From aba0e909dc20eceb1de985474af459f82e7b0b82 Mon Sep 17 00:00:00 2001 From: Moshe Shemesh Date: Thu, 5 Oct 2023 15:50:16 +0300 Subject: devlink: Hold devlink lock on health reporter dump get Devlink health dump get callback should take devlink lock as any other devlink callback. Otherwise, since devlink_mutex was removed, this callback is not protected from a race of the reporter being destroyed while handling the callback. Add devlink lock to the callback and to any call for devlink_health_do_dump(). This should be safe as non of the drivers dump callback implementation takes devlink lock. As devlink lock is added to any callback of dump, the reporter dump_lock is now redundant and can be removed. Fixes: d3efc2a6a6d8 ("net: devlink: remove devlink_mutex") Signed-off-by: Moshe Shemesh Reviewed-by: Jiri Pirko Reviewed-by: Przemek Kitszel Link: https://lore.kernel.org/r/1696510216-189379-1-git-send-email-moshe@nvidia.com Signed-off-by: Jakub Kicinski --- net/devlink/health.c | 30 ++++++++++++++++-------------- 1 file changed, 16 insertions(+), 14 deletions(-) (limited to 'net/devlink') diff --git a/net/devlink/health.c b/net/devlink/health.c index 638cad8d5c65..51e6e81e31bb 100644 --- a/net/devlink/health.c +++ b/net/devlink/health.c @@ -58,7 +58,6 @@ struct devlink_health_reporter { struct devlink *devlink; struct devlink_port *devlink_port; struct devlink_fmsg *dump_fmsg; - struct mutex dump_lock; /* lock parallel read/write from dump buffers */ u64 graceful_period; bool auto_recover; bool auto_dump; @@ -125,7 +124,6 @@ __devlink_health_reporter_create(struct devlink *devlink, reporter->graceful_period = graceful_period; reporter->auto_recover = !!ops->recover; reporter->auto_dump = !!ops->dump; - mutex_init(&reporter->dump_lock); return reporter; } @@ -226,7 +224,6 @@ EXPORT_SYMBOL_GPL(devlink_health_reporter_create); static void devlink_health_reporter_free(struct devlink_health_reporter *reporter) { - mutex_destroy(&reporter->dump_lock); if (reporter->dump_fmsg) devlink_fmsg_free(reporter->dump_fmsg); kfree(reporter); @@ -625,10 +622,10 @@ int devlink_health_report(struct devlink_health_reporter *reporter, } if (reporter->auto_dump) { - mutex_lock(&reporter->dump_lock); + devl_lock(devlink); /* store current dump of current error, for later analysis */ devlink_health_do_dump(reporter, priv_ctx, NULL); - mutex_unlock(&reporter->dump_lock); + devl_unlock(devlink); } if (!reporter->auto_recover) @@ -1262,7 +1259,7 @@ out: } static struct devlink_health_reporter * -devlink_health_reporter_get_from_cb(struct netlink_callback *cb) +devlink_health_reporter_get_from_cb_lock(struct netlink_callback *cb) { const struct genl_info *info = genl_info_dump(cb); struct devlink_health_reporter *reporter; @@ -1272,10 +1269,12 @@ devlink_health_reporter_get_from_cb(struct netlink_callback *cb) devlink = devlink_get_from_attrs_lock(sock_net(cb->skb->sk), attrs); if (IS_ERR(devlink)) return NULL; - devl_unlock(devlink); reporter = devlink_health_reporter_get_from_attrs(devlink, attrs); - devlink_put(devlink); + if (!reporter) { + devl_unlock(devlink); + devlink_put(devlink); + } return reporter; } @@ -1284,16 +1283,20 @@ int devlink_nl_cmd_health_reporter_dump_get_dumpit(struct sk_buff *skb, { struct devlink_nl_dump_state *state = devlink_dump_state(cb); struct devlink_health_reporter *reporter; + struct devlink *devlink; int err; - reporter = devlink_health_reporter_get_from_cb(cb); + reporter = devlink_health_reporter_get_from_cb_lock(cb); if (!reporter) return -EINVAL; - if (!reporter->ops->dump) + devlink = reporter->devlink; + if (!reporter->ops->dump) { + devl_unlock(devlink); + devlink_put(devlink); return -EOPNOTSUPP; + } - mutex_lock(&reporter->dump_lock); if (!state->idx) { err = devlink_health_do_dump(reporter, NULL, cb->extack); if (err) @@ -1309,7 +1312,8 @@ int devlink_nl_cmd_health_reporter_dump_get_dumpit(struct sk_buff *skb, err = devlink_fmsg_dumpit(reporter->dump_fmsg, skb, cb, DEVLINK_CMD_HEALTH_REPORTER_DUMP_GET); unlock: - mutex_unlock(&reporter->dump_lock); + devl_unlock(devlink); + devlink_put(devlink); return err; } @@ -1326,9 +1330,7 @@ int devlink_nl_cmd_health_reporter_dump_clear_doit(struct sk_buff *skb, if (!reporter->ops->dump) return -EOPNOTSUPP; - mutex_lock(&reporter->dump_lock); devlink_health_dump_clear(reporter); - mutex_unlock(&reporter->dump_lock); return 0; } -- cgit v1.2.3