diff options
| -rw-r--r-- | runtime/procfs.c | 15 | ||||
| -rw-r--r-- | tapset-procfs.cxx | 71 |
2 files changed, 52 insertions, 34 deletions
diff --git a/runtime/procfs.c b/runtime/procfs.c index d6b75336..1d2ad837 100644 --- a/runtime/procfs.c +++ b/runtime/procfs.c @@ -38,6 +38,11 @@ static void _stp_close_procfs(void); */ static void _stp_rmdir_proc_module(void) { + if (!_stp_lock_transport_dir()) { + errk("Unable to lock transport directory.\n"); + return; + } + if (_stp_proc_root && _stp_proc_root->subdir == NULL) { if (atomic_read(&_stp_proc_root->count) != LAST_ENTRY_COUNT) _stp_warn("Removal of /proc/systemtap/%s\nis deferred until it is no longer in use.\n" @@ -46,12 +51,7 @@ static void _stp_rmdir_proc_module(void) _stp_proc_root = NULL; } - if (_stp_proc_stap) { - if (!_stp_lock_transport_dir()) { - errk("Unable to lock transport directory.\n"); - return; - } - + if (_stp_proc_stap && _stp_proc_stap->subdir == NULL) { /* Important! Do not attempt removal of /proc/systemtap */ /* if in use. This will put the PDE in deleted state */ /* pending usage count dropping to 0. During this time, */ @@ -63,9 +63,8 @@ static void _stp_rmdir_proc_module(void) remove_proc_entry("systemtap", NULL); _stp_proc_stap = NULL; } - - _stp_unlock_transport_dir(); } + _stp_unlock_transport_dir(); } diff --git a/tapset-procfs.cxx b/tapset-procfs.cxx index 63a59afb..0c33857b 100644 --- a/tapset-procfs.cxx +++ b/tapset-procfs.cxx @@ -103,7 +103,19 @@ void procfs_derived_probe::join_group (systemtap_session& s) { if (! s.procfs_derived_probes) - s.procfs_derived_probes = new procfs_derived_probe_group (); + { + s.procfs_derived_probes = new procfs_derived_probe_group (); + + // Make sure 'struct _stp_procfs_data' is defined early. + embeddedcode *ec = new embeddedcode; + ec->tok = NULL; + ec->code = string("struct _stp_procfs_data {\n") + + string(" const char *buffer;\n") + + string(" off_t off;\n") + + string(" unsigned long count;\n") + + string("};\n"); + s.embeds.push_back(ec); + } s.procfs_derived_probes->enroll (this); } @@ -208,13 +220,15 @@ procfs_derived_probe_group::emit_module_decls (systemtap_session& s) s.op->newline() << "static int _stp_procfs_read(char *page, char **start, off_t off, int count, int *eof, void *data) {"; s.op->newline(1) << "struct stap_procfs_probe *spp = (struct stap_procfs_probe *)data;"; - s.op->newline() << "int bytes = 0;"; - s.op->newline() << "string_t strdata = {'\\0'};"; + s.op->newline() << "struct _stp_procfs_data pdata;"; common_probe_entryfn_prologue (s.op, "STAP_SESSION_RUNNING", "spp->read_pp"); + s.op->newline() << "pdata.buffer = page;"; + s.op->newline() << "pdata.off = off;"; + s.op->newline() << "pdata.count = count;"; s.op->newline() << "if (c->data == NULL)"; - s.op->newline(1) << "c->data = &strdata;"; + s.op->newline(1) << "c->data = &pdata;"; s.op->newline(-1) << "else {"; s.op->newline(1) << "if (unlikely (atomic_inc_return (& skipped_count) > MAXSKIPPED)) {"; @@ -225,24 +239,16 @@ procfs_derived_probe_group::emit_module_decls (systemtap_session& s) s.op->newline() << "goto probe_epilogue;"; s.op->newline(-1) << "}"; - // call probe function (which copies data into strdata) + // call probe function s.op->newline() << "(*spp->read_ph) (c);"; - // copy string data into 'page' + // Note that _procfs_value_set copied string data into 'page' s.op->newline() << "c->data = NULL;"; - s.op->newline() << "bytes = strnlen(strdata, MAXSTRINGLEN - 1);"; - s.op->newline() << "if (off >= bytes)"; - s.op->newline(1) << "*eof = 1;"; - s.op->newline(-1) << "else {"; - s.op->newline(1) << "bytes -= off;"; - s.op->newline() << "if (bytes > count)"; - s.op->newline(1) << "bytes = count;"; - s.op->newline(-1) << "memcpy(page, strdata + off, bytes);"; - s.op->newline() << "*start = page;"; - s.op->newline(-1) << "}"; - common_probe_entryfn_epilogue (s.op); - s.op->newline() << "return bytes;"; + s.op->newline() << "if (pdata.count == 0)"; + s.op->newline(1) << "*eof = 1;"; + s.op->indent(-1); + s.op->newline() << "return pdata.count;"; s.op->newline(-1) << "}"; } @@ -251,16 +257,18 @@ procfs_derived_probe_group::emit_module_decls (systemtap_session& s) s.op->newline() << "static int _stp_procfs_write(struct file *file, const char *buffer, unsigned long count, void *data) {"; s.op->newline(1) << "struct stap_procfs_probe *spp = (struct stap_procfs_probe *)data;"; - s.op->newline() << "string_t strdata = {'\\0'};"; + s.op->newline() << "struct _stp_procfs_data pdata;"; common_probe_entryfn_prologue (s.op, "STAP_SESSION_RUNNING", "spp->write_pp"); s.op->newline() << "if (count > (MAXSTRINGLEN - 1))"; s.op->newline(1) << "count = MAXSTRINGLEN - 1;"; - s.op->newline(-1) << "_stp_copy_from_user(strdata, buffer, count);"; + s.op->indent(-1); + s.op->newline() << "pdata.buffer = buffer;"; + s.op->newline() << "pdata.count = count;"; s.op->newline() << "if (c->data == NULL)"; - s.op->newline(1) << "c->data = &strdata;"; + s.op->newline(1) << "c->data = &pdata;"; s.op->newline(-1) << "else {"; s.op->newline(1) << "if (unlikely (atomic_inc_return (& skipped_count) > MAXSKIPPED)) {"; @@ -271,7 +279,7 @@ procfs_derived_probe_group::emit_module_decls (systemtap_session& s) s.op->newline() << "goto probe_epilogue;"; s.op->newline(-1) << "}"; - // call probe function (which copies data out of strdata) + // call probe function s.op->newline() << "(*spp->write_ph) (c);"; s.op->newline() << "c->data = NULL;"; @@ -389,11 +397,22 @@ procfs_var_expanding_visitor::visit_target_symbol (target_symbol* e) string locvalue = "CONTEXT->data"; if (! lvalue) - ec->code = string("strlcpy (THIS->__retvalue, ") + locvalue - + string(", MAXSTRINGLEN); /* pure */"); + ec->code = string("_stp_copy_from_user(THIS->__retvalue, ((struct _stp_procfs_data *)(") + + locvalue + string("))->buffer, ((struct _stp_procfs_data *)(") + locvalue + + string("))->count); /* pure */"); else - ec->code = string("strlcpy (") + locvalue - + string(", THIS->value, MAXSTRINGLEN);"); + ec->code = string("int bytes = 0;\n") + + string(" struct _stp_procfs_data *data = (struct _stp_procfs_data *)(") + locvalue + string(");\n") + + string(" bytes = strnlen(THIS->value, MAXSTRINGLEN - 1);\n") + + string(" if (data->off >= bytes)\n") + + string(" bytes = 0;\n") + + string(" else {\n") + + string(" bytes -= data->off;\n") + + string(" if (bytes > data->count)\n") + + string(" bytes = data->count;\n") + + string(" memcpy((void *)data->buffer, THIS->value + data->off, bytes);\n") + + string(" }\n") + + string(" data->count = bytes;\n"); fdecl->name = fname; fdecl->body = ec; |