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| author | Christian Krinitsin <mail@krinitsin.com> | 2025-07-03 19:39:53 +0200 |
|---|---|---|
| committer | Christian Krinitsin <mail@krinitsin.com> | 2025-07-03 19:39:53 +0200 |
| commit | dee4dcba78baf712cab403d47d9db319ab7f95d6 (patch) | |
| tree | 418478faf06786701a56268672f73d6b0b4eb239 /results/classifier/118/peripherals/1886097 | |
| parent | 4d9e26c0333abd39bdbd039dcdb30ed429c475ba (diff) | |
| download | emulator-bug-study-dee4dcba78baf712cab403d47d9db319ab7f95d6.tar.gz emulator-bug-study-dee4dcba78baf712cab403d47d9db319ab7f95d6.zip | |
restructure results
Diffstat (limited to 'results/classifier/118/peripherals/1886097')
| -rw-r--r-- | results/classifier/118/peripherals/1886097 | 101 |
1 files changed, 0 insertions, 101 deletions
diff --git a/results/classifier/118/peripherals/1886097 b/results/classifier/118/peripherals/1886097 deleted file mode 100644 index 465e2880..00000000 --- a/results/classifier/118/peripherals/1886097 +++ /dev/null @@ -1,101 +0,0 @@ -peripherals: 0.846 -user-level: 0.818 -mistranslation: 0.806 -semantic: 0.774 -graphic: 0.769 -debug: 0.742 -hypervisor: 0.741 -assembly: 0.713 -risc-v: 0.705 -architecture: 0.704 -permissions: 0.703 -VMM: 0.693 -network: 0.673 -ppc: 0.672 -vnc: 0.670 -device: 0.661 -virtual: 0.655 -performance: 0.653 -kernel: 0.648 -TCG: 0.645 -arm: 0.602 -register: 0.602 -PID: 0.600 -KVM: 0.571 -x86: 0.550 -socket: 0.547 -boot: 0.514 -files: 0.469 -i386: 0.308 - -Error in user-mode calculation of ELF program's brk - -There's a discrepancy between the way QEMU user-mode and Linux calculate the initial program break for statically-linked binaries. I have a binary with the following segments: - - Program Headers: - Type Offset VirtAddr PhysAddr FileSiz MemSiz Flg Align - EXIDX 0x065a14 0x00075a14 0x00075a14 0x00588 0x00588 R 0x4 - PHDR 0x0a3000 0x000a3000 0x000a3000 0x00160 0x00160 R 0x1000 - LOAD 0x0a3000 0x000a3000 0x000a3000 0x00160 0x00160 R 0x1000 - LOAD 0x000000 0x00010000 0x00010000 0x65fa0 0x65fa0 R E 0x10000 - LOAD 0x066b7c 0x00086b7c 0x00086b7c 0x02384 0x02384 RW 0x10000 - NOTE 0x000114 0x00010114 0x00010114 0x00044 0x00044 R 0x4 - TLS 0x066b7c 0x00086b7c 0x00086b7c 0x00010 0x00030 R 0x4 - GNU_STACK 0x000000 0x00000000 0x00000000 0x00000 0x00000 RW 0x8 - GNU_RELRO 0x066b7c 0x00086b7c 0x00086b7c 0x00484 0x00484 R 0x1 - LOAD 0x07e000 0x00089000 0x00089000 0x03ff4 0x03ff4 R E 0x1000 - LOAD 0x098000 0x00030000 0x00030000 0x01000 0x01000 RW 0x1000 - -The call to set_brk in Linux's binfmt_elf.c receives these arguments: - - set_brk(0xa3160, 0xa3160, 1) - -Whereas in QEMU, info->brk gets set to 0x88f00. When the binary is run in QEMU, it crashes on the second call to brk, whereas it runs fine on real ARM hardware. I think the trouble is that the program break is set to an address lower than the virtual address of a LOAD segment (the program headers, in this case). - -I believe that this discrepancy arises because in QEMU, info->brk is only incremented when the LOAD segment in question has PROT_WRITE. For this binary, the LOAD segment with write permissions and the highest virtual address is - - LOAD 0x066b7c 0x00086b7c 0x00086b7c 0x02384 0x02384 RW 0x10000 - -which overlaps with the TLS segment: - - TLS 0x066b7c 0x00086b7c 0x00086b7c 0x00010 0x00030 R 0x4 - -However, the Linux kernel puts the program break after the loadable segment with the highest virtual address, regardless of flags. So I think the fix is for QEMU to do the same. - -The QEMU project is currently moving its bug tracking to another system. -For this we need to know which bugs are still valid and which could be -closed already. Thus we are setting the bug state to "Incomplete" now. - -If the bug has already been fixed in the latest upstream version of QEMU, -then please close this ticket as "Fix released". - -If it is not fixed yet and you think that this bug report here is still -valid, then you have two options: - -1) If you already have an account on gitlab.com, please open a new ticket -for this problem in our new tracker here: - - https://gitlab.com/qemu-project/qemu/-/issues - -and then close this ticket here on Launchpad (or let it expire auto- -matically after 60 days). Please mention the URL of this bug ticket on -Launchpad in the new ticket on GitLab. - -2) If you don't have an account on gitlab.com and don't intend to get -one, but still would like to keep this ticket opened, then please switch -the state back to "New" within the next 60 days (otherwise it will get -closed as "Expired"). We will then eventually migrate the ticket auto- -matically to the new system (but you won't be the reporter of the bug -in the new system and thus won't get notified on changes anymore). - -Thank you and sorry for the inconvenience. - - - -This is an automated cleanup. This bug report has been moved to QEMU's -new bug tracker on gitlab.com and thus gets marked as 'expired' now. -Please continue with the discussion here: - - https://gitlab.com/qemu-project/qemu/-/issues/276 - - |
