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- bnc#798188 - Add $network to xend initscript dependencies

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- Add upstream patches to fix libxl bugs.  These patches have
  already been posted for inclusion in xen-4.2-testing.
  25912-partial-libxl.patch
  26372-tools-paths.patch
  26468-libxl-race.patch
  26469-libxl-race.patch

OBS-URL: https://build.opensuse.org/package/show/Virtualization/xen?expand=0&rev=227
This commit is contained in:
Charles Arnold 2013-02-04 19:40:21 +00:00 committed by Git OBS Bridge
parent 9ebaaebb19
commit f9e7bf330c
7 changed files with 800 additions and 5 deletions
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146
25912-partial-libxl.patch Normal file
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@ -0,0 +1,146 @@
No functional change.
The purpose is to make it easier to backport patches from Xen 4.3's
libxl, as Xen 4.3's libxl has had this done:
libxl: Enable -Wshadow.
It was convenient to invent $(CFLAGS_LIBXL) to do this.
Various renamings to avoid shadowing standard functions:
- index(3)
- listen(2)
- link(2)
- abort(3)
- abs(3)
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
In this patch we do not change the others, and we do not enable
-Wshadow. We're just trying to bring 4.2's libxl textually closer to
4.3's.
Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
---
tools/libxl/libxl_event.c | 34 +++++++++++++++++-----------------
1 files changed, 17 insertions(+), 17 deletions(-)
Index: xen-4.2.1-testing/tools/libxl/libxl_event.c
===================================================================
--- xen-4.2.1-testing.orig/tools/libxl/libxl_event.c
+++ xen-4.2.1-testing/tools/libxl/libxl_event.c
@@ -167,15 +167,15 @@ static void time_insert_finite(libxl__gc
}
static int time_register_finite(libxl__gc *gc, libxl__ev_time *ev,
- struct timeval abs)
+ struct timeval absolute)
{
int rc;
- rc = OSEVENT_HOOK(timeout_register, &ev->for_app_reg, abs, ev);
+ rc = OSEVENT_HOOK(timeout_register, &ev->for_app_reg, absolute, ev);
if (rc) return rc;
ev->infinite = 0;
- ev->abs = abs;
+ ev->abs = absolute;
time_insert_finite(gc, ev);
return 0;
@@ -202,16 +202,16 @@ static void time_done_debug(libxl__gc *g
int libxl__ev_time_register_abs(libxl__gc *gc, libxl__ev_time *ev,
libxl__ev_time_callback *func,
- struct timeval abs)
+ struct timeval absolute)
{
int rc;
CTX_LOCK;
DBG("ev_time=%p register abs=%lu.%06lu",
- ev, (unsigned long)abs.tv_sec, (unsigned long)abs.tv_usec);
+ ev, (unsigned long)absolute.tv_sec, (unsigned long)absolute.tv_usec);
- rc = time_register_finite(gc, ev, abs);
+ rc = time_register_finite(gc, ev, absolute);
if (rc) goto out;
ev->func = func;
@@ -228,7 +228,7 @@ int libxl__ev_time_register_rel(libxl__g
libxl__ev_time_callback *func,
int milliseconds /* as for poll(2) */)
{
- struct timeval abs;
+ struct timeval absolute;
int rc;
CTX_LOCK;
@@ -238,10 +238,10 @@ int libxl__ev_time_register_rel(libxl__g
if (milliseconds < 0) {
ev->infinite = 1;
} else {
- rc = time_rel_to_abs(gc, milliseconds, &abs);
+ rc = time_rel_to_abs(gc, milliseconds, &absolute);
if (rc) goto out;
- rc = time_register_finite(gc, ev, abs);
+ rc = time_register_finite(gc, ev, absolute);
if (rc) goto out;
}
@@ -255,26 +255,26 @@ int libxl__ev_time_register_rel(libxl__g
}
int libxl__ev_time_modify_abs(libxl__gc *gc, libxl__ev_time *ev,
- struct timeval abs)
+ struct timeval absolute)
{
int rc;
CTX_LOCK;
DBG("ev_time=%p modify abs==%lu.%06lu",
- ev, (unsigned long)abs.tv_sec, (unsigned long)abs.tv_usec);
+ ev, (unsigned long)absolute.tv_sec, (unsigned long)absolute.tv_usec);
assert(libxl__ev_time_isregistered(ev));
if (ev->infinite) {
- rc = time_register_finite(gc, ev, abs);
+ rc = time_register_finite(gc, ev, absolute);
if (rc) goto out;
} else {
- rc = OSEVENT_HOOK(timeout_modify, &ev->for_app_reg, abs);
+ rc = OSEVENT_HOOK(timeout_modify, &ev->for_app_reg, absolute);
if (rc) goto out;
LIBXL_TAILQ_REMOVE(&CTX->etimes, ev, entry);
- ev->abs = abs;
+ ev->abs = absolute;
time_insert_finite(gc, ev);
}
@@ -288,7 +288,7 @@ int libxl__ev_time_modify_abs(libxl__gc
int libxl__ev_time_modify_rel(libxl__gc *gc, libxl__ev_time *ev,
int milliseconds)
{
- struct timeval abs;
+ struct timeval absolute;
int rc;
CTX_LOCK;
@@ -304,10 +304,10 @@ int libxl__ev_time_modify_rel(libxl__gc
goto out;
}
- rc = time_rel_to_abs(gc, milliseconds, &abs);
+ rc = time_rel_to_abs(gc, milliseconds, &absolute);
if (rc) goto out;
- rc = libxl__ev_time_modify_abs(gc, ev, abs);
+ rc = libxl__ev_time_modify_abs(gc, ev, absolute);
if (rc) goto out;
rc = 0;

56
26372-tools-paths.patch Normal file
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@ -0,0 +1,56 @@
# HG changeset patch
# User Bamvor Jian Zhang <bjzhang@suse.com>
# Date 1357906948 0
# Node ID 2ad5792b4274d76ced39515cbd3f84898b181768
# Parent ba2d73234d73fc0faa027cd9bdfd3ac90642733c
fix wrong path while calling pygrub and libxl-save-helper
in current xen x86_64, the default libexec directory is /usr/lib/xen/bin,
while the private binder is /usr/lib64/xen/bin. but some commands(pygrub,
libxl-save-helper) located in private binder directory is called from
libexec directory which lead to the following error:
1, for pygrub bootloader:
libxl: debug: libxl_bootloader.c:429:bootloader_disk_attached_cb: /usr/lib/xen/bin/pygrub doesn't exist, falling back to config path
2, for libxl-save-helper:
libxl: cannot execute /usr/lib/xen/bin/libxl-save-helper: No such file or directory
libxl: error: libxl_utils.c:363:libxl_read_exactly: file/stream truncated reading ipc msg header from domain 3 save/restore helper stdout pipe
libxl: error: libxl_exec.c:118:libxl_report_child_exitstatus: domain 3 save/restore helper [10222] exited with error status 255
there are two ways to fix above error. the first one is make such command
store in the /usr/lib/xen/bin and /usr/lib64/xen/bin(symbol link to
previous), e.g. qemu-dm. The second way is using private binder dir
instead of libexec dir. e.g. xenconsole.
For these cases, the latter one is suitable.
Signed-off-by: Bamvor Jian Zhang <bjzhang@suse.com>
Committed-by: Ian Campbell <ian.campbell@citrix.com>
Index: xen-4.2.1-testing/tools/libxl/libxl_bootloader.c
===================================================================
--- xen-4.2.1-testing.orig/tools/libxl/libxl_bootloader.c
+++ xen-4.2.1-testing/tools/libxl/libxl_bootloader.c
@@ -419,7 +419,7 @@ static void bootloader_disk_attached_cb(
const char *bltmp;
struct stat st;
- bltmp = libxl__abs_path(gc, bootloader, libxl__libexec_path());
+ bltmp = libxl__abs_path(gc, bootloader, libxl__private_bindir_path());
/* Check to see if the file exists in this location; if not,
* fall back to checking the path */
LOG(DEBUG, "Checking for bootloader in libexec path: %s", bltmp);
Index: xen-4.2.1-testing/tools/libxl/libxl_save_callout.c
===================================================================
--- xen-4.2.1-testing.orig/tools/libxl/libxl_save_callout.c
+++ xen-4.2.1-testing/tools/libxl/libxl_save_callout.c
@@ -172,7 +172,7 @@ static void run_helper(libxl__egc *egc,
shs->stdout_what = GCSPRINTF("domain %"PRIu32" save/restore helper"
" stdout pipe", domid);
- *arg++ = getenv("LIBXL_SAVE_HELPER") ?: LIBEXEC "/" "libxl-save-helper";
+ *arg++ = getenv("LIBXL_SAVE_HELPER") ?: PRIVATE_BINDIR "/" "libxl-save-helper";
*arg++ = mode_arg;
const char **stream_fd_arg = arg++;
for (i=0; i<num_argnums; i++)

343
26468-libxl-race.patch Normal file
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@ -0,0 +1,343 @@
# HG changeset patch
# User Ian Jackson <ian.jackson@eu.citrix.com>
# Date 1359031672 0
# Node ID a181bf3e77df891c97fc20dff4e9b90b7584022b
# Parent 3e93c50982de4f2f7db99d92b04684556320541c
libxl: fix stale fd event callback race
Because there is not necessarily any lock held at the point the
application (eg, libvirt) calls libxl_osevent_occurred_timeout and
..._fd, in a multithreaded program those calls may be arbitrarily
delayed in relation to other activities within the program.
libxl therefore needs to be prepared to receive very old event
callbacks. Arrange for this to be the case for fd callbacks.
This requires a new layer of indirection through a "hook nexus" struct
which can outlive the libxl__ev_foo. Allocation and deallocation of
these nexi is mostly handled in the OSEVENT macros which wrap up
the application's callbacks.
Document the problem and the solution in a comment in libxl_event.c
just before the definition of struct libxl__osevent_hook_nexus.
There is still a race relating to libxl__osevent_occurred_timeout;
this will be addressed in the following patch.
Reported-by: Bamvor Jian Zhang <bjzhang@suse.com>
Cc: Bamvor Jian Zhang <bjzhang@suse.com>
Cc: Ian Campbell <Ian.Campbell@citrix.com>
Tested-by: Jim Fehlig <jfehlig@suse.com>
Acked-by: Jim Fehlig <jfehlig@suse.com>
Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Committed-by: Ian Campbell <ian.campbell@citrix.com>
Index: xen-4.2.1-testing/tools/libxl/libxl_event.c
===================================================================
--- xen-4.2.1-testing.orig/tools/libxl/libxl_event.c
+++ xen-4.2.1-testing/tools/libxl/libxl_event.c
@@ -38,23 +38,131 @@
* The application's registration hooks should be called ONLY via
* these macros, with the ctx locked. Likewise all the "occurred"
* entrypoints from the application should assert(!in_hook);
+ *
+ * During the hook call - including while the arguments are being
+ * evaluated - ev->nexus is guaranteed to be valid and refer to the
+ * nexus which is being used for this event registration. The
+ * arguments should specify ev->nexus for the for_libxl argument and
+ * ev->nexus->for_app_reg (or a pointer to it) for for_app_reg.
*/
-#define OSEVENT_HOOK_INTERN(retval, hookname, ...) do { \
- if (CTX->osevent_hooks) { \
- CTX->osevent_in_hook++; \
- retval CTX->osevent_hooks->hookname(CTX->osevent_user, __VA_ARGS__); \
- CTX->osevent_in_hook--; \
- } \
+#define OSEVENT_HOOK_INTERN(retval, failedp, evkind, hookop, nexusop, ...) do { \
+ if (CTX->osevent_hooks) { \
+ CTX->osevent_in_hook++; \
+ libxl__osevent_hook_nexi *nexi = &CTX->hook_##evkind##_nexi_idle; \
+ osevent_hook_pre_##nexusop(gc, ev, nexi, &ev->nexus); \
+ retval CTX->osevent_hooks->evkind##_##hookop \
+ (CTX->osevent_user, __VA_ARGS__); \
+ if ((failedp)) \
+ osevent_hook_failed_##nexusop(gc, ev, nexi, &ev->nexus); \
+ CTX->osevent_in_hook--; \
+ } \
} while (0)
-#define OSEVENT_HOOK(hookname, ...) ({ \
- int osevent_hook_rc = 0; \
- OSEVENT_HOOK_INTERN(osevent_hook_rc = , hookname, __VA_ARGS__); \
- osevent_hook_rc; \
+#define OSEVENT_HOOK(evkind, hookop, nexusop, ...) ({ \
+ int osevent_hook_rc = 0; \
+ OSEVENT_HOOK_INTERN(osevent_hook_rc =, !!osevent_hook_rc, \
+ evkind, hookop, nexusop, __VA_ARGS__); \
+ osevent_hook_rc; \
})
-#define OSEVENT_HOOK_VOID(hookname, ...) \
- OSEVENT_HOOK_INTERN(/* void */, hookname, __VA_ARGS__)
+#define OSEVENT_HOOK_VOID(evkind, hookop, nexusop, ...) \
+ OSEVENT_HOOK_INTERN(/* void */, 0, evkind, hookop, nexusop, __VA_ARGS__)
+
+/*
+ * The application's calls to libxl_osevent_occurred_... may be
+ * indefinitely delayed with respect to the rest of the program (since
+ * they are not necessarily called with any lock held). So the
+ * for_libxl value we receive may be (almost) arbitrarily old. All we
+ * know is that it came from this ctx.
+ *
+ * Therefore we may not free the object referred to by any for_libxl
+ * value until we free the whole libxl_ctx. And if we reuse it we
+ * must be able to tell when an old use turns up, and discard the
+ * stale event.
+ *
+ * Thus we cannot use the ev directly as the for_libxl value - we need
+ * a layer of indirection.
+ *
+ * We do this by keeping a pool of libxl__osevent_hook_nexus structs,
+ * and use pointers to them as for_libxl values. In fact, there are
+ * two pools: one for fds and one for timeouts. This ensures that we
+ * don't risk a type error when we upcast nexus->ev. In each nexus
+ * the ev is either null or points to a valid libxl__ev_time or
+ * libxl__ev_fd, as applicable.
+ *
+ * We /do/ allow ourselves to reassociate an old nexus with a new ev
+ * as otherwise we would have to leak nexi. (This reassociation
+ * might, of course, be an old ev being reused for a new purpose so
+ * simply comparing the ev pointer is not sufficient.) Thus the
+ * libxl_osevent_occurred functions need to check that the condition
+ * allegedly signalled by this event actually exists.
+ *
+ * The nexi and the lists are all protected by the ctx lock.
+ */
+
+struct libxl__osevent_hook_nexus {
+ void *ev;
+ void *for_app_reg;
+ LIBXL_SLIST_ENTRY(libxl__osevent_hook_nexus) next;
+};
+
+static void *osevent_ev_from_hook_nexus(libxl_ctx *ctx,
+ libxl__osevent_hook_nexus *nexus /* pass void *for_libxl */)
+{
+ return nexus->ev;
+}
+
+static void osevent_release_nexus(libxl__gc *gc,
+ libxl__osevent_hook_nexi *nexi_idle,
+ libxl__osevent_hook_nexus *nexus)
+{
+ nexus->ev = 0;
+ LIBXL_SLIST_INSERT_HEAD(nexi_idle, nexus, next);
+}
+
+/*----- OSEVENT* hook functions for nexusop "alloc" -----*/
+static void osevent_hook_pre_alloc(libxl__gc *gc, void *ev,
+ libxl__osevent_hook_nexi *nexi_idle,
+ libxl__osevent_hook_nexus **nexus_r)
+{
+ libxl__osevent_hook_nexus *nexus = LIBXL_SLIST_FIRST(nexi_idle);
+ if (nexus) {
+ LIBXL_SLIST_REMOVE_HEAD(nexi_idle, next);
+ } else {
+ nexus = libxl__zalloc(NOGC, sizeof(*nexus));
+ }
+ nexus->ev = ev;
+ *nexus_r = nexus;
+}
+static void osevent_hook_failed_alloc(libxl__gc *gc, void *ev,
+ libxl__osevent_hook_nexi *nexi_idle,
+ libxl__osevent_hook_nexus **nexus)
+{
+ osevent_release_nexus(gc, nexi_idle, *nexus);
+}
+
+/*----- OSEVENT* hook functions for nexusop "release" -----*/
+static void osevent_hook_pre_release(libxl__gc *gc, void *ev,
+ libxl__osevent_hook_nexi *nexi_idle,
+ libxl__osevent_hook_nexus **nexus)
+{
+ osevent_release_nexus(gc, nexi_idle, *nexus);
+}
+static void osevent_hook_failed_release(libxl__gc *gc, void *ev,
+ libxl__osevent_hook_nexi *nexi_idle,
+ libxl__osevent_hook_nexus **nexus)
+{
+ abort();
+}
+
+/*----- OSEVENT* hook functions for nexusop "noop" -----*/
+static void osevent_hook_pre_noop(libxl__gc *gc, void *ev,
+ libxl__osevent_hook_nexi *nexi_idle,
+ libxl__osevent_hook_nexus **nexus) { }
+static void osevent_hook_failed_noop(libxl__gc *gc, void *ev,
+ libxl__osevent_hook_nexi *nexi_idle,
+ libxl__osevent_hook_nexus **nexus) { }
+
/*
* fd events
@@ -72,7 +180,8 @@ int libxl__ev_fd_register(libxl__gc *gc,
DBG("ev_fd=%p register fd=%d events=%x", ev, fd, events);
- rc = OSEVENT_HOOK(fd_register, fd, &ev->for_app_reg, events, ev);
+ rc = OSEVENT_HOOK(fd,register, alloc, fd, &ev->nexus->for_app_reg,
+ events, ev->nexus);
if (rc) goto out;
ev->fd = fd;
@@ -97,7 +206,7 @@ int libxl__ev_fd_modify(libxl__gc *gc, l
DBG("ev_fd=%p modify fd=%d events=%x", ev, ev->fd, events);
- rc = OSEVENT_HOOK(fd_modify, ev->fd, &ev->for_app_reg, events);
+ rc = OSEVENT_HOOK(fd,modify, noop, ev->fd, &ev->nexus->for_app_reg, events);
if (rc) goto out;
ev->events = events;
@@ -119,7 +228,7 @@ void libxl__ev_fd_deregister(libxl__gc *
DBG("ev_fd=%p deregister fd=%d", ev, ev->fd);
- OSEVENT_HOOK_VOID(fd_deregister, ev->fd, ev->for_app_reg);
+ OSEVENT_HOOK_VOID(fd,deregister, release, ev->fd, ev->nexus->for_app_reg);
LIBXL_LIST_REMOVE(ev, entry);
ev->fd = -1;
@@ -171,7 +280,8 @@ static int time_register_finite(libxl__g
{
int rc;
- rc = OSEVENT_HOOK(timeout_register, &ev->for_app_reg, absolute, ev);
+ rc = OSEVENT_HOOK(timeout,register, alloc, &ev->nexus->for_app_reg,
+ absolute, ev->nexus);
if (rc) return rc;
ev->infinite = 0;
@@ -184,7 +294,7 @@ static int time_register_finite(libxl__g
static void time_deregister(libxl__gc *gc, libxl__ev_time *ev)
{
if (!ev->infinite) {
- OSEVENT_HOOK_VOID(timeout_deregister, ev->for_app_reg);
+ OSEVENT_HOOK_VOID(timeout,deregister, release, ev->nexus->for_app_reg);
LIBXL_TAILQ_REMOVE(&CTX->etimes, ev, entry);
}
}
@@ -270,7 +380,8 @@ int libxl__ev_time_modify_abs(libxl__gc
rc = time_register_finite(gc, ev, absolute);
if (rc) goto out;
} else {
- rc = OSEVENT_HOOK(timeout_modify, &ev->for_app_reg, absolute);
+ rc = OSEVENT_HOOK(timeout,modify, noop,
+ &ev->nexus->for_app_reg, absolute);
if (rc) goto out;
LIBXL_TAILQ_REMOVE(&CTX->etimes, ev, entry);
@@ -1009,35 +1120,54 @@ void libxl_osevent_register_hooks(libxl_
void libxl_osevent_occurred_fd(libxl_ctx *ctx, void *for_libxl,
- int fd, short events, short revents)
+ int fd, short events_ign, short revents_ign)
{
- libxl__ev_fd *ev = for_libxl;
-
EGC_INIT(ctx);
CTX_LOCK;
assert(!CTX->osevent_in_hook);
- assert(fd == ev->fd);
- revents &= ev->events;
- if (revents)
- ev->func(egc, ev, fd, ev->events, revents);
+ libxl__ev_fd *ev = osevent_ev_from_hook_nexus(ctx, for_libxl);
+ if (!ev) goto out;
+ if (ev->fd != fd) goto out;
+ struct pollfd check;
+ for (;;) {
+ check.fd = fd;
+ check.events = ev->events;
+ int r = poll(&check, 1, 0);
+ if (!r)
+ goto out;
+ if (r==1)
+ break;
+ assert(r<0);
+ if (errno != EINTR) {
+ LIBXL__EVENT_DISASTER(egc, "failed poll to check for fd", errno, 0);
+ goto out;
+ }
+ }
+
+ if (check.revents)
+ ev->func(egc, ev, fd, ev->events, check.revents);
+
+ out:
CTX_UNLOCK;
EGC_FREE;
}
void libxl_osevent_occurred_timeout(libxl_ctx *ctx, void *for_libxl)
{
- libxl__ev_time *ev = for_libxl;
-
EGC_INIT(ctx);
CTX_LOCK;
assert(!CTX->osevent_in_hook);
+ libxl__ev_time *ev = osevent_ev_from_hook_nexus(ctx, for_libxl);
+ if (!ev) goto out;
assert(!ev->infinite);
+
LIBXL_TAILQ_REMOVE(&CTX->etimes, ev, entry);
ev->func(egc, ev, &ev->abs);
+ out:
CTX_UNLOCK;
EGC_FREE;
}
Index: xen-4.2.1-testing/tools/libxl/libxl_internal.h
===================================================================
--- xen-4.2.1-testing.orig/tools/libxl/libxl_internal.h
+++ xen-4.2.1-testing/tools/libxl/libxl_internal.h
@@ -136,6 +136,8 @@ typedef struct libxl__gc libxl__gc;
typedef struct libxl__egc libxl__egc;
typedef struct libxl__ao libxl__ao;
typedef struct libxl__aop_occurred libxl__aop_occurred;
+typedef struct libxl__osevent_hook_nexus libxl__osevent_hook_nexus;
+typedef struct libxl__osevent_hook_nexi libxl__osevent_hook_nexi;
_hidden void libxl__alloc_failed(libxl_ctx *, const char *func,
size_t nmemb, size_t size) __attribute__((noreturn));
@@ -163,7 +165,7 @@ struct libxl__ev_fd {
libxl__ev_fd_callback *func;
/* remainder is private for libxl__ev_fd... */
LIBXL_LIST_ENTRY(libxl__ev_fd) entry;
- void *for_app_reg;
+ libxl__osevent_hook_nexus *nexus;
};
@@ -178,7 +180,7 @@ struct libxl__ev_time {
int infinite; /* not registered in list or with app if infinite */
LIBXL_TAILQ_ENTRY(libxl__ev_time) entry;
struct timeval abs;
- void *for_app_reg;
+ libxl__osevent_hook_nexus *nexus;
};
typedef struct libxl__ev_xswatch libxl__ev_xswatch;
@@ -329,6 +331,8 @@ struct libxl__ctx {
libxl__poller poller_app; /* libxl_osevent_beforepoll and _afterpoll */
LIBXL_LIST_HEAD(, libxl__poller) pollers_event, pollers_idle;
+ LIBXL_SLIST_HEAD(libxl__osevent_hook_nexi, libxl__osevent_hook_nexus)
+ hook_fd_nexi_idle, hook_timeout_nexi_idle;
LIBXL_LIST_HEAD(, libxl__ev_fd) efds;
LIBXL_TAILQ_HEAD(, libxl__ev_time) etimes;

228
26469-libxl-race.patch Normal file
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@ -0,0 +1,228 @@
# HG changeset patch
# User Ian Jackson <ian.jackson@eu.citrix.com>
# Date 1359031673 0
# Node ID a162a72e719a85799e3b08f52af7bb2147a407b8
# Parent a181bf3e77df891c97fc20dff4e9b90b7584022b
libxl: fix stale timeout event callback race
Because there is not necessarily any lock held at the point the
application (eg, libvirt) calls libxl_osevent_occurred_timeout, in a
multithreaded program those calls may be arbitrarily delayed in
relation to other activities within the program.
Specifically this means when ->timeout_deregister returns, libxl does
not know whether it can safely dispose of the for_libxl value or
whether it needs to retain it in case of an in-progress call to
_occurred_timeout.
The interface could be fixed by requiring the application to make a
new call into libxl to say that the deregistration was complete.
However that new call would have to be threaded through the
application's event loop; this is complicated and some application
authors are likely not to implement it properly. Furthermore the
easiest way to implement this facility in most event loops is to queue
up a time event for "now".
Shortcut all of this by having libxl always call timeout_modify
setting abs={0,0} (ie, ASAP) instead of timeout_deregister. This will
cause the application to call _occurred_timeout. When processing this
calldown we see that we were no longer actually interested and simply
throw it away.
Additionally, there is a race between _occurred_timeout and
->timeout_modify. If libxl ever adjusts the deadline for a timeout
the application may already be in the process of calling _occurred, in
which case the situation with for_app's lifetime becomes very
complicated. Therefore abolish libxl__ev_time_modify_{abs,rel} (which
have no callers) and promise to the application only ever to call
->timeout_modify with abs=={0,0}. The application still needs to cope
with ->timeout_modify racing with its internal function which calls
_occurred_timeout. Document this.
This is a forwards-compatible change for applications using the libxl
API, and will hopefully eliminate these races in callback-supplying
applications (such as libvirt) without the need for corresponding
changes to the application. (It is possible that this might expose
bugs in applications, though, as previously libxl would never call
libxl_osevent_hooks->timeout_modify and now it never calls
->timeout_deregister).
For clarity, fold the body of time_register_finite into its one
remaining call site. This makes the semantics of ev->infinite
slightly clearer.
Cc: Bamvor Jian Zhang <bjzhang@suse.com>
Cc: Ian Campbell <Ian.Campbell@citrix.com>
Tested-by: Jim Fehlig <jfehlig@suse.com>
Acked-by: Jim Fehlig <jfehlig@suse.com>
Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Committed-by: Ian Campbell <ian.campbell@citrix.com>
Index: xen-4.2.1-testing/tools/libxl/libxl_event.c
===================================================================
--- xen-4.2.1-testing.orig/tools/libxl/libxl_event.c
+++ xen-4.2.1-testing/tools/libxl/libxl_event.c
@@ -267,18 +267,11 @@ static int time_rel_to_abs(libxl__gc *gc
return 0;
}
-static void time_insert_finite(libxl__gc *gc, libxl__ev_time *ev)
-{
- libxl__ev_time *evsearch;
- LIBXL_TAILQ_INSERT_SORTED(&CTX->etimes, entry, ev, evsearch, /*empty*/,
- timercmp(&ev->abs, &evsearch->abs, >));
- ev->infinite = 0;
-}
-
static int time_register_finite(libxl__gc *gc, libxl__ev_time *ev,
struct timeval absolute)
{
int rc;
+ libxl__ev_time *evsearch;
rc = OSEVENT_HOOK(timeout,register, alloc, &ev->nexus->for_app_reg,
absolute, ev->nexus);
@@ -286,7 +279,8 @@ static int time_register_finite(libxl__g
ev->infinite = 0;
ev->abs = absolute;
- time_insert_finite(gc, ev);
+ LIBXL_TAILQ_INSERT_SORTED(&CTX->etimes, entry, ev, evsearch, /*empty*/,
+ timercmp(&ev->abs, &evsearch->abs, >));
return 0;
}
@@ -294,7 +288,12 @@ static int time_register_finite(libxl__g
static void time_deregister(libxl__gc *gc, libxl__ev_time *ev)
{
if (!ev->infinite) {
- OSEVENT_HOOK_VOID(timeout,deregister, release, ev->nexus->for_app_reg);
+ struct timeval right_away = { 0, 0 };
+ if (ev->nexus) /* only set if app provided hooks */
+ ev->nexus->ev = 0;
+ OSEVENT_HOOK_VOID(timeout,modify,
+ noop /* release nexus in _occurred_ */,
+ &ev->nexus->for_app_reg, right_away);
LIBXL_TAILQ_REMOVE(&CTX->etimes, ev, entry);
}
}
@@ -364,70 +363,6 @@ int libxl__ev_time_register_rel(libxl__g
return rc;
}
-int libxl__ev_time_modify_abs(libxl__gc *gc, libxl__ev_time *ev,
- struct timeval absolute)
-{
- int rc;
-
- CTX_LOCK;
-
- DBG("ev_time=%p modify abs==%lu.%06lu",
- ev, (unsigned long)absolute.tv_sec, (unsigned long)absolute.tv_usec);
-
- assert(libxl__ev_time_isregistered(ev));
-
- if (ev->infinite) {
- rc = time_register_finite(gc, ev, absolute);
- if (rc) goto out;
- } else {
- rc = OSEVENT_HOOK(timeout,modify, noop,
- &ev->nexus->for_app_reg, absolute);
- if (rc) goto out;
-
- LIBXL_TAILQ_REMOVE(&CTX->etimes, ev, entry);
- ev->abs = absolute;
- time_insert_finite(gc, ev);
- }
-
- rc = 0;
- out:
- time_done_debug(gc,__func__,ev,rc);
- CTX_UNLOCK;
- return rc;
-}
-
-int libxl__ev_time_modify_rel(libxl__gc *gc, libxl__ev_time *ev,
- int milliseconds)
-{
- struct timeval absolute;
- int rc;
-
- CTX_LOCK;
-
- DBG("ev_time=%p modify ms=%d", ev, milliseconds);
-
- assert(libxl__ev_time_isregistered(ev));
-
- if (milliseconds < 0) {
- time_deregister(gc, ev);
- ev->infinite = 1;
- rc = 0;
- goto out;
- }
-
- rc = time_rel_to_abs(gc, milliseconds, &absolute);
- if (rc) goto out;
-
- rc = libxl__ev_time_modify_abs(gc, ev, absolute);
- if (rc) goto out;
-
- rc = 0;
- out:
- time_done_debug(gc,__func__,ev,rc);
- CTX_UNLOCK;
- return rc;
-}
-
void libxl__ev_time_deregister(libxl__gc *gc, libxl__ev_time *ev)
{
CTX_LOCK;
@@ -1160,7 +1095,11 @@ void libxl_osevent_occurred_timeout(libx
CTX_LOCK;
assert(!CTX->osevent_in_hook);
- libxl__ev_time *ev = osevent_ev_from_hook_nexus(ctx, for_libxl);
+ libxl__osevent_hook_nexus *nexus = for_libxl;
+ libxl__ev_time *ev = osevent_ev_from_hook_nexus(ctx, nexus);
+
+ osevent_release_nexus(gc, &CTX->hook_timeout_nexi_idle, nexus);
+
if (!ev) goto out;
assert(!ev->infinite);
Index: xen-4.2.1-testing/tools/libxl/libxl_event.h
===================================================================
--- xen-4.2.1-testing.orig/tools/libxl/libxl_event.h
+++ xen-4.2.1-testing/tools/libxl/libxl_event.h
@@ -287,8 +287,10 @@ typedef struct libxl_osevent_hooks {
int (*timeout_register)(void *user, void **for_app_registration_out,
struct timeval abs, void *for_libxl);
int (*timeout_modify)(void *user, void **for_app_registration_update,
- struct timeval abs);
- void (*timeout_deregister)(void *user, void *for_app_registration);
+ struct timeval abs)
+ /* only ever called with abs={0,0}, meaning ASAP */;
+ void (*timeout_deregister)(void *user, void *for_app_registration)
+ /* will never be called */;
} libxl_osevent_hooks;
/* The application which calls register_fd_hooks promises to
@@ -337,6 +339,17 @@ typedef struct libxl_osevent_hooks {
* register (or modify), and pass it to subsequent calls to modify
* or deregister.
*
+ * Note that the application must cope with a call from libxl to
+ * timeout_modify racing with its own call to
+ * libxl__osevent_occurred_timeout. libxl guarantees that
+ * timeout_modify will only be called with abs={0,0} but the
+ * application must still ensure that libxl's attempt to cause the
+ * timeout to occur immediately is safely ignored even the timeout is
+ * actually already in the process of occurring.
+ *
+ * timeout_deregister is not used because it forms part of a
+ * deprecated unsafe mode of use of the API.
+ *
* osevent_register_hooks may be called only once for each libxl_ctx.
* libxl may make calls to register/modify/deregister from within
* any libxl function (indeed, it will usually call register from

4
init.xend
View File

@ -7,9 +7,9 @@
#
### BEGIN INIT INFO
# Provides: xend
# Required-Start: $syslog $remote_fs
# Required-Start: $syslog $network $remote_fs
# Should-Start: iscsi $time
# Required-Stop: $syslog $remote_fs
# Required-Stop: $syslog $network $remote_fs
# Should-Stop: iscsi $time
# Default-Start: 3 5
# Default-Stop: 0 1 2 6

17
xen.changes
View File

@ -1,3 +1,18 @@
-------------------------------------------------------------------
Fri Jan 25 14:57:30 MST 2013 - jfehlig@suse.com
- bnc#798188 - Add $network to xend initscript dependencies
-------------------------------------------------------------------
Thu Jan 24 15:57:12 MST 2013 - jfehlig@suse.com
- Add upstream patches to fix libxl bugs. These patches have
already been posted for inclusion in xen-4.2-testing.
25912-partial-libxl.patch
26372-tools-paths.patch
26468-libxl-race.patch
26469-libxl-race.patch
-------------------------------------------------------------------
Tue Jan 22 08:12:39 MST 2013 - carnold@novell.com
@ -18,7 +33,7 @@ Thu Jan 17 14:13:52 MST 2013 - carnold@novell.com
Removed reverse-24757-use-grant-references.patch
-------------------------------------------------------------------
Wed Jan 16 11:26:29 MST 2013
Wed Jan 16 11:26:29 MST 2013 - carnold@novell.com
- bnc#797523 - VUL-1: CVE-2012-6075: qemu / kvm-qemu: e1000
overflows under some conditions

11
xen.spec
View File

@ -15,7 +15,6 @@
# Please submit bugfixes or comments via http://bugs.opensuse.org/
#
Name: xen
ExclusiveArch: %ix86 x86_64
%define xvers 4.2
@ -115,7 +114,7 @@ BuildRequires: kernel-syms
BuildRequires: module-init-tools
BuildRequires: xorg-x11
%endif
Version: 4.2.1_03
Version: 4.2.1_04
Release: 0
PreReq: %insserv_prereq %fillup_prereq
Summary: Xen Virtualization: Hypervisor (aka VMM aka Microkernel)
@ -173,6 +172,7 @@ Patch25866: 25866-sercon-ns16550-pci-irq.patch
Patch25867: 25867-sercon-ns16550-parse.patch
Patch25874: 25874-x86-EFI-chain-cfg.patch
Patch25909: 25909-xenpm-consistent.patch
Patch25912: 25912-partial-libxl.patch
Patch25920: 25920-x86-APICV-enable.patch
Patch25921: 25921-x86-APICV-delivery.patch
Patch25922: 25922-x86-APICV-x2APIC.patch
@ -222,6 +222,9 @@ Patch26341: 26341-hvm-firmware-passthrough.patch
Patch26342: 26342-hvm-firmware-passthrough.patch
Patch26343: 26343-hvm-firmware-passthrough.patch
Patch26344: 26344-hvm-firmware-passthrough.patch
Patch26372: 26372-tools-paths.patch
Patch26468: 26468-libxl-race.patch
Patch26469: 26469-libxl-race.patch
Patch33: CVE-2012-5634-xsa33.patch
Patch34: CVE-2013-0151-xsa34.patch
Patch35: CVE-2013-0152-xsa35.patch
@ -689,6 +692,7 @@ tar xfj %{SOURCE6} -C $RPM_BUILD_DIR/%{xen_build_dir}/tools
%patch25867 -p1
%patch25874 -p1
%patch25909 -p1
%patch25912 -p1
%patch25920 -p1
%patch25921 -p1
%patch25922 -p1
@ -738,6 +742,9 @@ tar xfj %{SOURCE6} -C $RPM_BUILD_DIR/%{xen_build_dir}/tools
%patch26342 -p1
%patch26343 -p1
%patch26344 -p1
%patch26372 -p1
%patch26468 -p1
%patch26469 -p1
%patch33 -p1
%patch34 -p1
%patch35 -p1