kernel - Include physical cpu in ktrace header

* Record which cpu the system call (etc) is running on
  in the ktrace header.

diff --git a/sys/kern/kern_ktrace.c b/sys/kern/kern_ktrace.c
index 0ed4c1d..17c761f 100644 (file)
--- a/sys/kern/kern_ktrace.c
+++ b/sys/kern/kern_ktrace.c
@@ -57,73 +57,97 @@
 static MALLOC_DEFINE(M_KTRACE, "KTRACE", "KTRACE");
 
 #ifdef KTRACE
-static struct ktr_header *ktrgetheader (int type);
+static void ktrgetheader (struct ktr_header *kth, int type);
+static struct ktr_syscall *ktrgetsyscall(struct ktr_header *kth,
+                               struct ktr_syscall *ktp_cache, int narg);
+static void ktrputsyscall(struct ktr_syscall *ktp_cache,
+                               struct ktr_syscall *ktp);
 static void ktrwrite (struct lwp *, struct ktr_header *, struct uio *);
 static int ktrcanset (struct thread *,struct proc *);
-static int ktrsetchildren (struct thread *,struct proc *,int,int, ktrace_node_t);
+static int ktrsetchildren (struct thread *, struct proc *,
+                               int, int, ktrace_node_t);
 static int ktrops (struct thread *,struct proc *,int,int, ktrace_node_t);
 
 /*
  * MPSAFE
  */
-static struct ktr_header *
-ktrgetheader(int type)
+static
+void
+ktrgetheader(struct ktr_header *kth, int type)
 {
-       struct ktr_header *kth;
-       struct proc *p = curproc;       /* XXX */
-       struct lwp *lp = curthread->td_lwp;
+       thread_t td = curthread;
+       struct proc *p = td->td_proc;
+       struct lwp *lp = td->td_lwp;
 
-       kth = kmalloc(sizeof(struct ktr_header), M_KTRACE, M_WAITOK);
        kth->ktr_type = type;
        /* XXX threaded flag is a hack at the moment */
        kth->ktr_flags = (p->p_nthreads > 1) ? KTRH_THREADED : 0;
-       microtime(&kth->ktr_time);
+       kth->ktr_flags |= KTRH_CPUID_ENCODE(td->td_gd->gd_cpuid);
+       /*microtime(&kth->ktr_time); set in ktrwrite */
        kth->ktr_pid = p->p_pid;
        kth->ktr_tid = lp->lwp_tid;
        bcopy(p->p_comm, kth->ktr_comm, MAXCOMLEN + 1);
-       return (kth);
+}
+
+static
+struct ktr_syscall *
+ktrgetsyscall(struct ktr_header *kth, struct ktr_syscall *ktp_cache, int narg)
+{
+       size_t len;
+
+       len = offsetof(struct ktr_syscall, ktr_args[narg]);
+       if (len > sizeof(*ktp_cache))
+               ktp_cache = kmalloc(len, M_KTRACE, M_WAITOK);
+       kth->ktr_buf = (caddr_t)ktp_cache;
+       kth->ktr_len = (int)len;
+       return (ktp_cache);
+}
+
+static
+void
+ktrputsyscall(struct ktr_syscall *ktp_cache, struct ktr_syscall *ktp)
+{
+       if (ktp != ktp_cache)
+               kfree(ktp, M_KTRACE);
 }
 
 void
 ktrsyscall(struct lwp *lp, int code, int narg, register_t args[])
 {
-       struct  ktr_header *kth;
-       struct  ktr_syscall *ktp;
-       int len;
+       struct ktr_header kth;
+       struct ktr_syscall ktp_cache;
+       struct ktr_syscall *ktp;
        register_t *argp;
        int i;
 
-       len = offsetof(struct ktr_syscall, ktr_args) +
-             (narg * sizeof(register_t));
-
        /*
         * Setting the active bit prevents a ktrace recursion from the
         * ktracing op itself.
         */
        lp->lwp_traceflag |= KTRFAC_ACTIVE;
-       kth = ktrgetheader(KTR_SYSCALL);
-       ktp = kmalloc(len, M_KTRACE, M_WAITOK);
+       ktrgetheader(&kth, KTR_SYSCALL);
+
+       ktp = ktrgetsyscall(&kth, &ktp_cache, narg);
        ktp->ktr_code = code;
        ktp->ktr_narg = narg;
        argp = &ktp->ktr_args[0];
        for (i = 0; i < narg; i++)
                *argp++ = args[i];
-       kth->ktr_buf = (caddr_t)ktp;
-       kth->ktr_len = len;
-       ktrwrite(lp, kth, NULL);
-       kfree(ktp, M_KTRACE);
-       kfree(kth, M_KTRACE);
+       ktrwrite(lp, &kth, NULL);
+
+       ktrputsyscall(&ktp_cache, ktp);
        lp->lwp_traceflag &= ~KTRFAC_ACTIVE;
 }
 
 void
 ktrsysret(struct lwp *lp, int code, int error, register_t retval)
 {
-       struct ktr_header *kth;
+       struct ktr_header kth;
        struct ktr_sysret ktp;
 
        lp->lwp_traceflag |= KTRFAC_ACTIVE;
-       kth = ktrgetheader(KTR_SYSRET);
+       ktrgetheader(&kth, KTR_SYSRET);
+
        ktp.ktr_code = code;
        ktp.ktr_error = error;
        if (error == 0)
@@ -131,86 +155,85 @@ ktrsysret(struct lwp *lp, int code, int error, register_t retval)
        else
                ktp.ktr_retval = 0;
 
-       kth->ktr_buf = (caddr_t)&ktp;
-       kth->ktr_len = sizeof(struct ktr_sysret);
+       kth.ktr_buf = (caddr_t)&ktp;
+       kth.ktr_len = (int)sizeof(struct ktr_sysret);
 
-       ktrwrite(lp, kth, NULL);
-       kfree(kth, M_KTRACE);
+       ktrwrite(lp, &kth, NULL);
        lp->lwp_traceflag &= ~KTRFAC_ACTIVE;
 }
 
 void
 ktrnamei(struct lwp *lp, char *path)
 {
-       struct ktr_header *kth;
+       struct ktr_header kth;
 
        lp->lwp_traceflag |= KTRFAC_ACTIVE;
-       kth = ktrgetheader(KTR_NAMEI);
-       kth->ktr_len = strlen(path);
-       kth->ktr_buf = path;
+       ktrgetheader(&kth, KTR_NAMEI);
+
+       kth.ktr_len = (int)strlen(path);
+       kth.ktr_buf = path;
 
-       ktrwrite(lp, kth, NULL);
-       kfree(kth, M_KTRACE);
+       ktrwrite(lp, &kth, NULL);
        lp->lwp_traceflag &= ~KTRFAC_ACTIVE;
 }
 
 void
 ktrgenio(struct lwp *lp, int fd, enum uio_rw rw, struct uio *uio, int error)
 {
-       struct ktr_header *kth;
+       struct ktr_header kth;
        struct ktr_genio ktg;
 
        if (error)
                return;
        lp->lwp_traceflag |= KTRFAC_ACTIVE;
-       kth = ktrgetheader(KTR_GENIO);
+       ktrgetheader(&kth, KTR_GENIO);
+
        ktg.ktr_fd = fd;
        ktg.ktr_rw = rw;
-       kth->ktr_buf = (caddr_t)&ktg;
-       kth->ktr_len = sizeof(struct ktr_genio);
+       kth.ktr_buf = (caddr_t)&ktg;
+       kth.ktr_len = (int)sizeof(struct ktr_genio);
        uio->uio_offset = 0;
        uio->uio_rw = UIO_WRITE;
 
-       ktrwrite(lp, kth, uio);
-       kfree(kth, M_KTRACE);
+       ktrwrite(lp, &kth, uio);
        lp->lwp_traceflag &= ~KTRFAC_ACTIVE;
 }
 
 void
 ktrpsig(struct lwp *lp, int sig, sig_t action, sigset_t *mask, int code)
 {
-       struct ktr_header *kth;
+       struct ktr_header kth;
        struct ktr_psig kp;
 
        lp->lwp_traceflag |= KTRFAC_ACTIVE;
-       kth = ktrgetheader(KTR_PSIG);
+       ktrgetheader(&kth, KTR_PSIG);
+
        kp.signo = (char)sig;
        kp.action = action;
        kp.mask = *mask;
        kp.code = code;
-       kth->ktr_buf = (caddr_t)&kp;
-       kth->ktr_len = sizeof (struct ktr_psig);
+       kth.ktr_buf = (caddr_t)&kp;
+       kth.ktr_len = (int)sizeof(struct ktr_psig);
 
-       ktrwrite(lp, kth, NULL);
-       kfree(kth, M_KTRACE);
+       ktrwrite(lp, &kth, NULL);
        lp->lwp_traceflag &= ~KTRFAC_ACTIVE;
 }
 
 void
 ktrcsw(struct lwp *lp, int out, int user)
 {
-       struct ktr_header *kth;
-       struct  ktr_csw kc;
+       struct ktr_header kth;
+       struct ktr_csw kc;
 
        lp->lwp_traceflag |= KTRFAC_ACTIVE;
-       kth = ktrgetheader(KTR_CSW);
+       ktrgetheader(&kth, KTR_CSW);
+
        kc.out = out;
        kc.user = user;
-       kth->ktr_buf = (caddr_t)&kc;
-       kth->ktr_len = sizeof (struct ktr_csw);
+       kth.ktr_buf = (caddr_t)&kc;
+       kth.ktr_len = (int)sizeof(struct ktr_csw);
 
-       ktrwrite(lp, kth, NULL);
-       kfree(kth, M_KTRACE);
+       ktrwrite(lp, &kth, NULL);
        lp->lwp_traceflag &= ~KTRFAC_ACTIVE;
 }
 #endif
@@ -388,8 +411,9 @@ int
 sys_utrace(struct utrace_args *uap)
 {
 #ifdef KTRACE
-       struct ktr_header *kth;
+       struct ktr_header kth;
        struct thread *td = curthread;  /* XXX */
+       char cp_cache[64];
        caddr_t cp;
 
        if (!KTRPOINT(td, KTR_USER))
@@ -397,15 +421,19 @@ sys_utrace(struct utrace_args *uap)
        if (uap->len > KTR_USER_MAXLEN)
                return (EINVAL);
        td->td_lwp->lwp_traceflag |= KTRFAC_ACTIVE;
-       kth = ktrgetheader(KTR_USER);
-       cp = kmalloc(uap->len, M_KTRACE, M_WAITOK);
+       ktrgetheader(&kth, KTR_USER);
+       if (uap->len <= sizeof(cp_cache))
+               cp = cp_cache;
+       else
+               cp = kmalloc(uap->len, M_KTRACE, M_WAITOK);
+
        if (!copyin(uap->addr, cp, uap->len)) {
-               kth->ktr_buf = cp;
-               kth->ktr_len = uap->len;
-               ktrwrite(td->td_lwp, kth, NULL);
+               kth.ktr_buf = cp;
+               kth.ktr_len = uap->len;
+               ktrwrite(td->td_lwp, &kth, NULL);
        }
-       kfree(kth, M_KTRACE);
-       kfree(cp, M_KTRACE);
+       if (cp != cp_cache)
+               kfree(cp, M_KTRACE);
        td->td_lwp->lwp_traceflag &= ~KTRFAC_ACTIVE;
 
        return (0);
@@ -568,7 +596,13 @@ ktrwrite(struct lwp *lp, struct ktr_header *kth, struct uio *uio)
                if (uio != NULL)
                        kth->ktr_len += uio->uio_resid;
        }
+
+       /*
+        * NOTE: Must set timestamp after obtaining lock to ensure no
+        *       timestamp reversals in the output file.
+        */
        vn_lock(tracenode->kn_vp, LK_EXCLUSIVE | LK_RETRY);
+       microtime(&kth->ktr_time);
        error = VOP_WRITE(tracenode->kn_vp, &auio,
                          IO_UNIT | IO_APPEND, lp->lwp_thread->td_ucred);
        if (error == 0 && uio != NULL) {

diff --git a/sys/sys/ktrace.h b/sys/sys/ktrace.h
index 509a6fb..1784dc4 100644 (file)
--- a/sys/sys/ktrace.h
+++ b/sys/sys/ktrace.h
@@ -84,11 +84,14 @@ struct ktr_header {
        lwpid_t ktr_tid;                /* lwp id */
        char    ktr_comm[MAXCOMLEN+1];  /* command name */
        struct  timeval ktr_time;       /* timestamp */
-       caddr_t ktr_buf;
+       caddr_t ktr_buf;
 };
 
 #define KTRH_THREADED  0x0001          /* multiple threads present */
 
+#define KTRH_CPUID_ENCODE(cpuid)       (((cpuid) & 0xFF) << 8)
+#define KTRH_CPUID_DECODE(flags)       (((flags) >> 8) & 0xFF)
+
 /*
  * Test for kernel trace point (MP SAFE)
  */
@@ -110,9 +113,9 @@ struct ktr_syscall {
        short   ktr_code;               /* syscall number */
        short   ktr_narg;               /* number of arguments */
        /*
-        * followed by ktr_narg register_t
+        * Followed by ktr_narg register_t (can be more than 8)
         */
-       register_t      ktr_args[1];
+       register_t      ktr_args[8];
 };
 
 /*