[Qemu-devel] [PATCH v2 0/3] Misc small fixes in cmd.c

[Qemu-devel] [PATCH v2 0/3] Misc small fixes in cmd.c

[Pavel Borzenkov]

The first patch fixes coding style of the functions affected by next two
patches.
Second patch fixes potential NULL pointer dereference (return value of realloc
is not checked).
Third patch fixes potential memory leak (for the case when realloc returns
NULL).

Pavel Borzenkov (3):
  cmd: Fix coding style in cmd.c
  cmd: Fix potential NULL pointer dereference
  cmd: Fix potential memory leak

 cmd.c |  168 ++++++++++++++++++++++++++++++++---------------------------------
 1 files changed, 82 insertions(+), 86 deletions(-)

[Qemu-devel] [PATCH v2 1/3] cmd: Fix coding style in cmd.c

[Pavel Borzenkov]

Before the next patches, fix coding style of the affected functions.

Signed-off-by: Pavel Borzenkov <pavel.borzenkov@gmail.com>
---
 cmd.c |  168 ++++++++++++++++++++++++++++++++---------------------------------
 1 files changed, 82 insertions(+), 86 deletions(-)

diff --git a/cmd.c b/cmd.c
index f77897e..a6e3ef4 100644
--- a/cmd.c
+++ b/cmd.c
@@ -45,13 +45,11 @@ compare(const void *a, const void *b)
 		      ((const cmdinfo_t *)b)->name);
 }
 
-void
-add_command(
-	const cmdinfo_t	*ci)
+void add_command(const cmdinfo_t *ci)
 {
-	cmdtab = realloc((void *)cmdtab, ++ncmds * sizeof(*cmdtab));
-	cmdtab[ncmds - 1] = *ci;
-	qsort(cmdtab, ncmds, sizeof(*cmdtab), compare);
+    cmdtab = realloc((void *)cmdtab, ++ncmds * sizeof(*cmdtab));
+    cmdtab[ncmds - 1] = *ci;
+    qsort(cmdtab, ncmds, sizeof(*cmdtab), compare);
 }
 
 static int
@@ -122,16 +120,15 @@ find_command(
 	return NULL;
 }
 
-void
-add_user_command(char *optarg)
+void add_user_command(char *optarg)
 {
-	ncmdline++;
-	cmdline = realloc(cmdline, sizeof(char*) * (ncmdline));
-	if (!cmdline) {
-		perror("realloc");
-		exit(1);
-	}
-	cmdline[ncmdline-1] = optarg;
+    ncmdline++;
+    cmdline = realloc(cmdline, ncmdline * sizeof(char *));
+    if (!cmdline) {
+        perror("realloc");
+        exit(1);
+    }
+    cmdline[ncmdline-1] = optarg;
 }
 
 static int
@@ -160,45 +157,44 @@ static void prep_fetchline(void *opaque)
 
 static char *get_prompt(void);
 
-void
-command_loop(void)
+void command_loop(void)
 {
-	int		c, i, j = 0, done = 0, fetchable = 0, prompted = 0;
-	char		*input;
-	char		**v;
-	const cmdinfo_t	*ct;
-
-	for (i = 0; !done && i < ncmdline; i++) {
-		input = strdup(cmdline[i]);
-		if (!input) {
-			fprintf(stderr,
-				_("cannot strdup command '%s': %s\n"),
-				cmdline[i], strerror(errno));
-			exit(1);
-		}
-		v = breakline(input, &c);
-		if (c) {
-			ct = find_command(v[0]);
-			if (ct) {
-				if (ct->flags & CMD_FLAG_GLOBAL)
-					done = command(ct, c, v);
-				else {
-					j = 0;
-					while (!done && (j = args_command(j)))
-						done = command(ct, c, v);
-				}
-			} else
-				fprintf(stderr, _("command \"%s\" not found\n"),
-					v[0]);
-		}
-		doneline(input, v);
-	}
-	if (cmdline) {
-		free(cmdline);
-		return;
+    int c, i, j = 0, done = 0, fetchable = 0, prompted = 0;
+    char *input;
+    char **v;
+    const cmdinfo_t *ct;
+
+    for (i = 0; !done && i < ncmdline; i++) {
+        input = strdup(cmdline[i]);
+        if (!input) {
+            fprintf(stderr, _("cannot strdup command '%s': %s\n"),
+                    cmdline[i], strerror(errno));
+            exit(1);
+        }
+        v = breakline(input, &c);
+        if (c) {
+            ct = find_command(v[0]);
+            if (ct) {
+                if (ct->flags & CMD_FLAG_GLOBAL) {
+                    done = command(ct, c, v);
+                } else {
+                    j = 0;
+                    while (!done && (j = args_command(j))) {
+                        done = command(ct, c, v);
+                    }
+                }
+            } else {
+                fprintf(stderr, _("command \"%s\" not found\n"), v[0]);
+            }
 	}
+        doneline(input, v);
+    }
+    if (cmdline) {
+        free(cmdline);
+        return;
+    }
 
-	while (!done) {
+    while (!done) {
         if (!prompted) {
             printf("%s", get_prompt());
             fflush(stdout);
@@ -212,22 +208,24 @@ command_loop(void)
         if (!fetchable) {
             continue;
         }
-		if ((input = fetchline()) == NULL)
-			break;
-		v = breakline(input, &c);
-		if (c) {
-			ct = find_command(v[0]);
-			if (ct)
-				done = command(ct, c, v);
-			else
-				fprintf(stderr, _("command \"%s\" not found\n"),
-					v[0]);
-		}
-		doneline(input, v);
+        input = fetchline();
+        if (input == NULL) {
+            break;
+        }
+        v = breakline(input, &c);
+        if (c) {
+            ct = find_command(v[0]);
+            if (ct) {
+                done = command(ct, c, v);
+            } else {
+                fprintf(stderr, _("command \"%s\" not found\n"), v[0]);
+            }
+        }
+        doneline(input, v);
 
         prompted = 0;
         fetchable = 0;
-	}
+    }
     qemu_aio_set_fd_handler(STDIN_FILENO, NULL, NULL, NULL, NULL, NULL);
 }
 
@@ -331,29 +329,27 @@ static char *qemu_strsep(char **input, const char *delim)
     return result;
 }
 
-char **
-breakline(
-	char	*input,
-	int	*count)
+char **breakline(char *input, int *count)
 {
-	int	c = 0;
-	char	*p;
-	char	**rval = calloc(sizeof(char *), 1);
-
-	while (rval && (p = qemu_strsep(&input, " ")) != NULL) {
-		if (!*p)
-			continue;
-		c++;
-		rval = realloc(rval, sizeof(*rval) * (c + 1));
-		if (!rval) {
-			c = 0;
-			break;
-		}
-		rval[c - 1] = p;
-		rval[c] = NULL;
-	}
-	*count = c;
-	return rval;
+    int c = 0;
+    char *p;
+    char **rval = calloc(sizeof(char *), 1);
+
+    while (rval && (p = qemu_strsep(&input, " ")) != NULL) {
+        if (!*p) {
+            continue;
+        }
+        c++;
+        rval = realloc(rval, sizeof(*rval) * (c + 1));
+        if (!rval) {
+            c = 0;
+            break;
+        }
+        rval[c - 1] = p;
+        rval[c] = NULL;
+    }
+    *count = c;
+    return rval;
 }
 
 void
-- 
1.7.0.4

[Qemu-devel] [PATCH v2 2/3] cmd: Fix potential NULL pointer dereference

[Pavel Borzenkov]

Signed-off-by: Pavel Borzenkov <pavel.borzenkov@gmail.com>
---
 cmd.c |   11 +++--------
 1 files changed, 3 insertions(+), 8 deletions(-)

diff --git a/cmd.c b/cmd.c
index a6e3ef4..75415d8 100644
--- a/cmd.c
+++ b/cmd.c
@@ -47,7 +47,7 @@ compare(const void *a, const void *b)
 
 void add_command(const cmdinfo_t *ci)
 {
-    cmdtab = realloc((void *)cmdtab, ++ncmds * sizeof(*cmdtab));
+    cmdtab = g_realloc((void *)cmdtab, ++ncmds * sizeof(*cmdtab));
     cmdtab[ncmds - 1] = *ci;
     qsort(cmdtab, ncmds, sizeof(*cmdtab), compare);
 }
@@ -122,12 +122,7 @@ find_command(
 
 void add_user_command(char *optarg)
 {
-    ncmdline++;
-    cmdline = realloc(cmdline, ncmdline * sizeof(char *));
-    if (!cmdline) {
-        perror("realloc");
-        exit(1);
-    }
+    cmdline = g_realloc(cmdline, ++ncmdline * sizeof(char *));
     cmdline[ncmdline-1] = optarg;
 }
 
@@ -190,7 +185,7 @@ void command_loop(void)
         doneline(input, v);
     }
     if (cmdline) {
-        free(cmdline);
+        g_free(cmdline);
         return;
     }
 
-- 
1.7.0.4

[Qemu-devel] [PATCH v2 3/3] cmd: Fix potential memory leak

[Pavel Borzenkov]

Signed-off-by: Pavel Borzenkov <pavel.borzenkov@gmail.com>
---
 cmd.c |    9 +++++++--
 1 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/cmd.c b/cmd.c
index 75415d8..0806e18 100644
--- a/cmd.c
+++ b/cmd.c
@@ -329,16 +329,21 @@ char **breakline(char *input, int *count)
     int c = 0;
     char *p;
     char **rval = calloc(sizeof(char *), 1);
+    char **tmp;
 
     while (rval && (p = qemu_strsep(&input, " ")) != NULL) {
         if (!*p) {
             continue;
         }
         c++;
-        rval = realloc(rval, sizeof(*rval) * (c + 1));
-        if (!rval) {
+        tmp = realloc(rval, sizeof(*rval) * (c + 1));
+        if (!tmp) {
+            free(rval);
+            rval = NULL;
             c = 0;
             break;
+        } else {
+            rval = tmp;
         }
         rval[c - 1] = p;
         rval[c] = NULL;
-- 
1.7.0.4

Re: [Qemu-devel] [PATCH v2 0/3] Misc small fixes in cmd.c

[Stefan Hajnoczi]

On Mon, Oct 31, 2011 at 10:53:35PM +0400, Pavel Borzenkov wrote:
> The first patch fixes coding style of the functions affected by next two
> patches.
> Second patch fixes potential NULL pointer dereference (return value of realloc
> is not checked).
> Third patch fixes potential memory leak (for the case when realloc returns
> NULL).
> 
> Pavel Borzenkov (3):
>   cmd: Fix coding style in cmd.c
>   cmd: Fix potential NULL pointer dereference
>   cmd: Fix potential memory leak
> 
>  cmd.c |  168 ++++++++++++++++++++++++++++++++---------------------------------
>  1 files changed, 82 insertions(+), 86 deletions(-)

Thanks, applied to the trivial patches -next tree:

http://repo.or.cz/w/qemu/stefanha.git/shortlog/refs/heads/trivial-patches-next

Stefan