From 54841ab50c20d6fa6c9cc3eb826989da3a22d934 Mon Sep 17 00:00:00 2001 From: Wolfgang Denk Date: Mon, 28 Jun 2010 22:00:46 +0200 Subject: 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 Acked-by: Mike Frysinger --- common/cmd_onenand.c | 20 ++++++++++---------- 1 file changed, 10 insertions(+), 10 deletions(-) (limited to 'common/cmd_onenand.c') diff --git a/common/cmd_onenand.c b/common/cmd_onenand.c index 2646ae9..a3e46a3 100644 --- a/common/cmd_onenand.c +++ b/common/cmd_onenand.c @@ -32,7 +32,7 @@ static inline int str2long(char *p, ulong *num) return (*p != '\0' && *endptr == '\0') ? 1 : 0; } -static int arg_off_size(int argc, char *argv[], ulong *off, size_t *size) +static int arg_off_size(int argc, char * const argv[], ulong *off, size_t *size) { if (argc >= 1) { if (!(str2long(argv[0], off))) { @@ -330,13 +330,13 @@ static int onenand_dump(struct mtd_info *mtd, ulong off, int only_oob) return 0; } -static int do_onenand_info(cmd_tbl_t * cmdtp, int flag, int argc, char *argv[]) +static int do_onenand_info(cmd_tbl_t * cmdtp, int flag, int argc, char * const argv[]) { printf("%s\n", mtd->name); return 0; } -static int do_onenand_bad(cmd_tbl_t * cmdtp, int flag, int argc, char *argv[]) +static int do_onenand_bad(cmd_tbl_t * cmdtp, int flag, int argc, char * const argv[]) { ulong ofs; @@ -351,7 +351,7 @@ static int do_onenand_bad(cmd_tbl_t * cmdtp, int flag, int argc, char *argv[]) return 0; } -static int do_onenand_read(cmd_tbl_t * cmdtp, int flag, int argc, char *argv[]) +static int do_onenand_read(cmd_tbl_t * cmdtp, int flag, int argc, char * const argv[]) { char *s; int oob = 0; @@ -383,7 +383,7 @@ static int do_onenand_read(cmd_tbl_t * cmdtp, int flag, int argc, char *argv[]) return ret == 0 ? 0 : 1; } -static int do_onenand_write(cmd_tbl_t * cmdtp, int flag, int argc, char *argv[]) +static int do_onenand_write(cmd_tbl_t * cmdtp, int flag, int argc, char * const argv[]) { ulong addr, ofs; size_t len; @@ -409,7 +409,7 @@ static int do_onenand_write(cmd_tbl_t * cmdtp, int flag, int argc, char *argv[]) return ret == 0 ? 0 : 1; } -static int do_onenand_erase(cmd_tbl_t * cmdtp, int flag, int argc, char *argv[]) +static int do_onenand_erase(cmd_tbl_t * cmdtp, int flag, int argc, char * const argv[]) { ulong ofs; int ret = 0; @@ -445,7 +445,7 @@ static int do_onenand_erase(cmd_tbl_t * cmdtp, int flag, int argc, char *argv[]) return ret == 0 ? 0 : 1; } -static int do_onenand_test(cmd_tbl_t * cmdtp, int flag, int argc, char *argv[]) +static int do_onenand_test(cmd_tbl_t * cmdtp, int flag, int argc, char * const argv[]) { ulong ofs; int ret = 0; @@ -470,7 +470,7 @@ static int do_onenand_test(cmd_tbl_t * cmdtp, int flag, int argc, char *argv[]) return ret == 0 ? 0 : 1; } -static int do_onenand_dump(cmd_tbl_t * cmdtp, int flag, int argc, char *argv[]) +static int do_onenand_dump(cmd_tbl_t * cmdtp, int flag, int argc, char * const argv[]) { ulong ofs; int ret = 0; @@ -493,7 +493,7 @@ static int do_onenand_dump(cmd_tbl_t * cmdtp, int flag, int argc, char *argv[]) return ret == 0 ? 1 : 0; } -static int do_onenand_markbad(cmd_tbl_t * cmdtp, int flag, int argc, char *argv[]) +static int do_onenand_markbad(cmd_tbl_t * cmdtp, int flag, int argc, char * const argv[]) { int ret = 0; ulong addr; @@ -537,7 +537,7 @@ static cmd_tbl_t cmd_onenand_sub[] = { U_BOOT_CMD_MKENT(markbad, CONFIG_SYS_MAXARGS, 0, do_onenand_markbad, "", ""), }; -static int do_onenand(cmd_tbl_t * cmdtp, int flag, int argc, char *argv[]) +static int do_onenand(cmd_tbl_t * cmdtp, int flag, int argc, char * const argv[]) { cmd_tbl_t *c; -- cgit v1.1