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-rw-r--r--sys/conf/files1
-rw-r--r--sys/ddb/db_capture.c301
-rw-r--r--sys/ddb/db_command.c1
-rw-r--r--sys/ddb/db_input.c1
-rw-r--r--sys/ddb/db_main.c3
-rw-r--r--sys/ddb/db_output.c8
-rw-r--r--sys/ddb/ddb.h15
7 files changed, 330 insertions, 0 deletions
diff --git a/sys/conf/files b/sys/conf/files
index 9b3142a..cd5b153 100644
--- a/sys/conf/files
+++ b/sys/conf/files
@@ -350,6 +350,7 @@ crypto/sha2/sha2.c optional crypto | geom_bde | ipsec | random | \
sctp
ddb/db_access.c optional ddb
ddb/db_break.c optional ddb
+ddb/db_capture.c optional ddb
ddb/db_command.c optional ddb
ddb/db_examine.c optional ddb
ddb/db_expr.c optional ddb
diff --git a/sys/ddb/db_capture.c b/sys/ddb/db_capture.c
new file mode 100644
index 0000000..4e6dd7c
--- /dev/null
+++ b/sys/ddb/db_capture.c
@@ -0,0 +1,301 @@
+/*-
+ * Copyright (c) 2007 Robert N. M. Watson
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+/*
+ * DDB capture support: capture kernel debugger output into a fixed-size
+ * buffer for later dumping to disk or extraction from user space.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/param.h>
+#include <sys/conf.h>
+#include <sys/kernel.h>
+#include <sys/kerneldump.h>
+#include <sys/malloc.h>
+#include <sys/msgbuf.h>
+#include <sys/priv.h>
+#include <sys/sx.h>
+#include <sys/sysctl.h>
+#include <sys/systm.h>
+
+#include <ddb/ddb.h>
+#include <ddb/db_lex.h>
+
+/*
+ * While it would be desirable to use a small block-sized buffer and dump
+ * incrementally to disk in fixed-size blocks, it's not possible to enter
+ * kernel dumper routines without restarting the kernel, which is undesirable
+ * in the midst of debugging. Instead, we maintain a large static global
+ * buffer that we fill from DDB's output routines.
+ */
+static MALLOC_DEFINE(M_DB_CAPTURE, "db_capture", "DDB capture buffer");
+
+#define DB_CAPTURE_DEFAULTBUFSIZE 48*1024
+#define DB_CAPTURE_MAXBUFSIZE 512*1024
+
+static char *db_capture_buf;
+static u_int db_capture_bufsize = DB_CAPTURE_DEFAULTBUFSIZE;
+static u_int db_capture_maxbufsize = DB_CAPTURE_MAXBUFSIZE; /* Read-only. */
+static u_int db_capture_bufoff; /* Next location to write in buffer. */
+static int db_capture_inpager; /* Suspend capture in pager. */
+static int db_capture_inprogress; /* DDB capture currently in progress. */
+
+struct sx db_capture_sx; /* Lock against user thread races. */
+SX_SYSINIT(db_capture_sx, &db_capture_sx, "db_capture_sx");
+
+static SYSCTL_NODE(_debug_ddb, OID_AUTO, capture, CTLFLAG_RW, 0,
+ "DDB capture options");
+
+SYSCTL_UINT(_debug_ddb_capture, OID_AUTO, bytes, CTLFLAG_RD,
+ &db_capture_bufoff, 0, "Bytes of data in DDB capture buffer");
+
+SYSCTL_UINT(_debug_ddb_capture, OID_AUTO, maxbufsize, CTLFLAG_RD,
+ &db_capture_maxbufsize, 0,
+ "Maximum value for debug.ddb.capture.bufsize");
+
+/*
+ * Boot-time allocation of the DDB capture buffer, if any.
+ */
+static void
+db_capture_sysinit(__unused void *dummy)
+{
+
+ TUNABLE_INT_FETCH("debug.ddb.capture.bufsize", &db_capture_bufsize);
+ if (db_capture_bufsize > DB_CAPTURE_MAXBUFSIZE)
+ db_capture_bufsize = DB_CAPTURE_MAXBUFSIZE;
+
+ if (db_capture_bufsize != 0)
+ db_capture_buf = malloc(db_capture_bufsize, M_DB_CAPTURE,
+ M_WAITOK);
+}
+SYSINIT(db_capture, SI_SUB_DDB_SERVICES, SI_ORDER_ANY, db_capture_sysinit,
+ NULL);
+
+/*
+ * Run-time adjustment of the capture buffer.
+ */
+static int
+sysctl_debug_ddb_capture_bufsize(SYSCTL_HANDLER_ARGS)
+{
+ u_int len, size;
+ char *buf;
+ int error;
+
+ size = db_capture_bufsize;
+ error = sysctl_handle_int(oidp, &size, 0, req);
+ if (error || req->newptr == NULL)
+ return (error);
+ if (size > DB_CAPTURE_MAXBUFSIZE)
+ return (EINVAL);
+
+ sx_xlock(&db_capture_sx);
+ if (size != 0) {
+ /*
+ * Potentially the buffer is quite large, so if we can't
+ * allocate it, fail rather than waiting.
+ */
+ buf = malloc(size, M_DB_CAPTURE, M_NOWAIT);
+ if (buf == NULL) {
+ sx_xunlock(&db_capture_sx);
+ return (ENOMEM);
+ }
+ len = min(db_capture_bufoff, size);
+ } else {
+ buf = NULL;
+ len = 0;
+ }
+ if (db_capture_buf != NULL && buf != NULL)
+ bcopy(db_capture_buf, buf, len);
+ if (db_capture_buf != NULL)
+ free(db_capture_buf, M_DB_CAPTURE);
+ db_capture_bufoff = len;
+ db_capture_buf = buf;
+ db_capture_bufsize = size;
+ sx_xunlock(&db_capture_sx);
+
+ KASSERT(db_capture_bufoff <= db_capture_bufsize,
+ ("sysctl_debug_ddb_capture_bufsize: bufoff > bufsize"));
+ KASSERT(db_capture_bufsize <= DB_CAPTURE_MAXBUFSIZE,
+ ("sysctl_debug_ddb_capture_maxbufsize: bufsize > maxbufsize"));
+
+ return (0);
+}
+SYSCTL_PROC(_debug_ddb_capture, OID_AUTO, bufsize, CTLTYPE_UINT|CTLFLAG_RW,
+ 0, 0, sysctl_debug_ddb_capture_bufsize, "IU",
+ "Size of DDB capture buffer");
+
+/*
+ * Sysctl to read out the capture buffer from userspace. We require
+ * privilege as sensitive process/memory information may be accessed.
+ */
+static int
+sysctl_debug_ddb_capture_data(SYSCTL_HANDLER_ARGS)
+{
+ int error;
+ char ch;
+
+ error = priv_check(req->td, PRIV_DDB_CAPTURE);
+ if (error)
+ return (error);
+
+ sx_slock(&db_capture_sx);
+ error = SYSCTL_OUT(req, db_capture_buf, db_capture_bufoff);
+ sx_sunlock(&db_capture_sx);
+ if (error)
+ return (error);
+ ch = '\0';
+ return (SYSCTL_OUT(req, &ch, sizeof(ch)));
+}
+SYSCTL_PROC(_debug_ddb_capture, OID_AUTO, data, CTLTYPE_STRING | CTLFLAG_RD,
+ NULL, 0, sysctl_debug_ddb_capture_data, "A", "DDB capture data");
+
+/*
+ * Routines for capturing DDB output into a fixed-size buffer. These are
+ * invoked from DDB's input and output routines. If we hit the limit on the
+ * buffer, we simply drop further data.
+ */
+void
+db_capture_write(char *buffer, u_int buflen)
+{
+ u_int len;
+
+ if (db_capture_inprogress == 0 || db_capture_inpager)
+ return;
+ len = min(buflen, db_capture_bufsize - db_capture_bufoff);
+ bcopy(buffer, db_capture_buf + db_capture_bufoff, len);
+ db_capture_bufoff += len;
+
+ KASSERT(db_capture_bufoff <= db_capture_bufsize,
+ ("db_capture_write: bufoff > bufsize"));
+}
+
+void
+db_capture_writech(char ch)
+{
+
+ return (db_capture_write(&ch, sizeof(ch)));
+}
+
+void
+db_capture_enterpager(void)
+{
+
+ db_capture_inpager = 1;
+}
+
+void
+db_capture_exitpager(void)
+{
+
+ db_capture_inpager = 0;
+}
+
+/*
+ * Reset capture state, which flushes buffers.
+ */
+static void
+db_capture_reset(void)
+{
+
+ db_capture_inprogress = 0;
+ db_capture_bufoff = 0;
+}
+
+/*
+ * Start capture. Only one session is allowed at any time, but we may
+ * continue a previous session, so the buffer isn't reset.
+ */
+static void
+db_capture_start(void)
+{
+
+ if (db_capture_inprogress) {
+ db_printf("Capture already started\n");
+ return;
+ }
+ db_capture_inprogress = 1;
+}
+
+/*
+ * Terminate DDB output capture.
+ */
+static void
+db_capture_stop(void)
+{
+
+ if (db_capture_inprogress == 0) {
+ db_printf("Capture not started\n");
+ return;
+ }
+ db_capture_inprogress = 0;
+}
+
+/*-
+ * DDB(4) command to manage capture:
+ *
+ * capture on - start DDB output capture
+ * capture off - stop DDB output capture
+ * capture reset - reset DDB capture buffer (also stops capture)
+ * capture status - print DDB output capture status
+ */
+static void
+db_capture_usage(void)
+{
+
+ db_error("capture [on|off|reset|status]\n");
+}
+
+void
+db_capture_cmd(db_expr_t addr, boolean_t have_addr, db_expr_t count,
+ char *modif)
+{
+ int t;
+
+ t = db_read_token();
+ if (t != tIDENT) {
+ db_capture_usage();
+ return;
+ }
+ if (db_read_token() != tEOL)
+ db_error("?\n");
+ if (strcmp(db_tok_string, "on") == 0)
+ db_capture_start();
+ else if (strcmp(db_tok_string, "off") == 0)
+ db_capture_stop();
+ else if (strcmp(db_tok_string, "reset") == 0)
+ db_capture_reset();
+ else if (strcmp(db_tok_string, "status") == 0) {
+ db_printf("%u/%u bytes used\n", db_capture_bufoff,
+ db_capture_bufsize);
+ if (db_capture_inprogress)
+ db_printf("capture is on\n");
+ else
+ db_printf("capture is off\n");
+ } else
+ db_capture_usage();
+}
diff --git a/sys/ddb/db_command.c b/sys/ddb/db_command.c
index 71ead73..c5c820c 100644
--- a/sys/ddb/db_command.c
+++ b/sys/ddb/db_command.c
@@ -141,6 +141,7 @@ static struct command db_commands[] = {
{ "kill", db_kill, CS_OWN, 0 },
{ "watchdog", db_watchdog, 0, 0 },
{ "thread", db_set_thread, CS_OWN, 0 },
+ { "capture", db_capture_cmd, CS_OWN, 0 },
{ (char *)0, }
};
diff --git a/sys/ddb/db_input.c b/sys/ddb/db_input.c
index 27af265..dc07a1d 100644
--- a/sys/ddb/db_input.c
+++ b/sys/ddb/db_input.c
@@ -323,6 +323,7 @@ db_readline(lstart, lsize)
while (!db_inputchar(cngetc()))
continue;
+ db_capture_write(lstart, db_le - db_lbuf_start);
db_printf("\n"); /* synch output position */
*db_le = 0;
diff --git a/sys/ddb/db_main.c b/sys/ddb/db_main.c
index c196bf7..0a9fbf7 100644
--- a/sys/ddb/db_main.c
+++ b/sys/ddb/db_main.c
@@ -36,6 +36,7 @@ __FBSDID("$FreeBSD$");
#include <sys/pcpu.h>
#include <sys/proc.h>
#include <sys/reboot.h>
+#include <sys/sysctl.h>
#include <machine/kdb.h>
#include <machine/pcb.h>
@@ -45,6 +46,8 @@ __FBSDID("$FreeBSD$");
#include <ddb/db_command.h>
#include <ddb/db_sym.h>
+SYSCTL_NODE(_debug, OID_AUTO, ddb, CTLFLAG_RW, 0, "DDB settings");
+
static dbbe_init_f db_init;
static dbbe_trap_f db_trap;
static dbbe_trace_f db_trace_self_wrapper;
diff --git a/sys/ddb/db_output.c b/sys/ddb/db_output.c
index 40f56ba..531fef8 100644
--- a/sys/ddb/db_output.c
+++ b/sys/ddb/db_output.c
@@ -90,11 +90,13 @@ db_force_whitespace()
if (next_tab <= db_output_position) {
while (last_print < next_tab) { /* DON'T send a tab!!! */
cnputc(' ');
+ db_capture_writech(' ');
last_print++;
}
}
else {
cnputc(' ');
+ db_capture_writech(' ');
last_print++;
}
}
@@ -137,12 +139,14 @@ db_putchar(c, arg)
*/
db_force_whitespace();
cnputc(c);
+ db_capture_writech(c);
db_output_position++;
db_last_non_space = db_output_position;
}
else if (c == '\n') {
/* Newline */
cnputc(c);
+ db_capture_writech(c);
db_output_position = 0;
db_last_non_space = 0;
db_check_interrupt();
@@ -155,6 +159,7 @@ db_putchar(c, arg)
else if (c == '\r') {
/* Return */
cnputc(c);
+ db_capture_writech(c);
db_output_position = 0;
db_last_non_space = 0;
db_check_interrupt();
@@ -170,6 +175,7 @@ db_putchar(c, arg)
else if (c == '\007') {
/* bell */
cnputc(c);
+ /* No need to beep in a log: db_capture_writech(c); */
}
/* other characters are assumed non-printing */
}
@@ -206,6 +212,7 @@ db_pager(void)
{
int c, done;
+ db_capture_enterpager();
db_printf("--More--\r");
done = 0;
while (!done) {
@@ -249,6 +256,7 @@ db_pager(void)
db_force_whitespace();
db_printf("\r");
db_newlines = 0;
+ db_capture_exitpager();
}
/*
diff --git a/sys/ddb/ddb.h b/sys/ddb/ddb.h
index 716740b..cb516cc 100644
--- a/sys/ddb/ddb.h
+++ b/sys/ddb/ddb.h
@@ -37,6 +37,10 @@
#ifndef _DDB_DDB_H_
#define _DDB_DDB_H_
+#ifdef SYSCTL_DECL
+SYSCTL_DECL(_debug_ddb);
+#endif
+
#include <machine/db_machdep.h> /* type definitions */
#ifndef DB_MAXARGS
@@ -126,6 +130,7 @@ int db_value_of_name(const char *name, db_expr_t *valuep);
int db_write_bytes(vm_offset_t addr, size_t size, char *data);
db_cmdfcn_t db_breakpoint_cmd;
+db_cmdfcn_t db_capture_cmd;
db_cmdfcn_t db_continue_cmd;
db_cmdfcn_t db_delete_cmd;
db_cmdfcn_t db_deletehwatch_cmd;
@@ -168,4 +173,14 @@ struct command {
struct command_table *more; /* another level of command */
};
+/*
+ * Interface between DDB and the DDB output capture facility.
+ */
+struct dumperinfo;
+void db_capture_dump(struct dumperinfo *di);
+void db_capture_enterpager(void);
+void db_capture_exitpager(void);
+void db_capture_write(char *buffer, u_int buflen);
+void db_capture_writech(char ch);
+
#endif /* !_DDB_DDB_H_ */
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