-----Original Message----- From: Marek Vasut [mailto:marex@denx.de] Sent: Wednesday, June 01, 2016 6:51 PM To: Rajesh Bhagat rajesh.bhagat@nxp.com; u-boot@lists.denx.de Cc: york sun york.sun@nxp.com; Sriram Dash sriram.dash@nxp.com Subject: Re: [PATCH] drivers: usb: fsl: Fix NULL terminating issue for usb controller name string
On 06/01/2016 01:17 PM, Rajesh Bhagat wrote:
Fixes NULL terminating issue for usb controller name string and performs code cleanup for intializing variables current_usb_controller and usb_phy.
Signed-off-by: Rajesh Bhagat rajesh.bhagat@nxp.com
drivers/usb/host/ehci-fsl.c | 10 ++++------ 1 files changed, 4 insertions(+), 6 deletions(-)
diff --git a/drivers/usb/host/ehci-fsl.c b/drivers/usb/host/ehci-fsl.c index a43d37d..a806993 100644 --- a/drivers/usb/host/ehci-fsl.c +++ b/drivers/usb/host/ehci-fsl.c @@ -49,11 +49,9 @@ int ehci_hcd_init(int index, enum usb_init_type init, struct usb_ehci *ehci = NULL; const char *phy_type = NULL; size_t len;
- char current_usb_controller[5];
- char current_usb_controller[5] = {0};
#ifdef CONFIG_SYS_FSL_USB_INTERNAL_UTMI_PHY
- char usb_phy[5];
- usb_phy[0] = '\0';
- char usb_phy[5] = {0};
#endif if (has_erratum_a007075()) { /* @@ -64,8 +62,8 @@ int ehci_hcd_init(int index, enum usb_init_type init, */ mdelay(5); }
- memset(current_usb_controller, '\0', 5);
- snprintf(current_usb_controller, 4, "usb%d", index+1);
- snprintf(current_usb_controller, sizeof(current_usb_controller),
"usb%d", index+1);What is the actual problem here ? snprintf() will add the \0 at the end of the string, so I don't see any "null terminating issue" in the code. I can understand using the sizeof() in the snprintf(), which is valid, but that's all.
Hello Marek,
It is surprising for me too, but same can be verified even on x86 machine using below test program, Can it be compiler optimization of memset?
Output #1 : current_usb_controller usb Output #2 : current_usb_controller usb1 (Expected Output)
int main() { int index = 0; #if 1 char current_usb_controller[5]; memset(current_usb_controller, '\0', 5); snprintf(current_usb_controller, 4, "usb%d", index+1); #else char current_usb_controller[5] = {0}; snprintf(current_usb_controller, sizeof(current_usb_controller), "usb%d", index+1); #endif
printf("current_usb_controller %s\n", current_usb_controller); return 0; }
Best Regards, Rajesh Bhagat
switch (index) { case 0:
-- Best regards, Marek Vasut