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_mem.c | 40 ++++++++++++++++++++-------------------- 1 file changed, 20 insertions(+), 20 deletions(-) (limited to 'common/cmd_mem.c') diff --git a/common/cmd_mem.c b/common/cmd_mem.c index 1839330..bcea399 100644 --- a/common/cmd_mem.c +++ b/common/cmd_mem.c @@ -43,7 +43,7 @@ #define PRINTF(fmt,args...) #endif -static int mod_mem(cmd_tbl_t *, int, int, int, char *[]); +static int mod_mem(cmd_tbl_t *, int, int, int, char * const []); /* Display values from last command. * Memory modify remembered values are different from display memory. @@ -60,7 +60,7 @@ static ulong base_address = 0; * md{.b, .w, .l} {addr} {len} */ #define DISP_LINE_LEN 16 -int do_mem_md ( cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +int do_mem_md ( cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) { ulong addr, length; #if defined(CONFIG_HAS_DATAFLASH) @@ -158,16 +158,16 @@ int do_mem_md ( cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) return (rc); } -int do_mem_mm ( cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +int do_mem_mm ( cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) { return mod_mem (cmdtp, 1, flag, argc, argv); } -int do_mem_nm ( cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +int do_mem_nm ( cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) { return mod_mem (cmdtp, 0, flag, argc, argv); } -int do_mem_mw ( cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +int do_mem_mw ( cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) { ulong addr, writeval, count; int size; @@ -211,7 +211,7 @@ int do_mem_mw ( cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) } #ifdef CONFIG_MX_CYCLIC -int do_mem_mdc ( cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +int do_mem_mdc ( cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) { int i; ulong count; @@ -240,7 +240,7 @@ int do_mem_mdc ( cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) return 0; } -int do_mem_mwc ( cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +int do_mem_mwc ( cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) { int i; ulong count; @@ -270,7 +270,7 @@ int do_mem_mwc ( cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) } #endif /* CONFIG_MX_CYCLIC */ -int do_mem_cmp (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +int do_mem_cmp (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) { ulong addr1, addr2, count, ngood; int size; @@ -355,7 +355,7 @@ int do_mem_cmp (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) return rcode; } -int do_mem_cp ( cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +int do_mem_cp ( cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) { ulong addr, dest, count; int size; @@ -463,7 +463,7 @@ int do_mem_cp ( cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) return 0; } -int do_mem_base (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +int do_mem_base (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) { if (argc > 1) { /* Set new base address. @@ -476,7 +476,7 @@ int do_mem_base (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) return 0; } -int do_mem_loop (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +int do_mem_loop (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) { ulong addr, length, i, junk; int size; @@ -547,7 +547,7 @@ int do_mem_loop (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) } #ifdef CONFIG_LOOPW -int do_mem_loopw (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +int do_mem_loopw (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) { ulong addr, length, i, data; int size; @@ -626,7 +626,7 @@ int do_mem_loopw (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) * configured using CONFIG_SYS_ALT_MEMTEST. The complete test loops until * interrupted by ctrl-c or by a failure of one of the sub-tests. */ -int do_mem_mtest (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +int do_mem_mtest (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) { vu_long *addr, *start, *end; ulong val; @@ -984,7 +984,7 @@ int do_mem_mtest (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) * nm{.b, .w, .l} {addr} */ static int -mod_mem(cmd_tbl_t *cmdtp, int incrflag, int flag, int argc, char *argv[]) +mod_mem(cmd_tbl_t *cmdtp, int incrflag, int flag, int argc, char * const argv[]) { ulong addr, i; int nbytes, size; @@ -1089,7 +1089,7 @@ mod_mem(cmd_tbl_t *cmdtp, int incrflag, int flag, int argc, char *argv[]) #ifndef CONFIG_CRC32_VERIFY -int do_mem_crc (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +int do_mem_crc (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) { ulong addr, length; ulong crc; @@ -1120,7 +1120,7 @@ int do_mem_crc (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) #else /* CONFIG_CRC32_VERIFY */ -int do_mem_crc (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +int do_mem_crc (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) { ulong addr, length; ulong crc; @@ -1128,7 +1128,7 @@ int do_mem_crc (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) ulong vcrc; int verify; int ac; - char **av; + char * const *av; if (argc < 3) { usage: @@ -1175,7 +1175,7 @@ int do_mem_crc (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) #endif /* CONFIG_CRC32_VERIFY */ #ifdef CONFIG_CMD_MD5SUM -int do_md5sum(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +int do_md5sum(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) { unsigned long addr, len; unsigned int i; @@ -1200,7 +1200,7 @@ int do_md5sum(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) #endif #ifdef CONFIG_CMD_SHA1 -int do_sha1sum(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +int do_sha1sum(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) { unsigned long addr, len; unsigned int i; @@ -1225,7 +1225,7 @@ int do_sha1sum(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) #endif #ifdef CONFIG_CMD_UNZIP -int do_unzip ( cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +int do_unzip ( cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) { unsigned long src, dst; unsigned long src_len = ~0UL, dst_len = ~0UL; -- cgit v1.1