Display mask on enter to sigreturn, not on exit
sys_sigreturn() performs ugly manipulations in order to show
signal mask which is restored by this syscall: on syscall entry,
fetches it from the stack, saves it in tcp->u_arg[]
(where it used to overflow this array - fixed sometime ago),
then retrieves the mask and displays it on syscall exit.
Apparently, the motivation is to make it slightly more obvious
to user that signal mask is restored only when this syscall returns.
IMO, this hardly justifies the necessary hacks. It is much easier
to display the mask at the point when we fetch it - on syscall entry.
While at it, I made it so that we do display returned value/errno.
I see no point in hiding it and showing uninformative "= ?" instead.
Example of pause() being interrupted by ALRM which has installed handler
which re-arms ALRM:
Before the patch:
rt_sigsuspend([INT]) = ? ERESTARTNOHAND (To be restarted)
--- {si_signo=SIGALRM, si_code=SI_KERNEL} (Alarm clock) ---
alarm(1) = 0
sigreturn() = ? (mask now [INT])
After:
rt_sigsuspend([INT]) = ? ERESTARTNOHAND (To be restarted)
--- {si_signo=SIGALRM, si_code=SI_KERNEL} (Alarm clock) ---
alarm(1) = 0
sigreturn() (mask [INT]) = -1 EINTR (Interrupted system call)
* defs.h: Declare struct pt_regs i386_regs and struct pt_regs x86_64_regs.
* syscall.c: Remove "static" keywork from these structures' definitions.
* signal.c (sys_sigreturn): Display mask on enter, not on exit.
Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
diff --git a/signal.c b/signal.c
index 1e36973..11396bd 100644
--- a/signal.c
+++ b/signal.c
@@ -1117,95 +1117,63 @@
if (entering(tcp)) {
struct pt_regs regs;
struct sigcontext_struct sc;
- tcp->u_arg[0] = 0;
+ sigset_t sigm;
if (ptrace(PTRACE_GETREGS, tcp->pid, NULL, (void *)®s) == -1)
return 0;
if (umove(tcp, regs.ARM_sp, &sc) < 0)
return 0;
- tcp->u_arg[0] = 1;
- tcp->u_arg[1] = sc.oldmask;
- } else {
- sigset_t sigm;
- tcp->u_rval = tcp->u_error = 0;
- if (tcp->u_arg[0] == 0)
- return 0;
- long_to_sigset(tcp->u_arg[1], &sigm);
- tcp->auxstr = sprintsigmask("mask now ", &sigm, 0);
- return RVAL_NONE | RVAL_STR;
+ long_to_sigset(sc.oldmask, &sigm);
+ tprints(sprintsigmask(") (mask ", &sigm, 0);
}
return 0;
#elif defined(S390) || defined(S390X)
if (entering(tcp)) {
long usp;
struct sigcontext_struct sc;
- tcp->u_arg[0] = 0;
if (upeek(tcp, PT_GPR15, &usp) < 0)
return 0;
- if (umove(tcp, usp+__SIGNAL_FRAMESIZE, &sc) < 0)
+ if (umove(tcp, usp + __SIGNAL_FRAMESIZE, &sc) < 0)
return 0;
- tcp->u_arg[0] = 1;
- memcpy(&tcp->u_arg[1], &sc.oldmask[0], NSIG / 8);
- } else {
- tcp->u_rval = tcp->u_error = 0;
- if (tcp->u_arg[0] == 0)
- return 0;
- tcp->auxstr = sprintsigmask("mask now ", (sigset_t *)&tcp->u_arg[1], 0);
- return RVAL_NONE | RVAL_STR;
+ tprints(sprintsigmask(") (mask ", (sigset_t *)&sc.oldmask[0], 0);
}
return 0;
#elif defined(I386)
if (entering(tcp)) {
- long esp;
struct sigcontext_struct sc;
- tcp->u_arg[0] = 0;
- if (upeek(tcp, 4*UESP, &esp) < 0)
- return 0;
- if (umove(tcp, esp, &sc) < 0)
- return 0;
- tcp->u_arg[0] = 1;
- tcp->u_arg[1] = sc.oldmask;
- }
- else {
+ /* Note: on i386, sc is followed on stack by struct fpstate
+ * and after it an additional u32 extramask[1] which holds
+ * upper half of the mask. We can fetch it there
+ * if/when we'd want to display the full mask...
+ */
sigset_t sigm;
- tcp->u_rval = tcp->u_error = 0;
- if (tcp->u_arg[0] == 0)
+ if (umove(tcp, i386_regs.esp, &sc) < 0)
return 0;
- long_to_sigset(tcp->u_arg[1], &sigm);
- tcp->auxstr = sprintsigmask("mask now ", &sigm, 0);
- return RVAL_NONE | RVAL_STR;
+ long_to_sigset(sc.oldmask, &sigm);
+ tprints(sprintsigmask(") (mask ", &sigm, 0));
}
return 0;
#elif defined(IA64)
if (entering(tcp)) {
struct sigcontext sc;
long sp;
+ sigset_t sigm;
/* offset of sigcontext in the kernel's sigframe structure: */
# define SIGFRAME_SC_OFFSET 0x90
- tcp->u_arg[0] = 0;
if (upeek(tcp, PT_R12, &sp) < 0)
return 0;
if (umove(tcp, sp + 16 + SIGFRAME_SC_OFFSET, &sc) < 0)
return 0;
- tcp->u_arg[0] = 1;
- memcpy(tcp->u_arg + 1, &sc.sc_mask, NSIG / 8);
- }
- else {
- sigset_t sigm;
- tcp->u_rval = tcp->u_error = 0;
- if (tcp->u_arg[0] == 0)
- return 0;
sigemptyset(&sigm);
- memcpy(&sigm, tcp->u_arg + 1, NSIG / 8);
- tcp->auxstr = sprintsigmask("mask now ", &sigm, 0);
- return RVAL_NONE | RVAL_STR;
+ memcpy(&sigm, &sc.sc_mask, NSIG / 8);
+ tprints(sprintsigmask(") (mask ", &sigm, 0);
}
return 0;
#elif defined(POWERPC)
if (entering(tcp)) {
long esp;
struct sigcontext_struct sc;
- tcp->u_arg[0] = 0;
- if (upeek(tcp, sizeof(unsigned long)*PT_R1, &esp) < 0)
+ sigset_t sigm;
+ if (upeek(tcp, sizeof(unsigned long) * PT_R1, &esp) < 0)
return 0;
/* Skip dummy stack frame. */
#ifdef POWERPC64
@@ -1218,61 +1186,34 @@
#endif
if (umove(tcp, esp, &sc) < 0)
return 0;
- tcp->u_arg[0] = 1;
- tcp->u_arg[1] = sc.oldmask;
- }
- else {
- sigset_t sigm;
- tcp->u_rval = tcp->u_error = 0;
- if (tcp->u_arg[0] == 0)
- return 0;
- long_to_sigset(tcp->u_arg[1], &sigm);
- tcp->auxstr = sprintsigmask("mask now ", &sigm, 0);
- return RVAL_NONE | RVAL_STR;
+ long_to_sigset(sc.oldmask, &sigm);
+ tprints(sprintsigmask(") (mask ", &sigm, 0);
}
return 0;
#elif defined(M68K)
if (entering(tcp)) {
long usp;
struct sigcontext sc;
- tcp->u_arg[0] = 0;
+ sigset_t sigm;
if (upeek(tcp, 4*PT_USP, &usp) < 0)
return 0;
if (umove(tcp, usp, &sc) < 0)
return 0;
- tcp->u_arg[0] = 1;
- tcp->u_arg[1] = sc.sc_mask;
- }
- else {
- sigset_t sigm;
- tcp->u_rval = tcp->u_error = 0;
- if (tcp->u_arg[0] == 0)
- return 0;
- long_to_sigset(tcp->u_arg[1], &sigm);
- tcp->auxstr = sprintsigmask("mask now ", &sigm, 0);
- return RVAL_NONE | RVAL_STR;
+ long_to_sigset(sc.sc_mask, &sigm);
+ tprints(sprintsigmask(") (mask ", &sigm, 0);
}
return 0;
#elif defined(ALPHA)
if (entering(tcp)) {
long fp;
struct sigcontext_struct sc;
- tcp->u_arg[0] = 0;
+ sigset_t sigm;
if (upeek(tcp, REG_FP, &fp) < 0)
return 0;
if (umove(tcp, fp, &sc) < 0)
return 0;
- tcp->u_arg[0] = 1;
- tcp->u_arg[1] = sc.sc_mask;
- }
- else {
- sigset_t sigm;
- tcp->u_rval = tcp->u_error = 0;
- if (tcp->u_arg[0] == 0)
- return 0;
- long_to_sigset(tcp->u_arg[1], &sigm);
- tcp->auxstr = sprintsigmask("mask now ", &sigm, 0);
- return RVAL_NONE | RVAL_STR;
+ long_to_sigset(sc.sc_mask, &sigm);
+ tprints(sprintsigmask(") (mask ", &sigm, 0);
}
return 0;
#elif defined (SPARC) || defined (SPARC64)
@@ -1280,7 +1221,7 @@
long i1;
struct pt_regs regs;
m_siginfo_t si;
- tcp->u_arg[0] = 0;
+ sigset_t sigm;
if (ptrace(PTRACE_GETREGS, tcp->pid, (char *)®s, 0) < 0) {
perror("sigreturn: PTRACE_GETREGS");
return 0;
@@ -1290,16 +1231,8 @@
perror("sigreturn: umove");
return 0;
}
- tcp->u_arg[0] = 1;
- tcp->u_arg[1] = si.si_mask;
- } else {
- sigset_t sigm;
- tcp->u_rval = tcp->u_error = 0;
- if (tcp->u_arg[0] == 0)
- return 0;
- long_to_sigset(tcp->u_arg[1], &sigm);
- tcp->auxstr = sprintsigmask("mask now ", &sigm, 0);
- return RVAL_NONE | RVAL_STR;
+ long_to_sigset(si.si_mask, &sigm);
+ tprints(sprintsigmask(") (mask ", &sigm, 0);
}
return 0;
#elif defined (LINUX_MIPSN32) || defined (LINUX_MIPSN64)
@@ -1308,23 +1241,15 @@
if (entering(tcp)) {
long sp;
struct ucontext uc;
- tcp->u_arg[0] = 0;
+ sigset_t sigm;
if (upeek(tcp, REG_SP, &sp) < 0)
return 0;
/* There are six words followed by a 128-byte siginfo. */
sp = sp + 6 * 4 + 128;
if (umove(tcp, sp, &uc) < 0)
return 0;
- tcp->u_arg[0] = 1;
- tcp->u_arg[1] = *(long *) &uc.uc_sigmask;
- } else {
- sigset_t sigm;
- tcp->u_rval = tcp->u_error = 0;
- if (tcp->u_arg[0] == 0)
- return 0;
- long_to_sigset(tcp->u_arg[1], &sigm);
- tcp->auxstr = sprintsigmask("mask now ", &sigm, 0);
- return RVAL_NONE | RVAL_STR;
+ long_to_sigset(*(long *) &uc.uc_sigmask, &sigm);
+ tprints(sprintsigmask(") (mask ", &sigm, 0);
}
return 0;
#elif defined(MIPS)
@@ -1332,7 +1257,7 @@
long sp;
struct pt_regs regs;
m_siginfo_t si;
- tcp->u_arg[0] = 0;
+ sigset_t sigm;
if (ptrace(PTRACE_GETREGS, tcp->pid, (char *)®s, 0) < 0) {
perror("sigreturn: PTRACE_GETREGS");
return 0;
@@ -1340,65 +1265,40 @@
sp = regs.regs[29];
if (umove(tcp, sp, &si) < 0)
return 0;
- tcp->u_arg[0] = 1;
- tcp->u_arg[1] = si.si_mask;
- } else {
- sigset_t sigm;
- tcp->u_rval = tcp->u_error = 0;
- if (tcp->u_arg[0] == 0)
- return 0;
- long_to_sigset(tcp->u_arg[1], &sigm);
- tcp->auxstr = sprintsigmask("mask now ", &sigm, 0);
- return RVAL_NONE | RVAL_STR;
+ long_to_sigset(si.si_mask, &sigm);
+ tprints(sprintsigmask(") (mask ", &sigm, 0);
}
return 0;
#elif defined(CRISV10) || defined(CRISV32)
if (entering(tcp)) {
struct sigcontext sc;
long regs[PT_MAX+1];
- tcp->u_arg[0] = 0;
+ sigset_t sigm;
if (ptrace(PTRACE_GETREGS, tcp->pid, NULL, (long)regs) < 0) {
perror("sigreturn: PTRACE_GETREGS");
return 0;
}
if (umove(tcp, regs[PT_USP], &sc) < 0)
return 0;
- tcp->u_arg[0] = 1;
- tcp->u_arg[1] = sc.oldmask;
- } else {
- sigset_t sigm;
- tcp->u_rval = tcp->u_error = 0;
- if (tcp->u_arg[0] == 0)
- return 0;
- long_to_sigset(tcp->u_arg[1], &sigm);
- tcp->auxstr = sprintsigmask("mask now ", &sigm, 0);
- return RVAL_NONE | RVAL_STR;
+ long_to_sigset(sc.oldmask, &sigm);
+ tprints(sprintsigmask(") (mask ", &sigm, 0);
}
return 0;
#elif defined(TILE)
if (entering(tcp)) {
struct ucontext uc;
long sp;
+ sigset_t sigm;
/* offset of ucontext in the kernel's sigframe structure */
# define SIGFRAME_UC_OFFSET C_ABI_SAVE_AREA_SIZE + sizeof(struct siginfo)
- tcp->u_arg[0] = 0;
if (upeek(tcp, PTREGS_OFFSET_SP, &sp) < 0)
return 0;
if (umove(tcp, sp + SIGFRAME_UC_OFFSET, &uc) < 0)
return 0;
- tcp->u_arg[0] = 1;
- memcpy(tcp->u_arg + 1, &uc.uc_sigmask, NSIG / 8);
- }
- else {
- sigset_t sigm;
- tcp->u_rval = tcp->u_error = 0;
- if (tcp->u_arg[0] == 0)
- return 0;
sigemptyset(&sigm);
- memcpy(&sigm, tcp->u_arg + 1, NSIG / 8);
- tcp->auxstr = sprintsigmask("mask now ", &sigm, 0);
- return RVAL_NONE | RVAL_STR;
+ memcpy(&sigm, &uc.uc_sigmask, NSIG / 8);
+ tprints(sprintsigmask(") (mask ", &sigm, 0);
}
return 0;
#elif defined(MICROBLAZE)
@@ -1406,22 +1306,14 @@
if (entering(tcp)) {
struct sigcontext sc;
long sp;
- tcp->u_arg[0] = 0;
+ sigset_t sigm;
/* Read r1, the stack pointer. */
if (upeek(tcp, 1 * 4, &sp) < 0)
return 0;
if (umove(tcp, sp, &sc) < 0)
return 0;
- tcp->u_arg[0] = 1;
- tcp->u_arg[1] = sc.oldmask;
- } else {
- sigset_t sigm;
- tcp->u_rval = tcp->u_error = 0;
- if (tcp->u_arg[0] == 0)
- return 0;
- long_to_sigset(tcp->u_arg[1], &sigm);
- tcp->auxstr = sprintsigmask("mask now ", &sigm, 0);
- return RVAL_NONE | RVAL_STR;
+ long_to_sigset(sc.oldmask, &sigm);
+ tprints(sprintsigmask(") (mask ", &sigm, 0);
}
return 0;
#else