Re: [PATCH 1/2] syscall_get_arch: remove useless function arguments

From: Richard Guy Briggs
Date: Fri Mar 21 2014 - 13:38:30 EST

On 14/03/11, Eric Paris wrote:
> Every caller of syscall_get_arch() uses current for the task and no
> implementors of the function need args. So just get rid of both of
> those things. Admittedly, since these are inline functions we aren't
> wasting stack space, but it just makes the prototypes better.
>
> Signed-off-by: Eric Paris <eparis@xxxxxxxxxx>
> Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
> Cc: linux-mips@xxxxxxxxxxxxxx
> Cc: linux390@xxxxxxxxxx
> Cc: x86@xxxxxxxxxx
> Cc: linux-kernel@xxxxxxxxxxxxxxx
> Cc: linux-s390@xxxxxxxxxxxxxxx
> Cc: linux-arch@xxxxxxxxxxxxxxx

Acked-by: Richard Guy Briggs <rgb@xxxxxxxxxx>

> ---
> arch/arm/include/asm/syscall.h | 3 +--
> arch/mips/include/asm/syscall.h | 2 +-
> arch/mips/kernel/ptrace.c | 2 +-
> arch/s390/include/asm/syscall.h | 5 ++---
> arch/x86/include/asm/syscall.h | 8 +++-----
> include/asm-generic/syscall.h | 4 +---
> kernel/seccomp.c | 4 ++--
> 7 files changed, 11 insertions(+), 17 deletions(-)
>
> diff --git a/arch/arm/include/asm/syscall.h b/arch/arm/include/asm/syscall.h
> index 73ddd72..ed805f1 100644
> --- a/arch/arm/include/asm/syscall.h
> +++ b/arch/arm/include/asm/syscall.h
> @@ -103,8 +103,7 @@ static inline void syscall_set_arguments(struct task_struct *task,
> memcpy(&regs->ARM_r0 + i, args, n * sizeof(args[0]));
> }
>
> -static inline int syscall_get_arch(struct task_struct *task,
> - struct pt_regs *regs)
> +static inline int syscall_get_arch(void)
> {
> /* ARM tasks don't change audit architectures on the fly. */
> return AUDIT_ARCH_ARM;
> diff --git a/arch/mips/include/asm/syscall.h b/arch/mips/include/asm/syscall.h
> index 81c8913..625e709 100644
> --- a/arch/mips/include/asm/syscall.h
> +++ b/arch/mips/include/asm/syscall.h
> @@ -101,7 +101,7 @@ extern const unsigned long sys_call_table[];
> extern const unsigned long sys32_call_table[];
> extern const unsigned long sysn32_call_table[];
>
> -static inline int __syscall_get_arch(void)
> +static inline int syscall_get_arch(void)
> {
> int arch = EM_MIPS;
> #ifdef CONFIG_64BIT
> diff --git a/arch/mips/kernel/ptrace.c b/arch/mips/kernel/ptrace.c
> index b52e1d2..65ba622 100644
> --- a/arch/mips/kernel/ptrace.c
> +++ b/arch/mips/kernel/ptrace.c
> @@ -671,7 +671,7 @@ asmlinkage void syscall_trace_enter(struct pt_regs *regs)
> if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
> trace_sys_enter(regs, regs->regs[2]);
>
> - audit_syscall_entry(__syscall_get_arch(),
> + audit_syscall_entry(syscall_get_arch(),
> regs->regs[2],
> regs->regs[4], regs->regs[5],
> regs->regs[6], regs->regs[7]);
> diff --git a/arch/s390/include/asm/syscall.h b/arch/s390/include/asm/syscall.h
> index cd29d2f..bebc0bd 100644
> --- a/arch/s390/include/asm/syscall.h
> +++ b/arch/s390/include/asm/syscall.h
> @@ -89,11 +89,10 @@ static inline void syscall_set_arguments(struct task_struct *task,
> regs->orig_gpr2 = args[0];
> }
>
> -static inline int syscall_get_arch(struct task_struct *task,
> - struct pt_regs *regs)
> +static inline int syscall_get_arch(void)
> {
> #ifdef CONFIG_COMPAT
> - if (test_tsk_thread_flag(task, TIF_31BIT))
> + if (test_tsk_thread_flag(current, TIF_31BIT))
> return AUDIT_ARCH_S390;
> #endif
> return sizeof(long) == 8 ? AUDIT_ARCH_S390X : AUDIT_ARCH_S390;
> diff --git a/arch/x86/include/asm/syscall.h b/arch/x86/include/asm/syscall.h
> index aea284b..7e6d0c4 100644
> --- a/arch/x86/include/asm/syscall.h
> +++ b/arch/x86/include/asm/syscall.h
> @@ -91,8 +91,7 @@ static inline void syscall_set_arguments(struct task_struct *task,
> memcpy(&regs->bx + i, args, n * sizeof(args[0]));
> }
>
> -static inline int syscall_get_arch(struct task_struct *task,
> - struct pt_regs *regs)
> +static inline int syscall_get_arch(void)
> {
> return AUDIT_ARCH_I386;
> }
> @@ -221,8 +220,7 @@ static inline void syscall_set_arguments(struct task_struct *task,
> }
> }
>
> -static inline int syscall_get_arch(struct task_struct *task,
> - struct pt_regs *regs)
> +static inline int syscall_get_arch(void)
> {
> #ifdef CONFIG_IA32_EMULATION
> /*
> @@ -234,7 +232,7 @@ static inline int syscall_get_arch(struct task_struct *task,
> *
> * x32 tasks should be considered AUDIT_ARCH_X86_64.
> */
> - if (task_thread_info(task)->status & TS_COMPAT)
> + if (task_thread_info(current)->status & TS_COMPAT)
> return AUDIT_ARCH_I386;
> #endif
> /* Both x32 and x86_64 are considered "64-bit". */
> diff --git a/include/asm-generic/syscall.h b/include/asm-generic/syscall.h
> index 5b09392..d401e54 100644
> --- a/include/asm-generic/syscall.h
> +++ b/include/asm-generic/syscall.h
> @@ -144,8 +144,6 @@ void syscall_set_arguments(struct task_struct *task, struct pt_regs *regs,
>
> /**
> * syscall_get_arch - return the AUDIT_ARCH for the current system call
> - * @task: task of interest, must be in system call entry tracing
> - * @regs: task_pt_regs() of @task
> *
> * Returns the AUDIT_ARCH_* based on the system call convention in use.
> *
> @@ -155,5 +153,5 @@ void syscall_set_arguments(struct task_struct *task, struct pt_regs *regs,
> * Architectures which permit CONFIG_HAVE_ARCH_SECCOMP_FILTER must
> * provide an implementation of this.
> */
> -int syscall_get_arch(struct task_struct *task, struct pt_regs *regs);
> +int syscall_get_arch(void);
> #endif /* _ASM_SYSCALL_H */
> diff --git a/kernel/seccomp.c b/kernel/seccomp.c
> index b7a1004..eda2da3 100644
> --- a/kernel/seccomp.c
> +++ b/kernel/seccomp.c
> @@ -95,7 +95,7 @@ u32 seccomp_bpf_load(int off)
> if (off == BPF_DATA(nr))
> return syscall_get_nr(current, regs);
> if (off == BPF_DATA(arch))
> - return syscall_get_arch(current, regs);
> + return syscall_get_arch();
> if (off >= BPF_DATA(args[0]) && off < BPF_DATA(args[6])) {
> unsigned long value;
> int arg = (off - BPF_DATA(args[0])) / sizeof(u64);
> @@ -351,7 +351,7 @@ static void seccomp_send_sigsys(int syscall, int reason)
> info.si_code = SYS_SECCOMP;
> info.si_call_addr = (void __user *)KSTK_EIP(current);
> info.si_errno = reason;
> - info.si_arch = syscall_get_arch(current, task_pt_regs(current));
> + info.si_arch = syscall_get_arch();
> info.si_syscall = syscall;
> force_sig_info(SIGSYS, &info, current);
> }
> --
> 1.8.5.3
>
> --
> Linux-audit mailing list
> Linux-audit@xxxxxxxxxx
> https://www.redhat.com/mailman/listinfo/linux-audit

- RGB

--
Richard Guy Briggs <rbriggs@xxxxxxxxxx>
Senior Software Engineer, Kernel Security, AMER ENG Base Operating Systems, Red Hat
Remote, Ottawa, Canada
Voice: +1.647.777.2635, Internal: (81) 32635, Alt: +1.613.693.0684x3545
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