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141 lines
3.3 KiB
141 lines
3.3 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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* Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) |
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*/ |
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#include <linux/module.h> |
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#include <linux/ptrace.h> |
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#include <linux/sched.h> |
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#include <linux/ftrace.h> |
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#include <asm/siginfo.h> |
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#include <asm/signal.h> |
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#include <asm/unistd.h> |
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#include <frame_kern.h> |
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#include <kern_util.h> |
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#include <os.h> |
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EXPORT_SYMBOL(block_signals); |
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EXPORT_SYMBOL(unblock_signals); |
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void block_signals_trace(void) |
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{ |
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block_signals(); |
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if (current_thread_info()) |
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trace_hardirqs_off(); |
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} |
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void unblock_signals_trace(void) |
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{ |
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if (current_thread_info()) |
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trace_hardirqs_on(); |
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unblock_signals(); |
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} |
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void um_trace_signals_on(void) |
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{ |
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if (current_thread_info()) |
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trace_hardirqs_on(); |
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} |
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void um_trace_signals_off(void) |
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{ |
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if (current_thread_info()) |
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trace_hardirqs_off(); |
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} |
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/* |
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* OK, we're invoking a handler |
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*/ |
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static void handle_signal(struct ksignal *ksig, struct pt_regs *regs) |
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{ |
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sigset_t *oldset = sigmask_to_save(); |
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int singlestep = 0; |
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unsigned long sp; |
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int err; |
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if ((current->ptrace & PT_DTRACE) && (current->ptrace & PT_PTRACED)) |
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singlestep = 1; |
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/* Did we come from a system call? */ |
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if (PT_REGS_SYSCALL_NR(regs) >= 0) { |
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/* If so, check system call restarting.. */ |
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switch (PT_REGS_SYSCALL_RET(regs)) { |
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case -ERESTART_RESTARTBLOCK: |
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case -ERESTARTNOHAND: |
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PT_REGS_SYSCALL_RET(regs) = -EINTR; |
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break; |
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case -ERESTARTSYS: |
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if (!(ksig->ka.sa.sa_flags & SA_RESTART)) { |
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PT_REGS_SYSCALL_RET(regs) = -EINTR; |
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break; |
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} |
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fallthrough; |
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case -ERESTARTNOINTR: |
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PT_REGS_RESTART_SYSCALL(regs); |
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PT_REGS_ORIG_SYSCALL(regs) = PT_REGS_SYSCALL_NR(regs); |
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break; |
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} |
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} |
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sp = PT_REGS_SP(regs); |
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if ((ksig->ka.sa.sa_flags & SA_ONSTACK) && (sas_ss_flags(sp) == 0)) |
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sp = current->sas_ss_sp + current->sas_ss_size; |
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#ifdef CONFIG_ARCH_HAS_SC_SIGNALS |
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if (!(ksig->ka.sa.sa_flags & SA_SIGINFO)) |
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err = setup_signal_stack_sc(sp, ksig, regs, oldset); |
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else |
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#endif |
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err = setup_signal_stack_si(sp, ksig, regs, oldset); |
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signal_setup_done(err, ksig, singlestep); |
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} |
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void do_signal(struct pt_regs *regs) |
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{ |
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struct ksignal ksig; |
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int handled_sig = 0; |
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while (get_signal(&ksig)) { |
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handled_sig = 1; |
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/* Whee! Actually deliver the signal. */ |
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handle_signal(&ksig, regs); |
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} |
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/* Did we come from a system call? */ |
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if (!handled_sig && (PT_REGS_SYSCALL_NR(regs) >= 0)) { |
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/* Restart the system call - no handlers present */ |
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switch (PT_REGS_SYSCALL_RET(regs)) { |
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case -ERESTARTNOHAND: |
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case -ERESTARTSYS: |
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case -ERESTARTNOINTR: |
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PT_REGS_ORIG_SYSCALL(regs) = PT_REGS_SYSCALL_NR(regs); |
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PT_REGS_RESTART_SYSCALL(regs); |
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break; |
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case -ERESTART_RESTARTBLOCK: |
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PT_REGS_ORIG_SYSCALL(regs) = __NR_restart_syscall; |
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PT_REGS_RESTART_SYSCALL(regs); |
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break; |
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} |
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} |
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/* |
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* This closes a way to execute a system call on the host. If |
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* you set a breakpoint on a system call instruction and singlestep |
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* from it, the tracing thread used to PTRACE_SINGLESTEP the process |
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* rather than PTRACE_SYSCALL it, allowing the system call to execute |
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* on the host. The tracing thread will check this flag and |
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* PTRACE_SYSCALL if necessary. |
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*/ |
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if (current->ptrace & PT_DTRACE) |
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current->thread.singlestep_syscall = |
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is_syscall(PT_REGS_IP(¤t->thread.regs)); |
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/* |
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* if there's no signal to deliver, we just put the saved sigmask |
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* back |
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*/ |
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if (!handled_sig) |
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restore_saved_sigmask(); |
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}
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