From: benjamin priour <priour...@gmail.com> Resend with proper subject line ...
Hi, Below is the fix to regression bug https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110198 Was bootstrapped and regtested successfully on x86_64-linux-gnu Considering mishap from last patch, I'd would appreciate if you could also regtest it, to be sure :) Thanks, Benjamin. g++.dg/analyzer/pr100244.C was failing after a patch of PR109439. The reason was a spurious preemptive return of get_store_value upon out-of-bounds read that was preventing further checks. Now instead, a boolean value check_poisoned goes to false when a OOB is detected, and is later on given to get_or_create_initial_value. gcc/analyzer/ChangeLog: * region-model-manager.cc (region_model_manager::get_or_create_initial_value): Take an optional boolean value to bypass poisoning checks * region-model-manager.h: Update declaration of the above function. * region-model.cc (region_model::get_store_value): No longer returns on OOB, but rather gives a boolean to get_or_create_initial_value. (region_model::check_region_access): Update docstring. (region_model::check_region_for_write): Update docstring. Signed-off-by: benjamin priour <priour...@gmail.com> --- gcc/analyzer/region-model-manager.cc | 5 +++-- gcc/analyzer/region-model-manager.h | 3 ++- gcc/analyzer/region-model.cc | 15 ++++++++------- 3 files changed, 13 insertions(+), 10 deletions(-) diff --git a/gcc/analyzer/region-model-manager.cc b/gcc/analyzer/region-model-manager.cc index 1453acf7bc9..4f11ef4bd29 100644 --- a/gcc/analyzer/region-model-manager.cc +++ b/gcc/analyzer/region-model-manager.cc @@ -293,9 +293,10 @@ region_model_manager::create_unique_svalue (tree type) necessary. */ const svalue * -region_model_manager::get_or_create_initial_value (const region *reg) +region_model_manager::get_or_create_initial_value (const region *reg, + bool check_poisoned) { - if (!reg->can_have_initial_svalue_p ()) + if (!reg->can_have_initial_svalue_p () && check_poisoned) return get_or_create_poisoned_svalue (POISON_KIND_UNINIT, reg->get_type ()); diff --git a/gcc/analyzer/region-model-manager.h b/gcc/analyzer/region-model-manager.h index 3340c3ebd1e..ff5333bf07c 100644 --- a/gcc/analyzer/region-model-manager.h +++ b/gcc/analyzer/region-model-manager.h @@ -49,7 +49,8 @@ public: tree type); const svalue *get_or_create_poisoned_svalue (enum poison_kind kind, tree type); - const svalue *get_or_create_initial_value (const region *reg); + const svalue *get_or_create_initial_value (const region *reg, + bool check_poisoned = true); const svalue *get_ptr_svalue (tree ptr_type, const region *pointee); const svalue *get_or_create_unaryop (tree type, enum tree_code op, const svalue *arg); diff --git a/gcc/analyzer/region-model.cc b/gcc/analyzer/region-model.cc index 6bc60f89f3d..187013a37cc 100644 --- a/gcc/analyzer/region-model.cc +++ b/gcc/analyzer/region-model.cc @@ -2373,8 +2373,9 @@ region_model::get_store_value (const region *reg, if (reg->empty_p ()) return m_mgr->get_or_create_unknown_svalue (reg->get_type ()); + bool check_poisoned = true; if (check_region_for_read (reg, ctxt)) - return m_mgr->get_or_create_unknown_svalue(reg->get_type()); + check_poisoned = false; /* Special-case: handle var_decls in the constant pool. */ if (const decl_region *decl_reg = reg->dyn_cast_decl_region ()) @@ -2427,7 +2428,7 @@ region_model::get_store_value (const region *reg, == RK_GLOBALS) return get_initial_value_for_global (reg); - return m_mgr->get_or_create_initial_value (reg); + return m_mgr->get_or_create_initial_value (reg, check_poisoned); } /* Return false if REG does not exist, true if it may do. @@ -2790,7 +2791,7 @@ region_model::get_string_size (const region *reg) const /* If CTXT is non-NULL, use it to warn about any problems accessing REG, using DIR to determine if this access is a read or write. - Return TRUE if an UNKNOWN_SVALUE needs be created. + Return TRUE if an OOB access was detected. If SVAL_HINT is non-NULL, use it as a hint in diagnostics about the value that would be written to REG. */ @@ -2804,10 +2805,10 @@ region_model::check_region_access (const region *reg, if (!ctxt) return false; - bool need_unknown_sval = false; + bool oob_access_detected = false; check_region_for_taint (reg, dir, ctxt); if (!check_region_bounds (reg, dir, sval_hint, ctxt)) - need_unknown_sval = true; + oob_access_detected = true; switch (dir) { @@ -2820,7 +2821,7 @@ region_model::check_region_access (const region *reg, check_for_writable_region (reg, ctxt); break; } - return need_unknown_sval; + return oob_access_detected; } /* If CTXT is non-NULL, use it to warn about any problems writing to REG. */ @@ -2834,7 +2835,7 @@ region_model::check_region_for_write (const region *dest_reg, } /* If CTXT is non-NULL, use it to warn about any problems reading from REG. - Returns TRUE if an unknown svalue needs be created. */ + Returns TRUE if an OOB read was detected. */ bool region_model::check_region_for_read (const region *src_reg, -- 2.34.1