Bug 1817111
| Summary: | ldd reports "not a dynamic executable" on a dynamic executable with a large LOAD section | ||
|---|---|---|---|
| Product: | Red Hat Enterprise Linux 8 | Reporter: | Jeff Bastian <jbastian> |
| Component: | glibc | Assignee: | glibc team <glibc-bugzilla> |
| Status: | CLOSED DUPLICATE | QA Contact: | qe-baseos-tools-bugs |
| Severity: | low | Docs Contact: | |
| Priority: | low | ||
| Version: | 8.2 | CC: | ashankar, codonell, dj, efuller, fweimer, jhladky, mnewsome, pfrankli, sipoyare |
| Target Milestone: | rc | ||
| Target Release: | 8.3 | ||
| Hardware: | All | ||
| OS: | Linux | ||
| Whiteboard: | |||
| Fixed In Version: | Doc Type: | If docs needed, set a value | |
| Doc Text: | Story Points: | --- | |
| Clone Of: | Environment: | ||
| Last Closed: | 2020-03-28 02:55:52 UTC | Type: | Bug |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Embargoed: | |||
ldd is a bash script that uses the exit status of the dynamic linker invoked with --verify; an exit status of 1 leads to the " not a dynamic executable" report. The following strace output shows the failed mmap which leads to the exit status of 1 for an executable with an oversize LOAD segment (that mmap failure is presumably related to the segfault reported in bug 1817106). [root@RHEL1 NPB_sources]# strace -f /lib64/ld-linux-x86-64.so.2 --verify bin/ft.D.x execve("/lib64/ld-linux-x86-64.so.2", ["/lib64/ld-linux-x86-64.so.2", "--verify", "bin/ft.D.x"], 0x7ffe379d6758 /* 29 vars */) = 0 brk(NULL) = 0x5555559e1000 arch_prctl(0x3001 /* ARCH_??? */, 0x7ffea098f140) = -1 EINVAL (Invalid argument) openat(AT_FDCWD, "bin/ft.D.x", O_RDONLY|O_CLOEXEC) = 3 read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\2\0>\0\1\0\0\0P\16@\0\0\0\0\0"..., 832) = 832 fstat(3, {st_mode=S_IFREG|0755, st_size=83168, ...}) = 0 getcwd("/root/BZ1815509/NPB_sources", 128) = 28 mmap(0x400000, 36864, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0) = 0x400000 mmap(0x608000, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x8000) = 0x608000 mmap(0x60a000, 85941318816, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = -1 ENOMEM (Cannot allocate memory) close(3) = 0 exit_group(1) = ? +++ exited with 1 +++ [root@RHEL1 NPB_sources]# The 'file' command, on the other hand, recognizes such an executable as dynamically linked. [root@RHEL1 NPB_sources]# file bin/ft.D.x bin/ft.D.x: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), dynamically linked, interpreter /lib64/ld-linux-x86-64.so.2, for GNU/Linux 3.2.0, BuildID[sha1]=7d80b696366eb0d1d1e4980b3eb953520d45614d, with debug_info, not stripped [root@RHEL1 NPB_sources]# Perhaps the dynamic linker needs a different exit code for the purpose of reporting mmap failures (in which case ldd would be modified to recognize it). See also sibling bug 1817106 about the binary crashing with a seg fault in the loader. Jeff, Thanks for submitting this! The use of ldd to identify a binary requires being able to map the executable into memory. Your alternatives to avoid this requirement are to use `file` or even better `eu-elfclassify` (from elfutils). I'm closing this as a duplicate of bug 1085549 which already calls out this enhancement request. *** This bug has been marked as a duplicate of bug 1085549 *** |
Description of problem: ldd reports "not a dynamic executable" on a dynamic executable with a large LOAD section (larger than system RAM + swap). If you add more swap space, ldd works correctly. For example, the NAS Parallel Benchmark 'ft' has an 85 GB LOAD section when compiled as a "class D" benchmark (*): ~]# readelf -l bin/ft.D.x | grep -A1 -e Type -e LOAD Type Offset VirtAddr PhysAddr FileSiz MemSiz Flags Align -- LOAD 0x0000000000000000 0x0000000000400000 0x0000000000400000 0x0000000000005df8 0x0000000000005df8 R E 0x200000 LOAD 0x0000000000006dc0 0x0000000000606dc0 0x0000000000606dc0 0x00000000000003cc 0x0000001402a18a80 RW 0x200000 ^^^^^^^^^^^^^^^^^^ | +-- = ~85 GB ~]# ldd bin/ft.D.x not a dynamic executable ~]# free -g total used free shared buff/cache available Mem: 45 0 42 0 2 44 Swap: 22 0 22 ~]# fallocate -l 64G swapfile ~]# chmod 600 swapfile ~]# mkswap swapfile Setting up swapspace version 1, size = 64 GiB (68719472640 bytes) no label, UUID=54cc7016-55fa-47e0-acc8-726375c5be5b ~]# swapon swapfile ~]# free -g total used free shared buff/cache available Mem: 45 0 42 0 2 44 Swap: 86 0 86 ~]# ldd bin/ft.D.x linux-vdso.so.1 (0x00007ffd5b9f8000) libgfortran.so.5 => /lib64/libgfortran.so.5 (0x00007fd52b3bb000) libm.so.6 => /lib64/libm.so.6 (0x00007fd52b039000) libgcc_s.so.1 => /lib64/libgcc_s.so.1 (0x00007fd52ae21000) libquadmath.so.0 => /lib64/libquadmath.so.0 (0x00007fd52abe0000) libc.so.6 => /lib64/libc.so.6 (0x00007fd52a81e000) libz.so.1 => /lib64/libz.so.1 (0x00007fd52a607000) /lib64/ld-linux-x86-64.so.2 (0x00007fd52b838000) Version-Release number of selected component (if applicable): glibc-2.28-101.el8.x86_64 gcc-gfortran-8.3.1-5.el8.x86_64 How reproducible: always Steps to Reproduce: 1. yum -y install gcc-gfortran openmpi openmpi-devel 2. wget https://www.nas.nasa.gov/assets/npb/NPB3.3.1.tar.gz 3. tar xf NPB3.3.1.tar.gz 4. cd NPB3.3.1/NPB3.3-OMP 5. cp config/make.def.template config/make.def 6. sed -i -e 's/f77/gfortran/' \ -e '/^[CF]FLAGS/ s/$/ -mcmodel=medium/' config/make.def 7. make ft CLASS=D 8. ldd bin/ft.D.x Actual results: not a dynamic executable Expected results: list of the linked libraries Additional info: (*) NPB classes: https://www.nas.nasa.gov/publications/npb_problem_sizes.html