c: introduce ubsan checking for assigment of VM types 4/4 Support instrumentation of functions called via pointers. To do so, record the declaration with the parameter types, so that it can be retrieved later. gcc/c: c-decl.cc (get_parm_info): Record function declaration for arguments. c-type.cc (process_vm_constraints): Instrument functions called via pointers. gcc/testsuide/gcc.dg: * ubsan/vm-bounds-2.c: Add warning. * ubsan/vm-bounds-5.c: New test. diff --git a/gcc/c/c-decl.cc b/gcc/c/c-decl.cc index 1af51c4acfc..c33adf7e5fe 100644 --- a/gcc/c/c-decl.cc +++ b/gcc/c/c-decl.cc @@ -8410,6 +8410,9 @@ get_parm_info (bool ellipsis, tree expr) declared types. The back end may override this later. */ DECL_ARG_TYPE (decl) = type; types = tree_cons (0, type, types); + + /* Record the decl for use of UBSan bounds checking. */ + TREE_PURPOSE (types) = decl; } break; diff --git a/gcc/c/c-typeck.cc b/gcc/c/c-typeck.cc index aeddac315fc..43e7b96a55f 100644 --- a/gcc/c/c-typeck.cc +++ b/gcc/c/c-typeck.cc @@ -3601,9 +3601,20 @@ process_vm_constraints (location_t location, } else { - /* Functions called via pointers are not yet supported. */ - return void_node; + while (FUNCTION_TYPE != TREE_CODE (function)) + function = TREE_TYPE (function); + + args = TREE_PURPOSE (TYPE_ARG_TYPES (function)); + + if (!args) + { + /* FIXME: this can happen when forming composite types for the + conditional operator. */ + warning_at (location, 0, "Function call not instrumented."); + return void_node; + } } + gcc_assert (PARM_DECL == TREE_CODE (args)); } FOR_EACH_VEC_SAFE_ELT (instr_vec, i, d) diff --git a/gcc/testsuite/gcc.dg/ubsan/vm-bounds-2.c b/gcc/testsuite/gcc.dg/ubsan/vm-bounds-2.c index 22f06231eaa..093cbddd2ea 100644 --- a/gcc/testsuite/gcc.dg/ubsan/vm-bounds-2.c +++ b/gcc/testsuite/gcc.dg/ubsan/vm-bounds-2.c @@ -31,7 +31,7 @@ void f(void) int u = 3; int v = 4; char a[u][v]; - (1 ? f1 : f2)(u, v, a); + (1 ? f1 : f2)(u, v, a); /* { dg-warning "Function call not instrumented." } */ } /* size expression in parameter */ diff --git a/gcc/testsuite/gcc.dg/ubsan/vm-bounds-5.c b/gcc/testsuite/gcc.dg/ubsan/vm-bounds-5.c new file mode 100644 index 00000000000..1a251e39deb --- /dev/null +++ b/gcc/testsuite/gcc.dg/ubsan/vm-bounds-5.c @@ -0,0 +1,72 @@ +/* { dg-do run } */ +/* { dg-options "-fsanitize=vla-bound" } */ + + +void foo1(void (*p)(int n, char (*a)[n])) +{ + char A0[3]; + (*p)(3, &A0); + (*p)(4, &A0); /* */ + /* { dg-output "bound 4 of type 'char \\\[\\\*\\\]' does not match bound 3 of type 'char \\\[3\\\]'\[^\n\r]*(\n|\r\n|\r)" } */ +} + +void b0(int n, char (*a)[n]) { } + + +int n; + +void foo2(void (*p)(int n, char (*a)[n])) +{ + n = 4; + char A0[3]; + (*p)(3, &A0); + (*p)(4, &A0); + /* { dg-output "\[^\n\r]*bound 4 of type 'char \\\[\\\*\\\]' does not match bound 3 of type 'char \\\[3\\\]'\[^\n\r]*(\n|\r\n|\r)" } */ +} + +void foo3(void (*p)(int n0, char (*a)[n])) +{ + n = 4; + char A0[3]; + (*p)(3, &A0); /* */ + /* { dg-output "\[^\n\r]*bound 4 of type 'char \\\[\\\*\\\]' does not match bound 3 of type 'char \\\[3\\\]'\[^\n\r]*(\n|\r\n|\r)" } */ + (*p)(4, &A0); /* */ + /* { dg-output "\[^\n\r]*bound 4 of type 'char \\\[\\\*\\\]' does not match bound 3 of type 'char \\\[3\\\]'\[^\n\r]*(\n|\r\n|\r)" } */ +} + +void foo4(void (*p)(int n, char (*a)[n])) +{ + n = 3; + char A0[3]; + (*p)(3, &A0); + (*p)(4, &A0); /* */ + /* { dg-output "\[^\n\r]*bound 4 of type 'char \\\[\\\*\\\]' does not match bound 3 of type 'char \\\[3\\\]'" } */ +} + + +void foo5(void (*p)(int n0, char (*a)[n])) +{ + n = 3; + char A0[3]; + (*p)(3, &A0); + (*p)(4, &A0); +} + + +void b1(int n0, char (*a)[n]) { } + + + +int main() +{ + foo1(&b0); + + foo2(&b1); + foo3(&b1); // we should diagnose mismatch and run-time discrepancies + + foo4(&b1); + foo5(&b1); // we should diagnose mismatch and run-time discrepancies +} + + +
Re: [C PATCH 4/4] introduce ubsan checking for assigment of VM types 4/4
Martin Uecker via Gcc-patches Mon, 29 May 2023 03:23:07 -0700
- [C PATCH 1/4] introduce ubsan checking for ... Martin Uecker via Gcc-patches
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- Re: [C PATCH 3/4] introduce ubsan ... Joseph Myers
- Re: [C PATCH 3/4] introduce ub... Martin Uecker via Gcc-patches