[PATCHv4] print stack trace after each syscall

[Masatake YAMATO]

> In the patch `delete_mmap_cache' is used as a trigger for updating
> proc/maps info cache.  It is called as expected when mmap and friends
> are traced.  However, if the tracing is disabled with -e option, strae
> misses the chance to updating the info cache.

Could you review this patch for the bug I reported and merge if appreciated.

`REQUIRED_BY_STACKTRACE' is introduced to trigger the `delete_mmap_cache'.

Masatake YAMATO



diff --git a/defs.h b/defs.h
index 7f76008..46188c9 100644
--- a/defs.h
+++ b/defs.h
@@ -557,6 +557,7 @@ extern const struct xlat whence_codes[];
 #define TRACE_DESC	040	/* Trace file descriptor-related syscalls. */
 #define TRACE_MEMORY	0100	/* Trace memory mapping-related syscalls. */
 #define SYSCALL_NEVER_FAILS	0200	/* Syscall is always successful. */
+#define REQUIRED_BY_STACKTRACE  0400	/* Trigger proc/maps cache updating */
 
 typedef enum {
 	CFLAG_NONE = 0,
diff --git a/linux/x86_64/syscallent.h b/linux/x86_64/syscallent.h
index 8e3a200..a710401 100644
--- a/linux/x86_64/syscallent.h
+++ b/linux/x86_64/syscallent.h
@@ -7,9 +7,9 @@
 	{ 2,	TF,	sys_lstat,		"lstat"		},  /* 6 */
 	{ 3,	TD,	sys_poll,		"poll"		},  /* 7 */
 	{ 3,	TD,	sys_lseek,		"lseek"		},  /* 8 */
-	{ 6,	TD|TM,	sys_mmap,		"mmap"		},  /* 9 */
-	{ 3,	TM,	sys_mprotect,		"mprotect"	},  /* 10 */
-	{ 2,	TM,	sys_munmap,		"munmap"	},  /* 11 */
+	{ 6,	TD|TM|RT,sys_mmap,		"mmap"		},  /* 9 */
+	{ 3,	TM|RT,	sys_mprotect,		"mprotect"	},  /* 10 */
+	{ 2,	TM|RT,	sys_munmap,		"munmap"	},  /* 11 */
 	{ 1,	TM,	sys_brk,		"brk"		},  /* 12 */
 	{ 4,	TS,	sys_rt_sigaction,	"rt_sigaction"	},  /* 13 */
 	{ 4,	TS,	sys_rt_sigprocmask,	"rt_sigprocmask"},  /* 14 */
@@ -23,7 +23,7 @@
 	{ 1,	TD,	sys_pipe,		"pipe"		},  /* 22 */
 	{ 5,	TD,	sys_select,		"select"	},  /* 23 */
 	{ 0,	0,	sys_sched_yield,	"sched_yield"	},  /* 24 */
-	{ 5,	TM,	sys_mremap,		"mremap"	},  /* 25 */
+	{ 5,	TM|RT,	sys_mremap,		"mremap"	},  /* 25 */
 	{ 3,	TM,	sys_msync,		"msync"		},  /* 26 */
 	{ 3,	TM,	sys_mincore,		"mincore"	},  /* 27 */
 	{ 3,	TM,	sys_madvise,		"madvise"	},  /* 28 */
@@ -57,7 +57,7 @@
 	{ 5,	TP,	sys_clone,		"clone"		},  /* 56 */
 	{ 0,	TP,	sys_fork,		"fork"		},  /* 57 */
 	{ 0,	TP,	sys_vfork,		"vfork"		},  /* 58 */
-	{ 3,	TF|TP,	sys_execve,		"execve"	},  /* 59 */
+	{ 3,	TF|TP|RT,sys_execve,		"execve"	},  /* 59 */
 	{ 1,	TP,	sys_exit,		"_exit"		},  /* 60 */
 	{ 4,	TP,	sys_wait4,		"wait4"		},  /* 61 */
 	{ 2,	TS,	sys_kill,		"kill"		},  /* 62 */
diff --git a/mem.c b/mem.c
index ca6caa1..ef273c7 100644
--- a/mem.c
+++ b/mem.c
@@ -175,11 +175,6 @@ static int
 print_mmap(struct tcb *tcp, long *u_arg, unsigned long long offset)
 {
 	if (entering(tcp)) {
-#ifdef USE_LIBUNWIND
-		if (stack_trace_enabled)
-			delete_mmap_cache(tcp);
-#endif
-
 		/* addr */
 		if (!u_arg[0])
 			tprints("NULL, ");
@@ -309,12 +304,6 @@ sys_munmap(struct tcb *tcp)
 		tprintf("%#lx, %lu",
 			tcp->u_arg[0], tcp->u_arg[1]);
 	}
-#ifdef USE_LIBUNWIND
-	else {
-		if (stack_trace_enabled)
-			delete_mmap_cache(tcp);
-	}
-#endif
 	return 0;
 }
 
@@ -326,12 +315,6 @@ sys_mprotect(struct tcb *tcp)
 			tcp->u_arg[0], tcp->u_arg[1]);
 		printflags(mmap_prot, tcp->u_arg[2], "PROT_???");
 	}
-#ifdef USE_LIBUNWIND
-	else {
-		if (stack_trace_enabled)
-			delete_mmap_cache(tcp);
-	}
-#endif
 	return 0;
 }
 
diff --git a/process.c b/process.c
index 22bb5b6..aaea9c5 100644
--- a/process.c
+++ b/process.c
@@ -992,12 +992,6 @@ sys_execve(struct tcb *tcp)
 			tprints("]");
 		}
 	}
-#ifdef USE_LIBUNWIND
-	else {
-		if (stack_trace_enabled)
-			delete_mmap_cache(tcp);
-	}
-#endif
 
 	return 0;
 }
diff --git a/syscall.c b/syscall.c
index b01c023..7ddde88 100644
--- a/syscall.c
+++ b/syscall.c
@@ -97,6 +97,7 @@
 #define TM TRACE_MEMORY
 #define NF SYSCALL_NEVER_FAILS
 #define MA MAX_ARGS
+#define RT REQUIRED_BY_STACKTRACE
 
 const struct_sysent sysent0[] = {
 #include "syscallent.h"
@@ -2712,6 +2713,11 @@ trace_syscall_exiting(struct tcb *tcp)
 #endif
 
  ret:
+#ifdef USE_LIBUNWIND
+	if (stack_trace_enabled)
+	  if (tcp->s_ent->sys_flags & REQUIRED_BY_STACKTRACE)
+	    delete_mmap_cache(tcp);
+#endif
 	tcp->flags &= ~TCB_INSYSCALL;
 	return 0;
 }