[src/trunk]: src/sys/arch/xen partially convert to kmem_alloc()

[jdolecek <jdolecek%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/10824fb4d957
branches:  trunk
changeset: 1008979:10824fb4d957
user:      jdolecek <jdolecek%NetBSD.org@localhost>
date:      Tue Apr 07 15:40:14 2020 +0000

description:
partially convert to kmem_alloc()

plug memory leak in one xenbus_probe_device_type() error path
when read_backend_details() fails

diffstat:

 sys/arch/xen/include/xenbus.h      |   3 +-
 sys/arch/xen/xenbus/xenbus_probe.c |  47 ++++++++++++++++++-------------------
 2 files changed, 25 insertions(+), 25 deletions(-)

diffs (163 lines):

diff -r 7830b76f7cf0 -r 10824fb4d957 sys/arch/xen/include/xenbus.h
--- a/sys/arch/xen/include/xenbus.h     Tue Apr 07 15:16:52 2020 +0000
+++ b/sys/arch/xen/include/xenbus.h     Tue Apr 07 15:40:14 2020 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: xenbus.h,v 1.19 2020/04/07 14:07:01 jdolecek Exp $ */
+/* $NetBSD: xenbus.h,v 1.20 2020/04/07 15:40:14 jdolecek Exp $ */
 /******************************************************************************
  * xenbus.h
  *
@@ -96,6 +96,7 @@
        int xbusd_has_error;
        /* for xenbus internal use */
        struct xenbus_watch xbusd_otherend_watch;
+       size_t xbusd_sz;                /* size of allocated structure */
        const char xbusd_path[1]; /* our path */
 };
 
diff -r 7830b76f7cf0 -r 10824fb4d957 sys/arch/xen/xenbus/xenbus_probe.c
--- a/sys/arch/xen/xenbus/xenbus_probe.c        Tue Apr 07 15:16:52 2020 +0000
+++ b/sys/arch/xen/xenbus/xenbus_probe.c        Tue Apr 07 15:40:14 2020 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: xenbus_probe.c,v 1.44 2020/04/07 14:07:01 jdolecek Exp $ */
+/* $NetBSD: xenbus_probe.c,v 1.45 2020/04/07 15:40:14 jdolecek Exp $ */
 /******************************************************************************
  * Talks to Xen Store to figure out what devices we have.
  *
@@ -29,7 +29,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: xenbus_probe.c,v 1.44 2020/04/07 14:07:01 jdolecek Exp $");
+__KERNEL_RCSID(0, "$NetBSD: xenbus_probe.c,v 1.45 2020/04/07 15:40:14 jdolecek Exp $");
 
 #if 0
 #define DPRINTK(fmt, args...) \
@@ -313,6 +313,7 @@
 {
        int err, i, pos, msize;
        int *lookup = NULL;
+       size_t lookup_sz = 0;
        unsigned long state;
        char **dir;
        unsigned int dir_n = 0;
@@ -331,16 +332,13 @@
                int minp;
                unsigned long minv;
                unsigned long *id;
+               size_t id_sz;
 
-               lookup = malloc(sizeof(int) * dir_n, M_DEVBUF,
-                   M_WAITOK | M_ZERO);
-               if (lookup == NULL)
-                       panic("can't malloc lookup");
+               lookup_sz = sizeof(int) * dir_n;
+               lookup = kmem_zalloc(lookup_sz, KM_SLEEP);
 
-               id = malloc(sizeof(unsigned long) * dir_n, M_DEVBUF,
-                   M_WAITOK | M_ZERO);
-               if (id == NULL)
-                       panic("can't malloc id");
+               id_sz = sizeof(unsigned long) * dir_n;
+               id = kmem_zalloc(id_sz, KM_SLEEP);
 
                /* Convert string values to numeric; skip invalid */
                for (i = 0; i < dir_n; i++) {
@@ -370,8 +368,9 @@
                        else
                                break;
                }
-               
-               free(id, M_DEVBUF);
+
+               kmem_free(id, id_sz);
+
                /* Adjust in case we had to skip non-numeric entries */
                dir_n = pos;
        }
@@ -387,15 +386,14 @@
                 * already has room for one char in xbusd_path.
                 */
                msize = sizeof(*xbusd) + strlen(path) + strlen(dir[i]) + 2;
-               xbusd = malloc(msize, M_DEVBUF, M_WAITOK | M_ZERO);
-               if (xbusd == NULL)
-                       panic("can't malloc xbusd");
-                       
+               xbusd = kmem_zalloc(msize, KM_SLEEP);
+               xbusd->xbusd_sz = msize;
+
                snprintf(__UNCONST(xbusd->xbusd_path),
                    msize - sizeof(*xbusd) + 1, "%s/%s", path, dir[i]);
                if (xenbus_lookup_device_path(xbusd->xbusd_path) != NULL) {
                        /* device already registered */
-                       free(xbusd, M_DEVBUF);
+                       kmem_free(xbusd, xbusd->xbusd_sz);
                        continue;
                }
                err = xenbus_read_ul(NULL, xbusd->xbusd_path, "state",
@@ -403,13 +401,13 @@
                if (err) {
                        printf("xenbus: can't get state "
                            "for %s (%d)\n", xbusd->xbusd_path, err);
-                       free(xbusd, M_DEVBUF);
+                       kmem_free(xbusd, xbusd->xbusd_sz);
                        err = 0;
                        continue;
                }
                if (state != XenbusStateInitialising) {
                        /* device is not new */
-                       free(xbusd, M_DEVBUF);
+                       kmem_free(xbusd, xbusd->xbusd_sz);
                        continue;
                }
 
@@ -425,7 +423,7 @@
                                break;
                        }
                        if (create(xbusd)) {
-                               free(xbusd, M_DEVBUF);
+                               kmem_free(xbusd, xbusd->xbusd_sz);
                                continue;
                        }
                } else {
@@ -437,19 +435,20 @@
                                printf("xenbus device type %s: id %s is not a"
                                    " number\n", type, dir[i]);
                                err = EFTYPE;
-                               free(xbusd, M_DEVBUF);
+                               kmem_free(xbusd, xbusd->xbusd_sz);
                                break;
                        }
                        err = read_backend_details(xbusd);
                        if (err != 0) {
                                printf("xenbus: can't get backend details "
                                    "for %s (%d)\n", xbusd->xbusd_path, err);
+                               kmem_free(xbusd, xbusd->xbusd_sz);
                                break;
                        }
                        xbusd->xbusd_u.f.f_dev = config_found_ia(xenbus_dev,
                            "xenbus", &xa, xenbus_print);
                        if (xbusd->xbusd_u.f.f_dev == NULL) {
-                               free(xbusd, M_DEVBUF);
+                               kmem_free(xbusd, xbusd->xbusd_sz);
                                continue;
                        }
                }
@@ -459,7 +458,7 @@
        }
        free(dir, M_DEVBUF);
        if (lookup)
-               free(lookup, M_DEVBUF);
+               kmem_free(lookup, lookup_sz);
        
        return err;
 }
@@ -569,7 +568,7 @@
        free_otherend_watch(xbusd);
        free_otherend_details(xbusd);
        xenbus_switch_state(xbusd, NULL, XenbusStateClosed);
-       free(xbusd, M_DEVBUF);
+       kmem_free(xbusd, xbusd->xbusd_sz);
        return 0;
 }