[RFC] patch to refactor ppc64 specific code from ppc-linux-tdep
Andreas Tobler
andreast-list@fgznet.ch
Sat Jan 26 16:24:00 GMT 2013
Hi Pedro,
On 21.01.13 16:49, Pedro Alves wrote:
> On 12/27/2012 09:36 PM, Andreas Tobler wrote:
>
>> in order to avoid code duplication for the FreeBSD powerpc port I
>> started to cut off common code from ppc-linux-tdep.c into a new file to
>> be used for FreeBSD and GNU/Linux PowerPC 64-bit. The file name is open
>> so far. Better namings are welcome.
>
> Thanks for doing this.
>
> IMO, the "common" monitor is practically meaningless, and raises the question
> of what's different between ppc64-common-tdep.c, and
> an hypothetical ppc64-tdep.c, and/or the rs6000-tdep.c, as the
> second would be about common ppc64 bits, and the latter, extant, _is also_
> about common ppc bits. IOW, if we need a new ppc function in the future that's
> be used by several OSs, how do we decide where it goes? "common" doesn't
> give any clue. So I'd suggest ppc64-linbsd-tdep.c, and/or
> rs6000-tdep.c/ppc64-tdep.c, for shared code that is not OS specific (yeah,
> rs6000-tdep.c is a misnomer nowadays).
First, thank you for the review.
I attached a revised version of the patch including the CL below. I hope
I matched your points.
I decided to leave ppc64-linbsd-tdep.c away and use ppc64-tdep.c|h with
the changes mentioned below to ppc-tdep.h/rs6000-tdep.c
Tested on ppc64-linux and on FreeBSD amd64 with an --enable-targets=all.
>> +/* An instruction to match. */
>> +
>> +struct insn_pattern
> ...
>> +
>> +int
>> +insns_match_pattern (CORE_ADDR pc, struct insn_pattern *pattern,
>> + unsigned int *insn);
>> +CORE_ADDR
>> +insn_d_field (unsigned int insn);
>
> These look like basic architecture/instruction pattern matching.
> I suggest moving to ppc-tdep.h/rs6000-tdep.c instead.
Done.
> If we're making these extern, then it'd be good to add a "ppc_" or
> "ppc64_" prefix (could be a separate step).
Done with ppc_ since the instructions could be used on ppc and ppc64
> Also, GDB's convention is that the function name goes on the first
> column in function definitions only, not declarations, and that
> declarations in .h files get an explicit "extern".
Done, not sure if I need the extern on ppc64-tdep.h too?
> Otherwise looks fine to me.
Again, thank you!
Andreas
2013-01-26 Andreas Tobler <andreast@fgznet.ch>
* Makefile.in (ALL_TARGET_OBS): Add new file ppc64-tdep.o.
(HFILES_NO_SRCDIR): Likewise.
(ALLDEPFILES): Likewise.
* configure.tgt: Add new file for powerpc-linux.
* ppc64-tdep.h: New file.
* ppc64-tdep.c: New file.
(insn_d, insn_ds, insn_xfx, ppc64_desc_entry_point): Move from
ppc-linux-tdep.c to here.
(PPC64_STANDARD_LINKAGE1_LEN, PPC64_STANDARD_LINKAGE2_LEN)
(PPC64_STANDARD_LINKAGE2_LEN): Likewise and use ARRAY_SIZE macro.
(ppc64_standard_linkage1_target, ppc64_standard_linkage2_target)
(ppc64_standard_linkage3_target, ppc64_skip_trampoline_code): Move
from ppc-linux-tdep.c to here.
(ppc64_convert_from_func_ptr_addr): Rename it from
ppc64_linux_convert_from_func_ptr_addr to
ppc64_convert_from_func_ptr_addr and move it from ppc-linux-tdep.c to
here.
* rs6000-tdep.c:
(read_insn): Move from ppc-linux-tdep.c to here.
(insns_match_pattern, insn_d_field, insn_ds_field): Move
from ppc-linux-tdep.c to here and rename them with the ppc_ prefix.
* ppc-linux-tdep.c: Include ppc64-tdep.h.
Removed above functions.
(ppc_linux_init_abi): Rename
ppc64_linux_convert_from_func_ptr_addr to
ppc64_convert_from_func_ptr_addr.
-------------- next part --------------
diff --git a/gdb/Makefile.in b/gdb/Makefile.in
index 68d545e..e0e08ca 100644
--- a/gdb/Makefile.in
+++ b/gdb/Makefile.in
@@ -565,7 +565,7 @@ ALL_TARGET_OBS = \
mt-tdep.o \
nto-tdep.o \
ppc-linux-tdep.o ppcnbsd-tdep.o ppcobsd-tdep.o ppc-sysv-tdep.o \
- rl78-tdep.o \
+ ppc64-tdep.o rl78-tdep.o \
rs6000-aix-tdep.o rs6000-tdep.o ppc-ravenscar-thread.o \
rs6000-lynx178-tdep.o \
rx-tdep.o \
@@ -807,7 +807,7 @@ amd64-linux-tdep.h linespec.h i387-tdep.h mn10300-tdep.h \
sparc64-tdep.h monitor.h ppcobsd-tdep.h srec.h solib-pa64.h \
coff-pe-read.h parser-defs.h gdb_ptrace.h mips-linux-tdep.h \
m68k-tdep.h spu-tdep.h jv-lang.h environ.h solib-irix.h amd64-tdep.h \
-doublest.h regset.h hppa-tdep.h ppc-linux-tdep.h rs6000-tdep.h \
+doublest.h regset.h hppa-tdep.h ppc-linux-tdep.h ppc64-tdep.h rs6000-tdep.h \
common/gdb_locale.h common/gdb_dirent.h arch-utils.h trad-frame.h gnu-nat.h \
language.h nbsd-tdep.h solib-svr4.h \
macroexp.h ui-file.h regcache.h gdb_string.h tracepoint.h i386-tdep.h \
@@ -1487,7 +1487,7 @@ ALLDEPFILES = \
solib-osf.c \
somread.c solib-som.c \
posix-hdep.c \
- ppc-sysv-tdep.c ppc-linux-nat.c ppc-linux-tdep.c \
+ ppc-sysv-tdep.c ppc-linux-nat.c ppc-linux-tdep.c ppc64-tdep.c \
ppcnbsd-nat.c ppcnbsd-tdep.c \
ppcobsd-nat.c ppcobsd-tdep.c \
procfs.c \
diff --git a/gdb/configure.tgt b/gdb/configure.tgt
index 5b77bb2..2b4eea0 100644
--- a/gdb/configure.tgt
+++ b/gdb/configure.tgt
@@ -405,7 +405,8 @@ powerpc-*-aix* | rs6000-*-*)
powerpc-*-linux* | powerpc64-*-linux*)
# Target: PowerPC running Linux
gdb_target_obs="rs6000-tdep.o ppc-linux-tdep.o ppc-sysv-tdep.o \
- solib-svr4.o solib-spu.o spu-multiarch.o \
+ ppc64-tdep.o solib-svr4.o solib-spu.o \
+ spu-multiarch.o \
glibc-tdep.o symfile-mem.o linux-tdep.o \
ravenscar-thread.o ppc-ravenscar-thread.o"
gdb_sim=../sim/ppc/libsim.a
diff --git a/gdb/ppc-linux-tdep.c b/gdb/ppc-linux-tdep.c
index 135dc75..cdf362f 100644
--- a/gdb/ppc-linux-tdep.c
+++ b/gdb/ppc-linux-tdep.c
@@ -35,6 +35,7 @@
#include "solib.h"
#include "solist.h"
#include "ppc-tdep.h"
+#include "ppc64-tdep.h"
#include "ppc-linux-tdep.h"
#include "glibc-tdep.h"
#include "trad-frame.h"
@@ -254,277 +255,6 @@ ppc_linux_return_value (struct gdbarch *gdbarch, struct value *function,
readbuf, writebuf);
}
-/* 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 0 (which is not a valid PPC instruction).
- 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 GNU/Linux function
- descriptor, return the descriptor's entry point. */
-static CORE_ADDR
-ppc64_desc_entry_point (struct gdbarch *gdbarch, CORE_ADDR desc)
-{
- enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
- /* The first word of the descriptor is the entry point. */
- return (CORE_ADDR) read_memory_unsigned_integer (desc, 8, byte_order);
-}
-
-
-/* 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_linkage1[] =
- {
- /* 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, 12, 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, 12, 1), 1 },
-
- /* mtctr r11 */
- { insn_xfx (-1, -1, -1, -1), insn_xfx (31, 11, 9, 467), 0 },
-
- /* ld r11, <any>(r12) <optional> */
- { insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 11, 12, 0, 0), 1 },
-
- /* bctr */
- { -1, 0x4e800420, 0 },
-
- { 0, 0, 0 }
- };
-#define PPC64_STANDARD_LINKAGE1_LEN \
- (sizeof (ppc64_standard_linkage1) / sizeof (ppc64_standard_linkage1[0]))
-
-static struct insn_pattern ppc64_standard_linkage2[] =
- {
- /* 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 },
-
- /* addi r12, r12, <any> <optional> */
- { insn_d (-1, -1, -1, 0), insn_d (14, 12, 12, 0), 1 },
-
- /* mtctr r11 */
- { insn_xfx (-1, -1, -1, -1), insn_xfx (31, 11, 9, 467), 0 },
-
- /* ld r2, <any>(r12) */
- { insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 2, 12, 0, 0), 0 },
-
- /* ld r11, <any>(r12) <optional> */
- { insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 11, 12, 0, 0), 1 },
-
- /* bctr */
- { -1, 0x4e800420, 0 },
-
- { 0, 0, 0 }
- };
-#define PPC64_STANDARD_LINKAGE2_LEN \
- (sizeof (ppc64_standard_linkage2) / sizeof (ppc64_standard_linkage2[0]))
-
-static struct insn_pattern ppc64_standard_linkage3[] =
- {
- /* std r2, 40(r1) */
- { -1, insn_ds (62, 2, 1, 40, 0), 0 },
-
- /* ld r11, <any>(r2) */
- { insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 11, 2, 0, 0), 0 },
-
- /* addi r2, r2, <any> <optional> */
- { insn_d (-1, -1, -1, 0), insn_d (14, 2, 2, 0), 1 },
-
- /* mtctr r11 */
- { insn_xfx (-1, -1, -1, -1), insn_xfx (31, 11, 9, 467), 0 },
-
- /* ld r11, <any>(r2) <optional> */
- { insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 11, 2, 0, 0), 1 },
-
- /* ld r2, <any>(r2) */
- { insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 2, 2, 0, 0), 0 },
-
- /* bctr */
- { -1, 0x4e800420, 0 },
-
- { 0, 0, 0 }
- };
-#define PPC64_STANDARD_LINKAGE3_LEN \
- (sizeof (ppc64_standard_linkage3) / sizeof (ppc64_standard_linkage3[0]))
-
-
-/* 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_linkage1_target (struct frame_info *frame,
- CORE_ADDR pc, unsigned int *insn)
-{
- struct gdbarch *gdbarch = get_frame_arch (frame);
- struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
-
- /* The address of the function descriptor this linkage function
- references. */
- CORE_ADDR desc
- = ((CORE_ADDR) get_frame_register_unsigned (frame,
- 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 (gdbarch, desc);
-}
-
static struct core_regset_section ppc_linux_vsx_regset_sections[] =
{
{ ".reg", 48 * 4, "general-purpose" },
@@ -573,45 +303,8 @@ static struct core_regset_section ppc64_linux_fp_regset_sections[] =
{ NULL, 0}
};
-static CORE_ADDR
-ppc64_standard_linkage2_target (struct frame_info *frame,
- CORE_ADDR pc, unsigned int *insn)
-{
- struct gdbarch *gdbarch = get_frame_arch (frame);
- struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
-
- /* The address of the function descriptor this linkage function
- references. */
- CORE_ADDR desc
- = ((CORE_ADDR) get_frame_register_unsigned (frame,
- 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 (gdbarch, desc);
-}
-
-static CORE_ADDR
-ppc64_standard_linkage3_target (struct frame_info *frame,
- CORE_ADDR pc, unsigned int *insn)
-{
- struct gdbarch *gdbarch = get_frame_arch (frame);
- struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
-
- /* The address of the function descriptor this linkage function
- references. */
- CORE_ADDR desc
- = ((CORE_ADDR) get_frame_register_unsigned (frame,
- tdep->ppc_gp0_regnum + 2)
- + insn_ds_field (insn[1]));
-
- /* The first word of the descriptor is the entry point. Return that. */
- return ppc64_desc_entry_point (gdbarch, desc);
-}
-
/* PLT stub in executable. */
-static struct insn_pattern powerpc32_plt_stub[] =
+static struct ppc_insn_pattern powerpc32_plt_stub[] =
{
{ 0xffff0000, 0x3d600000, 0 }, /* lis r11, xxxx */
{ 0xffff0000, 0x816b0000, 0 }, /* lwz r11, xxxx(r11) */
@@ -621,7 +314,7 @@ static struct insn_pattern powerpc32_plt_stub[] =
};
/* PLT stub in shared library. */
-static struct insn_pattern powerpc32_plt_stub_so[] =
+static struct ppc_insn_pattern powerpc32_plt_stub_so[] =
{
{ 0xffff0000, 0x817e0000, 0 }, /* lwz r11, xxxx(r30) */
{ 0xffffffff, 0x7d6903a6, 0 }, /* mtctr r11 */
@@ -666,134 +359,32 @@ ppc_skip_trampoline_code (struct frame_info *frame, CORE_ADDR pc)
enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
CORE_ADDR target = 0;
- if (insns_match_pattern (pc, powerpc32_plt_stub, insnbuf))
+ if (ppc_insns_match_pattern (pc, powerpc32_plt_stub, insnbuf))
{
/* Insn pattern is
lis r11, xxxx
lwz r11, xxxx(r11)
Branch target is in r11. */
- target = (insn_d_field (insnbuf[0]) << 16) | insn_d_field (insnbuf[1]);
+ target = (ppc_insn_d_field (insnbuf[0]) << 16)
+ | ppc_insn_d_field (insnbuf[1]);
target = read_memory_unsigned_integer (target, 4, byte_order);
}
- if (insns_match_pattern (pc, powerpc32_plt_stub_so, insnbuf))
+ if (ppc_insns_match_pattern (pc, powerpc32_plt_stub_so, insnbuf))
{
/* Insn pattern is
lwz r11, xxxx(r30)
Branch target is in r11. */
target = get_frame_register_unsigned (frame, tdep->ppc_gp0_regnum + 30)
- + insn_d_field (insnbuf[0]);
+ + ppc_insn_d_field (insnbuf[0]);
target = read_memory_unsigned_integer (target, 4, byte_order);
}
return target;
}
-/* 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 (struct frame_info *frame, CORE_ADDR pc)
-{
- unsigned int ppc64_standard_linkage1_insn[PPC64_STANDARD_LINKAGE1_LEN];
- unsigned int ppc64_standard_linkage2_insn[PPC64_STANDARD_LINKAGE2_LEN];
- unsigned int ppc64_standard_linkage3_insn[PPC64_STANDARD_LINKAGE3_LEN];
- CORE_ADDR target;
-
- if (insns_match_pattern (pc, ppc64_standard_linkage1,
- ppc64_standard_linkage1_insn))
- pc = ppc64_standard_linkage1_target (frame, pc,
- ppc64_standard_linkage1_insn);
- else if (insns_match_pattern (pc, ppc64_standard_linkage2,
- ppc64_standard_linkage2_insn))
- pc = ppc64_standard_linkage2_target (frame, pc,
- ppc64_standard_linkage2_insn);
- else if (insns_match_pattern (pc, ppc64_standard_linkage3,
- ppc64_standard_linkage3_insn))
- pc = ppc64_standard_linkage3_target (frame, pc,
- ppc64_standard_linkage3_insn);
- else
- return 0;
-
- /* The PLT descriptor will either point to the already resolved target
- address, or else to a glink stub. As the latter carry synthetic @plt
- symbols, find_solib_trampoline_target should be able to resolve them. */
- target = find_solib_trampoline_target (frame, pc);
- return target? target : pc;
-}
-
-
-/* Support for convert_from_func_ptr_addr (ARCH, ADDR, TARG) on PPC64
- GNU/Linux.
-
- Usually a function pointer's representation is simply the address
- of the function. On GNU/Linux on the PowerPC however, a function
- pointer may be a pointer to a function descriptor.
-
- For PPC64, a function descriptor is a TOC entry, in a data section,
- which contains three words: the first word is the address of the
- function, the second word is the TOC pointer (r2), and the third word
- is the static chain value.
-
- Throughout GDB it is currently assumed that a function pointer contains
- the address of the function, which is not easy to fix. In addition, the
- conversion of a function address to a function pointer would
- require allocation of a TOC entry in the inferior's memory space,
- with all its drawbacks. To be able to call C++ virtual methods in
- the inferior (which are called via function pointers),
- find_function_addr uses this function to get the function address
- from a function pointer.
-
- If ADDR points at what is clearly a function descriptor, transform
- it into the address of the corresponding function, if needed. Be
- conservative, otherwise GDB will do the transformation on any
- random addresses such as occur when there is no symbol table. */
-
-static CORE_ADDR
-ppc64_linux_convert_from_func_ptr_addr (struct gdbarch *gdbarch,
- CORE_ADDR addr,
- struct target_ops *targ)
-{
- enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
- struct target_section *s = target_section_by_addr (targ, addr);
-
- /* Check if ADDR points to a function descriptor. */
- if (s && strcmp (s->the_bfd_section->name, ".opd") == 0)
- {
- /* There may be relocations that need to be applied to the .opd
- section. Unfortunately, this function may be called at a time
- where these relocations have not yet been performed -- this can
- happen for example shortly after a library has been loaded with
- dlopen, but ld.so has not yet applied the relocations.
-
- To cope with both the case where the relocation has been applied,
- and the case where it has not yet been applied, we do *not* read
- the (maybe) relocated value from target memory, but we instead
- read the non-relocated value from the BFD, and apply the relocation
- offset manually.
-
- This makes the assumption that all .opd entries are always relocated
- by the same offset the section itself was relocated. This should
- always be the case for GNU/Linux executables and shared libraries.
- Note that other kind of object files (e.g. those added via
- add-symbol-files) will currently never end up here anyway, as this
- function accesses *target* sections only; only the main exec and
- shared libraries are ever added to the target. */
-
- gdb_byte buf[8];
- int res;
-
- res = bfd_get_section_contents (s->bfd, s->the_bfd_section,
- &buf, addr - s->addr, 8);
- if (res != 0)
- return extract_unsigned_integer (buf, 8, byte_order)
- - bfd_section_vma (s->bfd, s->the_bfd_section) + s->addr;
- }
-
- return addr;
-}
-
/* Wrappers to handle Linux-only registers. */
static void
@@ -1742,7 +1333,7 @@ ppc_linux_init_abi (struct gdbarch_info info,
/* Handle PPC GNU/Linux 64-bit function pointers (which are really
function descriptors). */
set_gdbarch_convert_from_func_ptr_addr
- (gdbarch, ppc64_linux_convert_from_func_ptr_addr);
+ (gdbarch, ppc64_convert_from_func_ptr_addr);
/* Shared library handling. */
set_gdbarch_skip_trampoline_code (gdbarch, ppc64_skip_trampoline_code);
diff --git a/gdb/ppc-tdep.h b/gdb/ppc-tdep.h
index 9be9666..b268e90 100644
--- a/gdb/ppc-tdep.h
+++ b/gdb/ppc-tdep.h
@@ -291,6 +291,23 @@ enum {
PPC_NUM_REGS
};
+/* An instruction to match. */
+
+struct ppc_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. */
+};
+
+extern int
+ppc_insns_match_pattern (CORE_ADDR pc, struct ppc_insn_pattern *pattern,
+ unsigned int *insn);
+extern CORE_ADDR
+ppc_insn_d_field (unsigned int insn);
+
+extern CORE_ADDR
+ppc_insn_ds_field (unsigned int insn);
/* Instruction size. */
#define PPC_INSN_SIZE 4
diff --git a/gdb/ppc64-tdep.c b/gdb/ppc64-tdep.c
new file mode 100644
index 0000000..cdf8f4d
--- /dev/null
+++ b/gdb/ppc64-tdep.c
@@ -0,0 +1,364 @@
+/* Common target-dependent code for ppc64 GDB, the GNU debugger.
+
+ Copyright (C) 2013 Free Software
+ Foundation, Inc.
+
+ This file is part of GDB.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
+
+#include "defs.h"
+#include "frame.h"
+#include "gdbcore.h"
+#include "ppc-tdep.h"
+#include "ppc64-tdep.h"
+
+/* 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))
+
+/* If DESC is the address of a 64-bit PowerPC FreeBSD function
+ descriptor, return the descriptor's entry point. */
+
+static CORE_ADDR
+ppc64_desc_entry_point (struct gdbarch *gdbarch, CORE_ADDR desc)
+{
+ enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
+ /* The first word of the descriptor is the entry point. */
+ return (CORE_ADDR) read_memory_unsigned_integer (desc, 8, byte_order);
+}
+
+/* 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 ppc_insn_pattern ppc64_standard_linkage1[] =
+ {
+ /* 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, 12, 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, 12, 1), 1 },
+
+ /* mtctr r11 */
+ { insn_xfx (-1, -1, -1, -1), insn_xfx (31, 11, 9, 467), 0 },
+
+ /* ld r11, <any>(r12) <optional> */
+ { insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 11, 12, 0, 0), 1 },
+
+ /* bctr */
+ { -1, 0x4e800420, 0 },
+
+ { 0, 0, 0 }
+ };
+
+#define PPC64_STANDARD_LINKAGE1_LEN ARRAY_SIZE (ppc64_standard_linkage1)
+
+static struct ppc_insn_pattern ppc64_standard_linkage2[] =
+ {
+ /* 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 },
+
+ /* addi r12, r12, <any> <optional> */
+ { insn_d (-1, -1, -1, 0), insn_d (14, 12, 12, 0), 1 },
+
+ /* mtctr r11 */
+ { insn_xfx (-1, -1, -1, -1), insn_xfx (31, 11, 9, 467), 0 },
+
+ /* ld r2, <any>(r12) */
+ { insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 2, 12, 0, 0), 0 },
+
+ /* ld r11, <any>(r12) <optional> */
+ { insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 11, 12, 0, 0), 1 },
+
+ /* bctr */
+ { -1, 0x4e800420, 0 },
+
+ { 0, 0, 0 }
+ };
+
+#define PPC64_STANDARD_LINKAGE2_LEN ARRAY_SIZE (ppc64_standard_linkage2)
+
+static struct ppc_insn_pattern ppc64_standard_linkage3[] =
+ {
+ /* std r2, 40(r1) */
+ { -1, insn_ds (62, 2, 1, 40, 0), 0 },
+
+ /* ld r11, <any>(r2) */
+ { insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 11, 2, 0, 0), 0 },
+
+ /* addi r2, r2, <any> <optional> */
+ { insn_d (-1, -1, -1, 0), insn_d (14, 2, 2, 0), 1 },
+
+ /* mtctr r11 */
+ { insn_xfx (-1, -1, -1, -1), insn_xfx (31, 11, 9, 467), 0 },
+
+ /* ld r11, <any>(r2) <optional> */
+ { insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 11, 2, 0, 0), 1 },
+
+ /* ld r2, <any>(r2) */
+ { insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 2, 2, 0, 0), 0 },
+
+ /* bctr */
+ { -1, 0x4e800420, 0 },
+
+ { 0, 0, 0 }
+ };
+
+#define PPC64_STANDARD_LINKAGE3_LEN ARRAY_SIZE (ppc64_standard_linkage3)
+
+/* 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_linkage1_target (struct frame_info *frame,
+ CORE_ADDR pc, unsigned int *insn)
+{
+ struct gdbarch *gdbarch = get_frame_arch (frame);
+ struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+
+ /* The address of the function descriptor this linkage function
+ references. */
+ CORE_ADDR desc
+ = ((CORE_ADDR) get_frame_register_unsigned (frame,
+ tdep->ppc_gp0_regnum + 2)
+ + (ppc_insn_d_field (insn[0]) << 16)
+ + ppc_insn_ds_field (insn[2]));
+
+ /* The first word of the descriptor is the entry point. Return that. */
+ return ppc64_desc_entry_point (gdbarch, desc);
+}
+
+static CORE_ADDR
+ppc64_standard_linkage2_target (struct frame_info *frame,
+ CORE_ADDR pc, unsigned int *insn)
+{
+ struct gdbarch *gdbarch = get_frame_arch (frame);
+ struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+
+ /* The address of the function descriptor this linkage function
+ references. */
+ CORE_ADDR desc
+ = ((CORE_ADDR) get_frame_register_unsigned (frame,
+ tdep->ppc_gp0_regnum + 2)
+ + (ppc_insn_d_field (insn[0]) << 16)
+ + ppc_insn_ds_field (insn[2]));
+
+ /* The first word of the descriptor is the entry point. Return that. */
+ return ppc64_desc_entry_point (gdbarch, desc);
+}
+
+static CORE_ADDR
+ppc64_standard_linkage3_target (struct frame_info *frame,
+ CORE_ADDR pc, unsigned int *insn)
+{
+ struct gdbarch *gdbarch = get_frame_arch (frame);
+ struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+
+ /* The address of the function descriptor this linkage function
+ references. */
+ CORE_ADDR desc
+ = ((CORE_ADDR) get_frame_register_unsigned (frame,
+ tdep->ppc_gp0_regnum + 2)
+ + ppc_insn_ds_field (insn[1]));
+
+ /* The first word of the descriptor is the entry point. Return that. */
+ return ppc64_desc_entry_point (gdbarch, desc);
+}
+
+
+/* Given that we've begun executing a call trampoline at PC, return
+ the entry point of the function the trampoline will go to. */
+
+CORE_ADDR
+ppc64_skip_trampoline_code (struct frame_info *frame, CORE_ADDR pc)
+{
+ unsigned int ppc64_standard_linkage1_insn[PPC64_STANDARD_LINKAGE1_LEN];
+ unsigned int ppc64_standard_linkage2_insn[PPC64_STANDARD_LINKAGE2_LEN];
+ unsigned int ppc64_standard_linkage3_insn[PPC64_STANDARD_LINKAGE3_LEN];
+ CORE_ADDR target;
+
+ if (ppc_insns_match_pattern (pc, ppc64_standard_linkage1,
+ ppc64_standard_linkage1_insn))
+ pc = ppc64_standard_linkage1_target (frame, pc,
+ ppc64_standard_linkage1_insn);
+ else if (ppc_insns_match_pattern (pc, ppc64_standard_linkage2,
+ ppc64_standard_linkage2_insn))
+ pc = ppc64_standard_linkage2_target (frame, pc,
+ ppc64_standard_linkage2_insn);
+ else if (ppc_insns_match_pattern (pc, ppc64_standard_linkage3,
+ ppc64_standard_linkage3_insn))
+ pc = ppc64_standard_linkage3_target (frame, pc,
+ ppc64_standard_linkage3_insn);
+ else
+ return 0;
+
+ /* The PLT descriptor will either point to the already resolved target
+ address, or else to a glink stub. As the latter carry synthetic @plt
+ symbols, find_solib_trampoline_target should be able to resolve them. */
+ target = find_solib_trampoline_target (frame, pc);
+ return target ? target : pc;
+}
+
+/* Support for convert_from_func_ptr_addr (ARCH, ADDR, TARG) on PPC64
+ GNU/Linux.
+
+ Usually a function pointer's representation is simply the address
+ of the function. On GNU/Linux on the PowerPC however, a function
+ pointer may be a pointer to a function descriptor.
+
+ For PPC64, a function descriptor is a TOC entry, in a data section,
+ which contains three words: the first word is the address of the
+ function, the second word is the TOC pointer (r2), and the third word
+ is the static chain value.
+
+ Throughout GDB it is currently assumed that a function pointer contains
+ the address of the function, which is not easy to fix. In addition, the
+ conversion of a function address to a function pointer would
+ require allocation of a TOC entry in the inferior's memory space,
+ with all its drawbacks. To be able to call C++ virtual methods in
+ the inferior (which are called via function pointers),
+ find_function_addr uses this function to get the function address
+ from a function pointer.
+
+ If ADDR points at what is clearly a function descriptor, transform
+ it into the address of the corresponding function, if needed. Be
+ conservative, otherwise GDB will do the transformation on any
+ random addresses such as occur when there is no symbol table. */
+
+CORE_ADDR
+ppc64_convert_from_func_ptr_addr (struct gdbarch *gdbarch,
+ CORE_ADDR addr,
+ struct target_ops *targ)
+{
+ enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
+ struct target_section *s = target_section_by_addr (targ, addr);
+
+ /* Check if ADDR points to a function descriptor. */
+ if (s && strcmp (s->the_bfd_section->name, ".opd") == 0)
+ {
+ /* There may be relocations that need to be applied to the .opd
+ section. Unfortunately, this function may be called at a time
+ where these relocations have not yet been performed -- this can
+ happen for example shortly after a library has been loaded with
+ dlopen, but ld.so has not yet applied the relocations.
+
+ To cope with both the case where the relocation has been applied,
+ and the case where it has not yet been applied, we do *not* read
+ the (maybe) relocated value from target memory, but we instead
+ read the non-relocated value from the BFD, and apply the relocation
+ offset manually.
+
+ This makes the assumption that all .opd entries are always relocated
+ by the same offset the section itself was relocated. This should
+ always be the case for GNU/Linux executables and shared libraries.
+ Note that other kind of object files (e.g. those added via
+ add-symbol-files) will currently never end up here anyway, as this
+ function accesses *target* sections only; only the main exec and
+ shared libraries are ever added to the target. */
+
+ gdb_byte buf[8];
+ int res;
+
+ res = bfd_get_section_contents (s->bfd, s->the_bfd_section,
+ &buf, addr - s->addr, 8);
+ if (res != 0)
+ return extract_unsigned_integer (buf, 8, byte_order)
+ - bfd_section_vma (s->bfd, s->the_bfd_section) + s->addr;
+ }
+
+ return addr;
+}
diff --git a/gdb/ppc64-tdep.h b/gdb/ppc64-tdep.h
new file mode 100644
index 0000000..6fefdf3
--- /dev/null
+++ b/gdb/ppc64-tdep.h
@@ -0,0 +1,35 @@
+/* Common target-dependent code for ppc64.
+
+ Copyright (C) 2013
+ Free Software Foundation, Inc.
+
+ This file is part of GDB.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
+
+#ifndef PPC64_TDEP_H
+#define PPC64_TDEP_H
+
+struct gdbarch;
+struct frame_info;
+struct target_ops;
+
+extern CORE_ADDR
+ppc64_skip_trampoline_code (struct frame_info *frame, CORE_ADDR pc);
+
+extern CORE_ADDR
+ppc64_convert_from_func_ptr_addr (struct gdbarch *gdbarch,
+ CORE_ADDR addr, struct target_ops *targ);
+
+#endif /* PPC64_TDEP_H */
diff --git a/gdb/rs6000-tdep.c b/gdb/rs6000-tdep.c
index a15f757..5bc1105 100644
--- a/gdb/rs6000-tdep.c
+++ b/gdb/rs6000-tdep.c
@@ -4238,6 +4238,68 @@ show_powerpc_exact_watchpoints (struct ui_file *file, int from_tty,
fprintf_filtered (file, _("Use of exact watchpoints is %s.\n"), value);
}
+/* Read a PPC instruction from memory. PPC instructions are always
+ big-endian, no matter what endianness the program is running in, so
+ we can hardcode BFD_ENDIAN_BIG for read_memory_unsigned_integer. */
+
+static unsigned int
+read_insn (CORE_ADDR pc)
+{
+ return read_memory_unsigned_integer (pc, 4, BFD_ENDIAN_BIG);
+}
+
+/* Return non-zero if the instructions at PC match the series
+ described in PATTERN, or zero otherwise. PATTERN is an array of
+ 'struct ppc_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 0 (which is not a valid PPC instruction).
+ 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. */
+
+int
+ppc_insns_match_pattern (CORE_ADDR pc, struct ppc_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. */
+
+CORE_ADDR
+ppc_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. */
+
+CORE_ADDR
+ppc_insn_ds_field (unsigned int insn)
+{
+ return ((((CORE_ADDR) insn & 0xfffc) ^ 0x8000) - 0x8000);
+}
+
/* Initialization code. */
/* -Wmissing-prototypes */
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