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https://github.com/AuxXxilium/linux_dsm_epyc7002.git
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17248ea036
Setting a kprobe on getname_flags() failed: $ echo 'p:tmr1 getname_flags +0(%r2):ustring' > kprobe_events -bash: echo: write error: Invalid argument Debugging the kprobes code showed that the address of getname_flags() is contained in the __bug_table. Kprobes doesn't allow to set probes at BUG() locations. $ objdump -j __bug_table -x build/fs/namei.o [..] 0000000000000108 R_390_PC32 .text+0x00000000000075a8 000000000000010c R_390_PC32 .L223+0x0000000000000004 I was expecting getname_flags() to start with a BUG(), but: 7598: e3 20 10 00 00 04 lg %r2,0(%r1) 759e: c0 f4 00 00 00 00 jg 759e <putname+0x7e> 75a0: R_390_PLT32DBL kmem_cache_free+0x2 75a4: a7 f4 00 01 j 75a6 <putname+0x86> 00000000000075a8 <getname_flags>: 75a8: c0 04 00 00 00 00 brcl 0,75a8 <getname_flags> 75ae: eb 6f f0 48 00 24 stmg %r6,%r15,72(%r15) 75b4: b9 04 00 ef lgr %r14,%r15 75b8: e3 f0 ff a8 ff 71 lay %r15,-88(%r15) So the BUG() is actually the last opcode of the previous function. Fix this by switching to using the MONITOR CALL (MC) instruction, and set the entry in __bug_table to the beginning of that MC. Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> |
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| .. | ||
| syscalls | ||
| vdso64 | ||
| .gitignore | ||
| alternative.c | ||
| asm-offsets.c | ||
| audit.c | ||
| audit.h | ||
| base.S | ||
| cache.c | ||
| compat_audit.c | ||
| compat_linux.c | ||
| compat_linux.h | ||
| compat_ptrace.h | ||
| compat_signal.c | ||
| cpcmd.c | ||
| crash_dump.c | ||
| debug.c | ||
| diag.c | ||
| dis.c | ||
| dumpstack.c | ||
| early_printk.c | ||
| early.c | ||
| ebcdic.c | ||
| entry.h | ||
| entry.S | ||
| fpu.c | ||
| ftrace.c | ||
| guarded_storage.c | ||
| head64.S | ||
| idle.c | ||
| ima_arch.c | ||
| ipl_vmparm.c | ||
| ipl.c | ||
| irq.c | ||
| jump_label.c | ||
| kdebugfs.c | ||
| kexec_elf.c | ||
| kexec_image.c | ||
| kprobes.c | ||
| lgr.c | ||
| machine_kexec_file.c | ||
| machine_kexec_reloc.c | ||
| machine_kexec.c | ||
| Makefile | ||
| mcount.S | ||
| module.c | ||
| nmi.c | ||
| nospec-branch.c | ||
| nospec-sysfs.c | ||
| os_info.c | ||
| perf_cpum_cf_common.c | ||
| perf_cpum_cf_diag.c | ||
| perf_cpum_cf_events.c | ||
| perf_cpum_cf.c | ||
| perf_cpum_sf.c | ||
| perf_event.c | ||
| perf_regs.c | ||
| pgm_check.S | ||
| process.c | ||
| processor.c | ||
| ptrace.c | ||
| reipl.S | ||
| relocate_kernel.S | ||
| runtime_instr.c | ||
| setup.c | ||
| signal.c | ||
| smp.c | ||
| stacktrace.c | ||
| sthyi.c | ||
| suspend.c | ||
| swsusp.S | ||
| sys_s390.c | ||
| sysinfo.c | ||
| time.c | ||
| topology.c | ||
| trace.c | ||
| traps.c | ||
| unwind_bc.c | ||
| uprobes.c | ||
| vdso.c | ||
| vmlinux.lds.S | ||
| vtime.c | ||