From 7e6cb2d0ace1cd889b7336dbaf24ed1f79fbd29e Mon Sep 17 00:00:00 2001
From: hpa <hpa>
Date: Tue, 4 Jan 2005 03:27:43 +0000
Subject: [PATCH] Fix xpread/xpwrite; call die() when we're dead to make sure
 we clean up

---
 extlinux/extlinux.c | 18 ++++++++++--------
 mtools/syslinux.c   | 30 +++++++++++++++---------------
 unix/syslinux.c     | 18 ++++++++----------
 3 files changed, 33 insertions(+), 33 deletions(-)

diff --git a/extlinux/extlinux.c b/extlinux/extlinux.c
index 9c22156..20b580c 100644
--- a/extlinux/extlinux.c
+++ b/extlinux/extlinux.c
@@ -186,25 +186,26 @@ void __attribute__((noreturn)) die(const char *msg)
 }
 
 /*
- * pread() and pwrite() augmented with retry on short access or EINTR.
+ * read/write wrapper functions
  */
 ssize_t xpread(int fd, void *buf, size_t count, off_t offset)
 {
+  char *bufp = (char *)buf;
   ssize_t rv;
   ssize_t done = 0;
 
   while ( count ) {
-    rv = pread(fd, buf, count, offset);
+    rv = pread(fd, bufp, count, offset);
     if ( rv == 0 ) {
       die("short read");
     } else if ( rv == -1 ) {
       if ( errno == EINTR ) {
 	continue;
       } else {
-	perror(program);
-	exit(1);
+	die(strerror(errno));
       }
     } else {
+      bufp += rv;
       offset += rv;
       done += rv;
       count -= rv;
@@ -214,23 +215,24 @@ ssize_t xpread(int fd, void *buf, size_t count, off_t offset)
   return done;
 }
 
-ssize_t xpwrite(int fd, void *buf, size_t count, off_t offset)
+ssize_t xpwrite(int fd, const void *buf, size_t count, off_t offset)
 {
+  const char *bufp = (const char *)buf;
   ssize_t rv;
   ssize_t done = 0;
 
   while ( count ) {
-    rv = pwrite(fd, buf, count, offset);
+    rv = pwrite(fd, bufp, count, offset);
     if ( rv == 0 ) {
       die("short write");
     } else if ( rv == -1 ) {
       if ( errno == EINTR ) {
 	continue;
       } else {
-	perror(program);
-	exit(1);
+	die(strerror(errno));
       }
     } else {
+      bufp += rv;
       offset += rv;
       done += rv;
       count -= rv;
diff --git a/mtools/syslinux.c b/mtools/syslinux.c
index 2db0a75..d7ff0a8 100644
--- a/mtools/syslinux.c
+++ b/mtools/syslinux.c
@@ -44,12 +44,18 @@ char *device;			/* Device to install to */
 pid_t mypid;
 off_t filesystem_offset = 0;	/* Offset of filesystem */
 
-void usage(void)
+void __attribute__((noreturn)) usage(void)
 {
   fprintf(stderr, "Usage: %s [-sf] [-o offset] device\n", program);
   exit(1);
 }
 
+void __attribute__((noreturn)) die(const char *msg)
+{
+  fprintf(stderr, "%s: %s\n", program, msg);
+  exit(1);
+}
+
 /*
  * read/write wrapper functions
  */
@@ -62,14 +68,12 @@ ssize_t xpread(int fd, void *buf, size_t count, off_t offset)
   while ( count ) {
     rv = pread(fd, bufp, count, offset);
     if ( rv == 0 ) {
-      fprintf(stderr, "%s: short read\n", program);
-      exit(1);
+      die("short read");
     } else if ( rv == -1 ) {
       if ( errno == EINTR ) {
 	continue;
       } else {
-	perror(program);
-	exit(1);
+	die(strerror(errno));
       }
     } else {
       bufp += rv;
@@ -82,23 +86,21 @@ ssize_t xpread(int fd, void *buf, size_t count, off_t offset)
   return done;
 }
 
-ssize_t xpwrite(int fd, void *buf, size_t count, off_t offset)
+ssize_t xpwrite(int fd, const void *buf, size_t count, off_t offset)
 {
-  char *bufp = (char *)buf;
+  const char *bufp = (const char *)buf;
   ssize_t rv;
   ssize_t done = 0;
 
   while ( count ) {
     rv = pwrite(fd, bufp, count, offset);
     if ( rv == 0 ) {
-      fprintf(stderr, "%s: short write\n", program);
-      exit(1);
+      die("short write");
     } else if ( rv == -1 ) {
       if ( errno == EINTR ) {
 	continue;
       } else {
-	perror(program);
-	exit(1);
+	die(strerror(errno));
       }
     } else {
       bufp += rv;
@@ -194,8 +196,7 @@ int main(int argc, char *argv[])
    * Check to see that what we got was indeed an MS-DOS boot sector/superblock
    */
   if( (errmsg = syslinux_check_bootsect(sectbuf)) ) {
-    fprintf(stderr, "%s: %s\n", program, errmsg);
-    exit(1);
+    die(errmsg);
   }
 
   /*
@@ -233,8 +234,7 @@ int main(int argc, char *argv[])
        (fwrite(syslinux_ldlinux, 1, syslinux_ldlinux_len, mtp) 
 	!= syslinux_ldlinux_len) ||
        (status = pclose(mtp), !WIFEXITED(status) || WEXITSTATUS(status)) ) {
-    fprintf(stderr, "%s: failed to create ldlinux.sys\n", program);
-    exit(1);
+    die("failed to create ldlinux.sys");
   }
 
   status = system("mattrib +r +h +s s:ldlinux.sys");
diff --git a/unix/syslinux.c b/unix/syslinux.c
index 276990d..32e9dde 100644
--- a/unix/syslinux.c
+++ b/unix/syslinux.c
@@ -104,25 +104,24 @@ void __attribute__((noreturn)) die(const char *msg)
  */
 ssize_t xpread(int fd, void *buf, size_t count, off_t offset)
 {
-  char *p = buf;
+  char *bufp = (char *)buf;
   ssize_t rv;
   ssize_t done = 0;
 
   while ( count ) {
-    rv = pread(fd, p, count, offset);
+    rv = pread(fd, bufp, count, offset);
     if ( rv == 0 ) {
       die("short read");
     } else if ( rv == -1 ) {
       if ( errno == EINTR ) {
 	continue;
       } else {
-	perror(program);
-	exit(1);
+	die(strerror(errno));
       }
     } else {
+      bufp += rv;
       offset += rv;
       done += rv;
-      p += rv;
       count -= rv;
     }
   }
@@ -132,25 +131,24 @@ ssize_t xpread(int fd, void *buf, size_t count, off_t offset)
 
 ssize_t xpwrite(int fd, const void *buf, size_t count, off_t offset)
 {
-  const char *p = buf;
+  const char *bufp = (const char *)buf;
   ssize_t rv;
   ssize_t done = 0;
 
   while ( count ) {
-    rv = pwrite(fd, p, count, offset);
+    rv = pwrite(fd, bufp, count, offset);
     if ( rv == 0 ) {
       die("short write");
     } else if ( rv == -1 ) {
       if ( errno == EINTR ) {
 	continue;
       } else {
-	perror(program);
-	exit(1);
+	die(strerror(errno));
       }
     } else {
+      bufp += rv;
       offset += rv;
       done += rv;
-      p += rv;
       count -= rv;
     }
   }
-- 
2.7.4