diff options
Diffstat (limited to 'arch/x86/kernel/signal.c')
| -rw-r--r-- | arch/x86/kernel/signal.c | 65 |
1 files changed, 43 insertions, 22 deletions
diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c index 548ddf7d6fd2..04cb3212db2d 100644 --- a/arch/x86/kernel/signal.c +++ b/arch/x86/kernel/signal.c @@ -146,7 +146,7 @@ static int restore_sigcontext(struct pt_regs *regs, buf = (void __user *)buf_val; } get_user_catch(err); - err |= fpu__restore_sig(buf, config_enabled(CONFIG_X86_32)); + err |= fpu__restore_sig(buf, IS_ENABLED(CONFIG_X86_32)); force_iret(); @@ -245,25 +245,24 @@ get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size, struct fpu *fpu = ¤t->thread.fpu; /* redzone */ - if (config_enabled(CONFIG_X86_64)) + if (IS_ENABLED(CONFIG_X86_64)) sp -= 128; - if (!onsigstack) { - /* This is the X/Open sanctioned signal stack switching. */ - if (ka->sa.sa_flags & SA_ONSTACK) { - if (current->sas_ss_size) - sp = current->sas_ss_sp + current->sas_ss_size; - } else if (config_enabled(CONFIG_X86_32) && - (regs->ss & 0xffff) != __USER_DS && - !(ka->sa.sa_flags & SA_RESTORER) && - ka->sa.sa_restorer) { - /* This is the legacy signal stack switching. */ - sp = (unsigned long) ka->sa.sa_restorer; - } + /* This is the X/Open sanctioned signal stack switching. */ + if (ka->sa.sa_flags & SA_ONSTACK) { + if (sas_ss_flags(sp) == 0) + sp = current->sas_ss_sp + current->sas_ss_size; + } else if (IS_ENABLED(CONFIG_X86_32) && + !onsigstack && + (regs->ss & 0xffff) != __USER_DS && + !(ka->sa.sa_flags & SA_RESTORER) && + ka->sa.sa_restorer) { + /* This is the legacy signal stack switching. */ + sp = (unsigned long) ka->sa.sa_restorer; } if (fpu->fpstate_active) { - sp = fpu__alloc_mathframe(sp, config_enabled(CONFIG_X86_32), + sp = fpu__alloc_mathframe(sp, IS_ENABLED(CONFIG_X86_32), &buf_fx, &math_size); *fpstate = (void __user *)sp; } @@ -391,7 +390,7 @@ static int __setup_rt_frame(int sig, struct ksignal *ksig, put_user_ex(&frame->uc, &frame->puc); /* Create the ucontext. */ - if (cpu_has_xsave) + if (boot_cpu_has(X86_FEATURE_XSAVE)) put_user_ex(UC_FP_XSTATE, &frame->uc.uc_flags); else put_user_ex(0, &frame->uc.uc_flags); @@ -442,7 +441,7 @@ static unsigned long frame_uc_flags(struct pt_regs *regs) { unsigned long flags; - if (cpu_has_xsave) + if (boot_cpu_has(X86_FEATURE_XSAVE)) flags = UC_FP_XSTATE | UC_SIGCONTEXT_SS; else flags = UC_SIGCONTEXT_SS; @@ -663,18 +662,18 @@ badframe: static inline int is_ia32_compat_frame(void) { - return config_enabled(CONFIG_IA32_EMULATION) && + return IS_ENABLED(CONFIG_IA32_EMULATION) && test_thread_flag(TIF_IA32); } static inline int is_ia32_frame(void) { - return config_enabled(CONFIG_X86_32) || is_ia32_compat_frame(); + return IS_ENABLED(CONFIG_X86_32) || is_ia32_compat_frame(); } static inline int is_x32_frame(void) { - return config_enabled(CONFIG_X86_X32_ABI) && test_thread_flag(TIF_X32); + return IS_ENABLED(CONFIG_X86_X32_ABI) && test_thread_flag(TIF_X32); } static int @@ -761,8 +760,30 @@ handle_signal(struct ksignal *ksig, struct pt_regs *regs) static inline unsigned long get_nr_restart_syscall(const struct pt_regs *regs) { -#ifdef CONFIG_X86_64 - if (is_ia32_task()) + /* + * This function is fundamentally broken as currently + * implemented. + * + * The idea is that we want to trigger a call to the + * restart_block() syscall and that we want in_ia32_syscall(), + * in_x32_syscall(), etc. to match whatever they were in the + * syscall being restarted. We assume that the syscall + * instruction at (regs->ip - 2) matches whatever syscall + * instruction we used to enter in the first place. + * + * The problem is that we can get here when ptrace pokes + * syscall-like values into regs even if we're not in a syscall + * at all. + * + * For now, we maintain historical behavior and guess based on + * stored state. We could do better by saving the actual + * syscall arch in restart_block or (with caveats on x32) by + * checking if regs->ip points to 'int $0x80'. The current + * behavior is incorrect if a tracer has a different bitness + * than the tracee. + */ +#ifdef CONFIG_IA32_EMULATION + if (current_thread_info()->status & (TS_COMPAT|TS_I386_REGS_POKED)) return __NR_ia32_restart_syscall; #endif #ifdef CONFIG_X86_X32_ABI |
