svn commit: r256571 - in head: cddl/contrib/opensolaris/lib/libdtrace/common cddl/lib/libdtrace sys/cddl/contrib/opensolaris/uts/common/dtrace sys/cddl/contrib/opensolaris/uts/common/sys sys/cddl/d...
Mark Johnston
markj at FreeBSD.org
Wed Oct 16 01:39:27 UTC 2013
Author: markj
Date: Wed Oct 16 01:39:26 2013
New Revision: 256571
URL: http://svnweb.freebsd.org/changeset/base/256571
Log:
Add a function, memstr, which can be used to convert a buffer of
null-separated strings to a single string. This can be used to print the
full arguments of a process using execsnoop (from the DTrace toolkit) or
with the following one-liner:
dtrace -n 'syscall::execve:return {trace(curpsinfo->pr_psargs);}'
Note that this relies on the process arguments being cached via the struct
proc, which means that it will not work for argvs longer than
kern.ps_arg_cache_limit. However, the following rather non-portable
script can be used to extract any argv at exec time:
fbt::kern_execve:entry
{
printf("%s", memstr(args[1]->begin_argv, ' ',
args[1]->begin_envv - args[1]->begin_argv));
}
The debug.dtrace.memstr_max sysctl limits the maximum argument size to
memstr(). Thanks to Brendan Gregg for helpful comments on freebsd-dtrace.
Tested by: Fabian Keil (earlier version)
MFC after: 2 weeks
Modified:
head/cddl/contrib/opensolaris/lib/libdtrace/common/dt_open.c
head/cddl/lib/libdtrace/psinfo.d
head/sys/cddl/contrib/opensolaris/uts/common/dtrace/dtrace.c
head/sys/cddl/contrib/opensolaris/uts/common/sys/dtrace.h
head/sys/cddl/dev/dtrace/dtrace_sysctl.c
Modified: head/cddl/contrib/opensolaris/lib/libdtrace/common/dt_open.c
==============================================================================
--- head/cddl/contrib/opensolaris/lib/libdtrace/common/dt_open.c Wed Oct 16 00:58:47 2013 (r256570)
+++ head/cddl/contrib/opensolaris/lib/libdtrace/common/dt_open.c Wed Oct 16 01:39:26 2013 (r256571)
@@ -311,6 +311,10 @@ static const dt_ident_t _dtrace_globals[
&dt_idops_func, "void(@)" },
{ "memref", DT_IDENT_FUNC, 0, DIF_SUBR_MEMREF, DT_ATTR_STABCMN, DT_VERS_1_1,
&dt_idops_func, "uintptr_t *(void *, size_t)" },
+#if !defined(sun)
+{ "memstr", DT_IDENT_FUNC, 0, DIF_SUBR_MEMSTR, DT_ATTR_STABCMN, DT_VERS_1_0,
+ &dt_idops_func, "string(void *, char, size_t)" },
+#endif
{ "min", DT_IDENT_AGGFUNC, 0, DTRACEAGG_MIN, DT_ATTR_STABCMN, DT_VERS_1_0,
&dt_idops_func, "void(@)" },
{ "mod", DT_IDENT_ACTFUNC, 0, DT_ACT_MOD, DT_ATTR_STABCMN,
Modified: head/cddl/lib/libdtrace/psinfo.d
==============================================================================
--- head/cddl/lib/libdtrace/psinfo.d Wed Oct 16 00:58:47 2013 (r256570)
+++ head/cddl/lib/libdtrace/psinfo.d Wed Oct 16 01:39:26 2013 (r256571)
@@ -57,7 +57,8 @@ translator psinfo_t < struct proc *T > {
pr_gid = T->p_ucred->cr_rgid;
pr_egid = T->p_ucred->cr_groups[0];
pr_addr = 0;
- pr_psargs = stringof(T->p_args->ar_args);
+ pr_psargs = (T->p_args->ar_args == 0) ? "" :
+ memstr(T->p_args->ar_args, ' ', T->p_args->ar_length);
pr_arglen = T->p_args->ar_length;
pr_jailid = T->p_ucred->cr_prison->pr_id;
};
Modified: head/sys/cddl/contrib/opensolaris/uts/common/dtrace/dtrace.c
==============================================================================
--- head/sys/cddl/contrib/opensolaris/uts/common/dtrace/dtrace.c Wed Oct 16 00:58:47 2013 (r256570)
+++ head/sys/cddl/contrib/opensolaris/uts/common/dtrace/dtrace.c Wed Oct 16 01:39:26 2013 (r256571)
@@ -185,6 +185,9 @@ hrtime_t dtrace_deadman_interval = NANOS
hrtime_t dtrace_deadman_timeout = (hrtime_t)10 * NANOSEC;
hrtime_t dtrace_deadman_user = (hrtime_t)30 * NANOSEC;
hrtime_t dtrace_unregister_defunct_reap = (hrtime_t)60 * NANOSEC;
+#if !defined(sun)
+int dtrace_memstr_max = 4096;
+#endif
/*
* DTrace External Variables
@@ -4920,6 +4923,45 @@ inetout: regs[rd] = (uintptr_t)end + 1;
break;
}
+#if !defined(sun)
+ case DIF_SUBR_MEMSTR: {
+ char *str = (char *)mstate->dtms_scratch_ptr;
+ uintptr_t mem = tupregs[0].dttk_value;
+ char c = tupregs[1].dttk_value;
+ size_t size = tupregs[2].dttk_value;
+ uint8_t n;
+ int i;
+
+ regs[rd] = 0;
+
+ if (size == 0)
+ break;
+
+ if (!dtrace_canload(mem, size - 1, mstate, vstate))
+ break;
+
+ if (!DTRACE_INSCRATCH(mstate, size)) {
+ DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
+ break;
+ }
+
+ if (dtrace_memstr_max != 0 && size > dtrace_memstr_max) {
+ *flags |= CPU_DTRACE_ILLOP;
+ break;
+ }
+
+ for (i = 0; i < size - 1; i++) {
+ n = dtrace_load8(mem++);
+ str[i] = (n == 0) ? c : n;
+ }
+ str[size - 1] = 0;
+
+ regs[rd] = (uintptr_t)str;
+ mstate->dtms_scratch_ptr += size;
+ break;
+ }
+#endif
+
case DIF_SUBR_TYPEREF: {
uintptr_t size = 4 * sizeof(uintptr_t);
uintptr_t *typeref = (uintptr_t *) P2ROUNDUP(mstate->dtms_scratch_ptr, sizeof(uintptr_t));
@@ -9102,6 +9144,9 @@ dtrace_difo_validate_helper(dtrace_difo_
subr == DIF_SUBR_NTOHL ||
subr == DIF_SUBR_NTOHLL ||
subr == DIF_SUBR_MEMREF ||
+#if !defined(sun)
+ subr == DIF_SUBR_MEMSTR ||
+#endif
subr == DIF_SUBR_TYPEREF)
break;
Modified: head/sys/cddl/contrib/opensolaris/uts/common/sys/dtrace.h
==============================================================================
--- head/sys/cddl/contrib/opensolaris/uts/common/sys/dtrace.h Wed Oct 16 00:58:47 2013 (r256570)
+++ head/sys/cddl/contrib/opensolaris/uts/common/sys/dtrace.h Wed Oct 16 01:39:26 2013 (r256571)
@@ -311,8 +311,9 @@ typedef enum dtrace_probespec {
#define DIF_SUBR_SX_SHARED_HELD 48
#define DIF_SUBR_SX_EXCLUSIVE_HELD 49
#define DIF_SUBR_SX_ISEXCLUSIVE 50
+#define DIF_SUBR_MEMSTR 51
-#define DIF_SUBR_MAX 50 /* max subroutine value */
+#define DIF_SUBR_MAX 51 /* max subroutine value */
typedef uint32_t dif_instr_t;
Modified: head/sys/cddl/dev/dtrace/dtrace_sysctl.c
==============================================================================
--- head/sys/cddl/dev/dtrace/dtrace_sysctl.c Wed Oct 16 00:58:47 2013 (r256570)
+++ head/sys/cddl/dev/dtrace/dtrace_sysctl.c Wed Oct 16 01:39:26 2013 (r256571)
@@ -80,3 +80,5 @@ sysctl_dtrace_providers(SYSCTL_HANDLER_A
SYSCTL_PROC(_debug_dtrace, OID_AUTO, providers, CTLTYPE_STRING | CTLFLAG_RD,
0, 0, sysctl_dtrace_providers, "A", "");
+SYSCTL_INT(_debug_dtrace, OID_AUTO, memstr_max, CTLFLAG_RW, &dtrace_memstr_max,
+ 0, "largest allowed argument to memstr(), 0 indicates no limit");
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