
|
else
|
|
handle_signal(&ksig, oldset, regs);
|
|
return;
|
|
}
|
|
|
|
/* No handlers present - check for system call restart */
|
|
clear_pt_regs_flag(regs, PIF_SYSCALL);
|
|
if (current->thread.system_call) {
|
|
regs->int_code = current->thread.system_call;
|
|
switch (regs->gprs[2]) {
|
|
case -ERESTART_RESTARTBLOCK:
|
|
/* Restart with sys_restart_syscall */
|
|
regs->gprs[2] = regs->orig_gpr2;
|
|
current->restart_block.arch_data = regs->psw.addr;
|
|
if (is_compat_task())
|
|
regs->psw.addr = VDSO32_SYMBOL(current, restart_syscall);
|
|
else
|
|
regs->psw.addr = VDSO64_SYMBOL(current, restart_syscall);
|
|
if (test_thread_flag(TIF_SINGLE_STEP))
|
|
clear_thread_flag(TIF_PER_TRAP);
|
|
break;
|
|
case -ERESTARTNOHAND:
|
|
case -ERESTARTSYS:
|
|
case -ERESTARTNOINTR:
|
|
regs->gprs[2] = regs->orig_gpr2;
|
|
regs->psw.addr = __rewind_psw(regs->psw, regs->int_code >> 16);
|
|
if (test_thread_flag(TIF_SINGLE_STEP))
|
|
clear_thread_flag(TIF_PER_TRAP);
|
|
break;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* If there's no signal to deliver, we just put the saved sigmask back.
|
|
*/
|
|
restore_saved_sigmask();
|
|
}
|