cvs commit: src/libexec/rtld-elf rtld.c rtld_lock.c rtld_lock.h

[Konstantin Belousov]

kib         2008-05-20 09:38:44 UTC

  FreeBSD src repository

  Modified files:        (Branch: RELENG_7)
    libexec/rtld-elf     rtld.c rtld_lock.c rtld_lock.h 
  Log:
  MFC
  rev. 1.126 of libexec/rtld-elf/rtld.c
  rev. 1.5 of libexec/rtld-elf/rtld_lock.c
  rev. 1.3 of libexec/rtld-elf/rtld_lock.h
  
  Fix the problem with the C++ exception handling for the multithreaded
  programs.
  
  From the PR description:
  The gcc runtime's _Unwind_Find_FDE function, invoked during exception
  handling's stack unwinding, is not safe to execute from within multiple
  threads. FreeBSD' s dl_iterate_phdr() however permits multiple threads
  to pass through it though. The result is surprisingly reliable infinite
  looping of one or more threads if they just happen to be unwinding at
  the same time.
  
  Introduce the new lock that is write locked around the dl_iterate_pdr,
  thus providing required exclusion for the stack unwinders.
  
  PR:     threads/123062
  Submitted by:   Andy Newman <an at atrn org>
  Reviewed by:    kan
  
  Revision   Changes    Path
  1.124.2.1  +5 -3      src/libexec/rtld-elf/rtld.c
  1.4.2.1    +2 -1      src/libexec/rtld-elf/rtld_lock.c
  1.2.20.1   +1 -0      src/libexec/rtld-elf/rtld_lock.h