path: root/arch/blackfin/lib
diff options
authorWolfgang Denk <wd@denx.de>2010-06-28 22:00:46 +0200
committerWolfgang Denk <wd@denx.de>2010-07-04 23:55:42 +0200
commit54841ab50c20d6fa6c9cc3eb826989da3a22d934 (patch)
tree400f22f0a12ff0ae6c472bed6ac648befc1744a2 /arch/blackfin/lib
parentb218ccb5435e64ac2318bb8b6c9594ef1cc724cd (diff)
Make sure that argv[] argument pointers are not modified.
The hush shell dynamically allocates (and re-allocates) memory for the argument strings in the "char *argv[]" argument vector passed to commands. Any code that modifies these pointers will cause serious corruption of the malloc data structures and crash U-Boot, so make sure the compiler can check that no such modifications are being done by changing the code into "char * const argv[]". This modification is the result of debugging a strange crash caused after adding a new command, which used the following argument processing code which has been working perfectly fine in all Unix systems since version 6 - but not so in U-Boot: int main (int argc, char **argv) { while (--argc > 0 && **++argv == '-') { /* ====> */ while (*++*argv) { switch (**argv) { case 'd': debug++; break; ... default: usage (); } } } ... } The line marked "====>" will corrupt the malloc data structures and usually cause U-Boot to crash when the next command gets executed by the shell. With the modification, the compiler will prevent this with an error: increment of read-only location '*argv' N.B.: The code above can be trivially rewritten like this: while (--argc > 0 && **++argv == '-') { char *arg = *argv; while (*++arg) { switch (*arg) { ... Signed-off-by: Wolfgang Denk <wd@denx.de> Acked-by: Mike Frysinger <vapier@gentoo.org>
Diffstat (limited to 'arch/blackfin/lib')
3 files changed, 4 insertions, 4 deletions
diff --git a/arch/blackfin/lib/boot.c b/arch/blackfin/lib/boot.c
index 951d5b0d0..37aa82a05 100644
--- a/arch/blackfin/lib/boot.c
+++ b/arch/blackfin/lib/boot.c
@@ -33,7 +33,7 @@ static char *make_command_line(void)
extern ulong bfin_poweron_retx;
-int do_bootm_linux(int flag, int argc, char *argv[], bootm_headers_t *images)
+int do_bootm_linux(int flag, int argc, char * const argv[], bootm_headers_t *images)
int (*appl) (char *cmdline);
char *cmdline;
diff --git a/arch/blackfin/lib/cmd_cache_dump.c b/arch/blackfin/lib/cmd_cache_dump.c
index de5840e4c..412e0198a 100644
--- a/arch/blackfin/lib/cmd_cache_dump.c
+++ b/arch/blackfin/lib/cmd_cache_dump.c
@@ -25,7 +25,7 @@ static int check_limit(const char *type, size_t start_limit, size_t end_limit, s
return 1;
-int do_icache_dump(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+int do_icache_dump(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
int cache_status = icache_status();
@@ -97,7 +97,7 @@ U_BOOT_CMD(icache_dump, 4, 0, do_icache_dump,
"icache_dump - dump current instruction cache\n",
"[way] [subbank] [set]");
-int do_dcache_dump(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+int do_dcache_dump(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
u32 way, bank, subbank, set;
u32 status, addr;
diff --git a/arch/blackfin/lib/kgdb.c b/arch/blackfin/lib/kgdb.c
index bd62d7105..4ca3fc731 100644
--- a/arch/blackfin/lib/kgdb.c
+++ b/arch/blackfin/lib/kgdb.c
@@ -417,7 +417,7 @@ void kgdb_putregs(struct pt_regs *regs, char *buf, int length)
-void kgdb_breakpoint(int argc, char *argv[])
+void kgdb_breakpoint(int argc, char * const argv[])
asm volatile ("excpt 0x1\n");