[PATCH] uml: system call path cleanup

This merges two sets of files which had no business being split apart in the
first place.

Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/um/include/syscall.h

@@ -0,0 +1,12 @@
+/*
+ * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
+ * Licensed under the GPL
+ */
+
+#ifndef __SYSCALL_USER_H
+#define __SYSCALL_USER_H
+
+extern int record_syscall_start(int syscall);
+extern void record_syscall_end(int index, long result);
+
+#endif

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

@@ -16,6 +16,8 @@ extern syscall_handler_t sys_rt_sigaction;
 
 extern syscall_handler_t old_mmap_i386;
 
+extern syscall_handler_t *sys_call_table[];
+
 #define EXECUTE_SYSCALL(syscall, regs) \
 	((long (*)(struct syscall_args)) (*sys_call_table[syscall]))(SYSCALL_ARGS(&regs->regs))
 

arch/um/include/sysdep-x86_64/syscalls.h

@@ -14,6 +14,8 @@ typedef long syscall_handler_t(void);
 
 extern syscall_handler_t *ia32_sys_call_table[];
 
+extern syscall_handler_t *sys_call_table[];
+
 #define EXECUTE_SYSCALL(syscall, regs) \
 	(((long (*)(long, long, long, long, long, long)) \
 	  (*sys_call_table[syscall]))(UPT_SYSCALL_ARG1(&regs->regs), \

arch/um/kernel/Makefile

@@ -18,7 +18,7 @@ obj-$(CONFIG_BLK_DEV_INITRD) += initrd.o
 obj-$(CONFIG_GPROF)	+= gprof_syms.o
 obj-$(CONFIG_GCOV)	+= gmon_syms.o
 obj-$(CONFIG_TTY_LOG)	+= tty_log.o
-obj-$(CONFIG_SYSCALL_DEBUG) += syscall_user.o
+obj-$(CONFIG_SYSCALL_DEBUG) += syscall.o
 
 obj-$(CONFIG_MODE_TT) += tt/
 obj-$(CONFIG_MODE_SKAS) += skas/

arch/um/kernel/skas/Makefile

@@ -4,7 +4,7 @@
 #
 
 obj-y := clone.o exec_kern.o mem.o mem_user.o mmu.o process.o process_kern.o \
-	syscall_kern.o syscall_user.o tlb.o trap_user.o uaccess.o \
+	syscall.o tlb.o trap_user.o uaccess.o
 
 subdir- := util
 

arch/um/kernel/skas/syscall.c

@@ -0,0 +1,50 @@
+/*
+ * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
+ * Licensed under the GPL
+ */
+
+#include "linux/sys.h"
+#include "linux/ptrace.h"
+#include "asm/errno.h"
+#include "asm/unistd.h"
+#include "asm/ptrace.h"
+#include "asm/current.h"
+#include "sysdep/syscalls.h"
+#include "kern_util.h"
+#include "syscall.h"
+
+void handle_syscall(union uml_pt_regs *r)
+{
+	struct pt_regs *regs = container_of(r, struct pt_regs, regs);
+	long result;
+	int syscall;
+#ifdef UML_CONFIG_SYSCALL_DEBUG
+  	int index;
+
+  	index = record_syscall_start(UPT_SYSCALL_NR(r));
+#endif
+	syscall_trace(r, 0);
+
+	current->thread.nsyscalls++;
+	nsyscalls++;
+
+	/* This should go in the declaration of syscall, but when I do that,
+	 * strace -f -c bash -c 'ls ; ls' breaks, sometimes not tracing
+	 * children at all, sometimes hanging when bash doesn't see the first
+	 * ls exit.
+	 * The assembly looks functionally the same to me.  This is
+	 *     gcc version 4.0.1 20050727 (Red Hat 4.0.1-5)
+	 * in case it's a compiler bug.
+	 */
+	syscall = UPT_SYSCALL_NR(r);
+	if((syscall >= NR_syscalls) || (syscall < 0))
+		result = -ENOSYS;
+	else result = EXECUTE_SYSCALL(syscall, regs);
+
+	REGS_SET_SYSCALL_RETURN(r->skas.regs, result);
+
+	syscall_trace(r, 1);
+#ifdef UML_CONFIG_SYSCALL_DEBUG
+  	record_syscall_end(index, result);
+#endif
+}

arch/um/kernel/syscall.c

@@ -0,0 +1,36 @@
+/*
+ * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
+ * Licensed under the GPL
+ */
+
+#include "kern_util.h"
+#include "syscall.h"
+#include "os.h"
+
+struct {
+	int syscall;
+	int pid;
+	long result;
+	unsigned long long start;
+	unsigned long long end;
+} syscall_record[1024];
+
+int record_syscall_start(int syscall)
+{
+	int max, index;
+
+	max = sizeof(syscall_record)/sizeof(syscall_record[0]);
+	index = next_syscall_index(max);
+
+	syscall_record[index].syscall = syscall;
+	syscall_record[index].pid = current_pid();
+	syscall_record[index].result = 0xdeadbeef;
+	syscall_record[index].start = os_usecs();
+	return(index);
+}
+
+void record_syscall_end(int index, long result)
+{
+	syscall_record[index].result = result;
+	syscall_record[index].end = os_usecs();
+}

arch/um/kernel/tt/syscall_kern.c

@@ -12,36 +12,41 @@
 #include "asm/uaccess.h"
 #include "asm/stat.h"
 #include "sysdep/syscalls.h"
+#include "sysdep/sigcontext.h"
 #include "kern_util.h"
+#include "syscall.h"
 
-extern syscall_handler_t *sys_call_table[];
-
-long execute_syscall_tt(void *r)
+void syscall_handler_tt(int sig, struct pt_regs *regs)
 {
-	struct pt_regs *regs = r;
-	long res;
+	void *sc;
+	long result;
 	int syscall;
-
 #ifdef CONFIG_SYSCALL_DEBUG
+	int index;
+  	index = record_syscall_start(syscall);
+#endif
+	sc = UPT_SC(&regs->regs);
+	SC_START_SYSCALL(sc);
+
+	syscall_trace(&regs->regs, 0);
+
 	current->thread.nsyscalls++;
 	nsyscalls++;
-#endif
 	syscall = UPT_SYSCALL_NR(&regs->regs);
 
 	if((syscall >= NR_syscalls) || (syscall < 0))
-		res = -ENOSYS;
-	else res = EXECUTE_SYSCALL(syscall, regs);
+		result = -ENOSYS;
+	else result = EXECUTE_SYSCALL(syscall, regs);
 
-	return(res);
-}
+	/* regs->sc may have changed while the system call ran (there may
+	 * have been an interrupt or segfault), so it needs to be refreshed.
+	 */
+	UPT_SC(&regs->regs) = sc;
 
-/*
- * Overrides for Emacs so that we follow Linus's tabbing style.
- * Emacs will notice this stuff at the end of the file and automatically
- * adjust the settings for this buffer only.  This must remain at the end
- * of the file.
- * ---------------------------------------------------------------------------
- * Local variables:
- * c-file-style: "linux"
- * End:
- */
+	SC_SET_SYSCALL_RETURN(sc, result);
+
+	syscall_trace(&regs->regs, 1);
+#ifdef CONFIG_SYSCALL_DEBUG
+  	record_syscall_end(index, result);
+#endif
+}