Commit a3386301 authored by Jinjie Ruan's avatar Jinjie Ruan Committed by Will Deacon
Browse files

arm64/ptrace: Return early for ptrace_report_syscall_entry() error 



The generic entry abort the syscall_trace_enter() sequence if
ptrace_report_syscall_entry() errors out, but arm64 not.

When ptrace requests interception, it should prevent all subsequent
system-call processing, including audit and seccomp. In preparation for
moving arm64 over to the generic entry code, return early if
ptrace_report_syscall_entry() encounters an error.

Reviewed-by: default avatarKevin Brodsky <kevin.brodsky@arm.com>
Signed-off-by: default avatarJinjie Ruan <ruanjinjie@huawei.com>
Signed-off-by: default avatarWill Deacon <will@kernel.org>
parent 741a9000

arch/arm64/kernel/ptrace.c

+9 −5
Original line number Diff line number Diff line
@@ -2372,15 +2372,18 @@ static __always_inline unsigned long ptrace_save_reg(struct pt_regs *regs, 
	return saved_reg;

}



static void report_syscall_entry(struct pt_regs *regs)

static int report_syscall_entry(struct pt_regs *regs)

{

	unsigned long saved_reg;

	int regno;

	int regno, ret;



	saved_reg = ptrace_save_reg(regs, PTRACE_SYSCALL_ENTER, &regno);

	if (ptrace_report_syscall_entry(regs))

	ret = ptrace_report_syscall_entry(regs);

	if (ret)

		forget_syscall(regs);

	regs->regs[regno] = saved_reg;



	return ret;

}



static void report_syscall_exit(struct pt_regs *regs)
@@ -2407,10 +2410,11 @@ static void report_syscall_exit(struct pt_regs *regs) 
int syscall_trace_enter(struct pt_regs *regs)

{

	unsigned long flags = read_thread_flags();

	int ret;



	if (flags & (_TIF_SYSCALL_EMU | _TIF_SYSCALL_TRACE)) {

		report_syscall_entry(regs);

		if (flags & _TIF_SYSCALL_EMU)

		ret = report_syscall_entry(regs);

		if (ret || (flags & _TIF_SYSCALL_EMU))

			return NO_SYSCALL;

	}