[Xen-devel] [PATCH 01 of 18] tools/blktap: fix access errors in convert_dev_name_to_num

[Olaf Hering <olaf@xxxxxxxxx>]

# HG changeset patch
# User Olaf Hering <olaf@xxxxxxxxx>
# Date 1333046226 -7200
# Node ID 1c86e2e5268d14587c736e3f575d0aa42869de83
# Parent  4bd752a4cdf323c41c50f8cd6286f566d67adeae
tools/blktap: fix access errors in convert_dev_name_to_num

xs_api.c: In function 'convert_dev_name_to_num':
xs_api.c:227:4: warning: value computed is not used [-Wunused-value]
xs_api.c:229:3: warning: value computed is not used [-Wunused-value]
xs_api.c:235:4: warning: value computed is not used [-Wunused-value]
xs_api.c:237:3: warning: value computed is not used [-Wunused-value]
xs_api.c:244:4: warning: value computed is not used [-Wunused-value]
xs_api.c:246:3: warning: value computed is not used [-Wunused-value]

ptr should be increased in each iteration, not the char it points to.
At the end p should be increased as well to get to the number, not the
char it points to.

Luckily, the function can not be called from ueblktap_setup() due to a
logic eror.

Signed-off-by: Olaf Hering <olaf@xxxxxxxxx>

diff -r 4bd752a4cdf3 -r 1c86e2e5268d tools/blktap/lib/xs_api.c
--- a/tools/blktap/lib/xs_api.c
+++ b/tools/blktap/lib/xs_api.c
@@ -210,40 +210,41 @@ done:
 }
 
 int convert_dev_name_to_num(char *name) {
-       char *p, *ptr;
+       char *p;
+       const char *ptr;
        int majors[10] = {3,22,33,34,56,57,88,89,90,91};
        int maj,i,ret = 0;
-       char *p_sd = "/dev/sd";
-       char *p_hd = "/dev/hd";
-       char *p_xvd = "/dev/xvd";
-       char *p_plx = "plx";
-       char *alpha = "abcdefghijklmnop";
+       static const char p_sd[] = "/dev/sd";
+       static const char p_hd[] = "/dev/hd";
+       static const char p_xvd[] = "/dev/xvd";
+       static const char p_plx[] = "plx";
+       static const char alpha[] = "abcdefghijklmnop";
 
        if (strstr(name, p_sd) != NULL) {
                p = name + strlen(p_sd);
                for(i = 0, ptr = alpha; i < strlen(alpha); i++) {
                        if(*ptr == *p)
                                break;
-                       *ptr++;
+                       ptr++;
                }
-               *p++;
+               p++;
                ret = BASE_DEV_VAL + (16*i) + atoi(p);
        } else if (strstr(name, p_hd) != NULL) {
                p = name + strlen(p_hd);
                for (i = 0, ptr = alpha; i < strlen(alpha); i++) {
                        if(*ptr == *p) break;
-                       *ptr++;
+                       ptr++;
                }
-               *p++;
+               p++;
                ret = (majors[i/2]*256) + atoi(p);
 
        } else if (strstr(name, p_xvd) != NULL) {
                p = name + strlen(p_xvd);
                for(i = 0, ptr = alpha; i < strlen(alpha); i++) {
                        if(*ptr == *p) break;
-                       *ptr++;
+                       ptr++;
                }
-               *p++;
+               p++;
                ret = (202*256) + (16*i) + atoi(p);
 
        } else if (strstr(name, p_plx) != NULL) {

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