From c253525edd51a027b7db30e077a6643a78544b0c Mon Sep 17 00:00:00 2001 From: Marek Polacek Date: Tue, 5 Sep 2017 15:55:04 +0000 Subject: [PATCH] re PR sanitizer/82072 (sanitizer does not detect an overflow from LLONG_MIN) PR sanitizer/82072 * convert.c (convert_to_integer_1) : Move the ubsan check earlier. * c-c++-common/ubsan/pr82072-2.c: New test. From-SVN: r251717 --- gcc/ChangeLog | 6 ++++++ gcc/convert.c | 13 +++++++------ gcc/testsuite/ChangeLog | 5 +++++ gcc/testsuite/c-c++-common/ubsan/pr82072-2.c | 15 +++++++++++++++ 4 files changed, 33 insertions(+), 6 deletions(-) create mode 100644 gcc/testsuite/c-c++-common/ubsan/pr82072-2.c diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 58d162972ba..2f6983ffa9e 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +2017-09-05 Marek Polacek + + PR sanitizer/82072 + * convert.c (convert_to_integer_1) : Move the ubsan + check earlier. + 2017-09-05 Wilco Dijkstra * explow.c (get_dynamic_stack_size): Improve dynamic alignment. diff --git a/gcc/convert.c b/gcc/convert.c index 139d790fd98..bfe18fb0f43 100644 --- a/gcc/convert.c +++ b/gcc/convert.c @@ -886,6 +886,12 @@ convert_to_integer_1 (tree type, tree expr, bool dofold) break; case NEGATE_EXPR: + /* Using unsigned arithmetic for signed types may hide overflow + bugs. */ + if (!TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (expr, 0))) + && sanitize_flags_p (SANITIZE_SI_OVERFLOW)) + break; + /* Fall through. */ case BIT_NOT_EXPR: /* This is not correct for ABS_EXPR, since we must test the sign before truncation. */ @@ -902,12 +908,7 @@ convert_to_integer_1 (tree type, tree expr, bool dofold) TYPE_UNSIGNED (typex)); if (!TYPE_UNSIGNED (typex)) - { - /* Using unsigned arithmetic may hide overflow bugs. */ - if (sanitize_flags_p (SANITIZE_SI_OVERFLOW)) - break; - typex = unsigned_type_for (typex); - } + typex = unsigned_type_for (typex); return convert (type, fold_build1 (ex_form, typex, convert (typex, diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 690bc5bacce..623e41417f9 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2017-09-05 Marek Polacek + + PR sanitizer/82072 + * c-c++-common/ubsan/pr82072-2.c: New test. + 2017-09-05 Paolo Carlini PR c++/81942 diff --git a/gcc/testsuite/c-c++-common/ubsan/pr82072-2.c b/gcc/testsuite/c-c++-common/ubsan/pr82072-2.c new file mode 100644 index 00000000000..ff8aca4d942 --- /dev/null +++ b/gcc/testsuite/c-c++-common/ubsan/pr82072-2.c @@ -0,0 +1,15 @@ +/* PR sanitizer/82072 */ +/* { dg-do run } */ +/* { dg-options "-fsanitize=signed-integer-overflow" } */ + +int +main () +{ + long long int l = -__LONG_LONG_MAX__ - 1; + unsigned int u; + u = -l; + asm volatile ("" : "+r" (u)); + return 0; +} + +/* { dg-output "negation of -9223372036854775808 cannot be represented in type 'long long int'\[^\n\r]*; cast to an unsigned type to negate this value to itself" } */ -- 2.30.2