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authorAlan Modra <amodra@gmail.com>2013-02-27 23:11:56 +0000
committerAlan Modra <amodra@gmail.com>2013-02-27 23:11:56 +0000
commit9d5781f8a245086dcdd3cd8fcddcd5b19c3a1e49 (patch)
treee53d7aa78570b4f92a31db6d49bb0e0a31374b61
parent71091f23fd90c0f1d04a0471ec561f07120b702c (diff)
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* target.h (Target::plt_fde_location, do_plt_fde_location): Declare.
* target.cc (Target::do_plt_fde_location): New function. * ehframe.h (class FDE): Add post_map field to u_.from_linker, accessor function, and constructor param. (struct Post_fde, Post_fdes): Declare. (Cie::write): Add post_fdes param. * ehframe.cc (Fde::write): Use plt_fde_location. (struct Post_fde): Define. (Cie::write): Stash FDEs added post merge mapping. (Eh_frame::add_ehframe_for_plt): Assert no new CIEs after mapping. Adjust Fde constructor call. Bump final_data_size_ for post map FDEs. (Eh_frame::do_sized_write): Arrange to write post map FDES after other FDEs. * powerpc.cc (Target_powerpc::do_plt_fde_location): New function. (Target_powerpc::has_glink): New function. (Target_powerpc::do_relax): Add eh_frame info for stubs. (struct Eh_cie, eh_frame_cie, glink_eh_frame_fde_64, glink_eh_frame_fde_32, default_fde): New data. (Stub_table::eh_frame_added_): New var. (Stub_table::find_long_branch_entry, stub_address, stub_offset): Make const. (Stub_table::add_eh_frame): New function. (Output_data_glink::add_eh_frame): New function. (Target_powerpc::make_glink_section): Call add_eh_frame.
-rw-r--r--gold/ChangeLog27
-rw-r--r--gold/ehframe.cc64
-rw-r--r--gold/ehframe.h32
-rw-r--r--gold/powerpc.cc185
-rw-r--r--gold/target.cc9
-rw-r--r--gold/target.h11
6 files changed, 303 insertions, 25 deletions
diff --git a/gold/ChangeLog b/gold/ChangeLog
index e9de821..0aa655e 100644
--- a/gold/ChangeLog
+++ b/gold/ChangeLog
@@ -1,3 +1,30 @@
+2013-02-28 Alan Modra <amodra@gmail.com>
+
+ * target.h (Target::plt_fde_location, do_plt_fde_location): Declare.
+ * target.cc (Target::do_plt_fde_location): New function.
+ * ehframe.h (class FDE): Add post_map field to u_.from_linker,
+ accessor function, and constructor param.
+ (struct Post_fde, Post_fdes): Declare.
+ (Cie::write): Add post_fdes param.
+ * ehframe.cc (Fde::write): Use plt_fde_location.
+ (struct Post_fde): Define.
+ (Cie::write): Stash FDEs added post merge mapping.
+ (Eh_frame::add_ehframe_for_plt): Assert no new CIEs after mapping.
+ Adjust Fde constructor call. Bump final_data_size_ for post map FDEs.
+ (Eh_frame::do_sized_write): Arrange to write post map FDES after
+ other FDEs.
+ * powerpc.cc (Target_powerpc::do_plt_fde_location): New function.
+ (Target_powerpc::has_glink): New function.
+ (Target_powerpc::do_relax): Add eh_frame info for stubs.
+ (struct Eh_cie, eh_frame_cie, glink_eh_frame_fde_64,
+ glink_eh_frame_fde_32, default_fde): New data.
+ (Stub_table::eh_frame_added_): New var.
+ (Stub_table::find_long_branch_entry, stub_address, stub_offset):
+ Make const.
+ (Stub_table::add_eh_frame): New function.
+ (Output_data_glink::add_eh_frame): New function.
+ (Target_powerpc::make_glink_section): Call add_eh_frame.
+
2013-02-15 Ian Lance Taylor <iant@google.com>
* options.h (DEFINE_uint64_alias): Define.
diff --git a/gold/ehframe.cc b/gold/ehframe.cc
index 1aaf346..82a6d6e 100644
--- a/gold/ehframe.cc
+++ b/gold/ehframe.cc
@@ -368,10 +368,13 @@ Fde::write(unsigned char* oview, section_offset_type offset,
if (this->object_ == NULL)
{
gold_assert(memcmp(oview + offset + 8, "\0\0\0\0\0\0\0\0", 8) == 0);
- Output_data* plt = this->u_.from_linker.plt;
- uint64_t poffset = plt->address() - (address + offset + 8);
+ uint64_t paddress;
+ off_t psize;
+ parameters->target().plt_fde_location(this->u_.from_linker.plt,
+ oview + offset + 8,
+ &paddress, &psize);
+ uint64_t poffset = paddress - (address + offset + 8);
int32_t spoffset = static_cast<int32_t>(poffset);
- off_t psize = plt->data_size();
uint32_t upsize = static_cast<uint32_t>(psize);
if (static_cast<uint64_t>(static_cast<int64_t>(spoffset)) != poffset
|| static_cast<off_t>(upsize) != psize)
@@ -438,15 +441,30 @@ Cie::set_output_offset(section_offset_type output_offset,
return output_offset + length;
}
-// Write the CIE to OVIEW starting at OFFSET. EH_FRAME_HDR is for FDE
-// recording. Round up the bytes to ADDRALIGN. Return the new
-// offset.
+// A FDE plus some info from a CIE to allow later writing of the FDE.
+
+struct Post_fde
+{
+ Post_fde(Fde* f, section_offset_type cie_off, unsigned char encoding)
+ : fde(f), cie_offset(cie_off), fde_encoding(encoding)
+ { }
+
+ Fde* fde;
+ section_offset_type cie_offset;
+ unsigned char fde_encoding;
+};
+
+// Write the CIE to OVIEW starting at OFFSET. Round up the bytes to
+// ADDRALIGN. ADDRESS is the virtual address of OVIEW.
+// EH_FRAME_HDR is the exception frame header for FDE recording.
+// POST_FDES stashes FDEs created after mappings were done, for later
+// writing. Return the new offset.
template<int size, bool big_endian>
section_offset_type
Cie::write(unsigned char* oview, section_offset_type offset,
uint64_t address, unsigned int addralign,
- Eh_frame_hdr* eh_frame_hdr)
+ Eh_frame_hdr* eh_frame_hdr, Post_fdes* post_fdes)
{
gold_assert((offset & (addralign - 1)) == 0);
@@ -479,9 +497,14 @@ Cie::write(unsigned char* oview, section_offset_type offset,
for (std::vector<Fde*>::const_iterator p = this->fdes_.begin();
p != this->fdes_.end();
++p)
- offset = (*p)->write<size, big_endian>(oview, offset, address, addralign,
- cie_offset, fde_encoding,
- eh_frame_hdr);
+ {
+ if ((*p)->post_map())
+ post_fdes->push_back(new Post_fde(*p, cie_offset, fde_encoding));
+ else
+ offset = (*p)->write<size, big_endian>(oview, offset, address,
+ addralign, cie_offset,
+ fde_encoding, eh_frame_hdr);
+ }
return offset;
}
@@ -1039,12 +1062,16 @@ Eh_frame::add_ehframe_for_plt(Output_data* plt, const unsigned char* cie_data,
pcie = *find_cie;
else
{
+ gold_assert(!this->mappings_are_done_);
pcie = new Cie(cie);
this->cie_offsets_.insert(pcie);
}
- Fde* fde = new Fde(plt, fde_data, fde_length);
+ Fde* fde = new Fde(plt, fde_data, fde_length, this->mappings_are_done_);
pcie->add_fde(fde);
+
+ if (this->mappings_are_done_)
+ this->final_data_size_ += align_address(fde_length + 8, this->addralign());
}
// Return the number of FDEs.
@@ -1169,17 +1196,28 @@ Eh_frame::do_sized_write(unsigned char* oview)
uint64_t address = this->address();
unsigned int addralign = this->addralign();
section_offset_type o = 0;
+ Post_fdes post_fdes;
for (Unmergeable_cie_offsets::iterator p =
this->unmergeable_cie_offsets_.begin();
p != this->unmergeable_cie_offsets_.end();
++p)
o = (*p)->write<size, big_endian>(oview, o, address, addralign,
- this->eh_frame_hdr_);
+ this->eh_frame_hdr_, &post_fdes);
for (Cie_offsets::iterator p = this->cie_offsets_.begin();
p != this->cie_offsets_.end();
++p)
o = (*p)->write<size, big_endian>(oview, o, address, addralign,
- this->eh_frame_hdr_);
+ this->eh_frame_hdr_, &post_fdes);
+ for (Post_fdes::iterator p = post_fdes.begin();
+ p != post_fdes.end();
+ ++p)
+ {
+ o = (*p)->fde->write<size, big_endian>(oview, o, address, addralign,
+ (*p)->cie_offset,
+ (*p)->fde_encoding,
+ this->eh_frame_hdr_);
+ delete *p;
+ }
}
#ifdef HAVE_TARGET_32_LITTLE
diff --git a/gold/ehframe.h b/gold/ehframe.h
index c3f82e9..de7c109 100644
--- a/gold/ehframe.h
+++ b/gold/ehframe.h
@@ -174,10 +174,14 @@ class Fde
}
// Create an FDE associated with a PLT.
- Fde(Output_data* plt, const unsigned char* contents, size_t length)
+ Fde(Output_data* plt, const unsigned char* contents, size_t length,
+ bool post_map)
: object_(NULL),
contents_(reinterpret_cast<const char*>(contents), length)
- { this->u_.from_linker.plt = plt; }
+ {
+ this->u_.from_linker.plt = plt;
+ this->u_.from_linker.post_map = post_map;
+ }
// Return the length of this FDE. Add 4 for the length and 4 for
// the offset to the CIE.
@@ -196,6 +200,11 @@ class Fde
output_offset);
}
+ // Return whether this FDE was added after merge mapping.
+ bool
+ post_map()
+ { return this->object_ == NULL && this->u_.from_linker.post_map; }
+
// Write the FDE to OVIEW starting at OFFSET. FDE_ENCODING is the
// encoding, from the CIE. Round up the bytes to ADDRALIGN if
// necessary. ADDRESS is the virtual address of OVIEW. Record the
@@ -229,12 +238,19 @@ class Fde
// The only linker generated FDEs are for PLT sections, and this
// points to the PLT section.
Output_data* plt;
+ // Set if the FDE was added after merge mapping.
+ bool post_map;
} from_linker;
} u_;
// FDE data.
std::string contents_;
};
+// FDEs stashed for later processing.
+
+struct Post_fde;
+typedef std::vector<Post_fde*> Post_fdes;
+
// This class holds a CIE.
class Cie
@@ -284,14 +300,16 @@ class Cie
set_output_offset(section_offset_type output_offset, unsigned int addralign,
Merge_map*);
- // Write the CIE to OVIEW starting at OFFSET. EH_FRAME_HDR is the
- // exception frame header for FDE recording. Round up the bytes to
- // ADDRALIGN. ADDRESS is the virtual address of OVIEW. Return the
- // new offset.
+ // Write the CIE to OVIEW starting at OFFSET. Round up the bytes to
+ // ADDRALIGN. ADDRESS is the virtual address of OVIEW.
+ // EH_FRAME_HDR is the exception frame header for FDE recording.
+ // POST_FDES stashes FDEs created after mappings were done, for later
+ // writing. Return the new offset.
template<int size, bool big_endian>
section_offset_type
write(unsigned char* oview, section_offset_type offset, uint64_t address,
- unsigned int addralign, Eh_frame_hdr* eh_frame_hdr);
+ unsigned int addralign, Eh_frame_hdr* eh_frame_hdr,
+ Post_fdes* post_fdes);
friend bool operator<(const Cie&, const Cie&);
friend bool operator==(const Cie&, const Cie&);
diff --git a/gold/powerpc.cc b/gold/powerpc.cc
index e192885..4521fc7 100644
--- a/gold/powerpc.cc
+++ b/gold/powerpc.cc
@@ -25,6 +25,7 @@
#include <algorithm>
#include "elfcpp.h"
+#include "dwarf.h"
#include "parameters.h"
#include "reloc.h"
#include "powerpc.h"
@@ -394,6 +395,10 @@ class Target_powerpc : public Sized_target<size, big_endian>
bool
do_relax(int, const Input_objects*, Symbol_table*, Layout*, const Task*);
+ void
+ do_plt_fde_location(const Output_data*, unsigned char*,
+ uint64_t*, off_t*) const;
+
// Stash info about branches, for stub generation.
void
push_branch(Powerpc_relobj<size, big_endian>* ppc_object,
@@ -526,6 +531,9 @@ class Target_powerpc : public Sized_target<size, big_endian>
return this->glink_;
}
+ bool has_glink() const
+ { return this->glink_ != NULL; }
+
// Get the GOT section.
const Output_data_got_powerpc<size, big_endian>*
got_section() const
@@ -2277,6 +2285,7 @@ Target_powerpc<size, big_endian>::do_relax(int pass,
if ((*p)->size_update())
{
again = true;
+ (*p)->add_eh_frame(layout);
os_need_update.insert((*p)->output_section());
}
}
@@ -2332,6 +2341,54 @@ Target_powerpc<size, big_endian>::do_relax(int pass,
return again;
}
+template<int size, bool big_endian>
+void
+Target_powerpc<size, big_endian>::do_plt_fde_location(const Output_data* plt,
+ unsigned char* oview,
+ uint64_t* paddress,
+ off_t* plen) const
+{
+ uint64_t address = plt->address();
+ off_t len = plt->data_size();
+
+ if (plt == this->glink_)
+ {
+ // See Output_data_glink::do_write() for glink contents.
+ if (size == 64)
+ {
+ // There is one word before __glink_PLTresolve
+ address += 8;
+ len -= 8;
+ }
+ else if (parameters->options().output_is_position_independent())
+ {
+ // There are two FDEs for a position independent glink.
+ // The first covers the branch table, the second
+ // __glink_PLTresolve at the end of glink.
+ off_t resolve_size = this->glink_->pltresolve_size;
+ if (oview[9] == 0)
+ len -= resolve_size;
+ else
+ {
+ address += len - resolve_size;
+ len = resolve_size;
+ }
+ }
+ }
+ else
+ {
+ // Must be a stub table.
+ const Stub_table<size, big_endian>* stub_table
+ = static_cast<const Stub_table<size, big_endian>*>(plt);
+ uint64_t stub_address = stub_table->stub_address();
+ len -= stub_address - address;
+ address = stub_address;
+ }
+
+ *paddress = address;
+ *plen = len;
+}
+
// A class to handle the PLT data.
template<int size, bool big_endian>
@@ -2774,6 +2831,60 @@ ha(uint32_t a)
return hi(a + 0x8000);
}
+template<int size>
+struct Eh_cie
+{
+ static const unsigned char eh_frame_cie[12];
+};
+
+template<int size>
+const unsigned char Eh_cie<size>::eh_frame_cie[] =
+{
+ 1, // CIE version.
+ 'z', 'R', 0, // Augmentation string.
+ 4, // Code alignment.
+ 0x80 - size / 8 , // Data alignment.
+ 65, // RA reg.
+ 1, // Augmentation size.
+ (elfcpp::DW_EH_PE_pcrel
+ | elfcpp::DW_EH_PE_sdata4), // FDE encoding.
+ elfcpp::DW_CFA_def_cfa, 1, 0 // def_cfa: r1 offset 0.
+};
+
+// Describe __glink_PLTresolve use of LR, 64-bit version.
+static const unsigned char glink_eh_frame_fde_64[] =
+{
+ 0, 0, 0, 0, // Replaced with offset to .glink.
+ 0, 0, 0, 0, // Replaced with size of .glink.
+ 0, // Augmentation size.
+ elfcpp::DW_CFA_advance_loc + 1,
+ elfcpp::DW_CFA_register, 65, 12,
+ elfcpp::DW_CFA_advance_loc + 4,
+ elfcpp::DW_CFA_restore_extended, 65
+};
+
+// Describe __glink_PLTresolve use of LR, 32-bit version.
+static const unsigned char glink_eh_frame_fde_32[] =
+{
+ 0, 0, 0, 0, // Replaced with offset to .glink.
+ 0, 0, 0, 0, // Replaced with size of .glink.
+ 0, // Augmentation size.
+ elfcpp::DW_CFA_advance_loc + 2,
+ elfcpp::DW_CFA_register, 65, 0,
+ elfcpp::DW_CFA_advance_loc + 4,
+ elfcpp::DW_CFA_restore_extended, 65
+};
+
+static const unsigned char default_fde[] =
+{
+ 0, 0, 0, 0, // Replaced with offset to stubs.
+ 0, 0, 0, 0, // Replaced with size of stubs.
+ 0, // Augmentation size.
+ elfcpp::DW_CFA_nop, // Pad.
+ elfcpp::DW_CFA_nop,
+ elfcpp::DW_CFA_nop
+};
+
template<bool big_endian>
static inline void
write_insn(unsigned char* p, uint32_t v)
@@ -2797,7 +2908,7 @@ class Stub_table : public Output_relaxed_input_section
: Output_relaxed_input_section(NULL, 0, 0),
targ_(targ), plt_call_stubs_(), long_branch_stubs_(),
orig_data_size_(0), plt_size_(0), last_plt_size_(0),
- branch_size_(0), last_branch_size_(0)
+ branch_size_(0), last_branch_size_(0), eh_frame_added_(false)
{ }
// Delayed Output_relaxed_input_section init.
@@ -2842,7 +2953,8 @@ class Stub_table : public Output_relaxed_input_section
add_long_branch_entry(const Powerpc_relobj<size, big_endian>*, Address);
Address
- find_long_branch_entry(const Powerpc_relobj<size, big_endian>*, Address);
+ find_long_branch_entry(const Powerpc_relobj<size, big_endian>*,
+ Address) const;
void
clear_stubs()
@@ -2871,14 +2983,14 @@ class Stub_table : public Output_relaxed_input_section
}
Address
- stub_address()
+ stub_address() const
{
return align_address(this->address() + this->orig_data_size_,
this->stub_align());
}
Address
- stub_offset()
+ stub_offset() const
{
return align_address(this->offset() + this->orig_data_size_,
this->stub_align());
@@ -2919,6 +3031,35 @@ class Stub_table : public Output_relaxed_input_section
return false;
}
+ // Add .eh_frame info for this stub section. Unlike other linker
+ // generated .eh_frame this is added late in the link, because we
+ // only want the .eh_frame info if this particular stub section is
+ // non-empty.
+ void
+ add_eh_frame(Layout* layout)
+ {
+ if (!this->eh_frame_added_)
+ {
+ if (!parameters->options().ld_generated_unwind_info())
+ return;
+
+ // Since we add stub .eh_frame info late, it must be placed
+ // after all other linker generated .eh_frame info so that
+ // merge mapping need not be updated for input sections.
+ // There is no provision to use a different CIE to that used
+ // by .glink.
+ if (!this->targ_->has_glink())
+ return;
+
+ layout->add_eh_frame_for_plt(this,
+ Eh_cie<size>::eh_frame_cie,
+ sizeof (Eh_cie<size>::eh_frame_cie),
+ default_fde,
+ sizeof (default_fde));
+ this->eh_frame_added_ = true;
+ }
+ }
+
Target_powerpc<size, big_endian>*
targ() const
{ return targ_; }
@@ -3118,6 +3259,8 @@ class Stub_table : public Output_relaxed_input_section
section_size_type orig_data_size_;
// size of stubs
section_size_type plt_size_, last_plt_size_, branch_size_, last_branch_size_;
+ // Whether .eh_frame info has been created for this stub section.
+ bool eh_frame_added_;
};
// Make a new stub table, and record.
@@ -3261,7 +3404,7 @@ template<int size, bool big_endian>
typename Stub_table<size, big_endian>::Address
Stub_table<size, big_endian>::find_long_branch_entry(
const Powerpc_relobj<size, big_endian>* object,
- Address to)
+ Address to) const
{
Branch_stub_ent ent(object, to);
typename Branch_stub_entries::const_iterator p
@@ -3281,6 +3424,37 @@ class Output_data_glink : public Output_section_data
: Output_section_data(16), targ_(targ)
{ }
+ void
+ add_eh_frame(Layout* layout)
+ {
+ if (!parameters->options().ld_generated_unwind_info())
+ return;
+
+ if (size == 64)
+ layout->add_eh_frame_for_plt(this,
+ Eh_cie<64>::eh_frame_cie,
+ sizeof (Eh_cie<64>::eh_frame_cie),
+ glink_eh_frame_fde_64,
+ sizeof (glink_eh_frame_fde_64));
+ else
+ {
+ // 32-bit .glink can use the default since the CIE return
+ // address reg, LR, is valid.
+ layout->add_eh_frame_for_plt(this,
+ Eh_cie<32>::eh_frame_cie,
+ sizeof (Eh_cie<32>::eh_frame_cie),
+ default_fde,
+ sizeof (default_fde));
+ // Except where LR is used in a PIC __glink_PLTresolve.
+ if (parameters->options().output_is_position_independent())
+ layout->add_eh_frame_for_plt(this,
+ Eh_cie<32>::eh_frame_cie,
+ sizeof (Eh_cie<32>::eh_frame_cie),
+ glink_eh_frame_fde_32,
+ sizeof (glink_eh_frame_fde_32));
+ }
+ }
+
protected:
// Write to a map file.
void
@@ -4086,6 +4260,7 @@ Target_powerpc<size, big_endian>::make_glink_section(Layout* layout)
if (this->glink_ == NULL)
{
this->glink_ = new Output_data_glink<size, big_endian>(this);
+ this->glink_->add_eh_frame(layout);
layout->add_output_section_data(".text", elfcpp::SHT_PROGBITS,
elfcpp::SHF_ALLOC | elfcpp::SHF_EXECINSTR,
this->glink_, ORDER_TEXT, false);
diff --git a/gold/target.cc b/gold/target.cc
index a47d74f..cc508c5 100644
--- a/gold/target.cc
+++ b/gold/target.cc
@@ -203,6 +203,15 @@ Target::set_view_to_nop(unsigned char* view, section_size_type view_size,
}
}
+// Return address and size to plug into eh_frame FDEs associated with a PLT.
+void
+Target::do_plt_fde_location(const Output_data* plt, unsigned char*,
+ uint64_t* address, off_t* len) const
+{
+ *address = plt->address();
+ *len = plt->data_size();
+}
+
// Class Sized_target.
// Set the EI_OSABI field of the ELF header if requested.
diff --git a/gold/target.h b/gold/target.h
index d4b9d0f..d75711e 100644
--- a/gold/target.h
+++ b/gold/target.h
@@ -240,6 +240,12 @@ class Target
adjust_elf_header(unsigned char* view, int len) const
{ return this->do_adjust_elf_header(view, len); }
+ // Return address and size to plug into eh_frame FDEs associated with a PLT.
+ void
+ plt_fde_location(const Output_data* plt, unsigned char* oview,
+ uint64_t* address, off_t* len) const
+ { return this->do_plt_fde_location(plt, oview, address, len); }
+
// Return whether NAME is a local label name. This is used to implement the
// --discard-locals options.
bool
@@ -530,6 +536,11 @@ class Target
virtual void
do_adjust_elf_header(unsigned char*, int) const = 0;
+ // Return address and size to plug into eh_frame FDEs associated with a PLT.
+ virtual void
+ do_plt_fde_location(const Output_data* plt, unsigned char* oview,
+ uint64_t* address, off_t* len) const;
+
// Virtual function which may be overridden by the child class.
virtual bool
do_is_local_label_name(const char*) const;