From: Eric W. Biederman <ebiederm@xmission.com>
Date: Mon, 26 Jun 2017 18:09:03 +0000 (-0500)
Subject: signal: Document the strange si_codes used by ptrace event stops
X-Git-Tag: for-linus-20180210~67^2~30
X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=f9886bc50a8e;p=linux-block.git

signal: Document the strange si_codes used by ptrace event stops

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
---

diff --git a/include/uapi/asm-generic/siginfo.h b/include/uapi/asm-generic/siginfo.h
index cbe1b0cc7a6a..7158421ac911 100644
--- a/include/uapi/asm-generic/siginfo.h
+++ b/include/uapi/asm-generic/siginfo.h
@@ -225,6 +225,11 @@ typedef struct siginfo {
 #define TRAP_HWBKPT     4	/* hardware breakpoint/watchpoint */
 #define NSIGTRAP	4
 
+/*
+ * There are an additional set of SIGTRAP si_codes used by ptrace
+ * that of the form: ((PTRACE_EVENT_XXX << 8) | SIGTRAP)
+ */
+
 /*
  * SIGCHLD si_codes
  */