[PATCH 2/2] powerpc/entry: entry clean up for common entry

[Luming Yu]

From: Yu Luming <luming.yu at gmail.com>

clean up do_syscall_trace_enter/leave and do_seccomp

 Signed-off-by: Luming Yu <luming.yu at shingroup.cn>
---
 arch/powerpc/kernel/interrupt.c     |   5 -
 arch/powerpc/kernel/ptrace/ptrace.c | 141 ----------------------------
 2 files changed, 146 deletions(-)

diff --git a/arch/powerpc/kernel/interrupt.c b/arch/powerpc/kernel/interrupt.c
index 7fe704946e96..609ba48034de 100644
--- a/arch/powerpc/kernel/interrupt.c
+++ b/arch/powerpc/kernel/interrupt.c
@@ -296,11 +296,6 @@ notrace unsigned long syscall_exit_prepare(unsigned long r3,
 		regs->gpr[3] = r3;
 	}
 
-	if (unlikely(ti_flags & _TIF_SYSCALL_DOTRACE)) {
-		do_syscall_trace_leave(regs);
-		ret |= _TIF_RESTOREALL;
-	}
-
 	local_irq_disable();
 	ret = interrupt_exit_user_prepare_main(ret, regs);
 
diff --git a/arch/powerpc/kernel/ptrace/ptrace.c b/arch/powerpc/kernel/ptrace/ptrace.c
index 727ed4a14545..6cd180bc36ab 100644
--- a/arch/powerpc/kernel/ptrace/ptrace.c
+++ b/arch/powerpc/kernel/ptrace/ptrace.c
@@ -21,9 +21,6 @@
 #include <asm/switch_to.h>
 #include <asm/debug.h>
 
-#define CREATE_TRACE_POINTS
-#include <trace/events/syscalls.h>
-
 #include "ptrace-decl.h"
 
 /*
@@ -195,144 +192,6 @@ long arch_ptrace(struct task_struct *child, long request,
 	return ret;
 }
 
-#ifdef CONFIG_SECCOMP
-static int do_seccomp(struct pt_regs *regs)
-{
-	if (!test_thread_flag(TIF_SECCOMP))
-		return 0;
-
-	/*
-	 * The ABI we present to seccomp tracers is that r3 contains
-	 * the syscall return value and orig_gpr3 contains the first
-	 * syscall parameter. This is different to the ptrace ABI where
-	 * both r3 and orig_gpr3 contain the first syscall parameter.
-	 */
-	regs->gpr[3] = -ENOSYS;
-
-	/*
-	 * We use the __ version here because we have already checked
-	 * TIF_SECCOMP. If this fails, there is nothing left to do, we
-	 * have already loaded -ENOSYS into r3, or seccomp has put
-	 * something else in r3 (via SECCOMP_RET_ERRNO/TRACE).
-	 */
-	if (__secure_computing(NULL))
-		return -1;
-
-	/*
-	 * The syscall was allowed by seccomp, restore the register
-	 * state to what audit expects.
-	 * Note that we use orig_gpr3, which means a seccomp tracer can
-	 * modify the first syscall parameter (in orig_gpr3) and also
-	 * allow the syscall to proceed.
-	 */
-	regs->gpr[3] = regs->orig_gpr3;
-
-	return 0;
-}
-#else
-static inline int do_seccomp(struct pt_regs *regs) { return 0; }
-#endif /* CONFIG_SECCOMP */
-
-/**
- * do_syscall_trace_enter() - Do syscall tracing on kernel entry.
- * @regs: the pt_regs of the task to trace (current)
- *
- * Performs various types of tracing on syscall entry. This includes seccomp,
- * ptrace, syscall tracepoints and audit.
- *
- * The pt_regs are potentially visible to userspace via ptrace, so their
- * contents is ABI.
- *
- * One or more of the tracers may modify the contents of pt_regs, in particular
- * to modify arguments or even the syscall number itself.
- *
- * It's also possible that a tracer can choose to reject the system call. In
- * that case this function will return an illegal syscall number, and will put
- * an appropriate return value in regs->r3.
- *
- * Return: the (possibly changed) syscall number.
- */
-long do_syscall_trace_enter(struct pt_regs *regs)
-{
-	u32 flags;
-
-	flags = read_thread_flags() & (_TIF_SYSCALL_EMU | _TIF_SYSCALL_TRACE);
-
-	if (flags) {
-		int rc = ptrace_report_syscall_entry(regs);
-
-		if (unlikely(flags & _TIF_SYSCALL_EMU)) {
-			/*
-			 * A nonzero return code from
-			 * ptrace_report_syscall_entry() tells us to prevent
-			 * the syscall execution, but we are not going to
-			 * execute it anyway.
-			 *
-			 * Returning -1 will skip the syscall execution. We want
-			 * to avoid clobbering any registers, so we don't goto
-			 * the skip label below.
-			 */
-			return -1;
-		}
-
-		if (rc) {
-			/*
-			 * The tracer decided to abort the syscall. Note that
-			 * the tracer may also just change regs->gpr[0] to an
-			 * invalid syscall number, that is handled below on the
-			 * exit path.
-			 */
-			goto skip;
-		}
-	}
-
-	/* Run seccomp after ptrace; allow it to set gpr[3]. */
-	if (do_seccomp(regs))
-		return -1;
-
-	/* Avoid trace and audit when syscall is invalid. */
-	if (regs->gpr[0] >= NR_syscalls)
-		goto skip;
-
-	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
-		trace_sys_enter(regs, regs->gpr[0]);
-
-	if (!is_32bit_task())
-		audit_syscall_entry(regs->gpr[0], regs->gpr[3], regs->gpr[4],
-				    regs->gpr[5], regs->gpr[6]);
-	else
-		audit_syscall_entry(regs->gpr[0],
-				    regs->gpr[3] & 0xffffffff,
-				    regs->gpr[4] & 0xffffffff,
-				    regs->gpr[5] & 0xffffffff,
-				    regs->gpr[6] & 0xffffffff);
-
-	/* Return the possibly modified but valid syscall number */
-	return regs->gpr[0];
-
-skip:
-	/*
-	 * If we are aborting explicitly, or if the syscall number is
-	 * now invalid, set the return value to -ENOSYS.
-	 */
-	regs->gpr[3] = -ENOSYS;
-	return -1;
-}
-
-void do_syscall_trace_leave(struct pt_regs *regs)
-{
-	int step;
-
-	audit_syscall_exit(regs);
-
-	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
-		trace_sys_exit(regs, regs->result);
-
-	step = test_thread_flag(TIF_SINGLESTEP);
-	if (step || test_thread_flag(TIF_SYSCALL_TRACE))
-		ptrace_report_syscall_exit(regs, step);
-}
-
 void __init pt_regs_check(void);
 
 /*
-- 
2.42.0.windows.2