From 43ed4267845899871890589c96b1302a1696525d Mon Sep 17 00:00:00 2001 From: Warner Losh Date: Sun, 9 Jan 2022 00:06:56 -0700 Subject: [PATCH] bsd-user/signal.c: do_sigaltstack Implement the meat of the sigaltstack(2) system call with do_sigaltstack. With that, all the stubbed out routines are complete, so remove now-incorrect comment. Signed-off-by: Stacey Son Signed-off-by: Kyle Evans Signed-off-by: Warner Losh Reviewed-by: Richard Henderson --- bsd-user/signal.c | 72 +++++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 67 insertions(+), 5 deletions(-) diff --git a/bsd-user/signal.c b/bsd-user/signal.c index 5c94bd02e3..ad22ba9d90 100644 --- a/bsd-user/signal.c +++ b/bsd-user/signal.c @@ -25,11 +25,6 @@ #include "hw/core/tcg-cpu-ops.h" #include "host-signal.h" -/* - * Stubbed out routines until we merge signal support from bsd-user - * fork. - */ - static struct target_sigaction sigact_table[TARGET_NSIG]; static void host_signal_handler(int host_sig, siginfo_t *info, void *puc); static void target_to_host_sigset_internal(sigset_t *d, @@ -573,6 +568,73 @@ static void host_signal_handler(int host_sig, siginfo_t *info, void *puc) cpu_exit(thread_cpu); } +/* do_sigaltstack() returns target values and errnos. */ +/* compare to kern/kern_sig.c sys_sigaltstack() and kern_sigaltstack() */ +abi_long do_sigaltstack(abi_ulong uss_addr, abi_ulong uoss_addr, abi_ulong sp) +{ + TaskState *ts = (TaskState *)thread_cpu->opaque; + int ret; + target_stack_t oss; + + if (uoss_addr) { + /* Save current signal stack params */ + oss.ss_sp = tswapl(ts->sigaltstack_used.ss_sp); + oss.ss_size = tswapl(ts->sigaltstack_used.ss_size); + oss.ss_flags = tswapl(sas_ss_flags(ts, sp)); + } + + if (uss_addr) { + target_stack_t *uss; + target_stack_t ss; + size_t minstacksize = TARGET_MINSIGSTKSZ; + + ret = -TARGET_EFAULT; + if (!lock_user_struct(VERIFY_READ, uss, uss_addr, 1)) { + goto out; + } + __get_user(ss.ss_sp, &uss->ss_sp); + __get_user(ss.ss_size, &uss->ss_size); + __get_user(ss.ss_flags, &uss->ss_flags); + unlock_user_struct(uss, uss_addr, 0); + + ret = -TARGET_EPERM; + if (on_sig_stack(ts, sp)) { + goto out; + } + + ret = -TARGET_EINVAL; + if (ss.ss_flags != TARGET_SS_DISABLE + && ss.ss_flags != TARGET_SS_ONSTACK + && ss.ss_flags != 0) { + goto out; + } + + if (ss.ss_flags == TARGET_SS_DISABLE) { + ss.ss_size = 0; + ss.ss_sp = 0; + } else { + ret = -TARGET_ENOMEM; + if (ss.ss_size < minstacksize) { + goto out; + } + } + + ts->sigaltstack_used.ss_sp = ss.ss_sp; + ts->sigaltstack_used.ss_size = ss.ss_size; + } + + if (uoss_addr) { + ret = -TARGET_EFAULT; + if (copy_to_user(uoss_addr, &oss, sizeof(oss))) { + goto out; + } + } + + ret = 0; +out: + return ret; +} + /* do_sigaction() return host values and errnos */ int do_sigaction(int sig, const struct target_sigaction *act, struct target_sigaction *oact) -- 2.39.5