Merged the signal frame cleanups and fixes from 2.4.

arch/um/include/frame.h

@@ -8,34 +8,34 @@
 
 #include "sysdep/frame.h"
 
-struct sc_frame {
+struct frame_common {
 	void *data;
 	int len;
 	int sig_index;
-	int sc_index;
 	int sr_index;
 	int sr_relative;
 	int sp_index;
+};
+
+struct sc_frame {
+	struct frame_common common;
+	int sc_index;
 	struct arch_frame_data arch;
 };
 
 extern struct sc_frame signal_frame_sc;
 
+extern struct sc_frame signal_frame_sc_sr;
+
 struct si_frame {
-	void *data;
-	int len;
-	int sig_index;
+	struct frame_common common;
 	int sip_index;
 	int si_index;
-	int sr_index;
-	int sr_relative;
-	int sp_index;
 };
 
 extern struct si_frame signal_frame_si;
 
 extern void capture_signal_stack(void);
-extern void set_sc_ip_sp(void *sc_ptr, unsigned long ip, unsigned long sp);
 
 #endif
 

arch/um/include/sysdep-i386/frame_kern.h

@@ -20,7 +20,8 @@ static inline void *sp_to_rt_sc(unsigned long sp)
 {
 	unsigned long sc;
 
-	sc = sp - signal_frame_si.sp_index + signal_frame_si.len - 4;
+	sc = sp - signal_frame_si.common.sp_index + 
+		signal_frame_si.common.len - 4;
 	return((void *) sc);
 }
 
@@ -28,7 +29,8 @@ static inline void *sp_to_mask(unsigned long sp)
 {
 	unsigned long mask;
 
-	mask = sp - signal_frame_sc.sp_index + signal_frame_sc.len - 8;
+	mask = sp - signal_frame_sc.common.sp_index + 
+		signal_frame_sc.common.len - 8;
 	return((void *) mask);
 }
 
@@ -38,7 +40,8 @@ static inline void *sp_to_rt_mask(unsigned long sp)
 {
 	unsigned long mask;
 
-	mask = sp - signal_frame_si.sp_index + signal_frame_si.len + 
+	mask = sp - signal_frame_si.common.sp_index + 
+		signal_frame_si.common.len + 
 		sc_size(&signal_frame_sc.arch) - 4;
 	return((void *) mask);
 }

arch/um/kernel/frame.c

@@ -12,6 +12,7 @@
 #include <sched.h>
 #include <errno.h>
 #include <sys/ptrace.h>
+#include <sys/syscall.h>
 #include <sys/mman.h>
 #include <asm/page.h>
 #include <asm/ptrace.h>
@@ -84,8 +85,8 @@ static int capture_stack(int (*child)(void *arg), void *arg, void *sp,
 		printf("capture_stack : waitpid failed - errno = %d\n", errno);
 		exit(1);
 	}
-	if(!WIFEXITED(status) || (WEXITSTATUS(status) != 0)){
-		printf("capture_stack : Expected exit status 0, "
+	if(!WIFSIGNALED(status) || (WTERMSIG(status) != 9)){
+		printf("capture_stack : Expected exit signal 9, "
 		       "got status = 0x%x\n", status);
 		exit(1);
 	}
@@ -103,28 +104,61 @@ static int capture_stack(int (*child)(void *arg), void *arg, void *sp,
 	return(len);
 }
 
-static void child_common(void *sp, int size, sighandler_t handler, int flags)
+struct common_raw {
+	void *stack;
+	int size;
+	unsigned long sig;
+	unsigned long sr;
+	unsigned long sp;	
+};
+
+#define SA_RESTORER (0x04000000)
+
+typedef unsigned long old_sigset_t;
+
+struct old_sigaction {
+	__sighandler_t handler;
+	old_sigset_t sa_mask;
+	unsigned long sa_flags;
+	void (*sa_restorer)(void);
+};
+
+static void child_common(struct common_raw *common, sighandler_t handler,
+			 int restorer, int flags)
 {
-	stack_t ss;
-	struct sigaction sa;
+	stack_t ss = ((stack_t) { .ss_sp	= common->stack,
+				  .ss_flags	= 0,
+				  .ss_size	= common->size });
+	int err;
 
 	if(ptrace(PTRACE_TRACEME, 0, 0, 0) < 0){
 		printf("PTRACE_TRACEME failed, errno = %d\n", errno);
 	}
-	ss.ss_sp = sp;
-	ss.ss_flags = 0;
-	ss.ss_size = size;
 	if(sigaltstack(&ss, NULL) < 0){
 		printf("sigaltstack failed - errno = %d\n", errno);
-		_exit(1);
+		kill(getpid(), SIGKILL);
 	}
 
+	if(restorer){
+		struct sigaction sa;
+
 		sa.sa_handler = handler;
 		sigemptyset(&sa.sa_mask);
 		sa.sa_flags = SA_ONSTACK | flags;
-	if(sigaction(SIGUSR1, &sa, NULL) < 0){
+		err = sigaction(SIGUSR1, &sa, NULL);
+	}
+	else {
+		struct old_sigaction sa;
+
+		sa.handler = handler;
+		sa.sa_mask = 0;
+		sa.sa_flags = (SA_ONSTACK | flags) & ~SA_RESTORER;
+		err = syscall(__NR_sigaction, SIGUSR1, &sa, NULL);
+	}
+	
+	if(err < 0){
 		printf("sigaction failed - errno = %d\n", errno);
-		_exit(1);
+		kill(getpid(), SIGKILL);
 	}
 
 	os_stop_process(os_getpid());
@@ -133,13 +167,12 @@ static void child_common(void *sp, int size, sighandler_t handler, int flags)
 /* Changed only during early boot */
 struct sc_frame signal_frame_sc;
 
+struct sc_frame signal_frame_sc_sr;
+
 struct sc_frame_raw {
-	void *stack;
-	int size;
-	unsigned long sig;
+	struct common_raw common;
 	unsigned long sc;
-	unsigned long sr;
-	unsigned long sp;
+	int restorer;
 	struct arch_frame_data_raw arch;
 };
 
@@ -148,20 +181,20 @@ static struct sc_frame_raw *raw_sc = NULL;
 
 static void sc_handler(int sig, struct sigcontext sc)
 {
-	raw_sc->sig = (unsigned long) &sig;
+	raw_sc->common.sig = (unsigned long) &sig;
+	raw_sc->common.sr = frame_restorer();
+	raw_sc->common.sp = frame_sp();
 	raw_sc->sc = (unsigned long) &sc;
-	raw_sc->sr = frame_restorer();
-	raw_sc->sp = frame_sp();
 	setup_arch_frame_raw(&raw_sc->arch, &sc);
 	os_stop_process(os_getpid());
-	_exit(0);
+	kill(getpid(), SIGKILL);
 }
 
 static int sc_child(void *arg)
 {
 	raw_sc = arg;
-	child_common(raw_sc->stack, raw_sc->size, (sighandler_t) sc_handler, 
-		     0);
+	child_common(&raw_sc->common, (sighandler_t) sc_handler, 
+		     raw_sc->restorer, 0);
 	return(-1);
 }
 
@@ -169,13 +202,9 @@ static int sc_child(void *arg)
 struct si_frame signal_frame_si;
 
 struct si_frame_raw {
-	void *stack;
-	int size;
-	unsigned long sig;
+	struct common_raw common;
 	unsigned long sip;
 	unsigned long si;
-	unsigned long sr;
-	unsigned long sp;
 };
 
 /* Changed only during early boot */
@@ -183,23 +212,59 @@ static struct si_frame_raw *raw_si = NULL;
 
 static void si_handler(int sig, siginfo_t *si)
 {
-	raw_si->sig = (unsigned long) &sig;
+	raw_si->common.sig = (unsigned long) &sig;
+	raw_si->common.sr = frame_restorer();
+	raw_si->common.sp = frame_sp();
 	raw_si->sip = (unsigned long) &si;
 	raw_si->si = (unsigned long) si;
-	raw_si->sr = frame_restorer();
-	raw_si->sp = frame_sp();
 	os_stop_process(os_getpid());
-	_exit(0);
+	kill(getpid(), SIGKILL);
 }
 
 static int si_child(void *arg)
 {
 	raw_si = arg;
-	child_common(raw_si->stack, raw_si->size, (sighandler_t) si_handler,
+	child_common(&raw_si->common, (sighandler_t) si_handler, 1, 
  		     SA_SIGINFO);
 	return(-1);
 }
 
+static int relative_sr(unsigned long sr, int sr_index, void *stack, 
+		       void *framep)
+{
+	unsigned long *srp = (unsigned long *) sr;
+	unsigned long frame = (unsigned long) framep;
+
+	if((*srp & PAGE_MASK) == (unsigned long) stack){
+		*srp -= sr;
+		*((unsigned long *) (frame + sr_index)) = *srp;
+		return(1);
+	}
+	else return(0);
+}
+
+static unsigned long capture_stack_common(int (*proc)(void *), void *arg, 
+					  struct common_raw *common_in, 
+					  void *top, void *sigstack, 
+					  int stack_len, 
+					  struct frame_common *common_out)
+{
+	unsigned long sig_top = (unsigned long) sigstack + stack_len, base;
+
+	common_in->stack = (void *) sigstack;
+	common_in->size = stack_len;
+	common_out->len = capture_stack(proc, arg, top, sig_top, 
+					&common_out->data);
+	base = sig_top - common_out->len;
+	common_out->sig_index = common_in->sig - base;
+	common_out->sp_index = common_in->sp - base;
+	common_out->sr_index = common_in->sr - base;
+	common_out->sr_relative = relative_sr(common_in->sr, 
+					      common_out->sr_index, sigstack, 
+					      common_out->data);
+	return(base);
+}
+
 void capture_signal_stack(void)
 {
 	struct sc_frame_raw raw_sc;
@@ -220,54 +285,29 @@ void capture_signal_stack(void)
 	top = (unsigned long) stack + PAGE_SIZE - sizeof(void *);
 	sig_top = (unsigned long) sigstack + PAGE_SIZE;
 
-	raw_sc.stack = sigstack;
-	raw_sc.size = PAGE_SIZE;
-	signal_frame_sc.len = capture_stack(sc_child, &raw_sc, (void *) top,
-					    sig_top, &signal_frame_sc.data);
-
-	/* These are the offsets within signal_frame_sc.data (counting from
-	 * the bottom) of sig, sc, SA_RESTORER, and the initial sp.
-	 */
+	/* Get the sigcontext, no sigrestorer layout */
+	raw_sc.restorer = 0;
+	base = capture_stack_common(sc_child, &raw_sc, &raw_sc.common, 
+				    (void *) top, sigstack, PAGE_SIZE, 
+				    &signal_frame_sc.common);
 
-	base = sig_top - signal_frame_sc.len;
-	signal_frame_sc.sig_index = raw_sc.sig - base;
 	signal_frame_sc.sc_index = raw_sc.sc - base;
-	signal_frame_sc.sr_index = raw_sc.sr - base;
-	if((*((unsigned long *) raw_sc.sr) & PAGE_MASK) == 
-	   (unsigned long) sigstack){
-		unsigned long *sr = (unsigned long *) raw_sc.sr;
-		unsigned long frame = (unsigned long) signal_frame_sc.data;
-
-		signal_frame_sc.sr_relative = 1;
-		*sr -= raw_sc.sr;
-		*((unsigned long *) (frame + signal_frame_sc.sr_index)) = *sr;
-	}
-	else signal_frame_sc.sr_relative = 0;
-	signal_frame_sc.sp_index = raw_sc.sp - base;
 	setup_arch_frame(&raw_sc.arch, &signal_frame_sc.arch);
 
-	/* Repeat for the siginfo variant */
+	/* Ditto for the sigcontext, sigrestorer layout */
+	raw_sc.restorer = 1;
+	base = capture_stack_common(sc_child, &raw_sc, &raw_sc.common, 
+				    (void *) top, sigstack, PAGE_SIZE, 
+				    &signal_frame_sc_sr.common);
+	signal_frame_sc_sr.sc_index = raw_sc.sc - base;
+
+	/* And the siginfo layout */
 
-	raw_si.stack = sigstack;
-	raw_si.size = PAGE_SIZE;
-	signal_frame_si.len = capture_stack(si_child, &raw_si, (void *) top,
-					    sig_top, &signal_frame_si.data);
-	base = sig_top - signal_frame_si.len;
-	signal_frame_si.sig_index = raw_si.sig - base;
+	base = capture_stack_common(si_child, &raw_si, &raw_si.common, 
+				    (void *) top, sigstack, PAGE_SIZE, 
+				    &signal_frame_si.common);
 	signal_frame_si.sip_index = raw_si.sip - base;
 	signal_frame_si.si_index = raw_si.si - base;
-	signal_frame_si.sr_index = raw_si.sr - base;
-	if((*((unsigned long *) raw_si.sr) & PAGE_MASK) == 
-	   (unsigned long) sigstack){
-		unsigned long *sr = (unsigned long *) raw_si.sr;
-		unsigned long frame = (unsigned long) signal_frame_si.data;
-
-		signal_frame_sc.sr_relative = 1;
-		*sr -= raw_si.sr;
-		*((unsigned long *) (frame + signal_frame_si.sr_index)) = *sr;
-	}
-	else signal_frame_si.sr_relative = 0;
-	signal_frame_si.sp_index = raw_si.sp - base;
 
 	if((munmap(stack, PAGE_SIZE) < 0) || 
 	   (munmap(sigstack, PAGE_SIZE) < 0)){
@@ -277,14 +317,6 @@ void capture_signal_stack(void)
 	}
 }
 
-void set_sc_ip_sp(void *sc_ptr, unsigned long ip, unsigned long sp)
-{
-	struct sigcontext *sc = sc_ptr;
-
-	SC_IP(sc) = ip;
-	SC_SP(sc) = sp;
-}
-
 /*
  * Overrides for Emacs so that we follow Linus's tabbing style.
  * Emacs will notice this stuff at the end of the file and automatically

arch/um/kernel/frame_kern.c

@@ -13,16 +13,25 @@
 static int copy_restorer(void (*restorer)(void), unsigned long start, 
 			 unsigned long sr_index, int sr_relative)
 {
-	if(restorer != 0){
-		if(copy_to_user((void *) (start + sr_index), &restorer, 
-				sizeof(restorer)))
-			return(1);
-	}
-	else if(sr_relative){
-		unsigned long *sr = (unsigned long *) (start + sr_index);
-		*sr += (unsigned long) sr;
+	unsigned long sr;
+
+	if(sr_relative){
+		sr = (unsigned long) restorer;
+		sr += start + sr_index;
+		restorer = (void (*)(void)) sr;
 	}
-	return(0);
+
+	return(copy_to_user((void *) (start + sr_index), &restorer, 
+			    sizeof(restorer)));
+}
+
+static int copy_sc_to_user(void *to, struct pt_regs *from)
+{
+	return(CHOOSE_MODE(copy_sc_to_user_tt(to, from->regs.mode.tt, 
+					      &signal_frame_sc_sr.arch),
+			   copy_sc_to_user_skas(to, &from->regs,
+						current->thread.cr2,
+						current->thread.err)));
 }
 
 int setup_signal_stack_si(unsigned long stack_top, int sig, 
@@ -34,27 +43,30 @@ int setup_signal_stack_si(unsigned long stack_top, int sig,
 	void *sip;
 	int sig_size = _NSIG_WORDS * sizeof(unsigned long);
 
-	start = stack_top - signal_frame_si.len - 
+	start = stack_top - signal_frame_si.common.len - 
 		sc_size(&signal_frame_sc.arch) - sig_size;
 	sip = (void *) (start + signal_frame_si.si_index);
-	sc = start + signal_frame_si.len;
+	sc = start + signal_frame_si.common.len;
 	sigs = sc + sc_size(&signal_frame_sc.arch);
-	if(copy_sc_to_user((void *) sc, regs->regs.sc, 
-			   &signal_frame_sc.arch) ||
-	   copy_to_user((void *) start, signal_frame_si.data,
-			signal_frame_si.len) ||
-	   copy_to_user((void *) (start + signal_frame_si.sig_index), &sig, 
-			sizeof(sig)) ||
+
+	if(restorer == NULL)
+		panic("setup_signal_stack_si - no restorer");
+
+	if(copy_sc_to_user((void *) sc, regs) ||
+	   copy_to_user((void *) start, signal_frame_si.common.data,
+			signal_frame_si.common.len) ||
+	   copy_to_user((void *) (start + signal_frame_si.common.sig_index), 
+			&sig, sizeof(sig)) ||
 	   copy_siginfo_to_user(sip, info) ||
 	   copy_to_user((void *) (start + signal_frame_si.sip_index), &sip,
 			sizeof(sip)) ||
 	   copy_to_user((void *) sigs, mask, sig_size) ||
-	   copy_restorer(restorer, start, signal_frame_si.sr_index,
-			 signal_frame_si.sr_relative))
+	   copy_restorer(restorer, start, signal_frame_si.common.sr_index,
+			 signal_frame_si.common.sr_relative))
 		return(1);
 	
 	PT_REGS_IP(regs) = handler;
-	PT_REGS_SP(regs) = start + signal_frame_sc.sp_index;
+	PT_REGS_SP(regs) = start + signal_frame_sc.common.sp_index;
 	return(0);
 }
 
@@ -62,26 +74,35 @@ int setup_signal_stack_sc(unsigned long stack_top, int sig,
 			  unsigned long handler, void (*restorer)(void), 
 			  struct pt_regs *regs, sigset_t *mask)
 {
+	struct frame_common *frame = &signal_frame_sc_sr.common;
+	void *user_sc;
 	int sig_size = (_NSIG_WORDS - 1) * sizeof(unsigned long);
-	unsigned long sigs, start = stack_top - signal_frame_sc.len - sig_size;
-	void *user_sc = (void *) (start + signal_frame_sc.sc_index);
+	unsigned long sigs, sr;
+	unsigned long start = stack_top - frame->len - sig_size;
+
+	user_sc = (void *) (start + signal_frame_sc_sr.sc_index);
+	if(restorer == NULL){
+		frame = &signal_frame_sc.common;
+		user_sc = (void *) (start + signal_frame_sc.sc_index);
+		sr = (unsigned long) frame->data;
+		sr += frame->sr_index;
+		sr = *((unsigned long *) sr);
+		restorer = ((void (*)(void)) sr);
+	}
 
-	sigs = start + signal_frame_sc.len;
-	if(copy_to_user((void *) start, signal_frame_sc.data, 
-			signal_frame_sc.len) ||
-	   copy_to_user((void *) (start + signal_frame_sc.sig_index), &sig,
+	sigs = start + frame->len;
+	if(copy_to_user((void *) start, frame->data, frame->len) ||
+	   copy_to_user((void *) (start + frame->sig_index), &sig, 
 			sizeof(sig)) ||
-	   copy_sc_to_user(user_sc, regs->regs.sc, &signal_frame_sc.arch) ||
+	   copy_sc_to_user(user_sc, regs) ||
 	   copy_to_user(sc_sigmask(user_sc), mask, sizeof(mask->sig[0])) ||
 	   copy_to_user((void *) sigs, &mask->sig[1], sig_size) ||
-	   copy_restorer(restorer, start, signal_frame_sc.sr_index,
-			 signal_frame_sc.sr_relative))
+	   copy_restorer(restorer, start, frame->sr_index, frame->sr_relative))
 		return(1);
 
 	PT_REGS_IP(regs) = handler;
-	PT_REGS_SP(regs) = start + signal_frame_sc.sp_index;
+	PT_REGS_SP(regs) = start + frame->sp_index;
 
-	set_sc_ip_sp(regs->regs.sc, handler, start + signal_frame_sc.sp_index);
 	return(0);
 }