Re: [PATCH -next V2] proc: support file->f_pos checking in mem_lseek
From: Zizhi Wo
Date: Fri Nov 10 2023 - 13:00:22 EST
I have missed fallthrough, and will fix it in V3.
Thanks,
Zizhi Wo
在 2023/11/10 12:34, kernel test robot 写道:
Hi WoZ1zh1,
kernel test robot noticed the following build warnings:
[auto build test WARNING on next-20231108]
url: https://github.com/intel-lab-lkp/linux/commits/WoZ1zh1/proc-support-file-f_pos-checking-in-mem_lseek/20231109-103353
base: next-20231108
patch link: https://lore.kernel.org/r/20231109102658.2075547-1-wozizhi%40huawei.com
patch subject: [PATCH -next V2] proc: support file->f_pos checking in mem_lseek
config: um-allnoconfig (https://download.01.org/0day-ci/archive/20231110/202311101239.ihy4cKpf-lkp@xxxxxxxxx/config)
compiler: clang version 17.0.0 (https://github.com/llvm/llvm-project.git 4a5ac14ee968ff0ad5d2cc1ffa0299048db4c88a)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231110/202311101239.ihy4cKpf-lkp@xxxxxxxxx/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@xxxxxxxxx>
| Closes: https://lore.kernel.org/oe-kbuild-all/202311101239.ihy4cKpf-lkp@xxxxxxxxx/
All warnings (new ones prefixed by >>):
In file included from fs/proc/base.c:68:
In file included from include/linux/swap.h:9:
In file included from include/linux/memcontrol.h:13:
In file included from include/linux/cgroup.h:26:
In file included from include/linux/kernel_stat.h:9:
In file included from include/linux/interrupt.h:11:
In file included from include/linux/hardirq.h:11:
In file included from arch/um/include/asm/hardirq.h:5:
In file included from include/asm-generic/hardirq.h:17:
In file included from include/linux/irq.h:20:
In file included from include/linux/io.h:13:
In file included from arch/um/include/asm/io.h:24:
include/asm-generic/io.h:547:31: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
547 | val = __raw_readb(PCI_IOBASE + addr);
| ~~~~~~~~~~ ^
include/asm-generic/io.h:560:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
560 | val = __le16_to_cpu((__le16 __force)__raw_readw(PCI_IOBASE + addr));
| ~~~~~~~~~~ ^
include/uapi/linux/byteorder/little_endian.h:37:51: note: expanded from macro '__le16_to_cpu'
37 | #define __le16_to_cpu(x) ((__force __u16)(__le16)(x))
| ^
In file included from fs/proc/base.c:68:
In file included from include/linux/swap.h:9:
In file included from include/linux/memcontrol.h:13:
In file included from include/linux/cgroup.h:26:
In file included from include/linux/kernel_stat.h:9:
In file included from include/linux/interrupt.h:11:
In file included from include/linux/hardirq.h:11:
In file included from arch/um/include/asm/hardirq.h:5:
In file included from include/asm-generic/hardirq.h:17:
In file included from include/linux/irq.h:20:
In file included from include/linux/io.h:13:
In file included from arch/um/include/asm/io.h:24:
include/asm-generic/io.h:573:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
573 | val = __le32_to_cpu((__le32 __force)__raw_readl(PCI_IOBASE + addr));
| ~~~~~~~~~~ ^
include/uapi/linux/byteorder/little_endian.h:35:51: note: expanded from macro '__le32_to_cpu'
35 | #define __le32_to_cpu(x) ((__force __u32)(__le32)(x))
| ^
In file included from fs/proc/base.c:68:
In file included from include/linux/swap.h:9:
In file included from include/linux/memcontrol.h:13:
In file included from include/linux/cgroup.h:26:
In file included from include/linux/kernel_stat.h:9:
In file included from include/linux/interrupt.h:11:
In file included from include/linux/hardirq.h:11:
In file included from arch/um/include/asm/hardirq.h:5:
In file included from include/asm-generic/hardirq.h:17:
In file included from include/linux/irq.h:20:
In file included from include/linux/io.h:13:
In file included from arch/um/include/asm/io.h:24:
include/asm-generic/io.h:584:33: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
584 | __raw_writeb(value, PCI_IOBASE + addr);
| ~~~~~~~~~~ ^
include/asm-generic/io.h:594:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
594 | __raw_writew((u16 __force)cpu_to_le16(value), PCI_IOBASE + addr);
| ~~~~~~~~~~ ^
include/asm-generic/io.h:604:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
604 | __raw_writel((u32 __force)cpu_to_le32(value), PCI_IOBASE + addr);
| ~~~~~~~~~~ ^
include/asm-generic/io.h:692:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
692 | readsb(PCI_IOBASE + addr, buffer, count);
| ~~~~~~~~~~ ^
include/asm-generic/io.h:700:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
700 | readsw(PCI_IOBASE + addr, buffer, count);
| ~~~~~~~~~~ ^
include/asm-generic/io.h:708:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
708 | readsl(PCI_IOBASE + addr, buffer, count);
| ~~~~~~~~~~ ^
include/asm-generic/io.h:717:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
717 | writesb(PCI_IOBASE + addr, buffer, count);
| ~~~~~~~~~~ ^
include/asm-generic/io.h:726:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
726 | writesw(PCI_IOBASE + addr, buffer, count);
| ~~~~~~~~~~ ^
include/asm-generic/io.h:735:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
735 | writesl(PCI_IOBASE + addr, buffer, count);
| ~~~~~~~~~~ ^
fs/proc/base.c:912:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
912 | case SEEK_SET:
| ^
fs/proc/base.c:912:2: note: insert '__attribute__((fallthrough));' to silence this warning
912 | case SEEK_SET:
| ^
| __attribute__((fallthrough));
fs/proc/base.c:912:2: note: insert 'break;' to avoid fall-through
912 | case SEEK_SET:
| ^
| break;
13 warnings generated.
vim +912 fs/proc/base.c
903
904 loff_t mem_lseek(struct file *file, loff_t offset, int orig)
905 {
906 loff_t ret = 0;
907
908 spin_lock(&file->f_lock);
909 switch (orig) {
910 case SEEK_CUR:
911 offset += file->f_pos;
> 912 case SEEK_SET:
913 /* to avoid userland mistaking f_pos=-9 as -EBADF=-9 */
914 if ((unsigned long long)offset >= -MAX_ERRNO)
915 ret = -EOVERFLOW;
916 break;
917 default:
918 ret = -EINVAL;
919 }
920 if (!ret) {
921 if (offset < 0 && !(unsigned_offsets(file))) {
922 ret = -EINVAL;
923 } else {
924 file->f_pos = offset;
925 ret = file->f_pos;
926 force_successful_syscall_return();
927 }
928 }
929
930 spin_unlock(&file->f_lock);
931 return ret;
932 }
933