[Bug ada/99624] Address sanitizer detects heap-buffer-overflow in namet.adb
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99624 Vittorio Zecca changed: What|Removed |Added Status|SUSPENDED |RESOLVED Resolution|--- |INVALID --- Comment #9 from Vittorio Zecca --- I believe this is invalid issue, the real issue is that gcc miscompiles the Ada compiler with the option -fsanitize=address. I am opening a new issue with the GNAT BUG DETECTED message.
[Bug ada/99624] Address sanitizer detects heap-buffer-overflow in namet.adb
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99624 --- Comment #8 from Vittorio Zecca --- Address sanitizer of Version 11.0.1 current trunk miscompiles the Ada compiler, maybe a previous version would work. Undefined behavior sanitizer works. I am now trying to build the Ada compiler with gcc 9.1.0.
[Bug ada/99624] Address sanitizer detects heap-buffer-overflow in namet.adb
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99624 --- Comment #7 from Eric Botcazou --- > If I compile the build with -gnata, thereby arming the pragma assert, > the build fails. Then this proves that the sanitizer does not work since the assertion does not trigger in a regular build, so there is no need to dig deeper. > Did you try building Ada with address sanitation? No, I don't think so.
[Bug ada/99624] Address sanitizer detects heap-buffer-overflow in namet.adb
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99624 --- Comment #6 from Vittorio Zecca --- It is not that easy, unfortunately. If I compile the build with -gnata, thereby arming the pragma assert, the build fails. So I had to build without -gnata. Now trying to build Ada with gcc 9.1.0 Earlier versions do not work. Did you try building Ada with address sanitation?
[Bug ada/99624] Address sanitizer detects heap-buffer-overflow in namet.adb
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99624 --- Comment #5 from Eric Botcazou --- > I am very very rusty on Ada, what should I do to check that Id is good? Probably put back the original assert on line 155.
[Bug ada/99624] Address sanitizer detects heap-buffer-overflow in namet.adb
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99624 --- Comment #4 from Vittorio Zecca --- I added pragma Assert (Id in Name_Entries.Table'Range); at namet.adb:156, but then I get at compile time namet.adb:156:25: warning: condition can only be False if invalid values present and the build stops. I am very very rusty on Ada, what should I do to check that Id is good?
[Bug ada/99624] Address sanitizer detects heap-buffer-overflow in namet.adb
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99624 Eric Botcazou changed: What|Removed |Added Status|WAITING |SUSPENDED --- Comment #3 from Eric Botcazou --- > Yes, probably gcc -fsanitize=address is miscompiling the Ada compiler. > I had to take out the -gnata option to disable pragma assert that was > failing. OK, thanks for the confirmation. > So I do not know if this is a genuine compiler bug or it is due to > miscompilation. Most probably -fsanitize=address does not work correctly on Ada code. > The Ada compiler compiled with the undefined behavior sanitizer > compiles and works fine with a successful run of the testsuite. Interesting data point, thanks.
[Bug ada/99624] Address sanitizer detects heap-buffer-overflow in namet.adb
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99624 --- Comment #2 from Vittorio Zecca --- Yes, probably gcc -fsanitize=address is miscompiling the Ada compiler. I had to take out the -gnata option to disable pragma assert that was failing. So I do not know if this is a genuine compiler bug or it is due to miscompilation. The Ada compiler compiled with the undefined behavior sanitizer compiles and works fine with a successful run of the testsuite.
[Bug ada/99624] Address sanitizer detects heap-buffer-overflow in namet.adb
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99624 Eric Botcazou changed: What|Removed |Added Status|NEW |WAITING --- Comment #1 from Eric Botcazou --- > While building the ada compiler the address sanitizer detecst an > heap-buffer-overflow in namet.adb line 157: > > Index : constant Int := Name_Entries.Table (Id).Name_Chars_Index; > > because Id=-3 The table is declared like this though: package Name_Entries is new Table.Table ( Table_Component_Type => Name_Entry, Table_Index_Type => Valid_Name_Id'Base, Table_Low_Bound => First_Name_Id, Table_Initial=> Alloc.Names_Initial, Table_Increment => Alloc.Names_Increment, Table_Name => "Name_Entries"); with: First_Name_Id : constant Name_Id := Names_Low_Bound + 2; -- Subscript of first entry in names table subtype Valid_Name_Id is Name_Id range First_Name_Id .. Name_Id'Last; -- All but No_Name and Error_Name and: Names_Low_Bound : constant := -3; so Id = -3 is well within the allowed range (9997 0-based index). Are you sure that Id is not equal to Names_Low_Bound, which would be the -2 0-based index and, therefore, -32 bytes since the size of Name_Entry is 16? On the other hand, this would mean that: pragma Assert (Is_Valid_Name (Id)); would have triggered because the compiler is supposed to be configured with assertions enabled on the mainline, so I'm quite at a loss here. It looks like the address sanitizer is miscompiling the Ada compiler?
[Bug ada/99624] Address sanitizer detects heap-buffer-overflow in namet.adb
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99624 Martin Liška changed: What|Removed |Added Blocks||86656 CC||ebotcazou at gcc dot gnu.org, ||marxin at gcc dot gnu.org Ever confirmed|0 |1 Last reconfirmed||2021-03-17 Status|UNCONFIRMED |NEW Referenced Bugs: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86656 [Bug 86656] [meta-bug] Issues found with -fsanitize=address
