x86/vdso, build: When vdso2c fails, unlink the output

This avoids bizarre failures if make is run again.

Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Link: http://lkml.kernel.org/r/1764385fe9931e8940b9d001132515448ea89523.1401464755.git.luto@amacapital.net
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

2 files changed, 14 insertions, 16 deletions

diff --git a/arch/x86/vdso/vdso2c.c b/arch/x86/vdso/vdso2c.c
index 81edd1ec9df8..fe8bfbf62612 100644
--- a/arch/x86/vdso/vdso2c.c
+++ b/arch/x86/vdso/vdso2c.c
@@ -14,6 +14,8 @@
 #include <linux/elf.h>
 #include <linux/types.h>
 
+const char *outfilename;
+
 /* Symbols that we need in vdso2c. */
 enum {
         sym_vvar_page,
@@ -44,6 +46,7 @@ static void fail(const char *format, ...)
         va_start(ap, format);
         fprintf(stderr, "Error: ");
         vfprintf(stderr, format, ap);
+        unlink(outfilename);
         exit(1);
         va_end(ap);
 }
@@ -82,17 +85,16 @@ static void fail(const char *format, ...)
 #undef Elf_Sym
 #undef Elf_Dyn
 
-static int go(void *addr, size_t len, FILE *outfile, const char *name)
+static void go(void *addr, size_t len, FILE *outfile, const char *name)
 {
         Elf64_Ehdr *hdr = (Elf64_Ehdr *)addr;
 
         if (hdr->e_ident[EI_CLASS] == ELFCLASS64) {
-                return go64(addr, len, outfile, name);
+                go64(addr, len, outfile, name);
         } else if (hdr->e_ident[EI_CLASS] == ELFCLASS32) {
-                return go32(addr, len, outfile, name);
+                go32(addr, len, outfile, name);
         } else {
-                fprintf(stderr, "Error: unknown ELF class\n");
-                return 1;
+                fail("unknown ELF class\n");
         }
 }
 
@@ -102,7 +104,6 @@ int main(int argc, char **argv)
         off_t len;
         void *addr;
         FILE *outfile;
-        int ret;
         char *name, *tmp;
         int namelen;
 
@@ -143,14 +144,15 @@ int main(int argc, char **argv)
         if (addr == MAP_FAILED)
                 err(1, "mmap");
 
-        outfile = fopen(argv[2], "w");
+        outfilename = argv[2];
+        outfile = fopen(outfilename, "w");
         if (!outfile)
                 err(1, "%s", argv[2]);
 
-        ret = go(addr, (size_t)len, outfile, name);
+        go(addr, (size_t)len, outfile, name);
 
         munmap(addr, len);
         fclose(outfile);
 
-        return ret;
+        return 0;
 }
diff --git a/arch/x86/vdso/vdso2c.h b/arch/x86/vdso/vdso2c.h
index 3dcc61e796e9..26a7c1fa7452 100644
--- a/arch/x86/vdso/vdso2c.h
+++ b/arch/x86/vdso/vdso2c.h
@@ -4,7 +4,7 @@
  * are built for 32-bit userspace.
  */
 
-static int GOFUNC(void *addr, size_t len, FILE *outfile, const char *name)
+static void GOFUNC(void *addr, size_t len, FILE *outfile, const char *name)
 {
         int found_load = 0;
         unsigned long load_size = -1;  /* Work around bogus warning */
@@ -62,10 +62,8 @@ static int GOFUNC(void *addr, size_t len, FILE *outfile, const char *name)
                         alt_sec = sh;
         }
 
-        if (!symtab_hdr) {
+        if (!symtab_hdr)
                 fail("no symbol table\n");
-                return 1;
-        }
 
         strtab_hdr = addr + hdr->e_shoff +
                 hdr->e_shentsize * symtab_hdr->sh_link;
@@ -112,7 +110,7 @@ static int GOFUNC(void *addr, size_t len, FILE *outfile, const char *name)
 
         if (!name) {
                 fwrite(addr, load_size, 1, outfile);
-                return 0;
+                return;
         }
 
         fprintf(outfile, "/* AUTOMATICALLY GENERATED -- DO NOT EDIT */\n\n");
@@ -152,6 +150,4 @@ static int GOFUNC(void *addr, size_t len, FILE *outfile, const char *name)
                                 required_syms[i], syms[i]);
         }
         fprintf(outfile, "};\n");
-
-        return 0;
 }