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| author | Petr Machata <pmachata@redhat.com> | 2014-01-09 23:41:50 +0100 |
|---|---|---|
| committer | Petr Machata <pmachata@redhat.com> | 2014-01-10 00:01:53 +0100 |
| commit | 35742523e3daa0e59de0c1c3fdd8e5ff52891967 (patch) | |
| tree | 83584d9f32951afacd3bc8a1729c3830ac44c32d | |
| parent | 6aafe5507b40eced6c12448b8b6f1079f0802d63 (diff) | |
| download | ltrace-35742523e3daa0e59de0c1c3fdd8e5ff52891967.tar.gz | |
Fix a problem in tracing across fork on PPC64
In order to avoid single-stepping through large portions of the
dynamic linker, ltrace remembers at which address the instruction that
resolved a PLT slot is. It then puts a breakpoint to this address so
that it can fast-forward to that address next time it needs to catch a
PLT slot being resolved.
When a process is cloned, the pointer to this breakpoint is simply
copied over to the new process, instead of being looked up in the new
process structures. This patches fixes this.
| -rw-r--r-- | sysdeps/linux-gnu/ppc/plt.c | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/sysdeps/linux-gnu/ppc/plt.c b/sysdeps/linux-gnu/ppc/plt.c index 3ec1397..8715da6 100644 --- a/sysdeps/linux-gnu/ppc/plt.c +++ b/sysdeps/linux-gnu/ppc/plt.c @@ -1,6 +1,6 @@ /* * This file is part of ltrace. - * Copyright (C) 2012,2013 Petr Machata, Red Hat Inc. + * Copyright (C) 2012,2013,2014 Petr Machata, Red Hat Inc. * Copyright (C) 2004,2008,2009 Juan Cespedes * Copyright (C) 2006 Paul Gilliam * @@ -1157,6 +1157,18 @@ int arch_process_clone(struct process *retp, struct process *proc) { retp->arch = proc->arch; + + if (retp->arch.dl_plt_update_bp != NULL) { + /* Point it to the corresponding breakpoint in RETP. + * It must be there, this part of PROC has already + * been cloned to RETP. */ + retp->arch.dl_plt_update_bp + = address2bpstruct(retp, + retp->arch.dl_plt_update_bp->addr); + + assert(retp->arch.dl_plt_update_bp != NULL); + } + return 0; } |