Re: [PATCH v8 4/5] Use the .ACCESS_WITH_SIZE in bound sanitizer.
Sid, Thanks a lot for the review. > On Apr 10, 2024, at 17:46, Siddhesh Poyarekar wrote: > > On 2024-03-29 12:07, Qing Zhao wrote: >> gcc/c-family/ChangeLog: >> * c-ubsan.cc (get_bound_from_access_with_size): New function. >> (ubsan_instrument_bounds): Handle call to .ACCESS_WITH_SIZE. >> gcc/testsuite/ChangeLog: >> * gcc.dg/ubsan/flex-array-counted-by-bounds-2.c: New test. >> * gcc.dg/ubsan/flex-array-counted-by-bounds-3.c: New test. >> * gcc.dg/ubsan/flex-array-counted-by-bounds-4.c: New test. >> * gcc.dg/ubsan/flex-array-counted-by-bounds.c: New test. >> --- > > This version looks fine to me for stage 1, but I'm not a maintainer so you'll > need an ack from one to commit. This patch is purely C FE changes. Joseph already approved it. thanks. Qing > > Thanks, > Sid > >> gcc/c-family/c-ubsan.cc | 42 + >> .../ubsan/flex-array-counted-by-bounds-2.c| 45 ++ >> .../ubsan/flex-array-counted-by-bounds-3.c| 34 ++ >> .../ubsan/flex-array-counted-by-bounds-4.c| 34 ++ >> .../ubsan/flex-array-counted-by-bounds.c | 46 +++ >> 5 files changed, 201 insertions(+) >> create mode 100644 >> gcc/testsuite/gcc.dg/ubsan/flex-array-counted-by-bounds-2.c >> create mode 100644 >> gcc/testsuite/gcc.dg/ubsan/flex-array-counted-by-bounds-3.c >> create mode 100644 >> gcc/testsuite/gcc.dg/ubsan/flex-array-counted-by-bounds-4.c >> create mode 100644 gcc/testsuite/gcc.dg/ubsan/flex-array-counted-by-bounds.c >> diff --git a/gcc/c-family/c-ubsan.cc b/gcc/c-family/c-ubsan.cc >> index 940982819ddf..7cd3c6aa5b88 100644 >> --- a/gcc/c-family/c-ubsan.cc >> +++ b/gcc/c-family/c-ubsan.cc >> @@ -376,6 +376,40 @@ ubsan_instrument_return (location_t loc) >>return build_call_expr_loc (loc, t, 1, build_fold_addr_expr_loc (loc, >> data)); >> } >> +/* Get the tree that represented the number of counted_by, i.e, the maximum >> + number of the elements of the object that the call to .ACCESS_WITH_SIZE >> + points to, this number will be the bound of the corresponding array. */ >> +static tree >> +get_bound_from_access_with_size (tree call) >> +{ >> + if (!is_access_with_size_p (call)) >> +return NULL_TREE; >> + >> + tree ref_to_size = CALL_EXPR_ARG (call, 1); >> + unsigned int class_of_size = TREE_INT_CST_LOW (CALL_EXPR_ARG (call, 2)); >> + tree type = TREE_TYPE (CALL_EXPR_ARG (call, 3)); >> + tree size = fold_build2 (MEM_REF, type, unshare_expr (ref_to_size), >> + build_int_cst (ptr_type_node, 0)); >> + /* If size is negative value, treat it as zero. */ >> + if (!TYPE_UNSIGNED (type)) >> + { >> +tree cond = fold_build2 (LT_EXPR, boolean_type_node, >> + unshare_expr (size), build_zero_cst (type)); >> +size = fold_build3 (COND_EXPR, type, cond, >> +build_zero_cst (type), size); >> + } >> + >> + /* Only when class_of_size is 1, i.e, the number of the elements of >> + the object type, return the size. */ >> + if (class_of_size != 1) >> +return NULL_TREE; >> + else >> +size = fold_convert (sizetype, size); >> + >> + return size; >> +} >> + >> + >> /* Instrument array bounds for ARRAY_REFs. We create special builtin, >> that gets expanded in the sanopt pass, and make an array dimension >> of it. ARRAY is the array, *INDEX is an index to the array. >> @@ -401,6 +435,14 @@ ubsan_instrument_bounds (location_t loc, tree array, >> tree *index, >>&& COMPLETE_TYPE_P (type) >>&& integer_zerop (TYPE_SIZE (type))) >> bound = build_int_cst (TREE_TYPE (TYPE_MIN_VALUE (domain)), -1); >> + else if (INDIRECT_REF_P (array) >> + && is_access_with_size_p ((TREE_OPERAND (array, 0 >> +{ >> + bound = get_bound_from_access_with_size ((TREE_OPERAND (array, 0))); >> + bound = fold_build2 (MINUS_EXPR, TREE_TYPE (bound), >> + bound, >> + build_int_cst (TREE_TYPE (bound), 1)); >> +} >>else >> return NULL_TREE; >> } >> diff --git a/gcc/testsuite/gcc.dg/ubsan/flex-array-counted-by-bounds-2.c >> b/gcc/testsuite/gcc.dg/ubsan/flex-array-counted-by-bounds-2.c >> new file mode 100644 >> index ..b503320628d2 >> --- /dev/null >> +++ b/gcc/testsuite/gcc.dg/ubsan/flex-array-counted-by-bounds-2.c >> @@ -0,0 +1,45 @@ >> +/* Test the attribute counted_by and its usage in >> + bounds sanitizer combined with VLA. */ >> +/* { dg-do run } */ >> +/* { dg-options "-fsanitize=bounds" } */ >> +/* { dg-output "index 11 out of bounds for type 'int >> \\\[\\\*\\\]\\\[\\\*\\\]'\[^\n\r]*(\n|\r\n|\r)" } */ >> +/* { dg-output "\[^\n\r]*index 20 out of bounds for type 'int >> \\\[\\\*\\\]\\\[\\\*\\\]\\\[\\\*\\\]'\[^\n\r]*(\n|\r\n|\r)" } */ >> +/* { dg-output "\[^\n\r]*index 11 out of bounds for type 'int >> \\\[\\\*\\\]\\\[\\\*\\\]'\[^\n\r]*(\n|\r\n|\r)" } */ >> +/* { dg-output "\[^\
Re: [PATCH v8 4/5] Use the .ACCESS_WITH_SIZE in bound sanitizer.
On 2024-03-29 12:07, Qing Zhao wrote: gcc/c-family/ChangeLog: * c-ubsan.cc (get_bound_from_access_with_size): New function. (ubsan_instrument_bounds): Handle call to .ACCESS_WITH_SIZE. gcc/testsuite/ChangeLog: * gcc.dg/ubsan/flex-array-counted-by-bounds-2.c: New test. * gcc.dg/ubsan/flex-array-counted-by-bounds-3.c: New test. * gcc.dg/ubsan/flex-array-counted-by-bounds-4.c: New test. * gcc.dg/ubsan/flex-array-counted-by-bounds.c: New test. --- This version looks fine to me for stage 1, but I'm not a maintainer so you'll need an ack from one to commit. Thanks, Sid gcc/c-family/c-ubsan.cc | 42 + .../ubsan/flex-array-counted-by-bounds-2.c| 45 ++ .../ubsan/flex-array-counted-by-bounds-3.c| 34 ++ .../ubsan/flex-array-counted-by-bounds-4.c| 34 ++ .../ubsan/flex-array-counted-by-bounds.c | 46 +++ 5 files changed, 201 insertions(+) create mode 100644 gcc/testsuite/gcc.dg/ubsan/flex-array-counted-by-bounds-2.c create mode 100644 gcc/testsuite/gcc.dg/ubsan/flex-array-counted-by-bounds-3.c create mode 100644 gcc/testsuite/gcc.dg/ubsan/flex-array-counted-by-bounds-4.c create mode 100644 gcc/testsuite/gcc.dg/ubsan/flex-array-counted-by-bounds.c diff --git a/gcc/c-family/c-ubsan.cc b/gcc/c-family/c-ubsan.cc index 940982819ddf..7cd3c6aa5b88 100644 --- a/gcc/c-family/c-ubsan.cc +++ b/gcc/c-family/c-ubsan.cc @@ -376,6 +376,40 @@ ubsan_instrument_return (location_t loc) return build_call_expr_loc (loc, t, 1, build_fold_addr_expr_loc (loc, data)); } +/* Get the tree that represented the number of counted_by, i.e, the maximum + number of the elements of the object that the call to .ACCESS_WITH_SIZE + points to, this number will be the bound of the corresponding array. */ +static tree +get_bound_from_access_with_size (tree call) +{ + if (!is_access_with_size_p (call)) +return NULL_TREE; + + tree ref_to_size = CALL_EXPR_ARG (call, 1); + unsigned int class_of_size = TREE_INT_CST_LOW (CALL_EXPR_ARG (call, 2)); + tree type = TREE_TYPE (CALL_EXPR_ARG (call, 3)); + tree size = fold_build2 (MEM_REF, type, unshare_expr (ref_to_size), + build_int_cst (ptr_type_node, 0)); + /* If size is negative value, treat it as zero. */ + if (!TYPE_UNSIGNED (type)) + { +tree cond = fold_build2 (LT_EXPR, boolean_type_node, +unshare_expr (size), build_zero_cst (type)); +size = fold_build3 (COND_EXPR, type, cond, + build_zero_cst (type), size); + } + + /* Only when class_of_size is 1, i.e, the number of the elements of + the object type, return the size. */ + if (class_of_size != 1) +return NULL_TREE; + else +size = fold_convert (sizetype, size); + + return size; +} + + /* Instrument array bounds for ARRAY_REFs. We create special builtin, that gets expanded in the sanopt pass, and make an array dimension of it. ARRAY is the array, *INDEX is an index to the array. @@ -401,6 +435,14 @@ ubsan_instrument_bounds (location_t loc, tree array, tree *index, && COMPLETE_TYPE_P (type) && integer_zerop (TYPE_SIZE (type))) bound = build_int_cst (TREE_TYPE (TYPE_MIN_VALUE (domain)), -1); + else if (INDIRECT_REF_P (array) + && is_access_with_size_p ((TREE_OPERAND (array, 0 + { + bound = get_bound_from_access_with_size ((TREE_OPERAND (array, 0))); + bound = fold_build2 (MINUS_EXPR, TREE_TYPE (bound), + bound, + build_int_cst (TREE_TYPE (bound), 1)); + } else return NULL_TREE; } diff --git a/gcc/testsuite/gcc.dg/ubsan/flex-array-counted-by-bounds-2.c b/gcc/testsuite/gcc.dg/ubsan/flex-array-counted-by-bounds-2.c new file mode 100644 index ..b503320628d2 --- /dev/null +++ b/gcc/testsuite/gcc.dg/ubsan/flex-array-counted-by-bounds-2.c @@ -0,0 +1,45 @@ +/* Test the attribute counted_by and its usage in + bounds sanitizer combined with VLA. */ +/* { dg-do run } */ +/* { dg-options "-fsanitize=bounds" } */ +/* { dg-output "index 11 out of bounds for type 'int \\\[\\\*\\\]\\\[\\\*\\\]'\[^\n\r]*(\n|\r\n|\r)" } */ +/* { dg-output "\[^\n\r]*index 20 out of bounds for type 'int \\\[\\\*\\\]\\\[\\\*\\\]\\\[\\\*\\\]'\[^\n\r]*(\n|\r\n|\r)" } */ +/* { dg-output "\[^\n\r]*index 11 out of bounds for type 'int \\\[\\\*\\\]\\\[\\\*\\\]'\[^\n\r]*(\n|\r\n|\r)" } */ +/* { dg-output "\[^\n\r]*index 10 out of bounds for type 'int \\\[\\\*\\\]'\[^\n\r]*(\n|\r\n|\r)" } */ + + +#include + +void __attribute__((__noinline__)) setup_and_test_vla (int n, int m) +{ + struct foo { + int n; + int p[][n] __attribute__((counted_by(n))); + } *f; + + f = (struct foo *) malloc (sizeof(struct foo) + m*sizeof(int[n])); + f->n = m; + f->p[m][n-1]=1; + return; +} + +void __attribute
Re: [PATCH v8 4/5] Use the .ACCESS_WITH_SIZE in bound sanitizer.
The C front-end changes in this patch are OK for GCC 15. -- Joseph S. Myers josmy...@redhat.com