| Message ID | 20190812033120.43013-3-natechancellor@gmail.com (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
| Series | Clang build fixes for MIPS | expand |
Hello, Nathan Chancellor wrote: > clang warns: > > arch/mips/include/asm/syscall.h:136:3: error: variable 'ret' is > uninitialized when used here [-Werror,-Wuninitialized] > ret |= mips_get_syscall_arg(args++, task, regs, i++); > ^~~ > arch/mips/include/asm/syscall.h:129:9: note: initialize the variable > 'ret' to silence this warning > int ret; > ^ > = 0 > 1 error generated. > > It's not wrong; however, it's not an issue in practice because ret is > only assigned to, not read from. ret could just be initialized to zero > but looking into it further, ret has been unused since it was first > added in 2012 so just get rid of it and update mips_get_syscall_arg's > return type since none of the return values are ever checked. If it is > ever needed again, this commit can be reverted and ret can be properly > initialized. Applied to mips-next. > commit 077ff3be06e8 > https://git.kernel.org/mips/c/077ff3be06e8 > > Fixes: c0ff3c53d4f9 ("MIPS: Enable HAVE_ARCH_TRACEHOOK.") > Link: https://github.com/ClangBuiltLinux/linux/issues/604 > Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> > Signed-off-by: Paul Burton <paul.burton@mips.com> Thanks, Paul [ This message was auto-generated; if you believe anything is incorrect then please email paul.burton@mips.com to report it. ]
diff --git a/arch/mips/include/asm/syscall.h b/arch/mips/include/asm/syscall.h index 83bb439597d8..25fa651c937d 100644 --- a/arch/mips/include/asm/syscall.h +++ b/arch/mips/include/asm/syscall.h @@ -54,7 +54,7 @@ static inline void mips_syscall_update_nr(struct task_struct *task, task_thread_info(task)->syscall = regs->regs[2]; } -static inline unsigned long mips_get_syscall_arg(unsigned long *arg, +static inline void mips_get_syscall_arg(unsigned long *arg, struct task_struct *task, struct pt_regs *regs, unsigned int n) { unsigned long usp __maybe_unused = regs->regs[29]; @@ -63,23 +63,24 @@ static inline unsigned long mips_get_syscall_arg(unsigned long *arg, case 0: case 1: case 2: case 3: *arg = regs->regs[4 + n]; - return 0; + return; #ifdef CONFIG_32BIT case 4: case 5: case 6: case 7: - return get_user(*arg, (int *)usp + n); + get_user(*arg, (int *)usp + n); + return; #endif #ifdef CONFIG_64BIT case 4: case 5: case 6: case 7: #ifdef CONFIG_MIPS32_O32 if (test_tsk_thread_flag(task, TIF_32BIT_REGS)) - return get_user(*arg, (int *)usp + n); + get_user(*arg, (int *)usp + n); else #endif *arg = regs->regs[4 + n]; - return 0; + return; #endif default: @@ -126,21 +127,13 @@ static inline void syscall_get_arguments(struct task_struct *task, { unsigned int i = 0; unsigned int n = 6; - int ret; /* O32 ABI syscall() */ if (mips_syscall_is_indirect(task, regs)) i++; while (n--) - ret |= mips_get_syscall_arg(args++, task, regs, i++); - - /* - * No way to communicate an error because this is a void function. - */ -#if 0 - return ret; -#endif + mips_get_syscall_arg(args++, task, regs, i++); } extern const unsigned long sys_call_table[];
clang warns: arch/mips/include/asm/syscall.h:136:3: error: variable 'ret' is uninitialized when used here [-Werror,-Wuninitialized] ret |= mips_get_syscall_arg(args++, task, regs, i++); ^~~ arch/mips/include/asm/syscall.h:129:9: note: initialize the variable 'ret' to silence this warning int ret; ^ = 0 1 error generated. It's not wrong; however, it's not an issue in practice because ret is only assigned to, not read from. ret could just be initialized to zero but looking into it further, ret has been unused since it was first added in 2012 so just get rid of it and update mips_get_syscall_arg's return type since none of the return values are ever checked. If it is ever needed again, this commit can be reverted and ret can be properly initialized. Fixes: c0ff3c53d4f9 ("MIPS: Enable HAVE_ARCH_TRACEHOOK.") Link: https://github.com/ClangBuiltLinux/linux/issues/604 Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> --- arch/mips/include/asm/syscall.h | 21 +++++++-------------- 1 file changed, 7 insertions(+), 14 deletions(-)