Use new STOP_EXEC feature

Cargo.toml

@@ -14,5 +14,6 @@ log = "0.4.8"
 [target.'cfg(target_os = "linux")'.dependencies]
 libc = "0.2.62"
 [target.'cfg(target_os = "redox")'.dependencies]
-redox_syscall = { git = "https://gitlab.redox-os.org/redox-os/syscall" }
+# redox_syscall = { git = "https://gitlab.redox-os.org/redox-os/syscall" }
+redox_syscall = { git = "https://gitlab.redox-os.org/jD91mZM2/syscall", branch = "ptrace-fexec" }
 strace = { git = "https://gitlab.redox-os.org/redox-os/strace-redox" }

src/os/redox.rs

@@ -119,7 +119,7 @@ impl super::Target for Os {
                 // TODO: Don't stop only on syscall, stop on first instruction.
                 // Single-stepping doesn't work across fexec yet for some reason.
                 // e!(tracer.next(strace::Flags::STOP_SINGLESTEP));
-                e!(tracer.next(strace::Flags::STOP_POST_SYSCALL));
+                e!(tracer.next(strace::Flags::STOP_EXEC));
 
                 Ok(Os {
                     pid,