From: Alain Schneble <a.s@realize.ch>
To: Eli Zaretskii <eliz@gnu.org>
Cc: emacs-devel@gnu.org
Subject: Re: SIGTRAP in kill emulation on Windows
Date: Thu, 25 Aug 2016 22:09:24 +0200 [thread overview]
Message-ID: <864m68ipaj.fsf@realize.ch> (raw)
In-Reply-To: <868tvkiplu.fsf@realize.ch> (Alain Schneble's message of "Thu, 25 Aug 2016 22:02:37 +0200")
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Alain Schneble <a.s@realize.ch> writes:
Sorry, the former patch was not the latest version. This is it:
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[-- Attachment #2: Support SIGTRAP in kill emulation on Windows --]
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From a0945f367998a12b0b1150c9105ae262664f4171 Mon Sep 17 00:00:00 2001
From: Alain Schneble <a.s@realize.ch>
Date: Thu, 25 Aug 2016 22:00:49 +0200
Subject: [PATCH] Support SIGTRAP in kill emulation on Windows
* src/w32proc.c (sys_kill): Translate SIGTRAP signal into a call to
DebugBreakProcess to cause a breakpoint exception to occur in the
specified process. Windows versions prior to Windows XP that do not
support DebugBreakProcess return -1 and errno set to ENOTSUP (as opposed
to EINVAL before this change).
* src/w32proc.c: Add typedef for DebugBreakProcess function pointer and
global variable to track state of run-time dynamic linking of this
function.
* etc/NEWS: Add entry to document that 'signal-process' now supports
SIGTRAP.
---
etc/NEWS | 8 ++++++++
src/w32.c | 2 ++
src/w32proc.c | 52 +++++++++++++++++++++++++++++++++++++++++++++++++---
3 files changed, 59 insertions(+), 3 deletions(-)
diff --git a/etc/NEWS b/etc/NEWS
index 494a091..3d055fc 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -599,6 +599,14 @@ still apply.)
Previously, on MS-Windows this function converted slash characters in
file names into backslashes. It no longer does that.
+---
+** 'signal-process' supports SIGTRAP on Windows XP and later.
+The 'kill' emulation on Windows now maps SIGTRAP to a call to Win32
+'DebugBreakProcess'. This causes the receiving process to break
+execution and return control to the debugger. If no debugger is
+attached to the receiving process, the call is typically ignored by
+the receiving process.
+
\f
* Installation Changes in Emacs 25.1
diff --git a/src/w32.c b/src/w32.c
index 1db3426..0f22387 100644
--- a/src/w32.c
+++ b/src/w32.c
@@ -330,6 +330,7 @@ static BOOL g_b_init_set_named_security_info_a;
static BOOL g_b_init_get_adapters_info;
BOOL g_b_init_compare_string_w;
+BOOL g_b_init_debug_break_process;
/*
BEGIN: Wrapper functions around OpenProcessToken
@@ -9653,6 +9654,7 @@ globals_of_w32 (void)
g_b_init_set_named_security_info_a = 0;
g_b_init_get_adapters_info = 0;
g_b_init_compare_string_w = 0;
+ g_b_init_debug_break_process = 0;
num_of_processors = 0;
/* The following sets a handler for shutdown notifications for
console apps. This actually applies to Emacs in both console and
diff --git a/src/w32proc.c b/src/w32proc.c
index 11a121f..bb637bc 100644
--- a/src/w32proc.c
+++ b/src/w32proc.c
@@ -66,6 +66,8 @@ along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. */
+ (filedata).file_base))
extern BOOL g_b_init_compare_string_w;
+extern BOOL g_b_init_debug_break_process;
+
int sys_select (int, SELECT_TYPE *, SELECT_TYPE *, SELECT_TYPE *,
struct timespec *, void *);
@@ -2494,6 +2496,9 @@ find_child_console (HWND hwnd, LPARAM arg)
return TRUE;
}
+typedef BOOL (WINAPI * DebugBreakProcess_Proc) (
+ HANDLE hProcess);
+
/* Emulate 'kill', but only for other processes. */
int
sys_kill (pid_t pid, int sig)
@@ -2507,9 +2512,9 @@ sys_kill (pid_t pid, int sig)
if (pid < 0)
pid = -pid;
- /* Only handle signals that will result in the process dying */
+ /* Only handle signals that can be mapped to a similar behavior on Windows */
if (sig != 0
- && sig != SIGINT && sig != SIGKILL && sig != SIGQUIT && sig != SIGHUP)
+ && sig != SIGINT && sig != SIGKILL && sig != SIGQUIT && sig != SIGHUP && sig != SIGTRAP)
{
errno = EINVAL;
return -1;
@@ -2552,7 +2557,11 @@ sys_kill (pid_t pid, int sig)
close the selected frame, which does not necessarily
terminates Emacs. But then we are not supposed to call
sys_kill with our own PID. */
- proc_hand = OpenProcess (PROCESS_TERMINATE, 0, pid);
+
+ DWORD desiredAccess =
+ (sig == SIGTRAP) ? PROCESS_ALL_ACCESS : PROCESS_TERMINATE;
+
+ proc_hand = OpenProcess (desiredAccess, 0, pid);
if (proc_hand == NULL)
{
errno = EPERM;
@@ -2648,6 +2657,43 @@ sys_kill (pid_t pid, int sig)
rc = -1;
}
}
+ else if (sig == SIGTRAP)
+ {
+ static DebugBreakProcess_Proc s_pfn_Debug_Break_Process = NULL;
+
+ if (g_b_init_debug_break_process == 0)
+ {
+ g_b_init_debug_break_process = 1;
+ s_pfn_Debug_Break_Process = (DebugBreakProcess_Proc)
+ GetProcAddress (GetModuleHandle ("kernel32.dll"),
+ "DebugBreakProcess");
+ }
+
+ if (s_pfn_Debug_Break_Process == NULL)
+ {
+ errno = ENOTSUP;
+ rc = -1;
+ }
+ else if (!s_pfn_Debug_Break_Process (proc_hand))
+ {
+ DWORD err = GetLastError ();
+
+ DebPrint (("sys_kill.DebugBreakProcess return %d "
+ "for pid %lu\n", err, pid));
+
+ switch (err)
+ {
+ case ERROR_ACCESS_DENIED:
+ errno = EPERM;
+ break;
+ default:
+ errno = EINVAL;
+ break;
+ }
+
+ rc = -1;
+ }
+ }
else
{
if (NILP (Vw32_start_process_share_console) && cp && cp->hwnd)
--
2.8.1.windows.1
next prev parent reply other threads:[~2016-08-25 20:09 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-08-25 15:08 SIGTRAP in kill emulation on Windows Alain Schneble
2016-08-25 16:18 ` Eli Zaretskii
2016-08-25 20:02 ` Alain Schneble
2016-08-25 20:09 ` Alain Schneble [this message]
2016-08-26 8:24 ` Eli Zaretskii
2016-08-26 8:58 ` Alain Schneble
2016-08-26 9:13 ` Eli Zaretskii
2016-08-26 9:31 ` Eli Zaretskii
2016-08-26 9:47 ` Alain Schneble
2016-08-26 10:19 ` Alain Schneble
2016-10-08 13:54 ` Eli Zaretskii
2016-10-08 14:36 ` Alain Schneble
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