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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 /board/esd/du440
parentb218ccb5435e64ac2318bb8b6c9594ef1cc724cd (diff)
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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 'board/esd/du440')
-rw-r--r--board/esd/du440/du440.c16
1 files changed, 8 insertions, 8 deletions
diff --git a/board/esd/du440/du440.c b/board/esd/du440/du440.c
index 111cce5..ba3c97c 100644
--- a/board/esd/du440/du440.c
+++ b/board/esd/du440/du440.c
@@ -409,7 +409,7 @@ int dcf77_status(void)
return mv;
}
-int do_dcf77(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+int do_dcf77(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
int mv;
u32 pin, pinold;
@@ -490,7 +490,7 @@ int usbhub_init(void)
return ret;
}
-int do_hubinit(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+int do_hubinit(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
usbhub_init();
return 0;
@@ -573,7 +573,7 @@ int boot_eeprom_write (unsigned dev_addr,
return rcode;
}
-int do_setup_boot_eeprom(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+int do_setup_boot_eeprom(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
ulong sdsdp[4];
@@ -673,7 +673,7 @@ int eeprom_write_enable (unsigned dev_addr, int state)
return state;
}
-int do_eep_wren (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+int do_eep_wren (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
int query = argc == 1;
int state = 0;
@@ -727,7 +727,7 @@ static int pld_interrupt(u32 arg)
return rc;
}
-int do_waitpwrirq(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+int do_waitpwrirq(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
got_pldirq = 0;
@@ -795,7 +795,7 @@ int dvi_init(void)
return ret;
}
-int do_dviinit(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+int do_dviinit(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
dvi_init();
return 0;
@@ -810,7 +810,7 @@ U_BOOT_CMD(
* TODO: 'time' command might be useful for others as well.
* Move to 'common' directory.
*/
-int do_time(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+int do_time(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
unsigned long long start, end;
char c, cmd[CONFIG_SYS_CBSIZE];
@@ -874,7 +874,7 @@ unsigned int prng(unsigned int max)
return Y;
}
-int do_gfxdemo(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+int do_gfxdemo(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
unsigned int color;
unsigned int x, y, dx, dy;