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_immap.c | 36 ++++++++++++++++++------------------ 1 file changed, 18 insertions(+), 18 deletions(-) (limited to 'common/cmd_immap.c') diff --git a/common/cmd_immap.c b/common/cmd_immap.c index 37e60582f..1f59c1e1d 100644 --- a/common/cmd_immap.c +++ b/common/cmd_immap.c @@ -43,14 +43,14 @@ DECLARE_GLOBAL_DATA_PTR; static void -unimplemented ( cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +unimplemented ( cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) { printf ("Sorry, but the '%s' command has not been implemented\n", cmdtp->name); } int -do_siuinfo (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +do_siuinfo (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) { volatile immap_t *immap = (immap_t *) CONFIG_SYS_IMMR; @@ -81,7 +81,7 @@ do_siuinfo (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) } int -do_memcinfo (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +do_memcinfo (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) { volatile immap_t *immap = (immap_t *) CONFIG_SYS_IMMR; @@ -133,7 +133,7 @@ do_memcinfo (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) } int -do_sitinfo (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +do_sitinfo (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) { unimplemented (cmdtp, flag, argc, argv); return 0; @@ -141,7 +141,7 @@ do_sitinfo (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) #ifdef CONFIG_8260 int -do_icinfo (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +do_icinfo (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) { unimplemented (cmdtp, flag, argc, argv); return 0; @@ -149,7 +149,7 @@ do_icinfo (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) #endif int -do_carinfo (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +do_carinfo (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) { volatile immap_t *immap = (immap_t *) CONFIG_SYS_IMMR; @@ -233,7 +233,7 @@ static void binary (char *label, uint value, int nbits) #endif int -do_iopinfo (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +do_iopinfo (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) { volatile immap_t *immap = (immap_t *) CONFIG_SYS_IMMR; @@ -316,7 +316,7 @@ do_iopinfo (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) * use *uint and set the address based on cmd + port */ int -do_iopset (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +do_iopset (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) { uint rcode = 0; iopin_t iopin; @@ -431,14 +431,14 @@ do_iopset (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) } int -do_dmainfo (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +do_dmainfo (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) { unimplemented (cmdtp, flag, argc, argv); return 0; } int -do_fccinfo (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +do_fccinfo (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) { unimplemented (cmdtp, flag, argc, argv); return 0; @@ -498,7 +498,7 @@ static void prbrg (int n, uint val) } int -do_brginfo (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +do_brginfo (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) { volatile immap_t *immap = (immap_t *) CONFIG_SYS_IMMR; @@ -522,7 +522,7 @@ do_brginfo (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) } int -do_i2cinfo (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +do_i2cinfo (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) { volatile immap_t *immap = (immap_t *) CONFIG_SYS_IMMR; @@ -569,42 +569,42 @@ do_i2cinfo (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) } int -do_sccinfo (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +do_sccinfo (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) { unimplemented (cmdtp, flag, argc, argv); return 0; } int -do_smcinfo (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +do_smcinfo (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) { unimplemented (cmdtp, flag, argc, argv); return 0; } int -do_spiinfo (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +do_spiinfo (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) { unimplemented (cmdtp, flag, argc, argv); return 0; } int -do_muxinfo (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +do_muxinfo (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) { unimplemented (cmdtp, flag, argc, argv); return 0; } int -do_siinfo (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +do_siinfo (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) { unimplemented (cmdtp, flag, argc, argv); return 0; } int -do_mccinfo (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +do_mccinfo (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) { unimplemented (cmdtp, flag, argc, argv); return 0; -- cgit v1.2.3-70-g09d2