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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/microblaze
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/microblaze')
-rw-r--r--arch/microblaze/cpu/interrupts.c4
-rw-r--r--arch/microblaze/lib/bootm.c2
2 files changed, 3 insertions, 3 deletions
diff --git a/arch/microblaze/cpu/interrupts.c b/arch/microblaze/cpu/interrupts.c
index 7a9d022..e9d53c1 100644
--- a/arch/microblaze/cpu/interrupts.c
+++ b/arch/microblaze/cpu/interrupts.c
@@ -173,7 +173,7 @@ void interrupt_handler (void)
#if defined(CONFIG_CMD_IRQ)
#ifdef CONFIG_SYS_INTC_0
-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;
@@ -193,7 +193,7 @@ int do_irqinfo (cmd_tbl_t * cmdtp, int flag, int argc, char *argv[])
return (0);
}
#else
-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[])
{
puts ("Undefined interrupt controller\n");
}
diff --git a/arch/microblaze/lib/bootm.c b/arch/microblaze/lib/bootm.c
index 2227a81..8e2c6d8 100644
--- a/arch/microblaze/lib/bootm.c
+++ b/arch/microblaze/lib/bootm.c
@@ -32,7 +32,7 @@
DECLARE_GLOBAL_DATA_PTR;
-int do_bootm_linux(int flag, int argc, char *argv[], bootm_headers_t *images)
+int do_bootm_linux(int flag, int argc, char * const argv[], bootm_headers_t *images)
{
/* First parameter is mapped to $r5 for kernel boot args */
void (*theKernel) (char *, ulong, ulong);