[PATCHv3 08/19] arm64: convert raw syscall invocation to C
From: catalin.marinas@arm.com (Catalin Marinas)
Date: 2018-06-19 14:21:30
Also in:
linux-fsdevel
On Mon, Jun 18, 2018 at 01:02:59PM +0100, Mark Rutland wrote:
quoted hunk ↗ jump to hunk
diff --git a/arch/arm64/kernel/syscall.c b/arch/arm64/kernel/syscall.c new file mode 100644 index 000000000000..b463b962d597 --- /dev/null +++ b/arch/arm64/kernel/syscall.c@@ -0,0 +1,30 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include <linux/nospec.h> +#include <linux/ptrace.h> + +long do_ni_syscall(struct pt_regs *regs); + +typedef long (*syscall_fn_t)(unsigned long, unsigned long, + unsigned long, unsigned long, + unsigned long, unsigned long); + +static void __invoke_syscall(struct pt_regs *regs, syscall_fn_t syscall_fn) +{ + regs->regs[0] = syscall_fn(regs->regs[0], regs->regs[1], + regs->regs[2], regs->regs[3], + regs->regs[4], regs->regs[5]); +} + +asmlinkage void invoke_syscall(struct pt_regs *regs, unsigned int scno, + unsigned int sc_nr, + syscall_fn_t syscall_table[]) +{ + if (scno < sc_nr) { + syscall_fn_t syscall_fn; + syscall_fn = syscall_table[array_index_nospec(scno, sc_nr)]; + __invoke_syscall(regs, syscall_fn); + } else { + regs->regs[0] = do_ni_syscall(regs); + } +}
While reviewing the subsequent patch, it crossed my mind that we no longer have any callers to do_ni_syscall() outside this file. Can we not more it here and have a similar implementation to __invoke_syscall() for consistency, i.e. set regs->regs[0]. -- Catalin