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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 /arch/nios2/cpu
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 'arch/nios2/cpu')
-rw-r--r--arch/nios2/cpu/epcs.c14
-rw-r--r--arch/nios2/cpu/interrupts.c2
-rw-r--r--arch/nios2/cpu/sysid.c2
3 files changed, 9 insertions, 9 deletions
diff --git a/arch/nios2/cpu/epcs.c b/arch/nios2/cpu/epcs.c
index ab7d746..2369431 100644
--- a/arch/nios2/cpu/epcs.c
+++ b/arch/nios2/cpu/epcs.c
@@ -472,7 +472,7 @@ static int epcs_sect_erased (int sect, unsigned *offset,
* Commands
***********************************************************************/
static
-void do_epcs_info (struct epcs_devinfo_t *dev, int argc, char *argv[])
+void do_epcs_info (struct epcs_devinfo_t *dev, int argc, char * const argv[])
{
int i;
unsigned char stat;
@@ -519,7 +519,7 @@ void do_epcs_info (struct epcs_devinfo_t *dev, int argc, char *argv[])
}
static
-void do_epcs_erase (struct epcs_devinfo_t *dev, int argc, char *argv[])
+void do_epcs_erase (struct epcs_devinfo_t *dev, int argc, char * const argv[])
{
unsigned start,end;
@@ -549,7 +549,7 @@ void do_epcs_erase (struct epcs_devinfo_t *dev, int argc, char *argv[])
}
static
-void do_epcs_protect (struct epcs_devinfo_t *dev, int argc, char *argv[])
+void do_epcs_protect (struct epcs_devinfo_t *dev, int argc, char * const argv[])
{
unsigned char stat;
@@ -585,7 +585,7 @@ void do_epcs_protect (struct epcs_devinfo_t *dev, int argc, char *argv[])
}
static
-void do_epcs_read (struct epcs_devinfo_t *dev, int argc, char *argv[])
+void do_epcs_read (struct epcs_devinfo_t *dev, int argc, char * const argv[])
{
ulong addr,off,cnt;
ulong sz;
@@ -617,7 +617,7 @@ void do_epcs_read (struct epcs_devinfo_t *dev, int argc, char *argv[])
}
static
-void do_epcs_write (struct epcs_devinfo_t *dev, int argc, char *argv[])
+void do_epcs_write (struct epcs_devinfo_t *dev, int argc, char * const argv[])
{
ulong addr,off,cnt;
ulong sz;
@@ -656,7 +656,7 @@ void do_epcs_write (struct epcs_devinfo_t *dev, int argc, char *argv[])
}
static
-void do_epcs_verify (struct epcs_devinfo_t *dev, int argc, char *argv[])
+void do_epcs_verify (struct epcs_devinfo_t *dev, int argc, char * const argv[])
{
ulong addr,off,cnt;
ulong sz;
@@ -690,7 +690,7 @@ void do_epcs_verify (struct epcs_devinfo_t *dev, int argc, char *argv[])
}
/*-----------------------------------------------------------------------*/
-int do_epcs (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+int do_epcs (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
int len;
struct epcs_devinfo_t *dev = epcs_dev_find ();
diff --git a/arch/nios2/cpu/interrupts.c b/arch/nios2/cpu/interrupts.c
index b552db4..63acfa9 100644
--- a/arch/nios2/cpu/interrupts.c
+++ b/arch/nios2/cpu/interrupts.c
@@ -239,7 +239,7 @@ int interrupt_init (void)
/*************************************************************************/
#if defined(CONFIG_CMD_IRQ)
-int do_irqinfo (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+int do_irqinfo (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
int i;
struct irq_action *act = vecs;
diff --git a/arch/nios2/cpu/sysid.c b/arch/nios2/cpu/sysid.c
index 77bc8b5..5fbc28b 100644
--- a/arch/nios2/cpu/sysid.c
+++ b/arch/nios2/cpu/sysid.c
@@ -44,7 +44,7 @@ void display_sysid (void)
}
-int do_sysid (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+int do_sysid (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
display_sysid ();
return (0);