From e974f4fddf385b81036609d6008b923377d18e99 Mon Sep 17 00:00:00 2001 From: Jess Frazelle Date: Tue, 15 Aug 2017 12:13:23 -0400 Subject: [PATCH] syscall: move ptrace setup to right before exec This will prevent any ptrace calls from getting trace output from the runtime itself setting up after fork. Fixes #21428. Change-Id: I9d835bd5a8f404394eb6237679f2111a72e5bc17 Reviewed-on: https://go-review.googlesource.com/55811 Run-TryBot: Ian Lance Taylor TryBot-Result: Gobot Gobot Reviewed-by: Ian Lance Taylor Reviewed-by: Avelino --- src/syscall/exec_linux.go | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-) diff --git a/src/syscall/exec_linux.go b/src/syscall/exec_linux.go index fd87b86ff8..bfbe2b3d59 100644 --- a/src/syscall/exec_linux.go +++ b/src/syscall/exec_linux.go @@ -199,14 +199,6 @@ func forkAndExecInChild1(argv0 *byte, argv, envv []*byte, chroot, dir *byte, att } } - // Enable tracing if requested. - if sys.Ptrace { - _, _, err1 = RawSyscall(SYS_PTRACE, uintptr(PTRACE_TRACEME), 0, 0) - if err1 != 0 { - goto childerror - } - } - // Session ID if sys.Setsid { _, _, err1 = RawSyscall(SYS_SETSID, 0, 0, 0) @@ -402,6 +394,16 @@ func forkAndExecInChild1(argv0 *byte, argv, envv []*byte, chroot, dir *byte, att } } + // Enable tracing if requested. + // Do this right before exec so that we don't unnecessarily trace the runtime + // setting up after the fork. See issue #21428. + if sys.Ptrace { + _, _, err1 = RawSyscall(SYS_PTRACE, uintptr(PTRACE_TRACEME), 0, 0) + if err1 != 0 { + goto childerror + } + } + // Time to exec. _, _, err1 = RawSyscall(SYS_EXECVE, uintptr(unsafe.Pointer(argv0)), -- 2.50.0