Commit ed3bb007 authored Mar 29, 2019 by Dmitry V. Levin Committed by Steven Rostedt (VMware) Apr 04, 2019

csky: Fix syscall_get_arguments() and syscall_set_arguments()

C-SKY syscall arguments are located in orig_a0,a1,a2,a3,regs[0],regs[1]
fields of struct pt_regs.

Due to an off-by-one bug and a bug in pointer arithmetic
syscall_get_arguments() was reading orig_a0,regs[1..5] fields instead.
Likewise, syscall_set_arguments() was writing orig_a0,regs[1..5] fields
instead.

Link: http://lkml.kernel.org/r/20190329171230.GB32456@altlinux.org



Fixes: 4859bfca ("csky: System Call")
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Will Drewry <wad@chromium.org>
Cc: stable@vger.kernel.org # v4.20+
Tested-by: Guo Ren <ren_guo@c-sky.com>
Acked-by: Guo Ren <ren_guo@c-sky.com>
Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

parent 10a16997

arch/csky/include/asm/syscall.h

+6 −4

Original line number	Diff line number	Diff line
		@@ -49,10 +49,11 @@ syscall_get_arguments(struct task_struct task, struct pt_regs regs,
		if (i == 0) {
		args[0] = regs->orig_a0;
		args++;
		i++;
		n--;
		} else {
		i--;
		}
		memcpy(args, &regs->a1 + i * sizeof(regs->a1), n * sizeof(args[0]));
		memcpy(args, &regs->a1 + i, n * sizeof(args[0]));
		}

		static inline void
		@@ -63,10 +64,11 @@ syscall_set_arguments(struct task_struct task, struct pt_regs regs,
		if (i == 0) {
		regs->orig_a0 = args[0];
		args++;
		i++;
		n--;
		} else {
		i--;
		}
		memcpy(&regs->a1 + i * sizeof(regs->a1), args, n * sizeof(regs->a0));
		memcpy(&regs->a1 + i, args, n * sizeof(regs->a1));
		}

		static inline int

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