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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 /drivers
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 'drivers')
-rw-r--r--drivers/gpio/pca953x.c2
-rw-r--r--drivers/misc/ds4510.c2
-rw-r--r--drivers/misc/fsl_pmic.c2
-rw-r--r--drivers/qe/qe.c2
4 files changed, 4 insertions, 4 deletions
diff --git a/drivers/gpio/pca953x.c b/drivers/gpio/pca953x.c
index e8273ee..d1065f4 100644
--- a/drivers/gpio/pca953x.c
+++ b/drivers/gpio/pca953x.c
@@ -150,7 +150,7 @@ cmd_tbl_t cmd_pca953x[] = {
#endif
};
-int do_pca953x(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+int do_pca953x(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
static uint8_t chip = CONFIG_SYS_I2C_PCA953X_ADDR;
int val;
diff --git a/drivers/misc/ds4510.c b/drivers/misc/ds4510.c
index f2510a3..5b33c1f 100644
--- a/drivers/misc/ds4510.c
+++ b/drivers/misc/ds4510.c
@@ -273,7 +273,7 @@ cmd_tbl_t cmd_ds4510[] = {
#endif
};
-int do_ds4510(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+int do_ds4510(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
static uint8_t chip = CONFIG_SYS_I2C_DS4510_ADDR;
cmd_tbl_t *c;
diff --git a/drivers/misc/fsl_pmic.c b/drivers/misc/fsl_pmic.c
index 87f0aed..274327f 100644
--- a/drivers/misc/fsl_pmic.c
+++ b/drivers/misc/fsl_pmic.c
@@ -156,7 +156,7 @@ static void pmic_dump(int numregs)
puts("\n");
}
-int do_pmic(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+int do_pmic(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
char *cmd;
int nregs;
diff --git a/drivers/qe/qe.c b/drivers/qe/qe.c
index 8882c4f..63cc68e 100644
--- a/drivers/qe/qe.c
+++ b/drivers/qe/qe.c
@@ -436,7 +436,7 @@ struct qe_firmware_info *qe_get_firmware_info(void)
return qe_firmware_uploaded ? &qe_firmware_info : NULL;
}
-static int qe_cmd(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+static int qe_cmd(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
ulong addr;