/* A state machine for detecting misuses of POSIX file descriptor APIs. Copyright (C) 2019-2023 Free Software Foundation, Inc. Contributed by Immad Mir . This file is part of GCC. GCC is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3, or (at your option) any later version. GCC is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with GCC; see the file COPYING3. If not see . */ #include "config.h" #define INCLUDE_MEMORY #include "system.h" #include "coretypes.h" #include "make-unique.h" #include "tree.h" #include "function.h" #include "basic-block.h" #include "gimple.h" #include "options.h" #include "diagnostic-path.h" #include "diagnostic-metadata.h" #include "analyzer/analyzer.h" #include "diagnostic-event-id.h" #include "analyzer/analyzer-logging.h" #include "analyzer/sm.h" #include "analyzer/pending-diagnostic.h" #include "analyzer/function-set.h" #include "analyzer/analyzer-selftests.h" #include "stringpool.h" #include "attribs.h" #include "analyzer/call-string.h" #include "analyzer/program-point.h" #include "analyzer/store.h" #include "analyzer/region-model.h" #include "bitmap.h" #include "analyzer/program-state.h" #include "analyzer/supergraph.h" #include "analyzer/analyzer-language.h" #include "analyzer/call-details.h" #include "analyzer/call-info.h" #if ENABLE_ANALYZER namespace ana { namespace { /* An enum for distinguishing between three different access modes. */ enum access_mode { READ_WRITE, READ_ONLY, WRITE_ONLY }; enum access_directions { DIRS_READ_WRITE, DIRS_READ, DIRS_WRITE }; /* An enum for distinguishing between dup, dup2 and dup3. */ enum dup { DUP_1, DUP_2, DUP_3 }; /* Enum for use by -Wanalyzer-fd-phase-mismatch. */ enum expected_phase { EXPECTED_PHASE_CAN_TRANSFER, /* can "read"/"write". */ EXPECTED_PHASE_CAN_BIND, EXPECTED_PHASE_CAN_LISTEN, EXPECTED_PHASE_CAN_ACCEPT, EXPECTED_PHASE_CAN_CONNECT }; class fd_state_machine : public state_machine { public: fd_state_machine (logger *logger); bool inherited_state_p () const final override { return false; } state_machine::state_t get_default_state (const svalue *sval) const final override { if (tree cst = sval->maybe_get_constant ()) { if (TREE_CODE (cst) == INTEGER_CST) { int val = TREE_INT_CST_LOW (cst); if (val >= 0) return m_constant_fd; else return m_invalid; } } return m_start; } bool on_stmt (sm_context *sm_ctxt, const supernode *node, const gimple *stmt) const final override; void on_condition (sm_context *sm_ctxt, const supernode *node, const gimple *stmt, const svalue *lhs, const tree_code op, const svalue *rhs) const final override; bool can_purge_p (state_t s) const final override; std::unique_ptr on_leak (tree var) const final override; bool is_unchecked_fd_p (state_t s) const; bool is_valid_fd_p (state_t s) const; bool is_socket_fd_p (state_t s) const; bool is_datagram_socket_fd_p (state_t s) const; bool is_stream_socket_fd_p (state_t s) const; bool is_closed_fd_p (state_t s) const; bool is_constant_fd_p (state_t s) const; bool is_readonly_fd_p (state_t s) const; bool is_writeonly_fd_p (state_t s) const; enum access_mode get_access_mode_from_flag (int flag) const; /* Function for one-to-one correspondence between valid and unchecked states. */ state_t valid_to_unchecked_state (state_t state) const; void mark_as_valid_fd (region_model *model, sm_state_map *smap, const svalue *fd_sval, const extrinsic_state &ext_state) const; bool on_socket (const call_details &cd, bool successful, sm_context *sm_ctxt, const extrinsic_state &ext_state) const; bool on_bind (const call_details &cd, bool successful, sm_context *sm_ctxt, const extrinsic_state &ext_state) const; bool on_listen (const call_details &cd, bool successful, sm_context *sm_ctxt, const extrinsic_state &ext_state) const; bool on_accept (const call_details &cd, bool successful, sm_context *sm_ctxt, const extrinsic_state &ext_state) const; bool on_connect (const call_details &cd, bool successful, sm_context *sm_ctxt, const extrinsic_state &ext_state) const; /* State for a constant file descriptor (>= 0) */ state_t m_constant_fd; /* States representing a file descriptor that hasn't yet been checked for validity after opening, for three different access modes. */ state_t m_unchecked_read_write; state_t m_unchecked_read_only; state_t m_unchecked_write_only; /* States for representing a file descriptor that is known to be valid (>= 0), for three different access modes. */ state_t m_valid_read_write; state_t m_valid_read_only; state_t m_valid_write_only; /* State for a file descriptor that is known to be invalid (< 0). */ state_t m_invalid; /* State for a file descriptor that has been closed. */ state_t m_closed; /* States for FDs relating to socket APIs. */ /* Result of successful "socket" with SOCK_DGRAM. */ state_t m_new_datagram_socket; /* Result of successful "socket" with SOCK_STREAM. */ state_t m_new_stream_socket; /* Result of successful "socket" with unknown type. */ state_t m_new_unknown_socket; /* The above after a successful call to "bind". */ state_t m_bound_datagram_socket; state_t m_bound_stream_socket; state_t m_bound_unknown_socket; /* A bound socket after a successful call to "listen" (stream or unknown). */ state_t m_listening_stream_socket; /* (i) the new FD as a result of a succesful call to "accept" on a listening socket (via a passive open), or (ii) an active socket after a successful call to "connect" (via an active open). */ state_t m_connected_stream_socket; /* State for a file descriptor that we do not want to track anymore . */ state_t m_stop; /* Stashed constant values from the frontend. These could be NULL. */ tree m_O_ACCMODE; tree m_O_RDONLY; tree m_O_WRONLY; tree m_SOCK_STREAM; tree m_SOCK_DGRAM; private: void on_open (sm_context *sm_ctxt, const supernode *node, const gimple *stmt, const gcall *call) const; void on_creat (sm_context *sm_ctxt, const supernode *node, const gimple *stmt, const gcall *call) const; void on_close (sm_context *sm_ctxt, const supernode *node, const gimple *stmt, const gcall *call) const; void on_read (sm_context *sm_ctxt, const supernode *node, const gimple *stmt, const gcall *call, const tree callee_fndecl) const; void on_write (sm_context *sm_ctxt, const supernode *node, const gimple *stmt, const gcall *call, const tree callee_fndecl) const; void check_for_open_fd (sm_context *sm_ctxt, const supernode *node, const gimple *stmt, const gcall *call, const tree callee_fndecl, enum access_directions access_fn) const; void make_valid_transitions_on_condition (sm_context *sm_ctxt, const supernode *node, const gimple *stmt, const svalue *lhs) const; void make_invalid_transitions_on_condition (sm_context *sm_ctxt, const supernode *node, const gimple *stmt, const svalue *lhs) const; void check_for_fd_attrs (sm_context *sm_ctxt, const supernode *node, const gimple *stmt, const gcall *call, const tree callee_fndecl, const char *attr_name, access_directions fd_attr_access_dir) const; void check_for_dup (sm_context *sm_ctxt, const supernode *node, const gimple *stmt, const gcall *call, const tree callee_fndecl, enum dup kind) const; state_t get_state_for_socket_type (const svalue *socket_type_sval) const; bool check_for_socket_fd (const call_details &cd, bool successful, sm_context *sm_ctxt, const svalue *fd_sval, const supernode *node, state_t old_state, bool *complained = NULL) const; bool check_for_new_socket_fd (const call_details &cd, bool successful, sm_context *sm_ctxt, const svalue *fd_sval, const supernode *node, state_t old_state, enum expected_phase expected_phase) const; }; /* Base diagnostic class relative to fd_state_machine. */ class fd_diagnostic : public pending_diagnostic { public: fd_diagnostic (const fd_state_machine &sm, tree arg) : m_sm (sm), m_arg (arg) { } bool subclass_equal_p (const pending_diagnostic &base_other) const override { return same_tree_p (m_arg, ((const fd_diagnostic &)base_other).m_arg); } label_text describe_state_change (const evdesc::state_change &change) override { if (change.m_old_state == m_sm.get_start_state ()) { if (change.m_new_state == m_sm.m_unchecked_read_write || change.m_new_state == m_sm.m_valid_read_write) return change.formatted_print ("opened here as read-write"); if (change.m_new_state == m_sm.m_unchecked_read_only || change.m_new_state == m_sm.m_valid_read_only) return change.formatted_print ("opened here as read-only"); if (change.m_new_state == m_sm.m_unchecked_write_only || change.m_new_state == m_sm.m_valid_write_only) return change.formatted_print ("opened here as write-only"); if (change.m_new_state == m_sm.m_new_datagram_socket) return change.formatted_print ("datagram socket created here"); if (change.m_new_state == m_sm.m_new_stream_socket) return change.formatted_print ("stream socket created here"); if (change.m_new_state == m_sm.m_new_unknown_socket || change.m_new_state == m_sm.m_connected_stream_socket) return change.formatted_print ("socket created here"); } if (change.m_new_state == m_sm.m_bound_datagram_socket) return change.formatted_print ("datagram socket bound here"); if (change.m_new_state == m_sm.m_bound_stream_socket) return change.formatted_print ("stream socket bound here"); if (change.m_new_state == m_sm.m_bound_unknown_socket || change.m_new_state == m_sm.m_connected_stream_socket) return change.formatted_print ("socket bound here"); if (change.m_new_state == m_sm.m_listening_stream_socket) return change.formatted_print ("stream socket marked as passive here via %qs", "listen"); if (change.m_new_state == m_sm.m_closed) return change.formatted_print ("closed here"); if (m_sm.is_unchecked_fd_p (change.m_old_state) && m_sm.is_valid_fd_p (change.m_new_state)) { if (change.m_expr) return change.formatted_print ( "assuming %qE is a valid file descriptor (>= 0)", change.m_expr); else return change.formatted_print ("assuming a valid file descriptor"); } if (m_sm.is_unchecked_fd_p (change.m_old_state) && change.m_new_state == m_sm.m_invalid) { if (change.m_expr) return change.formatted_print ( "assuming %qE is an invalid file descriptor (< 0)", change.m_expr); else return change.formatted_print ("assuming an invalid file descriptor"); } return label_text (); } diagnostic_event::meaning get_meaning_for_state_change ( const evdesc::state_change &change) const final override { if (change.m_old_state == m_sm.get_start_state () && (m_sm.is_unchecked_fd_p (change.m_new_state) || change.m_new_state == m_sm.m_new_datagram_socket || change.m_new_state == m_sm.m_new_stream_socket || change.m_new_state == m_sm.m_new_unknown_socket)) return diagnostic_event::meaning (diagnostic_event::VERB_acquire, diagnostic_event::NOUN_resource); if (change.m_new_state == m_sm.m_closed) return diagnostic_event::meaning (diagnostic_event::VERB_release, diagnostic_event::NOUN_resource); return diagnostic_event::meaning (); } protected: const fd_state_machine &m_sm; tree m_arg; }; class fd_param_diagnostic : public fd_diagnostic { public: fd_param_diagnostic (const fd_state_machine &sm, tree arg, tree callee_fndecl, const char *attr_name, int arg_idx) : fd_diagnostic (sm, arg), m_callee_fndecl (callee_fndecl), m_attr_name (attr_name), m_arg_idx (arg_idx) { } fd_param_diagnostic (const fd_state_machine &sm, tree arg, tree callee_fndecl) : fd_diagnostic (sm, arg), m_callee_fndecl (callee_fndecl), m_attr_name (NULL), m_arg_idx (-1) { } bool subclass_equal_p (const pending_diagnostic &base_other) const override { const fd_param_diagnostic &sub_other = (const fd_param_diagnostic &)base_other; return (same_tree_p (m_arg, sub_other.m_arg) && same_tree_p (m_callee_fndecl, sub_other.m_callee_fndecl) && m_arg_idx == sub_other.m_arg_idx && ((m_attr_name) ? (strcmp (m_attr_name, sub_other.m_attr_name) == 0) : true)); } void inform_filedescriptor_attribute (access_directions fd_dir) { if (m_attr_name) switch (fd_dir) { case DIRS_READ_WRITE: inform (DECL_SOURCE_LOCATION (m_callee_fndecl), "argument %d of %qD must be an open file descriptor, due to " "%<__attribute__((%s(%d)))%>", m_arg_idx + 1, m_callee_fndecl, m_attr_name, m_arg_idx + 1); break; case DIRS_WRITE: inform (DECL_SOURCE_LOCATION (m_callee_fndecl), "argument %d of %qD must be a readable file descriptor, due " "to %<__attribute__((%s(%d)))%>", m_arg_idx + 1, m_callee_fndecl, m_attr_name, m_arg_idx + 1); break; case DIRS_READ: inform (DECL_SOURCE_LOCATION (m_callee_fndecl), "argument %d of %qD must be a writable file descriptor, due " "to %<__attribute__((%s(%d)))%>", m_arg_idx + 1, m_callee_fndecl, m_attr_name, m_arg_idx + 1); break; } } protected: tree m_callee_fndecl; const char *m_attr_name; /* ARG_IDX is 0-based. */ int m_arg_idx; }; class fd_leak : public fd_diagnostic { public: fd_leak (const fd_state_machine &sm, tree arg) : fd_diagnostic (sm, arg) {} const char * get_kind () const final override { return "fd_leak"; } int get_controlling_option () const final override { return OPT_Wanalyzer_fd_leak; } bool emit (rich_location *rich_loc) final override { /*CWE-775: Missing Release of File Descriptor or Handle after Effective Lifetime */ diagnostic_metadata m; m.add_cwe (775); if (m_arg) return warning_meta (rich_loc, m, get_controlling_option (), "leak of file descriptor %qE", m_arg); else return warning_meta (rich_loc, m, get_controlling_option (), "leak of file descriptor"); } label_text describe_state_change (const evdesc::state_change &change) final override { if (m_sm.is_unchecked_fd_p (change.m_new_state)) { m_open_event = change.m_event_id; return label_text::borrow ("opened here"); } return fd_diagnostic::describe_state_change (change); } label_text describe_final_event (const evdesc::final_event &ev) final override { if (m_open_event.known_p ()) { if (ev.m_expr) return ev.formatted_print ("%qE leaks here; was opened at %@", ev.m_expr, &m_open_event); else return ev.formatted_print ("leaks here; was opened at %@", &m_open_event); } else { if (ev.m_expr) return ev.formatted_print ("%qE leaks here", ev.m_expr); else return ev.formatted_print ("leaks here"); } } private: diagnostic_event_id_t m_open_event; }; class fd_access_mode_mismatch : public fd_param_diagnostic { public: fd_access_mode_mismatch (const fd_state_machine &sm, tree arg, enum access_directions fd_dir, const tree callee_fndecl, const char *attr_name, int arg_idx) : fd_param_diagnostic (sm, arg, callee_fndecl, attr_name, arg_idx), m_fd_dir (fd_dir) { } fd_access_mode_mismatch (const fd_state_machine &sm, tree arg, enum access_directions fd_dir, const tree callee_fndecl) : fd_param_diagnostic (sm, arg, callee_fndecl), m_fd_dir (fd_dir) { } const char * get_kind () const final override { return "fd_access_mode_mismatch"; } int get_controlling_option () const final override { return OPT_Wanalyzer_fd_access_mode_mismatch; } bool emit (rich_location *rich_loc) final override { bool warned; switch (m_fd_dir) { case DIRS_READ: warned = warning_at (rich_loc, get_controlling_option (), "%qE on read-only file descriptor %qE", m_callee_fndecl, m_arg); break; case DIRS_WRITE: warned = warning_at (rich_loc, get_controlling_option (), "%qE on write-only file descriptor %qE", m_callee_fndecl, m_arg); break; default: gcc_unreachable (); } if (warned) inform_filedescriptor_attribute (m_fd_dir); return warned; } label_text describe_final_event (const evdesc::final_event &ev) final override { switch (m_fd_dir) { case DIRS_READ: return ev.formatted_print ("%qE on read-only file descriptor %qE", m_callee_fndecl, m_arg); case DIRS_WRITE: return ev.formatted_print ("%qE on write-only file descriptor %qE", m_callee_fndecl, m_arg); default: gcc_unreachable (); } } private: enum access_directions m_fd_dir; }; class fd_double_close : public fd_diagnostic { public: fd_double_close (const fd_state_machine &sm, tree arg) : fd_diagnostic (sm, arg) { } const char * get_kind () const final override { return "fd_double_close"; } int get_controlling_option () const final override { return OPT_Wanalyzer_fd_double_close; } bool emit (rich_location *rich_loc) final override { diagnostic_metadata m; // CWE-1341: Multiple Releases of Same Resource or Handle m.add_cwe (1341); return warning_meta (rich_loc, m, get_controlling_option (), "double % of file descriptor %qE", m_arg); } label_text describe_state_change (const evdesc::state_change &change) override { if (m_sm.is_unchecked_fd_p (change.m_new_state)) return label_text::borrow ("opened here"); if (change.m_new_state == m_sm.m_closed) { m_first_close_event = change.m_event_id; return change.formatted_print ("first %qs here", "close"); } return fd_diagnostic::describe_state_change (change); } label_text describe_final_event (const evdesc::final_event &ev) final override { if (m_first_close_event.known_p ()) return ev.formatted_print ("second %qs here; first %qs was at %@", "close", "close", &m_first_close_event); return ev.formatted_print ("second %qs here", "close"); } private: diagnostic_event_id_t m_first_close_event; }; class fd_use_after_close : public fd_param_diagnostic { public: fd_use_after_close (const fd_state_machine &sm, tree arg, const tree callee_fndecl, const char *attr_name, int arg_idx) : fd_param_diagnostic (sm, arg, callee_fndecl, attr_name, arg_idx) { } fd_use_after_close (const fd_state_machine &sm, tree arg, const tree callee_fndecl) : fd_param_diagnostic (sm, arg, callee_fndecl) { } const char * get_kind () const final override { return "fd_use_after_close"; } int get_controlling_option () const final override { return OPT_Wanalyzer_fd_use_after_close; } bool emit (rich_location *rich_loc) final override { bool warned; warned = warning_at (rich_loc, get_controlling_option (), "%qE on closed file descriptor %qE", m_callee_fndecl, m_arg); if (warned) inform_filedescriptor_attribute (DIRS_READ_WRITE); return warned; } label_text describe_state_change (const evdesc::state_change &change) override { if (m_sm.is_unchecked_fd_p (change.m_new_state)) return label_text::borrow ("opened here"); if (change.m_new_state == m_sm.m_closed) { m_first_close_event = change.m_event_id; return change.formatted_print ("closed here"); } return fd_diagnostic::describe_state_change (change); } label_text describe_final_event (const evdesc::final_event &ev) final override { if (m_first_close_event.known_p ()) return ev.formatted_print ( "%qE on closed file descriptor %qE; %qs was at %@", m_callee_fndecl, m_arg, "close", &m_first_close_event); else return ev.formatted_print ("%qE on closed file descriptor %qE", m_callee_fndecl, m_arg); } private: diagnostic_event_id_t m_first_close_event; }; class fd_use_without_check : public fd_param_diagnostic { public: fd_use_without_check (const fd_state_machine &sm, tree arg, const tree callee_fndecl, const char *attr_name, int arg_idx) : fd_param_diagnostic (sm, arg, callee_fndecl, attr_name, arg_idx) { } fd_use_without_check (const fd_state_machine &sm, tree arg, const tree callee_fndecl) : fd_param_diagnostic (sm, arg, callee_fndecl) { } const char * get_kind () const final override { return "fd_use_without_check"; } int get_controlling_option () const final override { return OPT_Wanalyzer_fd_use_without_check; } bool emit (rich_location *rich_loc) final override { bool warned; warned = warning_at (rich_loc, get_controlling_option (), "%qE on possibly invalid file descriptor %qE", m_callee_fndecl, m_arg); if (warned) inform_filedescriptor_attribute (DIRS_READ_WRITE); return warned; } label_text describe_state_change (const evdesc::state_change &change) override { if (m_sm.is_unchecked_fd_p (change.m_new_state)) { m_first_open_event = change.m_event_id; return label_text::borrow ("opened here"); } return fd_diagnostic::describe_state_change (change); } label_text describe_final_event (const evdesc::final_event &ev) final override { if (m_first_open_event.known_p ()) return ev.formatted_print ( "%qE could be invalid: unchecked value from %@", m_arg, &m_first_open_event); else return ev.formatted_print ("%qE could be invalid", m_arg); } private: diagnostic_event_id_t m_first_open_event; }; /* Concrete pending_diagnostic subclass for -Wanalyzer-fd-phase-mismatch. */ class fd_phase_mismatch : public fd_param_diagnostic { public: fd_phase_mismatch (const fd_state_machine &sm, tree arg, const tree callee_fndecl, state_machine::state_t actual_state, enum expected_phase expected_phase) : fd_param_diagnostic (sm, arg, callee_fndecl), m_actual_state (actual_state), m_expected_phase (expected_phase) { gcc_assert (m_sm.is_socket_fd_p (actual_state)); switch (expected_phase) { case EXPECTED_PHASE_CAN_TRANSFER: gcc_assert (actual_state == m_sm.m_new_stream_socket || actual_state == m_sm.m_bound_stream_socket || actual_state == m_sm.m_listening_stream_socket); break; case EXPECTED_PHASE_CAN_BIND: gcc_assert (actual_state == m_sm.m_bound_datagram_socket || actual_state == m_sm.m_bound_stream_socket || actual_state == m_sm.m_bound_unknown_socket || actual_state == m_sm.m_connected_stream_socket || actual_state == m_sm.m_listening_stream_socket); break; case EXPECTED_PHASE_CAN_LISTEN: gcc_assert (actual_state == m_sm.m_new_stream_socket || actual_state == m_sm.m_new_unknown_socket || actual_state == m_sm.m_connected_stream_socket); break; case EXPECTED_PHASE_CAN_ACCEPT: gcc_assert (actual_state == m_sm.m_new_stream_socket || actual_state == m_sm.m_new_unknown_socket || actual_state == m_sm.m_bound_stream_socket || actual_state == m_sm.m_bound_unknown_socket || actual_state == m_sm.m_connected_stream_socket); break; case EXPECTED_PHASE_CAN_CONNECT: gcc_assert (actual_state == m_sm.m_bound_datagram_socket || actual_state == m_sm.m_bound_stream_socket || actual_state == m_sm.m_bound_unknown_socket || actual_state == m_sm.m_listening_stream_socket || actual_state == m_sm.m_connected_stream_socket); break; } } const char * get_kind () const final override { return "fd_phase_mismatch"; } bool subclass_equal_p (const pending_diagnostic &base_other) const final override { const fd_phase_mismatch &sub_other = (const fd_phase_mismatch &)base_other; if (!fd_param_diagnostic ::subclass_equal_p (sub_other)) return false; return (m_actual_state == sub_other.m_actual_state && m_expected_phase == sub_other.m_expected_phase); } int get_controlling_option () const final override { return OPT_Wanalyzer_fd_phase_mismatch; } bool emit (rich_location *rich_loc) final override { /* CWE-666: Operation on Resource in Wrong Phase of Lifetime. */ diagnostic_metadata m; m.add_cwe (666); return warning_at (rich_loc, get_controlling_option (), "%qE on file descriptor %qE in wrong phase", m_callee_fndecl, m_arg); } label_text describe_final_event (const evdesc::final_event &ev) final override { switch (m_expected_phase) { case EXPECTED_PHASE_CAN_TRANSFER: { if (m_actual_state == m_sm.m_new_stream_socket) return ev.formatted_print ("%qE expects a stream socket to be connected via %qs" " but %qE has not yet been bound", m_callee_fndecl, "accept", m_arg); if (m_actual_state == m_sm.m_bound_stream_socket) return ev.formatted_print ("%qE expects a stream socket to be connected via %qs" " but %qE is not yet listening", m_callee_fndecl, "accept", m_arg); if (m_actual_state == m_sm.m_listening_stream_socket) return ev.formatted_print ("%qE expects a stream socket to be connected via" " the return value of %qs" " but %qE is listening; wrong file descriptor?", m_callee_fndecl, "accept", m_arg); } break; case EXPECTED_PHASE_CAN_BIND: { if (m_actual_state == m_sm.m_bound_datagram_socket || m_actual_state == m_sm.m_bound_stream_socket || m_actual_state == m_sm.m_bound_unknown_socket) return ev.formatted_print ("%qE expects a new socket file descriptor" " but %qE has already been bound", m_callee_fndecl, m_arg); if (m_actual_state == m_sm.m_connected_stream_socket) return ev.formatted_print ("%qE expects a new socket file descriptor" " but %qE is already connected", m_callee_fndecl, m_arg); if (m_actual_state == m_sm.m_listening_stream_socket) return ev.formatted_print ("%qE expects a new socket file descriptor" " but %qE is already listening", m_callee_fndecl, m_arg); } break; case EXPECTED_PHASE_CAN_LISTEN: { if (m_actual_state == m_sm.m_new_stream_socket || m_actual_state == m_sm.m_new_unknown_socket) return ev.formatted_print ("%qE expects a bound stream socket file descriptor" " but %qE has not yet been bound", m_callee_fndecl, m_arg); if (m_actual_state == m_sm.m_connected_stream_socket) return ev.formatted_print ("%qE expects a bound stream socket file descriptor" " but %qE is connected", m_callee_fndecl, m_arg); } break; case EXPECTED_PHASE_CAN_ACCEPT: { if (m_actual_state == m_sm.m_new_stream_socket || m_actual_state == m_sm.m_new_unknown_socket) return ev.formatted_print ("%qE expects a listening stream socket file descriptor" " but %qE has not yet been bound", m_callee_fndecl, m_arg); if (m_actual_state == m_sm.m_bound_stream_socket || m_actual_state == m_sm.m_bound_unknown_socket) return ev.formatted_print ("%qE expects a listening stream socket file descriptor" " whereas %qE is bound but not yet listening", m_callee_fndecl, m_arg); if (m_actual_state == m_sm.m_connected_stream_socket) return ev.formatted_print ("%qE expects a listening stream socket file descriptor" " but %qE is connected", m_callee_fndecl, m_arg); } break; case EXPECTED_PHASE_CAN_CONNECT: { if (m_actual_state == m_sm.m_bound_datagram_socket || m_actual_state == m_sm.m_bound_stream_socket || m_actual_state == m_sm.m_bound_unknown_socket) return ev.formatted_print ("%qE expects a new socket file descriptor but %qE is bound", m_callee_fndecl, m_arg); else return ev.formatted_print ("%qE expects a new socket file descriptor", m_callee_fndecl); } break; } gcc_unreachable (); } private: state_machine::state_t m_actual_state; enum expected_phase m_expected_phase; }; /* Enum for use by -Wanalyzer-fd-type-mismatch. */ enum expected_type { EXPECTED_TYPE_SOCKET, EXPECTED_TYPE_STREAM_SOCKET }; /* Concrete pending_diagnostic subclass for -Wanalyzer-fd-type-mismatch. */ class fd_type_mismatch : public fd_param_diagnostic { public: fd_type_mismatch (const fd_state_machine &sm, tree arg, const tree callee_fndecl, state_machine::state_t actual_state, enum expected_type expected_type) : fd_param_diagnostic (sm, arg, callee_fndecl), m_actual_state (actual_state), m_expected_type (expected_type) { } const char * get_kind () const final override { return "fd_type_mismatch"; } bool subclass_equal_p (const pending_diagnostic &base_other) const final override { const fd_type_mismatch &sub_other = (const fd_type_mismatch &)base_other; if (!fd_param_diagnostic ::subclass_equal_p (sub_other)) return false; return (m_actual_state == sub_other.m_actual_state && m_expected_type == sub_other.m_expected_type); } int get_controlling_option () const final override { return OPT_Wanalyzer_fd_type_mismatch; } bool emit (rich_location *rich_loc) final override { switch (m_expected_type) { default: gcc_unreachable (); case EXPECTED_TYPE_SOCKET: return warning_at (rich_loc, get_controlling_option (), "%qE on non-socket file descriptor %qE", m_callee_fndecl, m_arg); case EXPECTED_TYPE_STREAM_SOCKET: if (m_sm.is_datagram_socket_fd_p (m_actual_state)) return warning_at (rich_loc, get_controlling_option (), "%qE on datagram socket file descriptor %qE", m_callee_fndecl, m_arg); else return warning_at (rich_loc, get_controlling_option (), "%qE on non-stream-socket file descriptor %qE", m_callee_fndecl, m_arg); } } label_text describe_final_event (const evdesc::final_event &ev) final override { switch (m_expected_type) { default: break; gcc_unreachable (); case EXPECTED_TYPE_SOCKET: case EXPECTED_TYPE_STREAM_SOCKET: if (!m_sm.is_socket_fd_p (m_actual_state)) return ev.formatted_print ("%qE expects a socket file descriptor" " but %qE is not a socket", m_callee_fndecl, m_arg); } gcc_assert (m_expected_type == EXPECTED_TYPE_STREAM_SOCKET); gcc_assert (m_sm.is_datagram_socket_fd_p (m_actual_state)); return ev.formatted_print ("%qE expects a stream socket file descriptor" " but %qE is a datagram socket", m_callee_fndecl, m_arg); } private: state_machine::state_t m_actual_state; enum expected_type m_expected_type; }; fd_state_machine::fd_state_machine (logger *logger) : state_machine ("file-descriptor", logger), m_constant_fd (add_state ("fd-constant")), m_unchecked_read_write (add_state ("fd-unchecked-read-write")), m_unchecked_read_only (add_state ("fd-unchecked-read-only")), m_unchecked_write_only (add_state ("fd-unchecked-write-only")), m_valid_read_write (add_state ("fd-valid-read-write")), m_valid_read_only (add_state ("fd-valid-read-only")), m_valid_write_only (add_state ("fd-valid-write-only")), m_invalid (add_state ("fd-invalid")), m_closed (add_state ("fd-closed")), m_new_datagram_socket (add_state ("fd-new-datagram-socket")), m_new_stream_socket (add_state ("fd-new-stream-socket")), m_new_unknown_socket (add_state ("fd-new-unknown-socket")), m_bound_datagram_socket (add_state ("fd-bound-datagram-socket")), m_bound_stream_socket (add_state ("fd-bound-stream-socket")), m_bound_unknown_socket (add_state ("fd-bound-unknown-socket")), m_listening_stream_socket (add_state ("fd-listening-stream-socket")), m_connected_stream_socket (add_state ("fd-connected-stream-socket")), m_stop (add_state ("fd-stop")), m_O_ACCMODE (get_stashed_constant_by_name ("O_ACCMODE")), m_O_RDONLY (get_stashed_constant_by_name ("O_RDONLY")), m_O_WRONLY (get_stashed_constant_by_name ("O_WRONLY")), m_SOCK_STREAM (get_stashed_constant_by_name ("SOCK_STREAM")), m_SOCK_DGRAM (get_stashed_constant_by_name ("SOCK_DGRAM")) { } bool fd_state_machine::is_unchecked_fd_p (state_t s) const { return (s == m_unchecked_read_write || s == m_unchecked_read_only || s == m_unchecked_write_only); } bool fd_state_machine::is_valid_fd_p (state_t s) const { return (s == m_valid_read_write || s == m_valid_read_only || s == m_valid_write_only); } bool fd_state_machine::is_socket_fd_p (state_t s) const { return (s == m_new_datagram_socket || s == m_new_stream_socket || s == m_new_unknown_socket || s == m_bound_datagram_socket || s == m_bound_stream_socket || s == m_bound_unknown_socket || s == m_listening_stream_socket || s == m_connected_stream_socket); } bool fd_state_machine::is_datagram_socket_fd_p (state_t s) const { return (s == m_new_datagram_socket || s == m_new_unknown_socket || s == m_bound_datagram_socket || s == m_bound_unknown_socket); } bool fd_state_machine::is_stream_socket_fd_p (state_t s) const { return (s == m_new_stream_socket || s == m_new_unknown_socket || s == m_bound_stream_socket || s == m_bound_unknown_socket || s == m_listening_stream_socket || s == m_connected_stream_socket); } enum access_mode fd_state_machine::get_access_mode_from_flag (int flag) const { if (m_O_ACCMODE && TREE_CODE (m_O_ACCMODE) == INTEGER_CST) { const unsigned HOST_WIDE_INT mask_val = TREE_INT_CST_LOW (m_O_ACCMODE); const unsigned HOST_WIDE_INT masked_flag = flag & mask_val; if (m_O_RDONLY && TREE_CODE (m_O_RDONLY) == INTEGER_CST) if (masked_flag == TREE_INT_CST_LOW (m_O_RDONLY)) return READ_ONLY; if (m_O_WRONLY && TREE_CODE (m_O_WRONLY) == INTEGER_CST) if (masked_flag == TREE_INT_CST_LOW (m_O_WRONLY)) return WRITE_ONLY; } return READ_WRITE; } bool fd_state_machine::is_readonly_fd_p (state_t state) const { return (state == m_unchecked_read_only || state == m_valid_read_only); } bool fd_state_machine::is_writeonly_fd_p (state_t state) const { return (state == m_unchecked_write_only || state == m_valid_write_only); } bool fd_state_machine::is_closed_fd_p (state_t state) const { return (state == m_closed); } bool fd_state_machine::is_constant_fd_p (state_t state) const { return (state == m_constant_fd); } fd_state_machine::state_t fd_state_machine::valid_to_unchecked_state (state_t state) const { if (state == m_valid_read_write) return m_unchecked_read_write; else if (state == m_valid_write_only) return m_unchecked_write_only; else if (state == m_valid_read_only) return m_unchecked_read_only; else gcc_unreachable (); return NULL; } void fd_state_machine::mark_as_valid_fd (region_model *model, sm_state_map *smap, const svalue *fd_sval, const extrinsic_state &ext_state) const { smap->set_state (model, fd_sval, m_valid_read_write, NULL, ext_state); } bool fd_state_machine::on_stmt (sm_context *sm_ctxt, const supernode *node, const gimple *stmt) const { if (const gcall *call = dyn_cast (stmt)) if (tree callee_fndecl = sm_ctxt->get_fndecl_for_call (call)) { if (is_named_call_p (callee_fndecl, "open", call, 2)) { on_open (sm_ctxt, node, stmt, call); return true; } // "open" if (is_named_call_p (callee_fndecl, "creat", call, 2)) { on_creat (sm_ctxt, node, stmt, call); return true; } // "creat" if (is_named_call_p (callee_fndecl, "close", call, 1)) { on_close (sm_ctxt, node, stmt, call); return true; } // "close" if (is_named_call_p (callee_fndecl, "write", call, 3)) { on_write (sm_ctxt, node, stmt, call, callee_fndecl); return true; } // "write" if (is_named_call_p (callee_fndecl, "read", call, 3)) { on_read (sm_ctxt, node, stmt, call, callee_fndecl); return true; } // "read" if (is_named_call_p (callee_fndecl, "dup", call, 1)) { check_for_dup (sm_ctxt, node, stmt, call, callee_fndecl, DUP_1); return true; } if (is_named_call_p (callee_fndecl, "dup2", call, 2)) { check_for_dup (sm_ctxt, node, stmt, call, callee_fndecl, DUP_2); return true; } if (is_named_call_p (callee_fndecl, "dup3", call, 3)) { check_for_dup (sm_ctxt, node, stmt, call, callee_fndecl, DUP_3); return true; } { // Handle __attribute__((fd_arg)) check_for_fd_attrs (sm_ctxt, node, stmt, call, callee_fndecl, "fd_arg", DIRS_READ_WRITE); // Handle __attribute__((fd_arg_read)) check_for_fd_attrs (sm_ctxt, node, stmt, call, callee_fndecl, "fd_arg_read", DIRS_READ); // Handle __attribute__((fd_arg_write)) check_for_fd_attrs (sm_ctxt, node, stmt, call, callee_fndecl, "fd_arg_write", DIRS_WRITE); } } return false; } void fd_state_machine::check_for_fd_attrs ( sm_context *sm_ctxt, const supernode *node, const gimple *stmt, const gcall *call, const tree callee_fndecl, const char *attr_name, access_directions fd_attr_access_dir) const { tree attrs = TYPE_ATTRIBUTES (TREE_TYPE (callee_fndecl)); attrs = lookup_attribute (attr_name, attrs); if (!attrs) return; if (!TREE_VALUE (attrs)) return; auto_bitmap argmap; for (tree idx = TREE_VALUE (attrs); idx; idx = TREE_CHAIN (idx)) { unsigned int val = TREE_INT_CST_LOW (TREE_VALUE (idx)) - 1; bitmap_set_bit (argmap, val); } if (bitmap_empty_p (argmap)) return; for (unsigned arg_idx = 0; arg_idx < gimple_call_num_args (call); arg_idx++) { tree arg = gimple_call_arg (call, arg_idx); tree diag_arg = sm_ctxt->get_diagnostic_tree (arg); state_t state = sm_ctxt->get_state (stmt, arg); bool bit_set = bitmap_bit_p (argmap, arg_idx); if (TREE_CODE (TREE_TYPE (arg)) != INTEGER_TYPE) continue; if (bit_set) // Check if arg_idx is marked by any of the file descriptor // attributes { if (is_closed_fd_p (state)) { sm_ctxt->warn (node, stmt, arg, make_unique (*this, diag_arg, callee_fndecl, attr_name, arg_idx)); continue; } if (!(is_valid_fd_p (state) || (state == m_stop))) { if (!is_constant_fd_p (state)) { sm_ctxt->warn (node, stmt, arg, make_unique (*this, diag_arg, callee_fndecl, attr_name, arg_idx)); continue; } } switch (fd_attr_access_dir) { case DIRS_READ_WRITE: break; case DIRS_READ: if (is_writeonly_fd_p (state)) { sm_ctxt->warn ( node, stmt, arg, make_unique (*this, diag_arg, DIRS_WRITE, callee_fndecl, attr_name, arg_idx)); } break; case DIRS_WRITE: if (is_readonly_fd_p (state)) { sm_ctxt->warn ( node, stmt, arg, make_unique (*this, diag_arg, DIRS_READ, callee_fndecl, attr_name, arg_idx)); } break; } } } } void fd_state_machine::on_open (sm_context *sm_ctxt, const supernode *node, const gimple *stmt, const gcall *call) const { tree lhs = gimple_call_lhs (call); if (lhs) { tree arg = gimple_call_arg (call, 1); enum access_mode mode = READ_WRITE; if (TREE_CODE (arg) == INTEGER_CST) { int flag = TREE_INT_CST_LOW (arg); mode = get_access_mode_from_flag (flag); } switch (mode) { case READ_ONLY: sm_ctxt->on_transition (node, stmt, lhs, m_start, m_unchecked_read_only); break; case WRITE_ONLY: sm_ctxt->on_transition (node, stmt, lhs, m_start, m_unchecked_write_only); break; default: sm_ctxt->on_transition (node, stmt, lhs, m_start, m_unchecked_read_write); } } else { sm_ctxt->warn (node, stmt, NULL_TREE, make_unique (*this, NULL_TREE)); } } void fd_state_machine::on_creat (sm_context *sm_ctxt, const supernode *node, const gimple *stmt, const gcall *call) const { tree lhs = gimple_call_lhs (call); if (lhs) sm_ctxt->on_transition (node, stmt, lhs, m_start, m_unchecked_write_only); else sm_ctxt->warn (node, stmt, NULL_TREE, make_unique (*this, NULL_TREE)); } void fd_state_machine::check_for_dup (sm_context *sm_ctxt, const supernode *node, const gimple *stmt, const gcall *call, const tree callee_fndecl, enum dup kind) const { tree lhs = gimple_call_lhs (call); tree arg_1 = gimple_call_arg (call, 0); state_t state_arg_1 = sm_ctxt->get_state (stmt, arg_1); if (state_arg_1 == m_stop) return; if (!(is_constant_fd_p (state_arg_1) || is_valid_fd_p (state_arg_1) || state_arg_1 == m_start)) { check_for_open_fd (sm_ctxt, node, stmt, call, callee_fndecl, DIRS_READ_WRITE); return; } switch (kind) { case DUP_1: if (lhs) { if (is_constant_fd_p (state_arg_1) || state_arg_1 == m_start) sm_ctxt->set_next_state (stmt, lhs, m_unchecked_read_write); else sm_ctxt->set_next_state (stmt, lhs, valid_to_unchecked_state (state_arg_1)); } break; case DUP_2: case DUP_3: tree arg_2 = gimple_call_arg (call, 1); state_t state_arg_2 = sm_ctxt->get_state (stmt, arg_2); tree diag_arg_2 = sm_ctxt->get_diagnostic_tree (arg_2); if (state_arg_2 == m_stop) return; /* Check if -1 was passed as second argument to dup2. */ if (!(is_constant_fd_p (state_arg_2) || is_valid_fd_p (state_arg_2) || state_arg_2 == m_start)) { sm_ctxt->warn ( node, stmt, arg_2, make_unique (*this, diag_arg_2, callee_fndecl)); return; } /* dup2 returns value of its second argument on success.But, the access mode of the returned file descriptor depends on the duplicated file descriptor i.e the first argument. */ if (lhs) { if (is_constant_fd_p (state_arg_1) || state_arg_1 == m_start) sm_ctxt->set_next_state (stmt, lhs, m_unchecked_read_write); else sm_ctxt->set_next_state (stmt, lhs, valid_to_unchecked_state (state_arg_1)); } break; } } void fd_state_machine::on_close (sm_context *sm_ctxt, const supernode *node, const gimple *stmt, const gcall *call) const { tree arg = gimple_call_arg (call, 0); state_t state = sm_ctxt->get_state (stmt, arg); tree diag_arg = sm_ctxt->get_diagnostic_tree (arg); sm_ctxt->on_transition (node, stmt, arg, m_start, m_closed); sm_ctxt->on_transition (node, stmt, arg, m_unchecked_read_write, m_closed); sm_ctxt->on_transition (node, stmt, arg, m_unchecked_read_only, m_closed); sm_ctxt->on_transition (node, stmt, arg, m_unchecked_write_only, m_closed); sm_ctxt->on_transition (node, stmt, arg, m_valid_read_write, m_closed); sm_ctxt->on_transition (node, stmt, arg, m_valid_read_only, m_closed); sm_ctxt->on_transition (node, stmt, arg, m_valid_write_only, m_closed); sm_ctxt->on_transition (node, stmt, arg, m_constant_fd, m_closed); sm_ctxt->on_transition (node, stmt, arg, m_new_datagram_socket, m_closed); sm_ctxt->on_transition (node, stmt, arg, m_new_stream_socket, m_closed); sm_ctxt->on_transition (node, stmt, arg, m_new_unknown_socket, m_closed); sm_ctxt->on_transition (node, stmt, arg, m_bound_datagram_socket, m_closed); sm_ctxt->on_transition (node, stmt, arg, m_bound_stream_socket, m_closed); sm_ctxt->on_transition (node, stmt, arg, m_bound_unknown_socket, m_closed); sm_ctxt->on_transition (node, stmt, arg, m_listening_stream_socket, m_closed); sm_ctxt->on_transition (node, stmt, arg, m_connected_stream_socket, m_closed); if (is_closed_fd_p (state)) { sm_ctxt->warn (node, stmt, arg, make_unique (*this, diag_arg)); sm_ctxt->set_next_state (stmt, arg, m_stop); } } void fd_state_machine::on_read (sm_context *sm_ctxt, const supernode *node, const gimple *stmt, const gcall *call, const tree callee_fndecl) const { check_for_open_fd (sm_ctxt, node, stmt, call, callee_fndecl, DIRS_READ); } void fd_state_machine::on_write (sm_context *sm_ctxt, const supernode *node, const gimple *stmt, const gcall *call, const tree callee_fndecl) const { check_for_open_fd (sm_ctxt, node, stmt, call, callee_fndecl, DIRS_WRITE); } void fd_state_machine::check_for_open_fd ( sm_context *sm_ctxt, const supernode *node, const gimple *stmt, const gcall *call, const tree callee_fndecl, enum access_directions callee_fndecl_dir) const { tree arg = gimple_call_arg (call, 0); tree diag_arg = sm_ctxt->get_diagnostic_tree (arg); state_t state = sm_ctxt->get_state (stmt, arg); if (is_closed_fd_p (state)) { sm_ctxt->warn (node, stmt, arg, make_unique (*this, diag_arg, callee_fndecl)); } else { if (state == m_new_stream_socket || state == m_bound_stream_socket || state == m_listening_stream_socket) /* Complain about fncall on socket in wrong phase. */ sm_ctxt->warn (node, stmt, arg, make_unique (*this, diag_arg, callee_fndecl, state, EXPECTED_PHASE_CAN_TRANSFER)); else if (!(is_valid_fd_p (state) || state == m_new_datagram_socket || state == m_bound_unknown_socket || state == m_connected_stream_socket || state == m_start || state == m_stop)) { if (!is_constant_fd_p (state)) sm_ctxt->warn ( node, stmt, arg, make_unique (*this, diag_arg, callee_fndecl)); } switch (callee_fndecl_dir) { case DIRS_READ_WRITE: break; case DIRS_READ: if (is_writeonly_fd_p (state)) { tree diag_arg = sm_ctxt->get_diagnostic_tree (arg); sm_ctxt->warn (node, stmt, arg, make_unique ( *this, diag_arg, DIRS_WRITE, callee_fndecl)); } break; case DIRS_WRITE: if (is_readonly_fd_p (state)) { tree diag_arg = sm_ctxt->get_diagnostic_tree (arg); sm_ctxt->warn (node, stmt, arg, make_unique ( *this, diag_arg, DIRS_READ, callee_fndecl)); } break; } } } static bool add_constraint_ge_zero (region_model *model, const svalue *fd_sval, region_model_context *ctxt) { const svalue *zero = model->get_manager ()->get_or_create_int_cst (integer_type_node, 0); return model->add_constraint (fd_sval, GE_EXPR, zero, ctxt); } /* Get the state for a new socket type based on SOCKET_TYPE_SVAL, a SOCK_* value. */ state_machine::state_t fd_state_machine:: get_state_for_socket_type (const svalue *socket_type_sval) const { if (tree socket_type_cst = socket_type_sval->maybe_get_constant ()) { /* Attempt to use SOCK_* constants stashed from the frontend. */ if (tree_int_cst_equal (socket_type_cst, m_SOCK_STREAM)) return m_new_stream_socket; if (tree_int_cst_equal (socket_type_cst, m_SOCK_DGRAM)) return m_new_datagram_socket; } /* Unrecognized constant, or a symbolic "type" value. */ return m_new_unknown_socket; } /* Update the model and fd state for an outcome of a call to "socket", where SUCCESSFUL indicate which of the two outcomes. Return true if the outcome is feasible, or false to reject it. */ bool fd_state_machine::on_socket (const call_details &cd, bool successful, sm_context *sm_ctxt, const extrinsic_state &ext_state) const { const gcall *stmt = cd.get_call_stmt (); engine *eng = ext_state.get_engine (); const supergraph *sg = eng->get_supergraph (); const supernode *node = sg->get_supernode_for_stmt (stmt); region_model *model = cd.get_model (); if (successful) { if (gimple_call_lhs (stmt)) { conjured_purge p (model, cd.get_ctxt ()); region_model_manager *mgr = model->get_manager (); const svalue *new_fd = mgr->get_or_create_conjured_svalue (integer_type_node, stmt, cd.get_lhs_region (), p); if (!add_constraint_ge_zero (model, new_fd, cd.get_ctxt ())) return false; const svalue *socket_type_sval = cd.get_arg_svalue (1); state_machine::state_t new_state = get_state_for_socket_type (socket_type_sval); sm_ctxt->on_transition (node, stmt, new_fd, m_start, new_state); model->set_value (cd.get_lhs_region (), new_fd, cd.get_ctxt ()); } else sm_ctxt->warn (node, stmt, NULL_TREE, make_unique (*this, NULL_TREE)); } else { /* Return -1; set errno. */ model->update_for_int_cst_return (cd, -1, true); model->set_errno (cd); } return true; } /* Check that FD_SVAL is usable by socket APIs. Complain if it has been closed, if it is a non-socket, or is invalid. If COMPLAINED is non-NULL and a problem is found, write *COMPLAINED = true. If SUCCESSFUL is true, attempt to add the constraint that FD_SVAL >= 0. Return true if this outcome is feasible. */ bool fd_state_machine::check_for_socket_fd (const call_details &cd, bool successful, sm_context *sm_ctxt, const svalue *fd_sval, const supernode *node, state_t old_state, bool *complained) const { const gcall *stmt = cd.get_call_stmt (); if (is_closed_fd_p (old_state)) { tree diag_arg = sm_ctxt->get_diagnostic_tree (fd_sval); sm_ctxt->warn (node, stmt, fd_sval, make_unique (*this, diag_arg, cd.get_fndecl_for_call ())); if (complained) *complained = true; if (successful) return false; } else if (is_unchecked_fd_p (old_state) || is_valid_fd_p (old_state)) { /* Complain about non-socket. */ tree diag_arg = sm_ctxt->get_diagnostic_tree (fd_sval); sm_ctxt->warn (node, stmt, fd_sval, make_unique (*this, diag_arg, cd.get_fndecl_for_call (), old_state, EXPECTED_TYPE_SOCKET)); if (complained) *complained = true; if (successful) return false; } else if (old_state == m_invalid) { tree diag_arg = sm_ctxt->get_diagnostic_tree (fd_sval); sm_ctxt->warn (node, stmt, fd_sval, make_unique (*this, diag_arg, cd.get_fndecl_for_call ())); if (complained) *complained = true; if (successful) return false; } if (successful) if (!add_constraint_ge_zero (cd.get_model (), fd_sval, cd.get_ctxt ())) return false; return true; } /* For use by "bind" and "connect". As per fd_state_machine::check_for_socket_fd above, but also complain if we don't have a new socket, and check that we can read up to the size bytes from the address. */ bool fd_state_machine::check_for_new_socket_fd (const call_details &cd, bool successful, sm_context *sm_ctxt, const svalue *fd_sval, const supernode *node, state_t old_state, enum expected_phase expected_phase) const { bool complained = false; /* Check address and len. */ const svalue *address_sval = cd.get_arg_svalue (1); const svalue *len_sval = cd.get_arg_svalue (2); /* Check that we can read the given number of bytes from the address. */ region_model *model = cd.get_model (); const region *address_reg = model->deref_rvalue (address_sval, cd.get_arg_tree (1), cd.get_ctxt ()); const region *sized_address_reg = model->get_manager ()->get_sized_region (address_reg, NULL_TREE, len_sval); model->get_store_value (sized_address_reg, cd.get_ctxt ()); if (!check_for_socket_fd (cd, successful, sm_ctxt, fd_sval, node, old_state, &complained)) return false; else if (!complained && !(old_state == m_new_stream_socket || old_state == m_new_datagram_socket || old_state == m_new_unknown_socket || old_state == m_start || old_state == m_stop || old_state == m_constant_fd)) { /* Complain about "bind" or "connect" in wrong phase. */ tree diag_arg = sm_ctxt->get_diagnostic_tree (fd_sval); sm_ctxt->warn (node, cd.get_call_stmt (), fd_sval, make_unique (*this, diag_arg, cd.get_fndecl_for_call (), old_state, expected_phase)); if (successful) return false; } else if (!successful) { /* If we were in the start state, assume we had a new socket. */ if (old_state == m_start) sm_ctxt->set_next_state (cd.get_call_stmt (), fd_sval, m_new_unknown_socket); } /* Passing NULL as the address will lead to failure. */ if (successful) if (address_sval->all_zeroes_p ()) return false; return true; } /* Update the model and fd state for an outcome of a call to "bind", where SUCCESSFUL indicate which of the two outcomes. Return true if the outcome is feasible, or false to reject it. */ bool fd_state_machine::on_bind (const call_details &cd, bool successful, sm_context *sm_ctxt, const extrinsic_state &ext_state) const { const gcall *stmt = cd.get_call_stmt (); engine *eng = ext_state.get_engine (); const supergraph *sg = eng->get_supergraph (); const supernode *node = sg->get_supernode_for_stmt (stmt); const svalue *fd_sval = cd.get_arg_svalue (0); region_model *model = cd.get_model (); state_t old_state = sm_ctxt->get_state (stmt, fd_sval); if (!check_for_new_socket_fd (cd, successful, sm_ctxt, fd_sval, node, old_state, EXPECTED_PHASE_CAN_BIND)) return false; if (successful) { state_t next_state = NULL; if (old_state == m_new_stream_socket) next_state = m_bound_stream_socket; else if (old_state == m_new_datagram_socket) next_state = m_bound_datagram_socket; else if (old_state == m_new_unknown_socket) next_state = m_bound_unknown_socket; else if (old_state == m_start || old_state == m_constant_fd) next_state = m_bound_unknown_socket; else if (old_state == m_stop) next_state = m_stop; else gcc_unreachable (); sm_ctxt->set_next_state (cd.get_call_stmt (), fd_sval, next_state); model->update_for_zero_return (cd, true); } else { /* Return -1; set errno. */ model->update_for_int_cst_return (cd, -1, true); model->set_errno (cd); } return true; } /* Update the model and fd state for an outcome of a call to "listen", where SUCCESSFUL indicate which of the two outcomes. Return true if the outcome is feasible, or false to reject it. */ bool fd_state_machine::on_listen (const call_details &cd, bool successful, sm_context *sm_ctxt, const extrinsic_state &ext_state) const { const gcall *stmt = cd.get_call_stmt (); engine *eng = ext_state.get_engine (); const supergraph *sg = eng->get_supergraph (); const supernode *node = sg->get_supernode_for_stmt (cd.get_call_stmt ()); const svalue *fd_sval = cd.get_arg_svalue (0); region_model *model = cd.get_model (); state_t old_state = sm_ctxt->get_state (stmt, fd_sval); /* We expect a stream socket that's had "bind" called on it. */ if (!check_for_socket_fd (cd, successful, sm_ctxt, fd_sval, node, old_state)) return false; if (!(old_state == m_start || old_state == m_constant_fd || old_state == m_stop || old_state == m_invalid || old_state == m_bound_stream_socket || old_state == m_bound_unknown_socket /* Assume it's OK to call "listen" more than once. */ || old_state == m_listening_stream_socket)) { /* Complain about fncall on wrong type or in wrong phase. */ tree diag_arg = sm_ctxt->get_diagnostic_tree (fd_sval); if (is_stream_socket_fd_p (old_state)) sm_ctxt->warn (node, stmt, fd_sval, make_unique (*this, diag_arg, cd.get_fndecl_for_call (), old_state, EXPECTED_PHASE_CAN_LISTEN)); else sm_ctxt->warn (node, stmt, fd_sval, make_unique (*this, diag_arg, cd.get_fndecl_for_call (), old_state, EXPECTED_TYPE_STREAM_SOCKET)); if (successful) return false; } if (successful) { model->update_for_zero_return (cd, true); sm_ctxt->set_next_state (cd.get_call_stmt (), fd_sval, m_listening_stream_socket); } else { /* Return -1; set errno. */ model->update_for_int_cst_return (cd, -1, true); model->set_errno (cd); if (old_state == m_start) sm_ctxt->set_next_state (cd.get_call_stmt (), fd_sval, m_bound_stream_socket); } return true; } /* Update the model and fd state for an outcome of a call to "accept", where SUCCESSFUL indicate which of the two outcomes. Return true if the outcome is feasible, or false to reject it. */ bool fd_state_machine::on_accept (const call_details &cd, bool successful, sm_context *sm_ctxt, const extrinsic_state &ext_state) const { const gcall *stmt = cd.get_call_stmt (); engine *eng = ext_state.get_engine (); const supergraph *sg = eng->get_supergraph (); const supernode *node = sg->get_supernode_for_stmt (stmt); const svalue *fd_sval = cd.get_arg_svalue (0); const svalue *address_sval = cd.get_arg_svalue (1); const svalue *len_ptr_sval = cd.get_arg_svalue (2); region_model *model = cd.get_model (); state_t old_state = sm_ctxt->get_state (stmt, fd_sval); if (!address_sval->all_zeroes_p ()) { region_model_manager *mgr = model->get_manager (); /* We might have a union of various pointer types, rather than a pointer type; cast to (void *) before dereferencing. */ address_sval = mgr->get_or_create_cast (ptr_type_node, address_sval); const region *address_reg = model->deref_rvalue (address_sval, cd.get_arg_tree (1), cd.get_ctxt ()); const region *len_reg = model->deref_rvalue (len_ptr_sval, cd.get_arg_tree (2), cd.get_ctxt ()); const svalue *old_len_sval = model->get_store_value (len_reg, cd.get_ctxt ()); tree len_ptr = cd.get_arg_tree (2); tree star_len_ptr = build2 (MEM_REF, TREE_TYPE (TREE_TYPE (len_ptr)), len_ptr, build_int_cst (TREE_TYPE (len_ptr), 0)); old_len_sval = model->check_for_poison (old_len_sval, star_len_ptr, len_reg, cd.get_ctxt ()); if (successful) { conjured_purge p (model, cd.get_ctxt ()); const region *old_sized_address_reg = mgr->get_sized_region (address_reg, NULL_TREE, old_len_sval); const svalue *new_addr_sval = mgr->get_or_create_conjured_svalue (NULL_TREE, stmt, old_sized_address_reg, p); model->set_value (old_sized_address_reg, new_addr_sval, cd.get_ctxt ()); const svalue *new_addr_len = mgr->get_or_create_conjured_svalue (NULL_TREE, stmt, len_reg, p); model->set_value (len_reg, new_addr_len, cd.get_ctxt ()); } } /* We expect a stream socket in the "listening" state. */ if (!check_for_socket_fd (cd, successful, sm_ctxt, fd_sval, node, old_state)) return false; if (old_state == m_start || old_state == m_constant_fd) /* If we were in the start state (or a constant), assume we had the expected state. */ sm_ctxt->set_next_state (cd.get_call_stmt (), fd_sval, m_listening_stream_socket); else if (old_state == m_stop) { /* No further complaints. */ } else if (old_state != m_listening_stream_socket) { /* Complain about fncall on wrong type or in wrong phase. */ tree diag_arg = sm_ctxt->get_diagnostic_tree (fd_sval); if (is_stream_socket_fd_p (old_state)) sm_ctxt->warn (node, stmt, fd_sval, make_unique (*this, diag_arg, cd.get_fndecl_for_call (), old_state, EXPECTED_PHASE_CAN_ACCEPT)); else sm_ctxt->warn (node, stmt, fd_sval, make_unique (*this, diag_arg, cd.get_fndecl_for_call (), old_state, EXPECTED_TYPE_STREAM_SOCKET)); if (successful) return false; } if (successful) { /* Return new conjured FD in "connected" state. */ if (gimple_call_lhs (stmt)) { conjured_purge p (model, cd.get_ctxt ()); region_model_manager *mgr = model->get_manager (); const svalue *new_fd = mgr->get_or_create_conjured_svalue (integer_type_node, stmt, cd.get_lhs_region (), p); if (!add_constraint_ge_zero (model, new_fd, cd.get_ctxt ())) return false; sm_ctxt->on_transition (node, stmt, new_fd, m_start, m_connected_stream_socket); model->set_value (cd.get_lhs_region (), new_fd, cd.get_ctxt ()); } else sm_ctxt->warn (node, stmt, NULL_TREE, make_unique (*this, NULL_TREE)); } else { /* Return -1; set errno. */ model->update_for_int_cst_return (cd, -1, true); model->set_errno (cd); } return true; } /* Update the model and fd state for an outcome of a call to "connect", where SUCCESSFUL indicate which of the two outcomes. Return true if the outcome is feasible, or false to reject it. */ bool fd_state_machine::on_connect (const call_details &cd, bool successful, sm_context *sm_ctxt, const extrinsic_state &ext_state) const { const gcall *stmt = cd.get_call_stmt (); engine *eng = ext_state.get_engine (); const supergraph *sg = eng->get_supergraph (); const supernode *node = sg->get_supernode_for_stmt (stmt); const svalue *fd_sval = cd.get_arg_svalue (0); region_model *model = cd.get_model (); state_t old_state = sm_ctxt->get_state (stmt, fd_sval); if (!check_for_new_socket_fd (cd, successful, sm_ctxt, fd_sval, node, old_state, EXPECTED_PHASE_CAN_CONNECT)) return false; if (successful) { model->update_for_zero_return (cd, true); state_t next_state = NULL; if (old_state == m_new_stream_socket) next_state = m_connected_stream_socket; else if (old_state == m_new_datagram_socket) /* It's legal to call connect on a datagram socket, potentially more than once. We don't transition states for this. */ next_state = m_new_datagram_socket; else if (old_state == m_new_unknown_socket) next_state = m_stop; else if (old_state == m_start || old_state == m_constant_fd) next_state = m_stop; else if (old_state == m_stop) next_state = m_stop; else gcc_unreachable (); sm_ctxt->set_next_state (cd.get_call_stmt (), fd_sval, next_state); } else { /* Return -1; set errno. */ model->update_for_int_cst_return (cd, -1, true); model->set_errno (cd); /* TODO: perhaps transition to a failed state, since the portable way to handle a failed "connect" is to close the socket and try again with a new socket. */ } return true; } void fd_state_machine::on_condition (sm_context *sm_ctxt, const supernode *node, const gimple *stmt, const svalue *lhs, enum tree_code op, const svalue *rhs) const { if (tree cst = rhs->maybe_get_constant ()) { if (TREE_CODE (cst) == INTEGER_CST) { int val = TREE_INT_CST_LOW (cst); if (val == -1) { if (op == NE_EXPR) make_valid_transitions_on_condition (sm_ctxt, node, stmt, lhs); else if (op == EQ_EXPR) make_invalid_transitions_on_condition (sm_ctxt, node, stmt, lhs); } } } if (rhs->all_zeroes_p ()) { if (op == GE_EXPR) make_valid_transitions_on_condition (sm_ctxt, node, stmt, lhs); else if (op == LT_EXPR) make_invalid_transitions_on_condition (sm_ctxt, node, stmt, lhs); } } void fd_state_machine::make_valid_transitions_on_condition (sm_context *sm_ctxt, const supernode *node, const gimple *stmt, const svalue *lhs) const { sm_ctxt->on_transition (node, stmt, lhs, m_unchecked_read_write, m_valid_read_write); sm_ctxt->on_transition (node, stmt, lhs, m_unchecked_read_only, m_valid_read_only); sm_ctxt->on_transition (node, stmt, lhs, m_unchecked_write_only, m_valid_write_only); } void fd_state_machine::make_invalid_transitions_on_condition ( sm_context *sm_ctxt, const supernode *node, const gimple *stmt, const svalue *lhs) const { sm_ctxt->on_transition (node, stmt, lhs, m_unchecked_read_write, m_invalid); sm_ctxt->on_transition (node, stmt, lhs, m_unchecked_read_only, m_invalid); sm_ctxt->on_transition (node, stmt, lhs, m_unchecked_write_only, m_invalid); } bool fd_state_machine::can_purge_p (state_t s) const { if (is_unchecked_fd_p (s) || is_valid_fd_p (s) || is_socket_fd_p (s)) return false; else return true; } std::unique_ptr fd_state_machine::on_leak (tree var) const { return make_unique (*this, var); } } // namespace state_machine * make_fd_state_machine (logger *logger) { return new fd_state_machine (logger); } static bool get_fd_state (region_model_context *ctxt, sm_state_map **out_smap, const fd_state_machine **out_sm, unsigned *out_sm_idx, std::unique_ptr *out_sm_context) { if (!ctxt) return false; const state_machine *sm; if (!ctxt->get_fd_map (out_smap, &sm, out_sm_idx, out_sm_context)) return false; gcc_assert (sm); *out_sm = (const fd_state_machine *)sm; return true; } /* Specialcase hook for handling pipe, for use by kf_pipe::success::update_model. */ void region_model::mark_as_valid_fd (const svalue *sval, region_model_context *ctxt) { sm_state_map *smap; const fd_state_machine *fd_sm; if (!get_fd_state (ctxt, &smap, &fd_sm, NULL, NULL)) return; const extrinsic_state *ext_state = ctxt->get_ext_state (); if (!ext_state) return; fd_sm->mark_as_valid_fd (this, smap, sval, *ext_state); } /* Handle calls to "socket". See e.g. https://man7.org/linux/man-pages/man3/socket.3p.html */ class kf_socket : public known_function { public: class outcome_of_socket : public succeed_or_fail_call_info { public: outcome_of_socket (const call_details &cd, bool success) : succeed_or_fail_call_info (cd, success) {} bool update_model (region_model *model, const exploded_edge *, region_model_context *ctxt) const final override { const call_details cd (get_call_details (model, ctxt)); sm_state_map *smap; const fd_state_machine *fd_sm; std::unique_ptr sm_ctxt; if (!get_fd_state (ctxt, &smap, &fd_sm, NULL, &sm_ctxt)) return true; const extrinsic_state *ext_state = ctxt->get_ext_state (); if (!ext_state) return true; return fd_sm->on_socket (cd, m_success, sm_ctxt.get (), *ext_state); } }; bool matches_call_types_p (const call_details &cd) const final override { return cd.num_args () == 3; } void impl_call_post (const call_details &cd) const final override { if (cd.get_ctxt ()) { cd.get_ctxt ()->bifurcate (make_unique (cd, false)); cd.get_ctxt ()->bifurcate (make_unique (cd, true)); cd.get_ctxt ()->terminate_path (); } } }; /* Handle calls to "bind". See e.g. https://man7.org/linux/man-pages/man3/bind.3p.html */ class kf_bind : public known_function { public: class outcome_of_bind : public succeed_or_fail_call_info { public: outcome_of_bind (const call_details &cd, bool success) : succeed_or_fail_call_info (cd, success) {} bool update_model (region_model *model, const exploded_edge *, region_model_context *ctxt) const final override { const call_details cd (get_call_details (model, ctxt)); sm_state_map *smap; const fd_state_machine *fd_sm; std::unique_ptr sm_ctxt; if (!get_fd_state (ctxt, &smap, &fd_sm, NULL, &sm_ctxt)) return true; const extrinsic_state *ext_state = ctxt->get_ext_state (); if (!ext_state) return true; return fd_sm->on_bind (cd, m_success, sm_ctxt.get (), *ext_state); } }; bool matches_call_types_p (const call_details &cd) const final override { return (cd.num_args () == 3 && cd.arg_is_pointer_p (1)); } void impl_call_post (const call_details &cd) const final override { if (cd.get_ctxt ()) { cd.get_ctxt ()->bifurcate (make_unique (cd, false)); cd.get_ctxt ()->bifurcate (make_unique (cd, true)); cd.get_ctxt ()->terminate_path (); } } }; /* Handle calls to "listen". See e.g. https://man7.org/linux/man-pages/man3/listen.3p.html */ class kf_listen : public known_function { class outcome_of_listen : public succeed_or_fail_call_info { public: outcome_of_listen (const call_details &cd, bool success) : succeed_or_fail_call_info (cd, success) {} bool update_model (region_model *model, const exploded_edge *, region_model_context *ctxt) const final override { const call_details cd (get_call_details (model, ctxt)); sm_state_map *smap; const fd_state_machine *fd_sm; std::unique_ptr sm_ctxt; if (!get_fd_state (ctxt, &smap, &fd_sm, NULL, &sm_ctxt)) return true; const extrinsic_state *ext_state = ctxt->get_ext_state (); if (!ext_state) return true; return fd_sm->on_listen (cd, m_success, sm_ctxt.get (), *ext_state); } }; bool matches_call_types_p (const call_details &cd) const final override { return cd.num_args () == 2; } void impl_call_post (const call_details &cd) const final override { if (cd.get_ctxt ()) { cd.get_ctxt ()->bifurcate (make_unique (cd, false)); cd.get_ctxt ()->bifurcate (make_unique (cd, true)); cd.get_ctxt ()->terminate_path (); } } }; /* Handle calls to "accept". See e.g. https://man7.org/linux/man-pages/man3/accept.3p.html */ class kf_accept : public known_function { class outcome_of_accept : public succeed_or_fail_call_info { public: outcome_of_accept (const call_details &cd, bool success) : succeed_or_fail_call_info (cd, success) {} bool update_model (region_model *model, const exploded_edge *, region_model_context *ctxt) const final override { const call_details cd (get_call_details (model, ctxt)); sm_state_map *smap; const fd_state_machine *fd_sm; std::unique_ptr sm_ctxt; if (!get_fd_state (ctxt, &smap, &fd_sm, NULL, &sm_ctxt)) return true; const extrinsic_state *ext_state = ctxt->get_ext_state (); if (!ext_state) return true; return fd_sm->on_accept (cd, m_success, sm_ctxt.get (), *ext_state); } }; bool matches_call_types_p (const call_details &cd) const final override { return (cd.num_args () == 3 && cd.arg_is_pointer_p (1) && cd.arg_is_pointer_p (2)); } void impl_call_post (const call_details &cd) const final override { if (cd.get_ctxt ()) { cd.get_ctxt ()->bifurcate (make_unique (cd, false)); cd.get_ctxt ()->bifurcate (make_unique (cd, true)); cd.get_ctxt ()->terminate_path (); } } }; /* Handle calls to "connect". See e.g. https://man7.org/linux/man-pages/man3/connect.3p.html */ class kf_connect : public known_function { public: class outcome_of_connect : public succeed_or_fail_call_info { public: outcome_of_connect (const call_details &cd, bool success) : succeed_or_fail_call_info (cd, success) {} bool update_model (region_model *model, const exploded_edge *, region_model_context *ctxt) const final override { const call_details cd (get_call_details (model, ctxt)); sm_state_map *smap; const fd_state_machine *fd_sm; std::unique_ptr sm_ctxt; if (!get_fd_state (ctxt, &smap, &fd_sm, NULL, &sm_ctxt)) return true; const extrinsic_state *ext_state = ctxt->get_ext_state (); if (!ext_state) return true; return fd_sm->on_connect (cd, m_success, sm_ctxt.get (), *ext_state); } }; bool matches_call_types_p (const call_details &cd) const final override { return (cd.num_args () == 3 && cd.arg_is_pointer_p (1)); } void impl_call_post (const call_details &cd) const final override { if (cd.get_ctxt ()) { cd.get_ctxt ()->bifurcate (make_unique (cd, false)); cd.get_ctxt ()->bifurcate (make_unique (cd, true)); cd.get_ctxt ()->terminate_path (); } } }; /* Handler for "isatty"". See e.g. https://man7.org/linux/man-pages/man3/isatty.3.html */ class kf_isatty : public known_function { class outcome_of_isatty : public succeed_or_fail_call_info { public: outcome_of_isatty (const call_details &cd, bool success) : succeed_or_fail_call_info (cd, success) {} bool update_model (region_model *model, const exploded_edge *, region_model_context *ctxt) const final override { const call_details cd (get_call_details (model, ctxt)); if (m_success) { /* Return 1. */ model->update_for_int_cst_return (cd, 1, true); } else { /* Return 0; set errno. */ model->update_for_int_cst_return (cd, 0, true); model->set_errno (cd); } return feasible_p (cd, ctxt); } private: bool feasible_p (const call_details &cd, region_model_context *ctxt) const { if (m_success) { /* Can't be "success" on a closed/invalid fd. */ sm_state_map *smap; const fd_state_machine *fd_sm; std::unique_ptr sm_ctxt; if (!get_fd_state (ctxt, &smap, &fd_sm, NULL, &sm_ctxt)) return true; const extrinsic_state *ext_state = ctxt->get_ext_state (); if (!ext_state) return true; const svalue *fd_sval = cd.get_arg_svalue (0); state_machine::state_t old_state = sm_ctxt->get_state (cd.get_call_stmt (), fd_sval); if (fd_sm->is_closed_fd_p (old_state) || old_state == fd_sm->m_invalid) return false; } return true; } }; // class outcome_of_isatty public: bool matches_call_types_p (const call_details &cd) const final override { return cd.num_args () == 1; } void impl_call_post (const call_details &cd) const final override { if (cd.get_ctxt ()) { cd.get_ctxt ()->bifurcate (make_unique (cd, false)); cd.get_ctxt ()->bifurcate (make_unique (cd, true)); cd.get_ctxt ()->terminate_path (); } } }; /* Handler for calls to "pipe" and "pipe2". See e.g. https://www.man7.org/linux/man-pages/man2/pipe.2.html */ class kf_pipe : public known_function { class failure : public failed_call_info { public: failure (const call_details &cd) : failed_call_info (cd) {} bool update_model (region_model *model, const exploded_edge *, region_model_context *ctxt) const final override { /* Return -1; everything else is unchanged. */ const call_details cd (get_call_details (model, ctxt)); model->update_for_int_cst_return (cd, -1, true); return true; } }; class success : public success_call_info { public: success (const call_details &cd) : success_call_info (cd) {} bool update_model (region_model *model, const exploded_edge *, region_model_context *ctxt) const final override { const call_details cd (get_call_details (model, ctxt)); /* Return 0. */ model->update_for_zero_return (cd, true); /* Update fd array. */ region_model_manager *mgr = cd.get_manager (); tree arr_tree = cd.get_arg_tree (0); const svalue *arr_sval = cd.get_arg_svalue (0); for (int idx = 0; idx < 2; idx++) { const region *arr_reg = model->deref_rvalue (arr_sval, arr_tree, cd.get_ctxt ()); const svalue *idx_sval = mgr->get_or_create_int_cst (integer_type_node, idx); const region *element_reg = mgr->get_element_region (arr_reg, integer_type_node, idx_sval); conjured_purge p (model, cd.get_ctxt ()); const svalue *fd_sval = mgr->get_or_create_conjured_svalue (integer_type_node, cd.get_call_stmt (), element_reg, p); model->set_value (element_reg, fd_sval, cd.get_ctxt ()); model->mark_as_valid_fd (fd_sval, cd.get_ctxt ()); } return true; } }; public: kf_pipe (unsigned num_args) : m_num_args (num_args) { gcc_assert (num_args > 0); } bool matches_call_types_p (const call_details &cd) const final override { return (cd.num_args () == m_num_args && cd.arg_is_pointer_p (0)); } void impl_call_post (const call_details &cd) const final override { if (cd.get_ctxt ()) { cd.get_ctxt ()->bifurcate (make_unique (cd)); cd.get_ctxt ()->bifurcate (make_unique (cd)); cd.get_ctxt ()->terminate_path (); } } private: unsigned m_num_args; }; /* Handler for "read". ssize_t read(int fildes, void *buf, size_t nbyte); See e.g. https://man7.org/linux/man-pages/man2/read.2.html */ class kf_read : public known_function { public: bool matches_call_types_p (const call_details &cd) const final override { return (cd.num_args () == 3 && cd.arg_is_pointer_p (1) && cd.arg_is_size_p (2)); } /* For now, assume that any call to "read" fully clobbers the buffer passed in. This isn't quite correct (e.g. errors, partial reads; see PR analyzer/108689), but at least stops us falsely complaining about the buffer being uninitialized. */ void impl_call_pre (const call_details &cd) const final override { region_model *model = cd.get_model (); const svalue *ptr_sval = cd.get_arg_svalue (1); if (const region *reg = ptr_sval->maybe_get_region ()) { const region *base_reg = reg->get_base_region (); const svalue *new_sval = cd.get_or_create_conjured_svalue (base_reg); model->set_value (base_reg, new_sval, cd.get_ctxt ()); } } }; /* Populate KFM with instances of known functions relating to file descriptors. */ void register_known_fd_functions (known_function_manager &kfm) { kfm.add ("accept", make_unique ()); kfm.add ("bind", make_unique ()); kfm.add ("connect", make_unique ()); kfm.add ("isatty", make_unique ()); kfm.add ("listen", make_unique ()); kfm.add ("pipe", make_unique (1)); kfm.add ("pipe2", make_unique (2)); kfm.add ("read", make_unique ()); kfm.add ("socket", make_unique ()); } } // namespace ana #endif // ENABLE_ANALYZER