X-Git-Url: http://git.lttng.org./?a=blobdiff_plain;f=src%2Flttng-syscalls.c;h=d74851b7bc43224d1a5a1726a6dd32d0e8fabae3;hb=67bc1d565fa225616da47e417753bceb2982e7e2;hp=6b52b69bbf7dd2c3d0f50e2dfaa6b2f2d96a160f;hpb=5bcf4dbd5953ee62fc967b38f59cd25b6fec2111;p=lttng-modules.git diff --git a/src/lttng-syscalls.c b/src/lttng-syscalls.c index 6b52b69b..d74851b7 100644 --- a/src/lttng-syscalls.c +++ b/src/lttng-syscalls.c @@ -28,6 +28,7 @@ #include #include #include +#include #include #include #include @@ -135,6 +136,15 @@ struct lttng_syscall_filter { DECLARE_BITMAP(sc_exit, NR_syscalls); DECLARE_BITMAP(sc_compat_entry, NR_compat_syscalls); DECLARE_BITMAP(sc_compat_exit, NR_compat_syscalls); + + /* + * Reference counters keeping track of number of events enabled + * for each bit. + */ + u32 sc_entry_refcount_map[NR_syscalls]; + u32 sc_exit_refcount_map[NR_syscalls]; + u32 sc_compat_entry_refcount_map[NR_compat_syscalls]; + u32 sc_compat_exit_refcount_map[NR_compat_syscalls]; }; static void syscall_entry_event_unknown(struct hlist_head *unknown_action_list_head, @@ -256,33 +266,33 @@ void syscall_entry_event_call_func(struct hlist_head *action_list, void syscall_entry_event_probe(void *__data, struct pt_regs *regs, long id) { - struct lttng_channel *chan = __data; + struct lttng_kernel_channel_buffer *chan = __data; struct hlist_head *action_list, *unknown_action_list; const struct trace_syscall_entry *table, *entry; size_t table_len; if (unlikely(in_compat_syscall())) { - struct lttng_syscall_filter *filter = chan->sc_filter; + struct lttng_syscall_filter *filter = chan->priv->parent.sc_filter; if (id < 0 || id >= NR_compat_syscalls - || (!READ_ONCE(chan->syscall_all_entry) && !test_bit(id, filter->sc_compat_entry))) { + || (!READ_ONCE(chan->priv->parent.syscall_all_entry) && !test_bit(id, filter->sc_compat_entry))) { /* System call filtered out. */ return; } table = compat_sc_table.table; table_len = compat_sc_table.len; - unknown_action_list = &chan->sc_compat_unknown; + unknown_action_list = &chan->priv->parent.sc_compat_unknown; } else { - struct lttng_syscall_filter *filter = chan->sc_filter; + struct lttng_syscall_filter *filter = chan->priv->parent.sc_filter; if (id < 0 || id >= NR_syscalls - || (!READ_ONCE(chan->syscall_all_entry) && !test_bit(id, filter->sc_entry))) { + || (!READ_ONCE(chan->priv->parent.syscall_all_entry) && !test_bit(id, filter->sc_entry))) { /* System call filtered out. */ return; } table = sc_table.table; table_len = sc_table.len; - unknown_action_list = &chan->sc_unknown; + unknown_action_list = &chan->priv->parent.sc_unknown; } if (unlikely(id < 0 || id >= table_len)) { syscall_entry_event_unknown(unknown_action_list, regs, id); @@ -296,9 +306,9 @@ void syscall_entry_event_probe(void *__data, struct pt_regs *regs, long id) } if (unlikely(in_compat_syscall())) { - action_list = &chan->compat_sc_table[id]; + action_list = &chan->priv->parent.compat_sc_table[id]; } else { - action_list = &chan->sc_table[id]; + action_list = &chan->priv->parent.sc_table[id]; } if (unlikely(hlist_empty(action_list))) return; @@ -492,7 +502,7 @@ void syscall_exit_event_call_func(struct hlist_head *action_list, void syscall_exit_event_probe(void *__data, struct pt_regs *regs, long ret) { - struct lttng_channel *chan = __data; + struct lttng_kernel_channel_buffer *chan = __data; struct hlist_head *action_list, *unknown_action_list; const struct trace_syscall_entry *table, *entry; size_t table_len; @@ -501,27 +511,27 @@ void syscall_exit_event_probe(void *__data, struct pt_regs *regs, long ret) id = syscall_get_nr(current, regs); if (unlikely(in_compat_syscall())) { - struct lttng_syscall_filter *filter = chan->sc_filter; + struct lttng_syscall_filter *filter = chan->priv->parent.sc_filter; if (id < 0 || id >= NR_compat_syscalls - || (!READ_ONCE(chan->syscall_all_exit) && !test_bit(id, filter->sc_compat_exit))) { + || (!READ_ONCE(chan->priv->parent.syscall_all_exit) && !test_bit(id, filter->sc_compat_exit))) { /* System call filtered out. */ return; } table = compat_sc_exit_table.table; table_len = compat_sc_exit_table.len; - unknown_action_list = &chan->compat_sc_exit_unknown; + unknown_action_list = &chan->priv->parent.compat_sc_exit_unknown; } else { - struct lttng_syscall_filter *filter = chan->sc_filter; + struct lttng_syscall_filter *filter = chan->priv->parent.sc_filter; if (id < 0 || id >= NR_syscalls - || (!READ_ONCE(chan->syscall_all_exit) && !test_bit(id, filter->sc_exit))) { + || (!READ_ONCE(chan->priv->parent.syscall_all_exit) && !test_bit(id, filter->sc_exit))) { /* System call filtered out. */ return; } table = sc_exit_table.table; table_len = sc_exit_table.len; - unknown_action_list = &chan->sc_exit_unknown; + unknown_action_list = &chan->priv->parent.sc_exit_unknown; } if (unlikely(id < 0 || id >= table_len)) { syscall_exit_event_unknown(unknown_action_list, regs, id, ret); @@ -535,9 +545,9 @@ void syscall_exit_event_probe(void *__data, struct pt_regs *regs, long ret) } if (unlikely(in_compat_syscall())) { - action_list = &chan->compat_sc_exit_table[id]; + action_list = &chan->priv->parent.compat_sc_exit_table[id]; } else { - action_list = &chan->sc_exit_table[id]; + action_list = &chan->priv->parent.sc_exit_table[id]; } if (unlikely(hlist_empty(action_list))) return; @@ -616,8 +626,8 @@ int lttng_create_syscall_event_if_missing(const struct trace_syscall_entry *tabl struct hlist_head *chan_table, struct lttng_event_enabler *event_enabler, enum sc_type type) { - struct lttng_channel *chan = event_enabler->chan; - struct lttng_kernel_session *session = chan->session; + struct lttng_kernel_channel_buffer *chan = event_enabler->chan; + struct lttng_kernel_session *session = chan->parent.session; unsigned int i; /* Allocate events for each syscall matching enabler, insert into table */ @@ -694,46 +704,46 @@ int lttng_create_syscall_event_if_missing(const struct trace_syscall_entry *tabl */ int lttng_syscalls_register_event(struct lttng_event_enabler *event_enabler) { - struct lttng_channel *chan = event_enabler->chan; + struct lttng_kernel_channel_buffer *chan = event_enabler->chan; struct lttng_kernel_abi_event ev; int ret; wrapper_vmalloc_sync_mappings(); - if (!chan->sc_table) { + if (!chan->priv->parent.sc_table) { /* create syscall table mapping syscall to events */ - chan->sc_table = kzalloc(sizeof(struct lttng_kernel_event_recorder *) + chan->priv->parent.sc_table = kzalloc(sizeof(struct lttng_kernel_event_recorder *) * sc_table.len, GFP_KERNEL); - if (!chan->sc_table) + if (!chan->priv->parent.sc_table) return -ENOMEM; } - if (!chan->sc_exit_table) { + if (!chan->priv->parent.sc_exit_table) { /* create syscall table mapping syscall to events */ - chan->sc_exit_table = kzalloc(sizeof(struct lttng_kernel_event_recorder *) + chan->priv->parent.sc_exit_table = kzalloc(sizeof(struct lttng_kernel_event_recorder *) * sc_exit_table.len, GFP_KERNEL); - if (!chan->sc_exit_table) + if (!chan->priv->parent.sc_exit_table) return -ENOMEM; } #ifdef CONFIG_COMPAT - if (!chan->compat_sc_table) { + if (!chan->priv->parent.compat_sc_table) { /* create syscall table mapping compat syscall to events */ - chan->compat_sc_table = kzalloc(sizeof(struct lttng_kernel_event_recorder *) + chan->priv->parent.compat_sc_table = kzalloc(sizeof(struct lttng_kernel_event_recorder *) * compat_sc_table.len, GFP_KERNEL); - if (!chan->compat_sc_table) + if (!chan->priv->parent.compat_sc_table) return -ENOMEM; } - if (!chan->compat_sc_exit_table) { + if (!chan->priv->parent.compat_sc_exit_table) { /* create syscall table mapping compat syscall to events */ - chan->compat_sc_exit_table = kzalloc(sizeof(struct lttng_kernel_event_recorder *) + chan->priv->parent.compat_sc_exit_table = kzalloc(sizeof(struct lttng_kernel_event_recorder *) * compat_sc_exit_table.len, GFP_KERNEL); - if (!chan->compat_sc_exit_table) + if (!chan->priv->parent.compat_sc_exit_table) return -ENOMEM; } #endif - if (hlist_empty(&chan->sc_unknown)) { + if (hlist_empty(&chan->priv->parent.sc_unknown)) { const struct lttng_kernel_event_desc *desc = &__event_desc___syscall_entry_unknown; struct lttng_kernel_event_recorder *event_recorder; @@ -750,10 +760,10 @@ int lttng_syscalls_register_event(struct lttng_event_enabler *event_enabler) if (IS_ERR(event_recorder)) { return PTR_ERR(event_recorder); } - hlist_add_head(&event_recorder->priv->parent.u.syscall.node, &chan->sc_unknown); + hlist_add_head(&event_recorder->priv->parent.u.syscall.node, &chan->priv->parent.sc_unknown); } - if (hlist_empty(&chan->sc_compat_unknown)) { + if (hlist_empty(&chan->priv->parent.sc_compat_unknown)) { const struct lttng_kernel_event_desc *desc = &__event_desc___compat_syscall_entry_unknown; struct lttng_kernel_event_recorder *event_recorder; @@ -770,10 +780,10 @@ int lttng_syscalls_register_event(struct lttng_event_enabler *event_enabler) if (IS_ERR(event_recorder)) { return PTR_ERR(event_recorder); } - hlist_add_head(&event_recorder->priv->parent.u.syscall.node, &chan->sc_compat_unknown); + hlist_add_head(&event_recorder->priv->parent.u.syscall.node, &chan->priv->parent.sc_compat_unknown); } - if (hlist_empty(&chan->compat_sc_exit_unknown)) { + if (hlist_empty(&chan->priv->parent.compat_sc_exit_unknown)) { const struct lttng_kernel_event_desc *desc = &__event_desc___compat_syscall_exit_unknown; struct lttng_kernel_event_recorder *event_recorder; @@ -790,10 +800,10 @@ int lttng_syscalls_register_event(struct lttng_event_enabler *event_enabler) if (IS_ERR(event_recorder)) { return PTR_ERR(event_recorder); } - hlist_add_head(&event_recorder->priv->parent.u.syscall.node, &chan->compat_sc_exit_unknown); + hlist_add_head(&event_recorder->priv->parent.u.syscall.node, &chan->priv->parent.compat_sc_exit_unknown); } - if (hlist_empty(&chan->sc_exit_unknown)) { + if (hlist_empty(&chan->priv->parent.sc_exit_unknown)) { const struct lttng_kernel_event_desc *desc = &__event_desc___syscall_exit_unknown; struct lttng_kernel_event_recorder *event_recorder; @@ -810,48 +820,48 @@ int lttng_syscalls_register_event(struct lttng_event_enabler *event_enabler) if (IS_ERR(event_recorder)) { return PTR_ERR(event_recorder); } - hlist_add_head(&event_recorder->priv->parent.u.syscall.node, &chan->sc_exit_unknown); + hlist_add_head(&event_recorder->priv->parent.u.syscall.node, &chan->priv->parent.sc_exit_unknown); } ret = lttng_create_syscall_event_if_missing(sc_table.table, sc_table.len, - chan->sc_table, event_enabler, SC_TYPE_ENTRY); + chan->priv->parent.sc_table, event_enabler, SC_TYPE_ENTRY); if (ret) return ret; ret = lttng_create_syscall_event_if_missing(sc_exit_table.table, sc_exit_table.len, - chan->sc_exit_table, event_enabler, SC_TYPE_EXIT); + chan->priv->parent.sc_exit_table, event_enabler, SC_TYPE_EXIT); if (ret) return ret; #ifdef CONFIG_COMPAT ret = lttng_create_syscall_event_if_missing(compat_sc_table.table, compat_sc_table.len, - chan->compat_sc_table, event_enabler, SC_TYPE_COMPAT_ENTRY); + chan->priv->parent.compat_sc_table, event_enabler, SC_TYPE_COMPAT_ENTRY); if (ret) return ret; ret = lttng_create_syscall_event_if_missing(compat_sc_exit_table.table, compat_sc_exit_table.len, - chan->compat_sc_exit_table, event_enabler, SC_TYPE_COMPAT_EXIT); + chan->priv->parent.compat_sc_exit_table, event_enabler, SC_TYPE_COMPAT_EXIT); if (ret) return ret; #endif - if (!chan->sc_filter) { - chan->sc_filter = kzalloc(sizeof(struct lttng_syscall_filter), + if (!chan->priv->parent.sc_filter) { + chan->priv->parent.sc_filter = kzalloc(sizeof(struct lttng_syscall_filter), GFP_KERNEL); - if (!chan->sc_filter) + if (!chan->priv->parent.sc_filter) return -ENOMEM; } - if (!chan->sys_enter_registered) { + if (!chan->priv->parent.sys_enter_registered) { ret = lttng_wrapper_tracepoint_probe_register("sys_enter", (void *) syscall_entry_event_probe, chan); if (ret) return ret; - chan->sys_enter_registered = 1; + chan->priv->parent.sys_enter_registered = 1; } /* * We change the name of sys_exit tracepoint due to namespace * conflict with sys_exit syscall entry. */ - if (!chan->sys_exit_registered) { + if (!chan->priv->parent.sys_exit_registered) { ret = lttng_wrapper_tracepoint_probe_register("sys_exit", (void *) syscall_exit_event_probe, chan); if (ret) { @@ -859,7 +869,7 @@ int lttng_syscalls_register_event(struct lttng_event_enabler *event_enabler) (void *) syscall_entry_event_probe, chan)); return ret; } - chan->sys_exit_registered = 1; + chan->priv->parent.sys_exit_registered = 1; } return ret; } @@ -1238,38 +1248,38 @@ int lttng_syscalls_unregister_event_notifier_group( return 0; } -int lttng_syscalls_unregister_channel(struct lttng_channel *chan) +int lttng_syscalls_unregister_channel(struct lttng_kernel_channel_buffer *chan) { int ret; - if (!chan->sc_table) + if (!chan->priv->parent.sc_table) return 0; - if (chan->sys_enter_registered) { + if (chan->priv->parent.sys_enter_registered) { ret = lttng_wrapper_tracepoint_probe_unregister("sys_enter", (void *) syscall_entry_event_probe, chan); if (ret) return ret; - chan->sys_enter_registered = 0; + chan->priv->parent.sys_enter_registered = 0; } - if (chan->sys_exit_registered) { + if (chan->priv->parent.sys_exit_registered) { ret = lttng_wrapper_tracepoint_probe_unregister("sys_exit", (void *) syscall_exit_event_probe, chan); if (ret) return ret; - chan->sys_exit_registered = 0; + chan->priv->parent.sys_exit_registered = 0; } return 0; } -int lttng_syscalls_destroy_event(struct lttng_channel *chan) +int lttng_syscalls_destroy_event(struct lttng_kernel_channel_buffer *chan) { - kfree(chan->sc_table); - kfree(chan->sc_exit_table); + kfree(chan->priv->parent.sc_table); + kfree(chan->priv->parent.sc_exit_table); #ifdef CONFIG_COMPAT - kfree(chan->compat_sc_table); - kfree(chan->compat_sc_exit_table); + kfree(chan->priv->parent.compat_sc_table); + kfree(chan->priv->parent.compat_sc_exit_table); #endif - kfree(chan->sc_filter); + kfree(chan->priv->parent.sc_filter); return 0; } @@ -1367,6 +1377,7 @@ int lttng_syscall_filter_enable( { const char *syscall_name; unsigned long *bitmap; + u32 *refcount_map; int syscall_nr; syscall_name = get_syscall_name(desc_name, abi, entryexit); @@ -1389,9 +1400,11 @@ int lttng_syscall_filter_enable( switch (abi) { case LTTNG_SYSCALL_ABI_NATIVE: bitmap = filter->sc_entry; + refcount_map = filter->sc_entry_refcount_map; break; case LTTNG_SYSCALL_ABI_COMPAT: bitmap = filter->sc_compat_entry; + refcount_map = filter->sc_compat_entry_refcount_map; break; default: return -EINVAL; @@ -1401,9 +1414,11 @@ int lttng_syscall_filter_enable( switch (abi) { case LTTNG_SYSCALL_ABI_NATIVE: bitmap = filter->sc_exit; + refcount_map = filter->sc_exit_refcount_map; break; case LTTNG_SYSCALL_ABI_COMPAT: bitmap = filter->sc_compat_exit; + refcount_map = filter->sc_compat_exit_refcount_map; break; default: return -EINVAL; @@ -1412,9 +1427,10 @@ int lttng_syscall_filter_enable( default: return -EINVAL; } - if (test_bit(syscall_nr, bitmap)) - return -EEXIST; - bitmap_set(bitmap, syscall_nr, 1); + if (refcount_map[syscall_nr] == U32_MAX) + return -EOVERFLOW; + if (refcount_map[syscall_nr]++ == 0) + bitmap_set(bitmap, syscall_nr, 1); return 0; } @@ -1428,13 +1444,16 @@ int lttng_syscall_filter_enable_event_notifier( WARN_ON_ONCE(event_notifier->priv->parent.instrumentation != LTTNG_KERNEL_ABI_SYSCALL); + /* Skip unknown syscall */ + if (syscall_id == -1U) + return 0; + ret = lttng_syscall_filter_enable(group->sc_filter, event_notifier->priv->parent.desc->event_name, event_notifier->priv->parent.u.syscall.abi, event_notifier->priv->parent.u.syscall.entryexit); - if (ret) { - goto end; - } + if (ret) + return ret; switch (event_notifier->priv->parent.u.syscall.entryexit) { case LTTNG_SYSCALL_ENTRY: @@ -1471,16 +1490,22 @@ int lttng_syscall_filter_enable_event_notifier( hlist_add_head_rcu(&event_notifier->priv->parent.u.syscall.node, dispatch_list); end: - return ret ; + return ret; } int lttng_syscall_filter_enable_event( - struct lttng_channel *channel, + struct lttng_kernel_channel_buffer *channel, struct lttng_kernel_event_recorder *event_recorder) { + unsigned int syscall_id = event_recorder->priv->parent.u.syscall.syscall_id; + WARN_ON_ONCE(event_recorder->priv->parent.instrumentation != LTTNG_KERNEL_ABI_SYSCALL); - return lttng_syscall_filter_enable(channel->sc_filter, + /* Skip unknown syscall */ + if (syscall_id == -1U) + return 0; + + return lttng_syscall_filter_enable(channel->priv->parent.sc_filter, event_recorder->priv->parent.desc->event_name, event_recorder->priv->parent.u.syscall.abi, event_recorder->priv->parent.u.syscall.entryexit); @@ -1494,6 +1519,7 @@ int lttng_syscall_filter_disable( { const char *syscall_name; unsigned long *bitmap; + u32 *refcount_map; int syscall_nr; syscall_name = get_syscall_name(desc_name, abi, entryexit); @@ -1516,9 +1542,11 @@ int lttng_syscall_filter_disable( switch (abi) { case LTTNG_SYSCALL_ABI_NATIVE: bitmap = filter->sc_entry; + refcount_map = filter->sc_entry_refcount_map; break; case LTTNG_SYSCALL_ABI_COMPAT: bitmap = filter->sc_compat_entry; + refcount_map = filter->sc_compat_entry_refcount_map; break; default: return -EINVAL; @@ -1528,9 +1556,11 @@ int lttng_syscall_filter_disable( switch (abi) { case LTTNG_SYSCALL_ABI_NATIVE: bitmap = filter->sc_exit; + refcount_map = filter->sc_exit_refcount_map; break; case LTTNG_SYSCALL_ABI_COMPAT: bitmap = filter->sc_compat_exit; + refcount_map = filter->sc_compat_exit_refcount_map; break; default: return -EINVAL; @@ -1539,10 +1569,10 @@ int lttng_syscall_filter_disable( default: return -EINVAL; } - if (!test_bit(syscall_nr, bitmap)) - return -EEXIST; - bitmap_clear(bitmap, syscall_nr, 1); - + if (refcount_map[syscall_nr] == 0) + return -ENOENT; + if (--refcount_map[syscall_nr] == 0) + bitmap_clear(bitmap, syscall_nr, 1); return 0; } @@ -1550,25 +1580,37 @@ int lttng_syscall_filter_disable_event_notifier( struct lttng_kernel_event_notifier *event_notifier) { struct lttng_event_notifier_group *group = event_notifier->priv->group; + unsigned int syscall_id = event_notifier->priv->parent.u.syscall.syscall_id; int ret; WARN_ON_ONCE(event_notifier->priv->parent.instrumentation != LTTNG_KERNEL_ABI_SYSCALL); + /* Skip unknown syscall */ + if (syscall_id == -1U) + return 0; + ret = lttng_syscall_filter_disable(group->sc_filter, event_notifier->priv->parent.desc->event_name, event_notifier->priv->parent.u.syscall.abi, event_notifier->priv->parent.u.syscall.entryexit); - WARN_ON_ONCE(ret != 0); + if (ret) + return ret; hlist_del_rcu(&event_notifier->priv->parent.u.syscall.node); return 0; } int lttng_syscall_filter_disable_event( - struct lttng_channel *channel, + struct lttng_kernel_channel_buffer *channel, struct lttng_kernel_event_recorder *event_recorder) { - return lttng_syscall_filter_disable(channel->sc_filter, + unsigned int syscall_id = event_recorder->priv->parent.u.syscall.syscall_id; + + /* Skip unknown syscall */ + if (syscall_id == -1U) + return 0; + + return lttng_syscall_filter_disable(channel->priv->parent.sc_filter, event_recorder->priv->parent.desc->event_name, event_recorder->priv->parent.u.syscall.abi, event_recorder->priv->parent.u.syscall.entryexit); @@ -1688,7 +1730,7 @@ const struct file_operations lttng_syscall_list_fops = { /* * A syscall is enabled if it is traced for either entry or exit. */ -long lttng_channel_syscall_mask(struct lttng_channel *channel, +long lttng_channel_syscall_mask(struct lttng_kernel_channel_buffer *channel, struct lttng_kernel_abi_syscall_mask __user *usyscall_mask) { uint32_t len, sc_tables_len, bitmask_len; @@ -1708,14 +1750,14 @@ long lttng_channel_syscall_mask(struct lttng_channel *channel, tmp_mask = kzalloc(bitmask_len, GFP_KERNEL); if (!tmp_mask) return -ENOMEM; - filter = channel->sc_filter; + filter = channel->priv->parent.sc_filter; for (bit = 0; bit < sc_table.len; bit++) { char state; - if (channel->sc_table) { - if (!(READ_ONCE(channel->syscall_all_entry) - || READ_ONCE(channel->syscall_all_exit)) && filter) + if (channel->priv->parent.sc_table) { + if (!(READ_ONCE(channel->priv->parent.syscall_all_entry) + || READ_ONCE(channel->priv->parent.syscall_all_exit)) && filter) state = test_bit(bit, filter->sc_entry) || test_bit(bit, filter->sc_exit); else @@ -1728,9 +1770,9 @@ long lttng_channel_syscall_mask(struct lttng_channel *channel, for (; bit < sc_tables_len; bit++) { char state; - if (channel->compat_sc_table) { - if (!(READ_ONCE(channel->syscall_all_entry) - || READ_ONCE(channel->syscall_all_exit)) && filter) + if (channel->priv->parent.compat_sc_table) { + if (!(READ_ONCE(channel->priv->parent.syscall_all_entry) + || READ_ONCE(channel->priv->parent.syscall_all_exit)) && filter) state = test_bit(bit - sc_table.len, filter->sc_compat_entry) || test_bit(bit - sc_table.len,