/*
- * Copyright (c) 2006-2014 Apple Inc. All rights reserved.
+ * Copyright (c) 2006-2017 Apple Inc. All rights reserved.
*
* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
*
#include <sys/mount_internal.h>
#include <sys/kasl.h>
-#include <dev/random/randomdev.h>
+#include <sys/queue.h>
+#include <kern/kalloc.h>
#include <uuid/uuid.h>
strlcat(c_name, "(", sizeof(c_name));
strlcat(c_name, uuidstr, sizeof(c_name));
strlcat(c_name, ")", sizeof(c_name));
- if (0 != escape_str(c_name, strlen(c_name), sizeof(c_name))) {
+ if (0 != escape_str(c_name, strlen(c_name) + 1, sizeof(c_name))) {
return;
}
strlcat(t_name, "(", sizeof(t_name));
strlcat(t_name, uuidstr, sizeof(t_name));
strlcat(t_name, ")", sizeof(t_name));
- if (0 != escape_str(t_name, strlen(t_name), sizeof(t_name))) {
+ if (0 != escape_str(t_name, strlen(t_name) + 1, sizeof(t_name))) {
return;
}
#if DEBUG
}
}
+#if defined(__x86_64__)
+
+/*
+ * Log information about floating point exception handling
+ */
+
+static lck_mtx_t fpxlock;
+
+void
+fpxlog_init(void)
+{
+ lck_grp_attr_t *lck_grp_attr = lck_grp_attr_alloc_init();
+ lck_grp_t *lck_grp = lck_grp_alloc_init("fpx", lck_grp_attr);
+ lck_mtx_init(&fpxlock, lck_grp, LCK_ATTR_NULL);
+}
+
+struct fpx_event {
+ uuid_t fe_uuid;
+ uint32_t fe_code;
+ uint32_t fe_xcpt;
+ TAILQ_ENTRY(fpx_event) fe_link;
+};
+
+static bool
+match_fpx_event(const struct fpx_event *fe,
+ const uuid_t uuid, const uint32_t code, const uint32_t xcpt)
+{
+ return (code == fe->fe_code && xcpt == fe->fe_xcpt &&
+ 0 == memcmp(uuid, fe->fe_uuid, sizeof (uuid_t)));
+}
+
+#if FPX_EVENT_DBG
+static __attribute__((noinline)) void
+print_fpx_event(const char *pfx, const struct fpx_event *fe)
+{
+ uuid_string_t uustr;
+ uuid_unparse_upper(fe->fe_uuid, uustr);
+ printf("%s: code 0x%x xcpt 0x%x uuid '%s'\n",
+ pfx, fe->fe_code, fe->fe_xcpt, uustr);
+}
+#define DPRINTF_FPX_EVENT(pfx, fe) print_fpx_event(pfx, fe)
+#else
+#define DPRINTF_FPX_EVENT(pfx, fe) /* nothing */
+#endif
+
+#define MAX_DISTINCT_FPX_EVENTS 101 /* (approx one page of heap) */
+
+/*
+ * Filter to detect "new" <uuid, code, xcpt> tuples.
+ * Uses limited amount of state, managed LRU.
+ * Optimized to ignore repeated invocation with the same tuple.
+ *
+ * Note that there are 6 exception types, two types of FP, and
+ * many binaries, so don't make the list bound too small.
+ * It's also a linear search, so don't make it too large either.
+ * Next level filtering provided by syslogd, and summarization.
+ */
+static bool
+novel_fpx_event(const uuid_t uuid, uint32_t code, uint32_t xcpt)
+{
+ static TAILQ_HEAD(fpx_event_head, fpx_event) fehead =
+ TAILQ_HEAD_INITIALIZER(fehead);
+ struct fpx_event *fe;
+
+ lck_mtx_lock(&fpxlock);
+
+ fe = TAILQ_FIRST(&fehead);
+ if (NULL != fe &&
+ match_fpx_event(fe, uuid, code, xcpt)) {
+ /* seen before and element already at head */
+ lck_mtx_unlock(&fpxlock);
+ DPRINTF_FPX_EVENT("seen, head", fe);
+ return (false);
+ }
+
+ unsigned int count = 0;
+
+ TAILQ_FOREACH(fe, &fehead, fe_link) {
+ if (match_fpx_event(fe, uuid, code, xcpt)) {
+ /* seen before, now move element to head */
+ TAILQ_REMOVE(&fehead, fe, fe_link);
+ TAILQ_INSERT_HEAD(&fehead, fe, fe_link);
+ lck_mtx_unlock(&fpxlock);
+ DPRINTF_FPX_EVENT("seen, moved to head", fe);
+ return (false);
+ }
+ count++;
+ }
+
+ /* not recorded here => novel */
+
+ if (count >= MAX_DISTINCT_FPX_EVENTS) {
+ /* reuse LRU element */
+ fe = TAILQ_LAST(&fehead, fpx_event_head);
+ TAILQ_REMOVE(&fehead, fe, fe_link);
+ DPRINTF_FPX_EVENT("reusing", fe);
+ } else {
+ /* add a new element to the list */
+ fe = kalloc(sizeof (*fe));
+ }
+ memcpy(fe->fe_uuid, uuid, sizeof (uuid_t));
+ fe->fe_code = code;
+ fe->fe_xcpt = xcpt;
+ TAILQ_INSERT_HEAD(&fehead, fe, fe_link);
+ lck_mtx_unlock(&fpxlock);
+
+ DPRINTF_FPX_EVENT("novel", fe);
+
+ return (true);
+}
+
+void
+fpxlog(
+ int code, /* Mach exception code: e.g. 5 or 8 */
+ uint32_t stat, /* Full FP status register bits */
+ uint32_t ctrl, /* Full FP control register bits */
+ uint32_t xcpt) /* Exception bits from FP status */
+{
+ proc_t p = current_proc();
+ if (PROC_NULL == p)
+ return;
+
+ uuid_t uuid;
+ proc_getexecutableuuid(p, uuid, sizeof (uuid));
+
+ /*
+ * Check to see if an exception with this <uuid, code, xcpt>
+ * has been seen before. If "novel" then log a message.
+ */
+ if (!novel_fpx_event(uuid, code, xcpt))
+ return;
+
+ const size_t nmlen = 2 * MAXCOMLEN + 1;
+ char nm[nmlen] = {};
+ proc_selfname(nm, nmlen);
+ if (escape_str(nm, strlen(nm) + 1, nmlen))
+ snprintf(nm, nmlen, "(a.out)");
+
+ const size_t slen = 8 + 1 + 8 + 1;
+ char xcptstr[slen], csrstr[slen];
+
+ snprintf(xcptstr, slen, "%x.%x", code, xcpt);
+ if (ctrl == stat)
+ snprintf(csrstr, slen, "%x", ctrl);
+ else
+ snprintf(csrstr, slen, "%x.%x", ctrl, stat);
+
+#if DEVELOPMENT || DEBUG
+ printf("%s[%d]: com.apple.kernel.fpx: %s, %s\n",
+ nm, proc_pid(p), xcptstr, csrstr);
+#endif
+ kern_asl_msg(LOG_DEBUG, "messagetracer", 5,
+ /* 0 */ "com.apple.message.domain", "com.apple.kernel.fpx",
+ /* 1 */ "com.apple.message.signature", nm,
+ /* 2 */ "com.apple.message.signature2", xcptstr,
+ /* 3 */ "com.apple.message.value", csrstr,
+ /* 4 */ "com.apple.message.summarize", "YES",
+ NULL);
+}
+
+#else
+
+void
+fpxlog_init(void)
+{}
+
+#endif /* __x86_64__ */
projects / apple / xnu.git / blobdiff