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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/common
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/common')
-rw-r--r--board/esd/common/auto_update.c2
-rw-r--r--board/esd/common/cmd_loadpci.c2
-rw-r--r--board/esd/common/lcd.c2
-rw-r--r--board/esd/common/xilinx_jtag/micro.c2
4 files changed, 4 insertions, 4 deletions
diff --git a/board/esd/common/auto_update.c b/board/esd/common/auto_update.c
index c4a49e2..4dfea71 100644
--- a/board/esd/common/auto_update.c
+++ b/board/esd/common/auto_update.c
@@ -492,7 +492,7 @@ int do_auto_update(void)
return 0;
}
-int auto_update(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+int auto_update(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
do_auto_update();
diff --git a/board/esd/common/cmd_loadpci.c b/board/esd/common/cmd_loadpci.c
index eecae0a..87da27d 100644
--- a/board/esd/common/cmd_loadpci.c
+++ b/board/esd/common/cmd_loadpci.c
@@ -37,7 +37,7 @@ extern int do_source (cmd_tbl_t *, int, int, char *[]);
/*
* Command loadpci: wait for signal from host and boot image.
*/
-int do_loadpci(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+int do_loadpci(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
u32 *ptr = 0;
int count = 0;
diff --git a/board/esd/common/lcd.c b/board/esd/common/lcd.c
index 5c50b4c..9109b64 100644
--- a/board/esd/common/lcd.c
+++ b/board/esd/common/lcd.c
@@ -339,7 +339,7 @@ int lcd_init(uchar *lcd_reg, uchar *lcd_mem, S1D_REGS *regs, int reg_count,
return lcd_bmp(logo_bmp);
}
-int do_esdbmp(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+int do_esdbmp(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
ulong addr;
#ifdef CONFIG_VIDEO_SM501
diff --git a/board/esd/common/xilinx_jtag/micro.c b/board/esd/common/xilinx_jtag/micro.c
index 414e821..9823e5e 100644
--- a/board/esd/common/xilinx_jtag/micro.c
+++ b/board/esd/common/xilinx_jtag/micro.c
@@ -1828,7 +1828,7 @@ int xsvfExecute(void)
* ppzArgv - array of ptrs to strings (command-line arguments).
* Returns: int - Legacy return value: 1 = success; 0 = error.
*****************************************************************************/
-int do_cpld(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+int do_cpld(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
int iErrorCode;
char* pzXsvfFileName;