Re: [PATCH] netxen: memory corruption by netxen_p3_get_mac_addr.
From: santosh prasad nayak <hidden>
Date: 2012-03-04 09:17:44
Also in:
kernel-janitors
I would like to drop this patch. Actually I was trying to simulate the code block by generating assembly code which looked like as shown below. But later I realized it does not fit with present scenario. Its for different scenario. ------------------------------------------------------------------------------------------------------ 80483cb: 83 ec 2c sub $0x2c,%esp 80483ce: 66 c7 44 24 1e e1 2e movw $0x2ee1,0x1e(%esp) 80483d5: 66 c7 44 24 1c e1 2e movw $0x2ee1,0x1c(%esp) 80483dc: 0f b7 44 24 1c movzwl 0x1c(%esp),%eax 80483e1: c1 e0 04 shl $0x4,%eax 80483e4: 88 44 24 1b mov %al,0x1b(%esp) 80483e8: 0f b6 5c 24 1b movzbl 0x1b(%esp),%ebx 80483ed: 0f b7 4c 24 1c movzwl 0x1c(%esp),%ecx 80483f2: 0f b7 54 24 1e movzwl 0x1e(%esp),%edx ------------------------------------------------------------------------------------------------------------ Following assembly code looks very near to present scenario. And there is no data loss . ----------------------------------------------------------------------------------------------- 804839a: 83 ec 10 sub $0x10,%esp 804839d: 66 c7 44 24 0e e1 2e movw $0x2ee1,0xe(%esp) 80483a4: 66 c7 44 24 0c e1 2e movw $0x2ee1,0xc(%esp) 80483ab: 0f b7 44 24 0c movzwl 0xc(%esp),%eax 80483b0: ba 00 00 00 00 mov $0x0,%edx 80483b5: 0f a4 c2 04 shld $0x4,%eax,%edx 80483b9: c1 e0 04 shl $0x4,%eax 80483bc: 89 04 24 mov %eax,(%esp) 80483bf: 89 54 24 04 mov %edx,0x4(%esp) 80483c3: b8 00 00 00 00 mov $0x0,%eax --------------------------------------------------------------------------------------------------- Sorry for the inconvenience. Regarding endian issue: -------------------------------------- Can Rajesh or Dhananjay comment on it ? Is "le64_to_cpu" there intentionally ?? Regards santosh On Sun, Mar 4, 2012 at 12:05 AM, Dan Carpenter [off-list ref] wrote:
On Sat, Mar 03, 2012 at 10:31:27PM +0530, santosh nayak wrote:quoted
From: Santosh Nayak <redacted> 'mac_hi' and 'mac_lo' are 32 bit unsinged int but we are modifing 64 bit of memory during mac calculation. To fix this issue define a local variable of 64 bit and do mac calculation.I'm not seeing any memory corruption. How do you figure?quoted
Remove 'le64_to_cpu' to fix endian issue.I've add Dhananjay to the CC list to comment on the endian change. regards, dan carpenterquoted
Signed-off-by: Santosh Nayak <redacted> --- drivers/net/ethernet/qlogic/netxen/netxen_nic_hw.c | 7 ++++--- 1 files changed, 4 insertions(+), 3 deletions(-)diff --git a/drivers/net/ethernet/qlogic/netxen/netxen_nic_hw.c b/drivers/net/ethernet/qlogic/netxen/netxen_nic_hw.c index 0f81287..7ea930b 100644 --- a/drivers/net/ethernet/qlogic/netxen/netxen_nic_hw.c +++ b/drivers/net/ethernet/qlogic/netxen/netxen_nic_hw.c@@ -1069,7 +1069,8 @@ int netxen_get_flash_mac_addr(struct netxen_adapter *adapter, u64 *mac)int netxen_p3_get_mac_addr(struct netxen_adapter *adapter, u64 *mac) { - uint32_t crbaddr, mac_hi, mac_lo; + uint32_t crbaddr; + u64 mac_hi, mac_lo; int pci_func = adapter->ahw.pci_func; crbaddr = CRB_MAC_BLOCK_START +@@ -1079,9 +1080,9 @@ int netxen_p3_get_mac_addr(struct netxen_adapter *adapter, u64 *mac)mac_hi = NXRD32(adapter, crbaddr+4); if (pci_func & 1) - *mac = le64_to_cpu((mac_lo >> 16) | ((u64)mac_hi << 16)); + *mac = (mac_lo >> 16) | (mac_hi << 16); else - *mac = le64_to_cpu((u64)mac_lo | ((u64)mac_hi << 32)); + *mac = mac_lo | (mac_hi << 32); return 0; } -- 1.7.4.4 -- To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html