diff options
| -rw-r--r-- | sys/conf/files | 1 | ||||
| -rw-r--r-- | sys/ddb/db_capture.c | 301 | ||||
| -rw-r--r-- | sys/ddb/db_command.c | 1 | ||||
| -rw-r--r-- | sys/ddb/db_input.c | 1 | ||||
| -rw-r--r-- | sys/ddb/db_main.c | 3 | ||||
| -rw-r--r-- | sys/ddb/db_output.c | 8 | ||||
| -rw-r--r-- | sys/ddb/ddb.h | 15 |
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_ */ |
