[PATCH 1/2] x86,vdso: When vdso2c fails, unlink the output

Andy Lutomirski
2014-05-29T21:58:03Z

This avoids bizarre failures if make is run again.

Signed-off-by: Andy Lutomirski <luto@amacapital.net>
---
arch/x86/vdso/vdso2c.c | 20 +++++++++++---------
arch/x86/vdso/vdso2c.h | 10 +++-------
2 files changed, 14 insertions(+), 16 deletions(-)

diff --git a/arch/x86/vdso/vdso2c.c b/arch/x86/vdso/vdso2c.c
index 81edd1e..fe8bfbf 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 3dcc61e..26a7c1f 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;
}
--
1.9.3