return lmp;
}
-
-/* Macros for matching instructions. Note that, since all the
- operands are masked off before they're or-ed into the instruction,
- you can use -1 to make masks. */
-
-#define insn_d(opcd, rts, ra, d) \
- ((((opcd) & 0x3f) << 26) \
- | (((rts) & 0x1f) << 21) \
- | (((ra) & 0x1f) << 16) \
- | ((d) & 0xffff))
-
-#define insn_ds(opcd, rts, ra, d, xo) \
- ((((opcd) & 0x3f) << 26) \
- | (((rts) & 0x1f) << 21) \
- | (((ra) & 0x1f) << 16) \
- | ((d) & 0xfffc) \
- | ((xo) & 0x3))
-
-#define insn_xfx(opcd, rts, spr, xo) \
- ((((opcd) & 0x3f) << 26) \
- | (((rts) & 0x1f) << 21) \
- | (((spr) & 0x1f) << 16) \
- | (((spr) & 0x3e0) << 6) \
- | (((xo) & 0x3ff) << 1))
-
-/* Read a PPC instruction from memory. PPC instructions are always
- big-endian, no matter what endianness the program is running in, so
- we can't use read_memory_integer or one of its friends here. */
-static unsigned int
-read_insn (CORE_ADDR pc)
-{
- unsigned char buf[4];
-
- read_memory (pc, buf, 4);
- return (buf[0] << 24) | (buf[1] << 16) | (buf[2] << 8) | buf[3];
-}
-
-
-/* An instruction to match. */
-struct insn_pattern
-{
- unsigned int mask; /* mask the insn with this... */
- unsigned int data; /* ...and see if it matches this. */
- int optional; /* If non-zero, this insn may be absent. */
-};
-
-/* Return non-zero if the instructions at PC match the series
- described in PATTERN, or zero otherwise. PATTERN is an array of
- 'struct insn_pattern' objects, terminated by an entry whose mask is
- zero.
-
- When the match is successful, fill INSN[i] with what PATTERN[i]
- matched. If PATTERN[i] is optional, and the instruction wasn't
- present, set INSN[i] to -1. INSN should have as many elements as
- PATTERN. Note that, if PATTERN contains optional instructions
- which aren't present in memory, then INSN will have holes, so
- INSN[i] isn't necessarily the i'th instruction in memory. */
-static int
-insns_match_pattern (CORE_ADDR pc,
- struct insn_pattern *pattern,
- unsigned int *insn)
-{
- int i;
-
- for (i = 0; pattern[i].mask; i++)
- {
- insn[i] = read_insn (pc);
- if ((insn[i] & pattern[i].mask) == pattern[i].data)
- pc += 4;
- else if (pattern[i].optional)
- insn[i] = 0;
- else
- return 0;
- }
-
- return 1;
-}
-
-
-/* Return the 'd' field of the d-form instruction INSN, properly
- sign-extended. */
-static CORE_ADDR
-insn_d_field (unsigned int insn)
-{
- return ((((CORE_ADDR) insn & 0xffff) ^ 0x8000) - 0x8000);
-}
-
-
-/* Return the 'ds' field of the ds-form instruction INSN, with the two
- zero bits concatenated at the right, and properly
- sign-extended. */
-static CORE_ADDR
-insn_ds_field (unsigned int insn)
-{
- return ((((CORE_ADDR) insn & 0xfffc) ^ 0x8000) - 0x8000);
-}
-
-
-/* If DESC is the address of a 64-bit PowerPC Linux function
- descriptor, return the descriptor's entry point. */
-static CORE_ADDR
-ppc64_desc_entry_point (CORE_ADDR desc)
-{
- /* The first word of the descriptor is the entry point. */
- return (CORE_ADDR) read_memory_unsigned_integer (desc, 8);
-}
-
-
-/* Pattern for the standard linkage function. These are built by
- build_plt_stub in elf64-ppc.c, whose GLINK argument is always
- zero. */
-static struct insn_pattern ppc64_standard_linkage[] =
- {
- /* addis r12, r2, <any> */
- { insn_d (-1, -1, -1, 0), insn_d (15, 12, 2, 0), 0 },
-
- /* std r2, 40(r1) */
- { -1, insn_ds (62, 2, 1, 40, 0), 0 },
-
- /* ld r11, <any>(r12) */
- { insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 11, 12, 0, 0), 0 },
-
- /* addis r12, r12, 1 <optional> */
- { insn_d (-1, -1, -1, -1), insn_d (15, 12, 2, 1), 1 },
-
- /* ld r2, <any>(r12) */
- { insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 2, 12, 0, 0), 0 },
-
- /* addis r12, r12, 1 <optional> */
- { insn_d (-1, -1, -1, -1), insn_d (15, 12, 2, 1), 1 },
-
- /* mtctr r11 */
- { insn_xfx (-1, -1, -1, -1), insn_xfx (31, 11, 9, 467),
- 0 },
-
- /* ld r11, <any>(r12) */
- { insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 11, 12, 0, 0), 0 },
-
- /* bctr */
- { -1, 0x4e800420, 0 },
-
- { 0, 0, 0 }
- };
-#define PPC64_STANDARD_LINKAGE_LEN \
- (sizeof (ppc64_standard_linkage) / sizeof (ppc64_standard_linkage[0]))
-
-
-/* Recognize a 64-bit PowerPC Linux linkage function --- what GDB
- calls a "solib trampoline". */
-static int
-ppc64_in_solib_call_trampoline (CORE_ADDR pc, char *name)
-{
- /* Detecting solib call trampolines on PPC64 Linux is a pain.
-
- It's not specifically solib call trampolines that are the issue.
- Any call from one function to another function that uses a
- different TOC requires a trampoline, to save the caller's TOC
- pointer and then load the callee's TOC. An executable or shared
- library may have more than one TOC, so even intra-object calls
- may require a trampoline. Since executable and shared libraries
- will all have their own distinct TOCs, every inter-object call is
- also an inter-TOC call, and requires a trampoline --- so "solib
- call trampolines" are just a special case.
-
- The 64-bit PowerPC Linux ABI calls these call trampolines
- "linkage functions". Since they need to be near the functions
- that call them, they all appear in .text, not in any special
- section. The .plt section just contains an array of function
- descriptors, from which the linkage functions load the callee's
- entry point, TOC value, and environment pointer. So
- in_plt_section is useless. The linkage functions don't have any
- special linker symbols to name them, either.
-
- The only way I can see to recognize them is to actually look at
- their code. They're generated by ppc_build_one_stub and some
- other functions in bfd/elf64-ppc.c, so that should show us all
- the instruction sequences we need to recognize. */
- unsigned int insn[PPC64_STANDARD_LINKAGE_LEN];
-
- return insns_match_pattern (pc, ppc64_standard_linkage, insn);
-}
-
-
-/* When the dynamic linker is doing lazy symbol resolution, the first
- call to a function in another object will go like this:
-
- - The user's function calls the linkage function:
-
- 100007c4: 4b ff fc d5 bl 10000498
- 100007c8: e8 41 00 28 ld r2,40(r1)
-
- - The linkage function loads the entry point (and other stuff) from
- the function descriptor in the PLT, and jumps to it:
-
- 10000498: 3d 82 00 00 addis r12,r2,0
- 1000049c: f8 41 00 28 std r2,40(r1)
- 100004a0: e9 6c 80 98 ld r11,-32616(r12)
- 100004a4: e8 4c 80 a0 ld r2,-32608(r12)
- 100004a8: 7d 69 03 a6 mtctr r11
- 100004ac: e9 6c 80 a8 ld r11,-32600(r12)
- 100004b0: 4e 80 04 20 bctr
-
- - But since this is the first time that PLT entry has been used, it
- sends control to its glink entry. That loads the number of the
- PLT entry and jumps to the common glink0 code:
-
- 10000c98: 38 00 00 00 li r0,0
- 10000c9c: 4b ff ff dc b 10000c78
-
- - The common glink0 code then transfers control to the dynamic
- linker's fixup code:
-
- 10000c78: e8 41 00 28 ld r2,40(r1)
- 10000c7c: 3d 82 00 00 addis r12,r2,0
- 10000c80: e9 6c 80 80 ld r11,-32640(r12)
- 10000c84: e8 4c 80 88 ld r2,-32632(r12)
- 10000c88: 7d 69 03 a6 mtctr r11
- 10000c8c: e9 6c 80 90 ld r11,-32624(r12)
- 10000c90: 4e 80 04 20 bctr
-
- Eventually, this code will figure out how to skip all of this,
- including the dynamic linker. At the moment, we just get through
- the linkage function. */
-
-/* If the current thread is about to execute a series of instructions
- at PC matching the ppc64_standard_linkage pattern, and INSN is the result
- from that pattern match, return the code address to which the
- standard linkage function will send them. (This doesn't deal with
- dynamic linker lazy symbol resolution stubs.) */
-static CORE_ADDR
-ppc64_standard_linkage_target (CORE_ADDR pc, unsigned int *insn)
-{
- struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);
-
- /* The address of the function descriptor this linkage function
- references. */
- CORE_ADDR desc
- = ((CORE_ADDR) read_register (tdep->ppc_gp0_regnum + 2)
- + (insn_d_field (insn[0]) << 16)
- + insn_ds_field (insn[2]));
-
- /* The first word of the descriptor is the entry point. Return that. */
- return ppc64_desc_entry_point (desc);
-}
-
-
-/* Given that we've begun executing a call trampoline at PC, return
- the entry point of the function the trampoline will go to. */
-static CORE_ADDR
-ppc64_skip_trampoline_code (CORE_ADDR pc)
-{
- unsigned int ppc64_standard_linkage_insn[PPC64_STANDARD_LINKAGE_LEN];
-
- if (insns_match_pattern (pc, ppc64_standard_linkage,
- ppc64_standard_linkage_insn))
- return ppc64_standard_linkage_target (pc, ppc64_standard_linkage_insn);
- else
- return 0;
-}
-
-
-/* On 64-bit PowerPC Linux, the ELF header's e_entry field is the
- address of a function descriptor for the entry point function, not
- the actual entry point itself. So to find the actual address at
- which execution should begin, we need to fetch the function's entry
- point from that descriptor. */
-static CORE_ADDR
-ppc64_call_dummy_address (void)
-{
- return ppc64_desc_entry_point (entry_point_address ());
-}
-
-
enum {
ELF_NGREG = 48,
ELF_NFPREG = 33,
set_gdbarch_memory_remove_breakpoint (gdbarch,
ppc_linux_memory_remove_breakpoint);
- /* Shared library handling. */
- set_gdbarch_in_solib_call_trampoline (gdbarch, in_plt_section);
- set_gdbarch_skip_trampoline_code (gdbarch,
- ppc_linux_skip_trampoline_code);
set_solib_svr4_fetch_link_map_offsets
(gdbarch, ppc_linux_svr4_fetch_link_map_offsets);
}
-
- if (tdep->wordsize == 8)
- {
- set_gdbarch_call_dummy_address (gdbarch, ppc64_call_dummy_address);
- set_gdbarch_in_solib_call_trampoline
- (gdbarch, ppc64_in_solib_call_trampoline);
- set_gdbarch_skip_trampoline_code (gdbarch, ppc64_skip_trampoline_code);
- }
+ /* Shared library handling. */
+ set_gdbarch_in_solib_call_trampoline (gdbarch, in_plt_section);
+ set_gdbarch_skip_trampoline_code (gdbarch, ppc_linux_skip_trampoline_code);
}
void
projects / thirdparty / binutils-gdb.git / commitdiff
