From: Eugene Syromyatnikov <evgsyr@gmail.com>
Date: Tue, 16 Jul 2019 00:06:02 +0000 (+0200)
Subject: Add support for printing local arrays to print_array
X-Git-Tag: v5.3~15
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=c5af330802caf0092a10cc099c93e717420b5f4b;p=strace

Add support for printing local arrays to print_array

* defs.h (print_array_ex): Describe parameters.
(print_local_array): A wrapper for printing arrays in local memory
via print_array_ex.
* util.c (print_array_ex): Handle case of NULL tfetch_mem_func by
printing elements of array in local memory pointed by start_addr
parameter.
---

diff --git a/defs.h b/defs.h
index 337c9bd7..ccfe673c 100644
--- a/defs.h
+++ b/defs.h
@@ -852,8 +852,29 @@ typedef const char * (*sprint_obj_by_addr_fn)(struct tcb *, kernel_ulong_t);
 
 
 /**
- * @param flags Combination of xlat style settings and additional flags from
- *              enum print_array_flags.
+ * Array printing function with over-engineered interface.
+ *
+ * @param start_addr       If tfetch_mem_fn is non-NULL: address in tracee's
+ *                         memory where the start of the array is located.
+ *                         If tfetch_mem_fn is NULL: ignored.
+ * @param nmemb            Number of elements in array.
+ * @param elem_buf         If tfetch_mem_fn is non-NULL: a buffer where each
+ *                         element fetched by tfetch_mem_fn is stored.
+ *                         If tfetch_mem_fn is NULL: address of the start of
+ *                         the array in local memory.
+ * @param elem_size        Size (in bytes) of each element in the array.
+ * @param tfetch_mem_fn    Fetching function. If NULL, then elem_buf is treated
+ *                         as local array of nmemb members elem_size each;
+ *                         start_addr is ignored.
+ * @param print_func       Element printing callback.
+ * @param opaque_data      A value that is unconditionally passed to print_func
+ *                         in opaque_data argument.
+ * @param flags            Combination of xlat style settings and additional
+ *                         flags from enum print_array_flags.
+ * @param index_xlat       Xlat array that is used for printing indices.
+ * @param index_xlat_size  The size of xlat array.
+ * @param index_dflt       Default string for the values not found
+ *                         in index_xlat.
  */
 extern bool
 print_array_ex(struct tcb *,
@@ -868,6 +889,7 @@ print_array_ex(struct tcb *,
 	       const struct xlat *index_xlat,
 	       const char *index_dflt);
 
+/** Print an array from tracee's memory without any index printing features. */
 static inline bool
 print_array(struct tcb *const tcp,
 	    const kernel_ulong_t start_addr,
@@ -883,6 +905,22 @@ print_array(struct tcb *const tcp,
 			      0, NULL, NULL);
 }
 
+/** Shorthand for printing local arrays. */
+static inline bool
+print_local_array(struct tcb *tcp,
+		  void *start_addr,
+		  const size_t nmemb,
+		  void *const elem_buf,
+		  const size_t elem_size,
+		  print_fn print_func,
+		  void *const opaque_data,
+		  unsigned int flags)
+{
+	return print_array_ex(tcp, (uintptr_t) start_addr , nmemb,
+			      elem_buf, elem_size, NULL, print_func,
+			      opaque_data, flags, NULL, NULL);
+}
+
 extern kernel_ulong_t *
 fetch_indirect_syscall_args(struct tcb *, kernel_ulong_t addr, unsigned int n_args);
 
diff --git a/util.c b/util.c
index 34561c47..db733b83 100644
--- a/util.c
+++ b/util.c
@@ -1275,7 +1275,7 @@ bool
 print_array_ex(struct tcb *const tcp,
 	       const kernel_ulong_t start_addr,
 	       const size_t nmemb,
-	       void *const elem_buf,
+	       void *elem_buf,
 	       const size_t elem_size,
 	       tfetch_mem_fn tfetch_mem_func,
 	       print_fn print_func,
@@ -1298,7 +1298,10 @@ print_array_ex(struct tcb *const tcp,
 	const kernel_ulong_t end_addr = start_addr + size;
 
 	if (end_addr <= start_addr || size / elem_size != nmemb) {
-		printaddr(start_addr);
+		if (tfetch_mem_func)
+			printaddr(start_addr);
+		else
+			tprints("???");
 		return false;
 	}
 
@@ -1313,14 +1316,18 @@ print_array_ex(struct tcb *const tcp,
 		if (cur != start_addr)
 			tprints(", ");
 
-		if (!tfetch_mem_func(tcp, cur, elem_size, elem_buf)) {
-			if (cur == start_addr)
-				printaddr(cur);
-			else {
-				tprints("...");
-				printaddr_comment(cur);
+		if (tfetch_mem_func) {
+			if (!tfetch_mem_func(tcp, cur, elem_size, elem_buf)) {
+				if (cur == start_addr)
+					printaddr(cur);
+				else {
+					tprints("...");
+					printaddr_comment(cur);
+				}
+				break;
 			}
-			break;
+		} else {
+			elem_buf = (void *) (uintptr_t) cur;
 		}
 
 		if (cur == start_addr)