2009-11-25 Doug Kwan <dougkwan@google.com>
* arm.cc (Target_arm::Target_arm): Move method definition outside of class definition. Add code to handle --target1-rel, --target1-abs and --target2= options. (Target_arm::get_reloc_reloc_type): Change method to be non-static and const. (Target_arm::target1_is_rel_, Target_arm::target2_reloc_): New data member declaration. (Target_arm::Scan::local, Target_arm::Scan::global, Target_arm::Relocate::relocate, Target_arm::Relocatable_size_for_reloc::get_size_for_reloc): Adjust call to Target_arm::get_real_reloc_type. (Target_arm::get_real_reloc_type): Use command line options to determine real types of R_ARM_TARGET1 and R_ARM_TARGET2. * options.h (--target1-rel, --target1-abs, --target2): New ARM-only options.
This commit is contained in:
Doug Kwan
parent
e2b8f3c401
commit
5193828376
@ -1,3 +1,19 @@
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2009-11-25 Doug Kwan <dougkwan@google.com>
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* arm.cc (Target_arm::may_use_thumb2_nop): New method definition.
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(Arm_relocate_functions::thumb_branch_common): New metod declaration.
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(Arm_relocate_functions::abs12, Arm_relocate_functions::abs16): Fix
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formatting.
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(Arm_relocate_functions::thm_call): Replace body with a call to
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Arm_relocate_functions::thumb_branch_common.
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(Arm_relocate_functions::thm_jump24,
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Arm_relocate_functions::thm_xpc22): New method definitions.
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(Arm_relocate_functions::thumb_branch_common): New method definition.
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(Reloc_stub::stbu_type_for_reloc): Fix incorrect uses of bit-wise-or
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operator.
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(Target_arm::Relocate::relocate): Adjust call to thm_call.
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Add code to handle R_ARM_THM_XPC22 and R_ARM_THM_JUMP24.
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2009-11-24 Rafael Avila de Espindola <espindola@google.com>
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* Makefile.am: Build incremental-dump
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289
gold/arm.cc
289
gold/arm.cc
@ -1195,6 +1195,14 @@ class Target_arm : public Sized_target<32, big_endian>
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return false;
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}
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// Whether we have THUMB-2 NOP.W instruction.
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bool
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may_use_thumb2_nop() const
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{
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// FIXME: This should not hard-coded.
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return false;
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}
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// Process the relocations to determine unreferenced sections for
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// garbage collection.
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void
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@ -1750,6 +1758,13 @@ class Arm_relocate_functions : public Relocate_functions<32, big_endian>
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const Arm_relobj<big_endian>*, unsigned int,
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const Symbol_value<32>*, Arm_address, Arm_address, bool);
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// Handle THUMB long branches.
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static typename This::Status
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thumb_branch_common(unsigned int, const Relocate_info<32, big_endian>*,
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unsigned char *, const Sized_symbol<32>*,
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const Arm_relobj<big_endian>*, unsigned int,
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const Symbol_value<32>*, Arm_address, Arm_address, bool);
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public:
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// R_ARM_ABS8: S + A
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@ -1793,8 +1808,8 @@ class Arm_relocate_functions : public Relocate_functions<32, big_endian>
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// R_ARM_ABS12: S + A
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static inline typename This::Status
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abs12(unsigned char *view,
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const Sized_relobj<32, big_endian>* object,
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const Symbol_value<32>* psymval)
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const Sized_relobj<32, big_endian>* object,
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const Symbol_value<32>* psymval)
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{
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typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
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typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
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@ -1812,8 +1827,8 @@ class Arm_relocate_functions : public Relocate_functions<32, big_endian>
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// R_ARM_ABS16: S + A
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static inline typename This::Status
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abs16(unsigned char *view,
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const Sized_relobj<32, big_endian>* object,
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const Symbol_value<32>* psymval)
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const Sized_relobj<32, big_endian>* object,
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const Symbol_value<32>* psymval)
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{
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typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
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typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
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@ -1861,38 +1876,41 @@ class Arm_relocate_functions : public Relocate_functions<32, big_endian>
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// R_ARM_THM_CALL: (S + A) | T - P
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static inline typename This::Status
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thm_call(unsigned char *view,
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const Sized_relobj<32, big_endian>* object,
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const Symbol_value<32>* psymval,
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Arm_address address,
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Arm_address thumb_bit)
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thm_call(const Relocate_info<32, big_endian>* relinfo, unsigned char *view,
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const Sized_symbol<32>* gsym, const Arm_relobj<big_endian>* object,
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unsigned int r_sym, const Symbol_value<32>* psymval,
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Arm_address address, Arm_address thumb_bit,
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bool is_weakly_undefined_without_plt)
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{
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// A thumb call consists of two instructions.
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typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
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typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
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Valtype* wv = reinterpret_cast<Valtype*>(view);
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Valtype hi = elfcpp::Swap<16, big_endian>::readval(wv);
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Valtype lo = elfcpp::Swap<16, big_endian>::readval(wv + 1);
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// Must be a BL instruction. lo == 11111xxxxxxxxxxx.
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gold_assert((lo & 0xf800) == 0xf800);
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Reltype addend = utils::sign_extend<23>(((hi & 0x7ff) << 12)
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| ((lo & 0x7ff) << 1));
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Reltype x = (psymval->value(object, addend) | thumb_bit) - address;
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return thumb_branch_common(elfcpp::R_ARM_THM_CALL, relinfo, view, gsym,
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object, r_sym, psymval, address, thumb_bit,
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is_weakly_undefined_without_plt);
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}
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// If target has no thumb bit set, we need to either turn the BL
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// into a BLX (for ARMv5 or above) or generate a stub.
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if ((x & 1) == 0)
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{
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// This only works for ARMv5 and above with interworking enabled.
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lo &= 0xefff;
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}
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hi = utils::bit_select(hi, (x >> 12), 0x7ffU);
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lo = utils::bit_select(lo, (x >> 1), 0x7ffU);
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elfcpp::Swap<16, big_endian>::writeval(wv, hi);
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elfcpp::Swap<16, big_endian>::writeval(wv + 1, lo);
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return (utils::has_overflow<23>(x)
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? This::STATUS_OVERFLOW
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: This::STATUS_OKAY);
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// R_ARM_THM_JUMP24: (S + A) | T - P
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static inline typename This::Status
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thm_jump24(const Relocate_info<32, big_endian>* relinfo, unsigned char *view,
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const Sized_symbol<32>* gsym, const Arm_relobj<big_endian>* object,
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unsigned int r_sym, const Symbol_value<32>* psymval,
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Arm_address address, Arm_address thumb_bit,
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bool is_weakly_undefined_without_plt)
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{
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return thumb_branch_common(elfcpp::R_ARM_THM_JUMP24, relinfo, view, gsym,
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object, r_sym, psymval, address, thumb_bit,
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is_weakly_undefined_without_plt);
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}
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// R_ARM_THM_XPC22: (S + A) | T - P
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static inline typename This::Status
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thm_xpc22(const Relocate_info<32, big_endian>* relinfo, unsigned char *view,
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const Sized_symbol<32>* gsym, const Arm_relobj<big_endian>* object,
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unsigned int r_sym, const Symbol_value<32>* psymval,
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Arm_address address, Arm_address thumb_bit,
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bool is_weakly_undefined_without_plt)
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{
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return thumb_branch_common(elfcpp::R_ARM_THM_XPC22, relinfo, view, gsym,
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object, r_sym, psymval, address, thumb_bit,
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is_weakly_undefined_without_plt);
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}
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// R_ARM_BASE_PREL: B(S) + A - P
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@ -2292,6 +2310,183 @@ Arm_relocate_functions<big_endian>::arm_branch_common(
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? This::STATUS_OVERFLOW : This::STATUS_OKAY);
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}
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// Relocate THUMB long branches. This handles relocation types
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// R_ARM_THM_CALL, R_ARM_THM_JUMP24 and R_ARM_THM_XPC22.
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// If IS_WEAK_UNDEFINED_WITH_PLT is true. The target symbol is weakly
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// undefined and we do not use PLT in this relocation. In such a case,
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// the branch is converted into an NOP.
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template<bool big_endian>
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typename Arm_relocate_functions<big_endian>::Status
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Arm_relocate_functions<big_endian>::thumb_branch_common(
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unsigned int r_type,
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const Relocate_info<32, big_endian>* relinfo,
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unsigned char *view,
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const Sized_symbol<32>* gsym,
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const Arm_relobj<big_endian>* object,
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unsigned int r_sym,
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const Symbol_value<32>* psymval,
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Arm_address address,
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Arm_address thumb_bit,
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bool is_weakly_undefined_without_plt)
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{
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typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
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Valtype* wv = reinterpret_cast<Valtype*>(view);
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uint32_t upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
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uint32_t lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
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// FIXME: These tests are too loose and do not take THUMB/THUMB-2 difference
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// into account.
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bool is_bl_insn = (lower_insn & 0x1000U) == 0x1000U;
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bool is_blx_insn = (lower_insn & 0x1000U) == 0x0000U;
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// Check that the instruction is valid.
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if (r_type == elfcpp::R_ARM_THM_CALL)
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{
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if (!is_bl_insn && !is_blx_insn)
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return This::STATUS_BAD_RELOC;
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}
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else if (r_type == elfcpp::R_ARM_THM_JUMP24)
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{
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// This cannot be a BLX.
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if (!is_bl_insn)
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return This::STATUS_BAD_RELOC;
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}
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else if (r_type == elfcpp::R_ARM_THM_XPC22)
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{
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// Check for Thumb to Thumb call.
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if (!is_blx_insn)
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return This::STATUS_BAD_RELOC;
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if (thumb_bit != 0)
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{
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gold_warning(_("%s: Thumb BLX instruction targets "
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"thumb function '%s'."),
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object->name().c_str(),
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(gsym ? gsym->name() : "(local)"));
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// Convert BLX to BL.
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lower_insn |= 0x1000U;
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}
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}
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else
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gold_unreachable();
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// A branch to an undefined weak symbol is turned into a jump to
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// the next instruction unless a PLT entry will be created.
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// The jump to the next instruction is optimized as a NOP.W for
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// Thumb-2 enabled architectures.
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const Target_arm<big_endian>* arm_target =
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Target_arm<big_endian>::default_target();
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if (is_weakly_undefined_without_plt)
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{
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if (arm_target->may_use_thumb2_nop())
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{
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elfcpp::Swap<16, big_endian>::writeval(wv, 0xf3af);
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elfcpp::Swap<16, big_endian>::writeval(wv + 1, 0x8000);
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}
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else
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{
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elfcpp::Swap<16, big_endian>::writeval(wv, 0xe000);
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elfcpp::Swap<16, big_endian>::writeval(wv + 1, 0xbf00);
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}
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return This::STATUS_OKAY;
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}
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// Fetch the addend. We use the Thumb-2 encoding (backwards compatible
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// with Thumb-1) involving the J1 and J2 bits.
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uint32_t s = (upper_insn & (1 << 10)) >> 10;
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uint32_t upper = upper_insn & 0x3ff;
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uint32_t lower = lower_insn & 0x7ff;
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uint32_t j1 = (lower_insn & (1 << 13)) >> 13;
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uint32_t j2 = (lower_insn & (1 << 11)) >> 11;
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uint32_t i1 = j1 ^ s ? 0 : 1;
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uint32_t i2 = j2 ^ s ? 0 : 1;
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int32_t addend = (i1 << 23) | (i2 << 22) | (upper << 12) | (lower << 1);
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// Sign extend.
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addend = (addend | ((s ? 0 : 1) << 24)) - (1 << 24);
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Arm_address branch_target = psymval->value(object, addend);
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int32_t branch_offset = branch_target - address;
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// We need a stub if the branch offset is too large or if we need
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// to switch mode.
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bool may_use_blx = arm_target->may_use_blx();
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bool thumb2 = arm_target->using_thumb2();
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if ((!thumb2
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&& (branch_offset > THM_MAX_FWD_BRANCH_OFFSET
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|| (branch_offset < THM_MAX_BWD_BRANCH_OFFSET)))
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|| (thumb2
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&& (branch_offset > THM2_MAX_FWD_BRANCH_OFFSET
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|| (branch_offset < THM2_MAX_BWD_BRANCH_OFFSET)))
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|| ((thumb_bit == 0)
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&& (((r_type == elfcpp::R_ARM_THM_CALL) && !may_use_blx)
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|| r_type == elfcpp::R_ARM_THM_JUMP24)))
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{
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Stub_type stub_type =
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Reloc_stub::stub_type_for_reloc(r_type, address, branch_target,
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(thumb_bit != 0));
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if (stub_type != arm_stub_none)
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{
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Stub_table<big_endian>* stub_table =
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object->stub_table(relinfo->data_shndx);
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gold_assert(stub_table != NULL);
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Reloc_stub::Key stub_key(stub_type, gsym, object, r_sym, addend);
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Reloc_stub* stub = stub_table->find_reloc_stub(stub_key);
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gold_assert(stub != NULL);
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thumb_bit = stub->stub_template()->entry_in_thumb_mode() ? 1 : 0;
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branch_target = stub_table->address() + stub->offset() + addend;
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branch_offset = branch_target - address;
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}
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}
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// At this point, if we still need to switch mode, the instruction
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// must either be a BLX or a BL that can be converted to a BLX.
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if (thumb_bit == 0)
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{
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gold_assert(may_use_blx
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&& (r_type == elfcpp::R_ARM_THM_CALL
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|| r_type == elfcpp::R_ARM_THM_XPC22));
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// Make sure this is a BLX.
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lower_insn &= ~0x1000U;
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}
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else
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{
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// Make sure this is a BL.
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lower_insn |= 0x1000U;
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}
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uint32_t reloc_sign = (branch_offset < 0) ? 1 : 0;
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uint32_t relocation = static_cast<uint32_t>(branch_offset);
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if ((lower_insn & 0x5000U) == 0x4000U)
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// For a BLX instruction, make sure that the relocation is rounded up
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// to a word boundary. This follows the semantics of the instruction
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// which specifies that bit 1 of the target address will come from bit
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// 1 of the base address.
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relocation = (relocation + 2U) & ~3U;
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// Put BRANCH_OFFSET back into the insn. Assumes two's complement.
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// We use the Thumb-2 encoding, which is safe even if dealing with
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// a Thumb-1 instruction by virtue of our overflow check above. */
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upper_insn = (upper_insn & ~0x7ffU)
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| ((relocation >> 12) & 0x3ffU)
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| (reloc_sign << 10);
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lower_insn = (lower_insn & ~0x2fffU)
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| (((!((relocation >> 23) & 1U)) ^ reloc_sign) << 13)
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| (((!((relocation >> 22) & 1U)) ^ reloc_sign) << 11)
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| ((relocation >> 1) & 0x7ffU);
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elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
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elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
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return ((thumb2
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? utils::has_overflow<25>(relocation)
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: utils::has_overflow<23>(relocation))
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? This::STATUS_OVERFLOW
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: This::STATUS_OKAY);
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}
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// Get the GOT section, creating it if necessary.
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template<bool big_endian>
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@ -2543,7 +2738,8 @@ Reloc_stub::stub_type_for_reloc(
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// Thumb to thumb.
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if (!thumb_only)
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{
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stub_type = (parameters->options().shared() | should_force_pic_veneer)
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stub_type = (parameters->options().shared()
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|| should_force_pic_veneer)
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// PIC stubs.
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? ((may_use_blx
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&& (r_type == elfcpp::R_ARM_THM_CALL))
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@ -2563,7 +2759,8 @@ Reloc_stub::stub_type_for_reloc(
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}
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else
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{
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stub_type = (parameters->options().shared() | should_force_pic_veneer)
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stub_type = (parameters->options().shared()
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|| should_force_pic_veneer)
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? arm_stub_long_branch_thumb_only_pic // PIC stub.
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: arm_stub_long_branch_thumb_only; // non-PIC stub.
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}
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@ -4729,8 +4926,10 @@ Target_arm<big_endian>::Relocate::relocate(
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break;
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case elfcpp::R_ARM_THM_CALL:
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reloc_status = Arm_relocate_functions::thm_call(view, object, psymval,
|
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address, thumb_bit);
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reloc_status =
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Arm_relocate_functions::thm_call(relinfo, view, gsym, object, r_sym,
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psymval, address, thumb_bit,
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is_weakly_undefined_without_plt);
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break;
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||||
case elfcpp::R_ARM_XPC25:
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@ -4740,6 +4939,13 @@ Target_arm<big_endian>::Relocate::relocate(
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is_weakly_undefined_without_plt);
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break;
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case elfcpp::R_ARM_THM_XPC22:
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reloc_status =
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Arm_relocate_functions::thm_xpc22(relinfo, view, gsym, object, r_sym,
|
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psymval, address, thumb_bit,
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is_weakly_undefined_without_plt);
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||||
break;
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||||
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||||
case elfcpp::R_ARM_GOTOFF32:
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||||
{
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Arm_address got_origin;
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||||
@ -4842,6 +5048,13 @@ Target_arm<big_endian>::Relocate::relocate(
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||||
is_weakly_undefined_without_plt);
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||||
break;
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||||
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||||
case elfcpp::R_ARM_THM_JUMP24:
|
||||
reloc_status =
|
||||
Arm_relocate_functions::thm_jump24(relinfo, view, gsym, object, r_sym,
|
||||
psymval, address, thumb_bit,
|
||||
is_weakly_undefined_without_plt);
|
||||
break;
|
||||
|
||||
case elfcpp::R_ARM_PREL31:
|
||||
reloc_status = Arm_relocate_functions::prel31(view, object, psymval,
|
||||
address, thumb_bit);
|
||||
|
||||
Loading…
Reference in New Issue
Block a user