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119 lines
4.5 KiB
119 lines
4.5 KiB
6 years ago
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commit d4094b6a8883ae481c7644c5a210254efe92e9ad
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Author: Ulrich Weigand <ulrich.weigand@de.ibm.com>
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Date: Tue Feb 4 18:40:16 2014 +0100
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PowerPC64 ELFv2 ABI: no function descriptors
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This implements the most significant difference with the ELFv2 ABI:
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we no longer use function descriptors. The patch consists mostly
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of switching off code to deal with descriptors :-)
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In addition, when calling an inferior function, we no longer need
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to provide its TOC in r2. Instead, ELFv2 code expects to be called
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with r12 pointing to the code address itself.
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gdb/ChangeLog:
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* ppc-linux-tdep.c (ppc_linux_init_abi): Only call
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set_gdbarch_convert_from_func_ptr_addr and
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set_gdbarch_elf_make_msymbol_special for ELFv1.
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* ppc-sysv-tdep.c (ppc64_sysv_abi_push_param): Only handle
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function descriptors on ELFv1.
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(ppc64_sysv_abi_push_dummy_call): Likewise. On ELFv2,
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set up r12 at function entry.
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Index: gdb-7.6.1/gdb/ppc-linux-tdep.c
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===================================================================
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--- gdb-7.6.1.orig/gdb/ppc-linux-tdep.c
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+++ gdb-7.6.1/gdb/ppc-linux-tdep.c
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@@ -1331,13 +1331,16 @@ ppc_linux_init_abi (struct gdbarch_info
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if (tdep->wordsize == 8)
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{
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- /* Handle PPC GNU/Linux 64-bit function pointers (which are really
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- function descriptors). */
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- set_gdbarch_convert_from_func_ptr_addr
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- (gdbarch, ppc64_convert_from_func_ptr_addr);
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+ if (tdep->elf_abi == POWERPC_ELF_V1)
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+ {
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+ /* Handle PPC GNU/Linux 64-bit function pointers (which are really
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+ function descriptors). */
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+ set_gdbarch_convert_from_func_ptr_addr
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+ (gdbarch, ppc64_convert_from_func_ptr_addr);
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- set_gdbarch_elf_make_msymbol_special (gdbarch,
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- ppc64_elf_make_msymbol_special);
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+ set_gdbarch_elf_make_msymbol_special
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+ (gdbarch, ppc64_elf_make_msymbol_special);
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+ }
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/* Shared library handling. */
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set_gdbarch_skip_trampoline_code (gdbarch, ppc64_skip_trampoline_code);
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Index: gdb-7.6.1/gdb/ppc-sysv-tdep.c
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===================================================================
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--- gdb-7.6.1.orig/gdb/ppc-sysv-tdep.c
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+++ gdb-7.6.1/gdb/ppc-sysv-tdep.c
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@@ -1351,8 +1351,9 @@ ppc64_sysv_abi_push_param (struct gdbarc
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word = unpack_long (type, val);
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/* Convert any function code addresses into descriptors. */
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- if (TYPE_CODE (type) == TYPE_CODE_PTR
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- || TYPE_CODE (type) == TYPE_CODE_REF)
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+ if (tdep->elf_abi == POWERPC_ELF_V1
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+ && (TYPE_CODE (type) == TYPE_CODE_PTR
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+ || TYPE_CODE (type) == TYPE_CODE_REF))
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{
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struct type *target_type
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= check_typedef (TYPE_TARGET_TYPE (type));
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@@ -1552,24 +1553,32 @@ ppc64_sysv_abi_push_dummy_call (struct g
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breakpoint. */
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regcache_cooked_write_signed (regcache, tdep->ppc_lr_regnum, bp_addr);
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- /* Use the func_addr to find the descriptor, and use that to find
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- the TOC. If we're calling via a function pointer, the pointer
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- itself identifies the descriptor. */
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- {
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- struct type *ftype = check_typedef (value_type (function));
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- CORE_ADDR desc_addr = value_as_address (function);
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-
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- if (TYPE_CODE (ftype) == TYPE_CODE_PTR
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- || convert_code_addr_to_desc_addr (func_addr, &desc_addr))
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- {
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- /* The TOC is the second double word in the descriptor. */
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- CORE_ADDR toc =
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- read_memory_unsigned_integer (desc_addr + tdep->wordsize,
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- tdep->wordsize, byte_order);
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- regcache_cooked_write_unsigned (regcache,
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- tdep->ppc_gp0_regnum + 2, toc);
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- }
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- }
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+ /* In the ELFv1 ABI, use the func_addr to find the descriptor, and use
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+ that to find the TOC. If we're calling via a function pointer,
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+ the pointer itself identifies the descriptor. */
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+ if (tdep->elf_abi == POWERPC_ELF_V1)
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+ {
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+ struct type *ftype = check_typedef (value_type (function));
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+ CORE_ADDR desc_addr = value_as_address (function);
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+
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+ if (TYPE_CODE (ftype) == TYPE_CODE_PTR
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+ || convert_code_addr_to_desc_addr (func_addr, &desc_addr))
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+ {
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+ /* The TOC is the second double word in the descriptor. */
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+ CORE_ADDR toc =
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+ read_memory_unsigned_integer (desc_addr + tdep->wordsize,
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+ tdep->wordsize, byte_order);
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+
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+ regcache_cooked_write_unsigned (regcache,
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+ tdep->ppc_gp0_regnum + 2, toc);
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+ }
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+ }
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+
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+ /* In the ELFv2 ABI, we need to pass the target address in r12 since
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+ we may be calling a global entry point. */
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+ if (tdep->elf_abi == POWERPC_ELF_V2)
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+ regcache_cooked_write_unsigned (regcache,
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+ tdep->ppc_gp0_regnum + 12, func_addr);
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return sp;
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}
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