| Message ID | 20181013021457.13608-1-natechancellor@gmail.com |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
| Series | net: qla3xxx: Remove overflowing shift statement | expand |
From: Nathan Chancellor <natechancellor@gmail.com> Date: Fri, 12 Oct 2018 19:14:58 -0700 > Clang currently warns: > > drivers/net/ethernet/qlogic/qla3xxx.c:384:24: warning: signed shift > result (0xF00000000) requires 37 bits to represent, but 'int' only has > 32 bits [-Wshift-overflow] > ((ISP_NVRAM_MASK << 16) | qdev->eeprom_cmd_data)); > ~~~~~~~~~~~~~~ ^ ~~ > 1 warning generated. > > The warning is certainly accurate since ISP_NVRAM_MASK is defined as > (0x000F << 16) which is then shifted by 16, resulting in 64424509440, > well above UINT_MAX. > > Given that this is the only location in this driver where ISP_NVRAM_MASK > is shifted again, it seems likely that ISP_NVRAM_MASK was originally > defined without a shift and during the move of the shift to the > definition, this statement wasn't properly removed (since ISP_NVRAM_MASK > is used in the statenent right above this). Only the maintainers can > confirm this since this statment has been here since the driver was > first added to the kernel. > > Link: https://github.com/ClangBuiltLinux/linux/issues/127 > Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> If the qlogic/cavium folks aren't even going to look at and comment on this, that is not fair to you and your change. Applied, thanks Nathan.
diff --git a/drivers/net/ethernet/qlogic/qla3xxx.c b/drivers/net/ethernet/qlogic/qla3xxx.c index b48f76182049..10b075bc5959 100644 --- a/drivers/net/ethernet/qlogic/qla3xxx.c +++ b/drivers/net/ethernet/qlogic/qla3xxx.c @@ -380,8 +380,6 @@ static void fm93c56a_select(struct ql3_adapter *qdev) qdev->eeprom_cmd_data = AUBURN_EEPROM_CS_1; ql_write_nvram_reg(qdev, spir, ISP_NVRAM_MASK | qdev->eeprom_cmd_data); - ql_write_nvram_reg(qdev, spir, - ((ISP_NVRAM_MASK << 16) | qdev->eeprom_cmd_data)); } /*
Clang currently warns: drivers/net/ethernet/qlogic/qla3xxx.c:384:24: warning: signed shift result (0xF00000000) requires 37 bits to represent, but 'int' only has 32 bits [-Wshift-overflow] ((ISP_NVRAM_MASK << 16) | qdev->eeprom_cmd_data)); ~~~~~~~~~~~~~~ ^ ~~ 1 warning generated. The warning is certainly accurate since ISP_NVRAM_MASK is defined as (0x000F << 16) which is then shifted by 16, resulting in 64424509440, well above UINT_MAX. Given that this is the only location in this driver where ISP_NVRAM_MASK is shifted again, it seems likely that ISP_NVRAM_MASK was originally defined without a shift and during the move of the shift to the definition, this statement wasn't properly removed (since ISP_NVRAM_MASK is used in the statenent right above this). Only the maintainers can confirm this since this statment has been here since the driver was first added to the kernel. Link: https://github.com/ClangBuiltLinux/linux/issues/127 Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> --- I sent this diff in a RFC email to the email in the MAINTAINERS file with no response. Given that this driver has not received any actual Cavium/QLogic treatment since at least the moving of this file in commit aa43c2158d5a ("qlogic: Move the QLogic drivers") back in 2011, I'd be curious to see who is actually using this driver but I'll leave that for another time. I've added a few of the active 'drivers/net/ethernet/qlogic' Cavium developers (hope they don't mind) to see if this makes any sense since I don't have the hardware to test and I know they're active. drivers/net/ethernet/qlogic/qla3xxx.c | 2 -- 1 file changed, 2 deletions(-)