With copy relocation, address of protected data defined in the shared
library may be external. Compiler shouldn't asssume protected data will
be local. But due to
With copy relocation, address of protected data defined in the shared
library may be external. When there is a relocation against the
protected data symbol within the shared library, we need to check if we
should skip the definition in the executable copied from the protected
data. This patch adds ELF_RTYPE_CLASS_EXTERN_PROTECTED_DATA and defines
it for x86. If ELF_RTYPE_CLASS_EXTERN_PROTECTED_DATA isn't 0, do_lookup_x
will skip the data definition in the executable from copy reloc.
Cherry-pick from master: 62da1e3b00b51383ffa7efc89d8addda0502e107
[BZ #17711]
* elf/dl-lookup.c (do_lookup_x): When UNDEF_MAP is NULL, which
indicates it is called from do_lookup_x on relocation against
protected data, skip the data definion in the executable from
copy reloc.
(_dl_lookup_symbol_x): Pass ELF_RTYPE_CLASS_EXTERN_PROTECTED_DATA,
instead of ELF_RTYPE_CLASS_PLT, to do_lookup_x for
EXTERN_PROTECTED_DATA relocation against STT_OBJECT symbol.
* sysdeps/generic/ldsodefs.h * (ELF_RTYPE_CLASS_EXTERN_PROTECTED_DATA):
New. Defined to 4 if DL_EXTERN_PROTECTED_DATA is defined,
otherwise to 0.
* sysdeps/i386/dl-lookupcfg.h (DL_EXTERN_PROTECTED_DATA): New.
* sysdeps/i386/dl-machine.h (elf_machine_type_class): Set class
to ELF_RTYPE_CLASS_EXTERN_PROTECTED_DATA for R_386_GLOB_DAT.
* sysdeps/x86_64/dl-lookupcfg.h (DL_EXTERN_PROTECTED_DATA): New.
* sysdeps/x86_64/dl-machine.h (elf_machine_type_class): Set class
to ELF_RTYPE_CLASS_EXTERN_PROTECTED_DATA for R_X86_64_GLOB_DAT.
Way back in 2005 the atomic_exchange_and_add function was cleaned up to
avoid the explicit size checking and instead let gcc handle things itself.
Unfortunately that change ended up leaving beyond a cast to int, even when
the incoming value was a long. This has flown under the radar for a long
time due to the function not being heavily used in the tree (especially as
a full 64bit field), but a recent change to semaphores made some nptl tests
fail reliably. This is due to the code packing two 32bit values into one
64bit variable (where the high 32bits contained the number of waiters), and
then the whole variable being atomically updated between threads. On ia64,
that meant we never atomically updated the count, so sometimes the sem_post
would not wake up the waiters.
(cherry picked from commit cf31a2c79957936b60de34ea1e718e892baf669c)
Commit a059d359d86130b5fa74e04a978c8523a0293f77 changed the sigaction
struct to pass conform tests, but it ended up also changing the ABI for
32 bit builds. For 64 bit builds, changing the long to two ints works,
but for 32 bit builds, it inserts 4 extra bytes. This leads to many
packages randomly failing like bash that spews things like:
configure: line 471: wait_for: No record of process 0
Bracket the new member by a wordsize check to fix the ABI for 32bit.
(cherry picked from commit 7fde904c73c57faea48c9679bbdc0932d81b3a2f)
01b07c7...
by
Arjun Shankar <email address hidden>
