From c885ae0e4ebf207c861bf651dcf9282677281c06 Mon Sep 17 00:00:00 2001 From: Warner Losh Date: Sat, 8 Jan 2022 23:48:12 -0700 Subject: [PATCH] bsd-user/signal.c: implement do_sigreturn Implements the meat of a sigreturn(2) system call via do_sigreturn, and helper reset_signal_mask. Fix the prototype of do_sigreturn in qemu.h and remove do_rt_sigreturn since it's linux only. Signed-off-by: Stacey Son Signed-off-by: Kyle Evans Signed-off-by: Warner Losh Reviewed-by: Richard Henderson --- bsd-user/signal-common.h | 2 +- bsd-user/signal.c | 56 ++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 57 insertions(+), 1 deletion(-) diff --git a/bsd-user/signal-common.h b/bsd-user/signal-common.h index ee819266f5..786ec592d1 100644 --- a/bsd-user/signal-common.h +++ b/bsd-user/signal-common.h @@ -11,7 +11,7 @@ long do_rt_sigreturn(CPUArchState *env); abi_long do_sigaltstack(abi_ulong uss_addr, abi_ulong uoss_addr, abi_ulong sp); -long do_sigreturn(CPUArchState *env); +long do_sigreturn(CPUArchState *env, abi_ulong addr); void force_sig_fault(int sig, int code, abi_ulong addr); int host_to_target_signal(int sig); void host_to_target_sigset(target_sigset_t *d, const sigset_t *s); diff --git a/bsd-user/signal.c b/bsd-user/signal.c index 4b398745f4..150262a87e 100644 --- a/bsd-user/signal.c +++ b/bsd-user/signal.c @@ -627,6 +627,62 @@ static void setup_frame(int sig, int code, struct target_sigaction *ka, unlock_user_struct(frame, frame_addr, 1); } +static int reset_signal_mask(target_ucontext_t *ucontext) +{ + int i; + sigset_t blocked; + target_sigset_t target_set; + TaskState *ts = (TaskState *)thread_cpu->opaque; + + for (i = 0; i < TARGET_NSIG_WORDS; i++) { + if (__get_user(target_set.__bits[i], + &ucontext->uc_sigmask.__bits[i])) { + return -TARGET_EFAULT; + } + } + target_to_host_sigset_internal(&blocked, &target_set); + ts->signal_mask = blocked; + + return 0; +} + +/* See sys/$M/$M/exec_machdep.c sigreturn() */ +long do_sigreturn(CPUArchState *env, abi_ulong addr) +{ + long ret; + abi_ulong target_ucontext; + target_ucontext_t *ucontext = NULL; + + /* Get the target ucontext address from the stack frame */ + ret = get_ucontext_sigreturn(env, addr, &target_ucontext); + if (is_error(ret)) { + return ret; + } + trace_user_do_sigreturn(env, addr); + if (!lock_user_struct(VERIFY_READ, ucontext, target_ucontext, 0)) { + goto badframe; + } + + /* Set the register state back to before the signal. */ + if (set_mcontext(env, &ucontext->uc_mcontext, 1)) { + goto badframe; + } + + /* And reset the signal mask. */ + if (reset_signal_mask(ucontext)) { + goto badframe; + } + + unlock_user_struct(ucontext, target_ucontext, 0); + return -TARGET_EJUSTRETURN; + +badframe: + if (ucontext != NULL) { + unlock_user_struct(ucontext, target_ucontext, 0); + } + return -TARGET_EFAULT; +} + void signal_init(void) { TaskState *ts = (TaskState *)thread_cpu->opaque; -- 2.11.0