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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/i386
parentb218ccb5435e64ac2318bb8b6c9594ef1cc724cd (diff)
downloadu-boot-linaro-stable-54841ab50c20d6fa6c9cc3eb826989da3a22d934.tar.gz
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/i386')
-rw-r--r--arch/i386/cpu/cpu.c2
-rw-r--r--arch/i386/lib/board.c2
-rw-r--r--arch/i386/lib/bootm.c2
-rw-r--r--arch/i386/lib/interrupts.c2
-rw-r--r--arch/i386/lib/zimage.c2
5 files changed, 5 insertions, 5 deletions
diff --git a/arch/i386/cpu/cpu.c b/arch/i386/cpu/cpu.c
index 3010519e7..bd6aced87 100644
--- a/arch/i386/cpu/cpu.c
+++ b/arch/i386/cpu/cpu.c
@@ -56,7 +56,7 @@ int cpu_init_r(void)
return 0;
}
-int do_reset(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+int do_reset(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
printf ("resetting ...\n");
udelay(50000); /* wait 50 ms */
diff --git a/arch/i386/lib/board.c b/arch/i386/lib/board.c
index 3f849f654..0adc66455 100644
--- a/arch/i386/lib/board.c
+++ b/arch/i386/lib/board.c
@@ -431,7 +431,7 @@ void hang (void)
for (;;);
}
-unsigned long do_go_exec (ulong (*entry)(int, char *[]), int argc, char *argv[])
+unsigned long do_go_exec (ulong (*entry)(int, char *[]), int argc, char * const argv[])
{
/*
* x86 does not use a dedicated register to pass the pointer
diff --git a/arch/i386/lib/bootm.c b/arch/i386/lib/bootm.c
index f96d7bd6d..b36e58d9e 100644
--- a/arch/i386/lib/bootm.c
+++ b/arch/i386/lib/bootm.c
@@ -29,7 +29,7 @@
#include <asm/zimage.h>
/*cmd_boot.c*/
-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)
{
void *base_ptr;
ulong os_data, os_len;
diff --git a/arch/i386/lib/interrupts.c b/arch/i386/lib/interrupts.c
index 51def5995..5a2827828 100644
--- a/arch/i386/lib/interrupts.c
+++ b/arch/i386/lib/interrupts.c
@@ -136,7 +136,7 @@ void do_irq(int hw_irq)
}
#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 irq;
diff --git a/arch/i386/lib/zimage.c b/arch/i386/lib/zimage.c
index b39615a3e..89fe015e6 100644
--- a/arch/i386/lib/zimage.c
+++ b/arch/i386/lib/zimage.c
@@ -245,7 +245,7 @@ void boot_zimage(void *setup_base)
enter_realmode(((u32)setup_base+SETUP_START_OFFSET)>>4, 0, &regs, &regs);
}
-int do_zboot (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+int do_zboot (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
void *base_ptr;
void *bzImage_addr;