| Summary: | gcc miscompiles raid1.c from linux kernel | ||
|---|---|---|---|
| Product: | gcc | Reporter: | marcus |
| Component: | target | Assignee: | Jakub Jelinek <jakub> |
| Status: | RESOLVED FIXED | ||
| Severity: | normal | CC: | amodra, gcc-bugs, jakub, mmitchel |
| Priority: | P2 | Keywords: | wrong-code |
| Version: | 3.3 | ||
| Target Milestone: | 3.3.2 | ||
| Host: | powerpc64-linux | Target: | powerpc64-linux |
| Build: | powerpc-linux | Known to work: | |
| Known to fail: | Last reconfirmed: | 2003-06-22 13:12:19 | |
| Attachments: |
raid1 standalone testcase
test.gcc33.s test.gcc34.s |
||
|
Description
marcus
2003-06-04 08:17:27 UTC
Created attachment 4161 [details]
raid1 standalone testcase
compile with -O2
i forgot, compuile wizth -O2 to get the problem Hello, I have attached assembly generated by gcc 3.3 branch and mainline (20030603). Can you confirm whether these, when compiled, segfault? Thanks, Dara Created attachment 4163 [details]
test.gcc33.s
Created attachment 4164 [details]
test.gcc34.s
both do not crash anymore. i also single stepped the code and it appears to be no longer generating accesses with disk = -1 so i think this is good with 3.3 and 3.4. will this be added as a testcase? Alan, would you mind taking a look at this report? It looks rather as if the bug is fixed, but as Marcus suggests, perhaps the code in question could be used as a testcase. Thanks, Dara This should not be in waiting, it is fixed with 3.3 and on the mainline but it would be nice if someone came up with a testcase. Subject: Bug 11087 CVSROOT: /cvs/gcc Module name: gcc Changes by: jakub@gcc.gnu.org 2003-07-18 11:13:37 Modified files: gcc : ChangeLog loop.c gcc/testsuite : ChangeLog Added files: gcc/testsuite/gcc.c-torture/execute: 20030717-1.c Log message: PR target/11087 * loop.c (basic_induction_var): Check if convert_modes emitted any instructions. Remove them and return 0 if so. * gcc.c-torture/execute/20030717-1.c: New test. Patches: http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/ChangeLog.diff?cvsroot=gcc&r1=2.554&r2=2.555 http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/loop.c.diff?cvsroot=gcc&r1=1.464&r2=1.465 http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/ChangeLog.diff?cvsroot=gcc&r1=1.2895&r2=1.2896 http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/gcc.c-torture/execute/20030717-1.c.diff?cvsroot=gcc&r1=NONE&r2=1.1 Subject: Bug 11087 CVSROOT: /cvs/gcc Module name: gcc Branch: gcc-3_2-rhl8-branch Changes by: jakub@gcc.gnu.org 2003-07-18 11:17:45 Modified files: gcc : ChangeLog loop.c gcc/testsuite : ChangeLog Added files: gcc/testsuite/gcc.c-torture/execute: 20030717-1.c Log message: PR target/11087 * loop.c (basic_induction_var): Check if convert_modes emitted any instructions. Remove them and return 0 if so. * gcc.c-torture/execute/20030717-1.c: New test. Patches: http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/ChangeLog.diff?cvsroot=gcc&only_with_tag=gcc-3_2-rhl8-branch&r1=1.13152.2.657.2.27.2.146&r2=1.13152.2.657.2.27.2.147 http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/loop.c.diff?cvsroot=gcc&only_with_tag=gcc-3_2-rhl8-branch&r1=1.389.2.7.4.8&r2=1.389.2.7.4.9 http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/ChangeLog.diff?cvsroot=gcc&only_with_tag=gcc-3_2-rhl8-branch&r1=1.1672.2.166.2.8.2.58&r2=1.1672.2.166.2.8.2.59 http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/gcc.c-torture/execute/20030717-1.c.diff?cvsroot=gcc&only_with_tag=gcc-3_2-rhl8-branch&r1=NONE&r2=1.1.2.1 Subject: Bug 11087 CVSROOT: /cvs/gcc Module name: gcc Branch: gcc-3_3-rhl-branch Changes by: jakub@gcc.gnu.org 2003-07-18 11:20:20 Modified files: gcc : ChangeLog loop.c gcc/testsuite : ChangeLog Added files: gcc/testsuite/gcc.c-torture/execute: 20030717-1.c Log message: PR target/11087 * loop.c (basic_induction_var): Check if convert_modes emitted any instructions. Remove them and return 0 if so. * gcc.c-torture/execute/20030717-1.c: New test. Patches: http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/ChangeLog.diff?cvsroot=gcc&only_with_tag=gcc-3_3-rhl-branch&r1=1.16114.2.523.2.49&r2=1.16114.2.523.2.50 http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/loop.c.diff?cvsroot=gcc&only_with_tag=gcc-3_3-rhl-branch&r1=1.433.2.7.2.1&r2=1.433.2.7.2.2 http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/ChangeLog.diff?cvsroot=gcc&only_with_tag=gcc-3_3-rhl-branch&r1=1.2261.2.170.2.22&r2=1.2261.2.170.2.23 http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/gcc.c-torture/execute/20030717-1.c.diff?cvsroot=gcc&only_with_tag=gcc-3_3-rhl-branch&r1=NONE&r2=1.1.4.1 Jakub, the change log of this bug indicates that you added a testcase. Could you please close the bug if this is indeed the case? The problem itself is reportedly fixed on all active branches. I think this really should also be added to 3.3.2. I know it's late, but I suppose it was only accidentally that it wasn't comitted to the plain 3.3 branch, and it has received lots of testing on the other branches, and it leads to a miscompilation of the Linux kernel on at least powerpc and alpha. I don't understand Falk's comment. According to the audit trail, this is already fixed in GCC 3.3. However, it does not appear if Jakub's patch is on the 3.3 branch. Jakub, can you clarify this situation? If there is a patch for 3.3, please link to it from the audit trail so I can review it. Thanks. The patch was commited to the mainline and redhat's 2 branches and that is all. Subject: Re: gcc miscompiles raid1.c from linux kernel
On Mon, 2003-10-13 at 12:31, pinskia at gcc dot gnu dot org wrote:
> PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.
>
> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11087
>
>
>
> ------- Additional Comments From pinskia at gcc dot gnu dot org 2003-10-13 19:31 -------
> The patch was commited to the mainline and redhat's 2 branches and that is all.
So why does Marcus say that it is fixed in 3.3?
I don't know why Marcus considers it fixed in 3.3; the patch is certainly not in the 3.3-branch. I can reproduce the crash with raid1.c on alpha-linux with 3.3.2 20031013. The patch committed to 3_3-rhl-branch (linked in the audit trail) applies cleanly to the 3.3-branch and fixes the crash. By the way, I cannot reproduce it with the test case which was commited to 3_3-rhl-branch (20030717-1.c), so probably raid1.c should be taken as test case instead or additionally. Subject: Re: gcc miscompiles raid1.c from linux kernel Thanks for the additional information. The patch is OK for 3.3.2. Thanks, Subject: Bug 11087 CVSROOT: /cvs/gcc Module name: gcc Branch: gcc-3_3-branch Changes by: steven@gcc.gnu.org 2003-10-14 08:10:33 Modified files: gcc : ChangeLog loop.c Log message: 2003-10-14 Steven Bosscher <steven@gcc.gnu.org> PR target/11087 Backport from gcc-3_3-rhl-branch and mainline. 2003-07-17 Jakub Jelinek <jakub@redhat.com> * loop.c (basic_induction_var): Check if convert_modes emitted any instructions. Remove them and return 0 if so. Patches: http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/ChangeLog.diff?cvsroot=gcc&only_with_tag=gcc-3_3-branch&r1=1.16114.2.778&r2=1.16114.2.779 http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/loop.c.diff?cvsroot=gcc&only_with_tag=gcc-3_3-branch&r1=1.433.2.8&r2=1.433.2.9 I've commited this so that it's in before Mark starts rolling tarballs. I have not commited the test case from the rhl branches since it doesn't fail without the patch. Ok, what does this mean? "I've commited this so that it's in before Mark starts rolling tarballs. I have not commited the test case from the rhl branches since it doesn't fail without the patch." In which version/release the patch is included *and* the tarball is verified, that the patch is in? The RH raid1.c workaround was for RH 7.1 kernel 2.4.20 gcc 2.96 and the current kernel 2.6.0-test7 runs tests with gcc-3.2.2. So i tested gcc 2.95-3, 2.96, 3.3 and the new sources form cvs from yesterday (still open). And everyone crashs in raid1.c. I checked out the raid1.c standalone program, and it *never* crashs. So i thinks it´s not usefull for the testsuite. However i try to found out, what´s wrong with the alpha assembly code, but i doesn´t found anything wrong here ( i can´t singlestep the kernel code for read_balance and the standalone program seems to be fine.) Code; fffffc000050dd38 <read_balance+158/280> 0000000000000000 <_PC>: Code; fffffc000050dd38 <read_balance+158/280> 0: 10 00 a6 a0 ldl t4,16(t5) Code; fffffc000050dd3c <read_balance+15c/280> 4: 1f 04 ff 47 nop Code; fffffc000050dd40 <read_balance+160/280> 8: 24 15 82 40 subq t3,0x10,t3 Code; fffffc000050dd44 <read_balance+164/280> c: 25 31 a0 40 subl t4,0x1,t4 Code; fffffc000050dd48 <read_balance+168/280> 10: 00 00 44 a4 ldq t1,0(t3) Code; fffffc000050dd4c <read_balance+16c/280> 14: 0e 00 40 e4 beq t1,50 <_PC+0x50> fffffc000050dd88 <read_balance+1a8/280> Code; fffffc000050dd50 <read_balance+170/280> <===== 18: 58 00 22 a0 ldl t0,88(t1) <===== Code; fffffc000050dd54 <read_balance+174/280> 1c: 0c 00 20 e4 beq t0,50 <_PC+0x50> fffffc000050dd88 Can anyone tell me, why this code is wrong? $t3 seems to be a valid pointer, but $t1 got 1 and that fails. OK - what gcc release i can test with the patch included? Thanks Thomas http://alpha.steudten.com Subject: Re: gcc miscompiles raid1.c from linux kernel "tst at worldonline dot ch" <gcc-bugzilla@gcc.gnu.org> writes: > In which version/release the patch is included *and* the tarball is > verified, that the patch is in? In no release. It has been added to the 3.3 CVS branch and should therefore be in the 3.3.2 release tarball when it gets created. > So i tested gcc 2.95-3, 2.96, 3.3 and the new sources form cvs from > yesterday (still open). And everyone crashs in raid1.c. Are you sure the patch was already in when you checked out gcc? Is it mentioned in the changelog? > I checked out the raid1.c standalone program, and it *never* > crashs. That is weird. It certainly does for me: falk@juist:/tmp% uname -a Linux juist 2.6.0-test3 #2 Sat Aug 9 20:21:49 CEST 2003 alpha GNU/Linux falk@juist:/tmp% gcc-3.3 --version gcc-3.3 (GCC) 3.3.2 20031005 (Debian prerelease) falk@juist:/tmp% wget --quiet "http://gcc.gnu.org/bugzilla/attachment.cgi?id=4161&action=view" -O raid1.c falk@juist:/tmp% gcc-3.3 -O2 raid1.c && ./a.out zsh: segmentation fault (core dumped) ./a.out The crash goes away with the patch. Fixed for 3.3.2. The problem with the raid1.c in linux 2.4.21 and linux-2.6.0-test9-bk8 is gone and fixed for me. So gcc-3.3.2 is the prefered compiler for alpha in this days. Regards Tom |