MFC 302900,302902,302921,303461,304009:

Add a mask of optional ptrace() events.

302900:
Add a test for user signal delivery.

This test verifies we get the correct ptrace event details when a signal
is posted to a traced process from userland.

302902:
Add a mask of optional ptrace() events.

ptrace() now stores a mask of optional events in p_ptevents.  Currently
this mask is a single integer, but it can be expanded into an array of
integers in the future.

Two new ptrace requests can be used to manipulate the event mask:
PT_GET_EVENT_MASK fetches the current event mask and PT_SET_EVENT_MASK
sets the current event mask.

The current set of events include:
- PTRACE_EXEC: trace calls to execve().
- PTRACE_SCE: trace system call entries.
- PTRACE_SCX: trace syscam call exits.
- PTRACE_FORK: trace forks and auto-attach to new child processes.
- PTRACE_LWP: trace LWP events.

The S_PT_SCX and S_PT_SCE events in the procfs p_stops flags have
been replaced by PTRACE_SCE and PTRACE_SCX.  PTRACE_FORK replaces
P_FOLLOW_FORK and PTRACE_LWP replaces P2_LWP_EVENTS.

The PT_FOLLOW_FORK and PT_LWP_EVENTS ptrace requests remain for
compatibility but now simply toggle corresponding flags in the
event mask.

While here, document that PT_SYSCALL, PT_TO_SCE, and PT_TO_SCX both
modify the event mask and continue the traced process.

302921:
Rename PTRACE_SYSCALL to LINUX_PTRACE_SYSCALL.

303461:
Note that not all optional ptrace events use SIGTRAP.

New child processes attached due to PTRACE_FORK use SIGSTOP instead of
SIGTRAP.  All other ptrace events use SIGTRAP.

304009:
Remove description of P_FOLLOWFORK as this flag was removed.

1 files changed, 2 insertions, 2 deletions

diff --git a/sys/i386/linux/linux_ptrace.c b/sys/i386/linux/linux_ptrace.c
index 2925e6b..fbe66b4 100644
--- a/sys/i386/linux/linux_ptrace.c
+++ b/sys/i386/linux/linux_ptrace.c
@@ -69,7 +69,7 @@ __FBSDID("$FreeBSD$");
 #define PTRACE_ATTACH		16
 #define PTRACE_DETACH		17
 
-#define	PTRACE_SYSCALL		24
+#define	LINUX_PTRACE_SYSCALL	24
 
 #define PTRACE_GETREGS		12
 #define PTRACE_SETREGS		13
@@ -473,7 +473,7 @@ linux_ptrace(struct thread *td, struct linux_ptrace_args *uap)
 
 		break;
 	}
-	case PTRACE_SYSCALL:
+	case LINUX_PTRACE_SYSCALL:
 		/* fall through */
 	default:
 		printf("linux: ptrace(%u, ...) not implemented\n",