diff options
author | Alan Modra <amodra@gmail.com> | 2017-08-01 14:08:53 +0930 |
---|---|---|
committer | Alan Modra <amodra@gmail.com> | 2017-08-01 14:08:53 +0930 |
commit | be897fb774abfb0a44b3b87fe77bccafa336e638 (patch) | |
tree | 8b607740dccdbe530d2c1a87680c35b2320d354c /gold/layout.h | |
parent | 51b69c74c6464c59a5621d6f3d3967a576043fa8 (diff) | |
download | fsf-binutils-gdb-be897fb774abfb0a44b3b87fe77bccafa336e638.zip fsf-binutils-gdb-be897fb774abfb0a44b3b87fe77bccafa336e638.tar.gz fsf-binutils-gdb-be897fb774abfb0a44b3b87fe77bccafa336e638.tar.bz2 |
[GOLD] PowerPC recreate eh_frame for stubs on each relax pass
There is a very small but non-zero probability that a stub group
contains stubs on one relax pass, but does not on the next. In that
case we would get an FDE covering a zero length address range.
(Actually, it's even worse. Alignment padding for stubs can mean the
address for the non-existent stubs is past the end of the original
section to which stubs are attached, and due to the way
do_plt_fde_location calculates the length we can get a negative
length.) Fixing this properly requires removing the FDE.
Also, I have been implementing the __tls_get_addr_opt support for
gold, and that stub needs something other than the default FDE. The
necessary FDE will depend on the offset to the __tls_get_addr_opt
stub, which of course can change during relaxation. That means at the
very least, rewriting the FDE on each pass, possibly changing the FDE
size. I think that is better done by completely recreating PLT
eh_frame FDEs.
* ehframe.cc (Fde::operator==): New.
(Cie::remove_fde, Eh_frame::remove_ehframe_for_plt): New.
* ehframe.h (Fde::operator==): Declare.
(Cie::remove_fde, Eh_frame::remove_ehframe_for_plt): Likewise.
* layout.cc (Layout::remove_eh_frame_for_plt): New.
* layout.h (Layout::remove_eh_frame_for_plt): Declare.
* powerpc.cc (Target_powerpc::do_relax): Remove old eh_frame FDEs.
(Stub_table::add_eh_frame): Delete eh_frame_added_ condition.
Don't add eh_frame for empty stub section.
(Stub_table::remove_eh_frame): New.
Diffstat (limited to 'gold/layout.h')
-rw-r--r-- | gold/layout.h | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/gold/layout.h b/gold/layout.h index 5f58c2c..15ee924 100644 --- a/gold/layout.h +++ b/gold/layout.h @@ -653,6 +653,13 @@ class Layout size_t cie_length, const unsigned char* fde_data, size_t fde_length); + // Remove .eh_frame information for a PLT. FDEs using the CIE must + // be removed in reverse order to the order they were added. + void + remove_eh_frame_for_plt(Output_data* plt, const unsigned char* cie_data, + size_t cie_length, const unsigned char* fde_data, + size_t fde_length); + // Scan a .debug_info or .debug_types section, and add summary // information to the .gdb_index section. template<int size, bool big_endian> |