From eea4ad2cce289753aaa35b4e0258a76d8f8f367c Mon Sep 17 00:00:00 2001

From: Thierry Fauck <thierry@linux.vnet.ibm.com>

Date: Tue, 13 May 2014 07:48:24 -0400

Subject: [PATCH] Support for powerpc64 arch ppc64el

Signed-off-by: Thierry Fauck <thierry@linux.vnet.ibm.com>

	Add support for ppc64le proc and ELF ABIv2.

	Provides support for irelative and wchar

---

 ltrace-elf.c                           |    2 +-

 ltrace-elf.h                           |    1 +

 sysdeps/linux-gnu/ppc/arch.h           |   35 ++++-

 sysdeps/linux-gnu/ppc/fetch.c          |  244 +++++++++++++++++++++++++++++---

 sysdeps/linux-gnu/ppc/plt.c            |   98 ++++++++++++--

 sysdeps/linux-gnu/ppc/trace.c          |   10 ++

 testsuite/ltrace.main/system_calls.exp |    2 +-

 7 files changed, 356 insertions(+), 36 deletions(-)

diff --git a/ltrace-elf.c b/ltrace-elf.c

index 8997518..f638342 100644

--- a/ltrace-elf.c

+++ b/ltrace-elf.c

@@ -859,7 +859,7 @@ populate_plt(struct process *proc, const char *filename,

 	return 0;

 }

-static void

+void

 delete_symbol_chain(struct library_symbol *libsym)

 {

 	while (libsym != NULL) {

diff --git a/ltrace-elf.h b/ltrace-elf.h

index db4ffe9..4a824c4 100644

--- a/ltrace-elf.h

+++ b/ltrace-elf.h

@@ -166,6 +166,7 @@ int elf_read_next_uleb128(Elf_Data *data, GElf_Xword *offset, uint64_t *retp);

 /* Return whether there's AMOUNT more bytes after OFFSET in DATA.  */

 int elf_can_read_next(Elf_Data *data, GElf_Xword offset, GElf_Xword amount);

+void delete_symbol_chain(struct library_symbol *);

 #if __WORDSIZE == 32

 #define PRI_ELF_ADDR		PRIx32

 #define GELF_ADDR_CAST(x)	(void *)(uint32_t)(x)

diff --git a/sysdeps/linux-gnu/ppc/arch.h b/sysdeps/linux-gnu/ppc/arch.h

index bf9b5dc..7918a13 100644

--- a/sysdeps/linux-gnu/ppc/arch.h

+++ b/sysdeps/linux-gnu/ppc/arch.h

@@ -23,8 +23,8 @@

 #define LTRACE_PPC_ARCH_H

 #include <gelf.h>

+#include <stdbool.h>

-#define BREAKPOINT_VALUE { 0x7f, 0xe0, 0x00, 0x08 }

 #define BREAKPOINT_LENGTH 4

 #define DECR_PC_AFTER_BREAK 0

@@ -34,8 +34,33 @@

 #ifdef __powerpc64__ // Says 'ltrace' is 64 bits, says nothing about target.

 #define LT_ELFCLASS2	ELFCLASS64

 #define LT_ELF_MACHINE2	EM_PPC64

-#define ARCH_SUPPORTS_OPD

-#endif

+

+# ifdef __LITTLE_ENDIAN__

+# define BREAKPOINT_VALUE { 0x08, 0x00, 0xe0, 0x7f }

+# define ARCH_ENDIAN_LITTLE

+# else

+# define BREAKPOINT_VALUE { 0x7f, 0xe0, 0x00, 0x08 }

+# define ARCH_SUPPORTS_OPD

+# define ARCH_ENDIAN_BIG

+# endif

+

+# if _CALL_ELF != 2

+# define ARCH_SUPPORTS_OPD

+# define STACK_FRAME_OVERHEAD 112

+#  ifndef EF_PPC64_ABI

+#  define EF_PPC64_ABI 3

+#  endif

+# else /* _CALL_ELF == 2 ABIv2 */

+# define STACK_FRAME_OVERHEAD 32

+# endif /* CALL_ELF */

+

+#else

+#define BREAKPOINT_VALUE { 0x7f, 0xe0, 0x00, 0x08 }

+#define ARCH_ENDIAN_BIG

+# ifndef EF_PPC64_ABI

+# define EF_PPC64_ABI 3

+# endif

+#endif 	/* __powerpc64__ */

 #define ARCH_HAVE_SW_SINGLESTEP

 #define ARCH_HAVE_ADD_PLT_ENTRY

@@ -43,7 +68,6 @@

 #define ARCH_HAVE_TRANSLATE_ADDRESS

 #define ARCH_HAVE_DYNLINK_DONE

 #define ARCH_HAVE_FETCH_ARG

-#define ARCH_ENDIAN_BIG

 #define ARCH_HAVE_SIZEOF

 #define ARCH_HAVE_ALIGNOF

@@ -56,7 +80,8 @@ struct arch_ltelf_data {

 	Elf_Data *opd_data;

 	GElf_Addr opd_base;

 	GElf_Xword opd_size;

-	int secure_plt;

+	bool secure_plt : 1;

+	bool elfv2_abi  : 1;

 	Elf_Data *reladyn;

 	size_t reladyn_count;

diff --git a/sysdeps/linux-gnu/ppc/fetch.c b/sysdeps/linux-gnu/ppc/fetch.c

index ed38336..c9381c3 100644

--- a/sysdeps/linux-gnu/ppc/fetch.c

+++ b/sysdeps/linux-gnu/ppc/fetch.c

@@ -30,9 +30,11 @@

 #include "ptrace.h"

 #include "proc.h"

 #include "value.h"

+#include "ltrace-elf.h"

 static int allocate_gpr(struct fetch_context *ctx, struct process *proc,

-			struct arg_type_info *info, struct value *valuep);

+			struct arg_type_info *info, struct value *valuep,

+			size_t off, bool is_hfa_type);

 /* Floating point registers have the same width on 32-bit as well as

  * 64-bit PPC, but <ucontext.h> presents a different API depending on

@@ -62,7 +64,10 @@ struct fetch_context {

 		gregs64_t r64;

 	} regs;

 	struct fpregs_t fpregs;

-

+	int vgreg;

+	int struct_size;

+	int struct_hfa_size;

+	int struct_hfa_count;

 };

 static int

@@ -74,7 +79,8 @@ fetch_context_init(struct process *proc, struct fetch_context *context)

 	if (proc->e_machine == EM_PPC)

 		context->stack_pointer = proc->stack_pointer + 8;

 	else

-		context->stack_pointer = proc->stack_pointer + 112;

+		context->stack_pointer = proc->stack_pointer

+			+ STACK_FRAME_OVERHEAD;

 	/* When ltrace is 64-bit, we might use PTRACE_GETREGS to

 	 * obtain 64-bit as well as 32-bit registers.  But if we do it

@@ -118,6 +124,11 @@ arch_fetch_arg_init(enum tof type, struct process *proc,

 		return NULL;

 	}

+	context->vgreg = context->greg;

+	context->struct_size = 0;

+	context->struct_hfa_size = 0;

+	context->struct_hfa_count = 0;

+

 	/* Aggregates or unions of any length, and character strings

 	 * of length longer than 8 bytes, will be returned in a

 	 * storage buffer allocated by the caller. The caller will

@@ -125,8 +136,20 @@ arch_fetch_arg_init(enum tof type, struct process *proc,

 	 * in r3, causing the first explicit argument to be passed in

 	 * r4.  */

 	context->ret_struct = ret_info->type == ARGTYPE_STRUCT;

-	if (context->ret_struct)

+	if (context->ret_struct) {

+#if _CALL_ELF == 2

+		/* if R3 points to stack, parameters will be in R4.  */

+		uint64_t pstack_end = ptrace(PTRACE_PEEKTEXT, proc->pid,

+					proc->stack_pointer, 0);

+		if (((arch_addr_t)context->regs.r64[3] > proc->stack_pointer)

+		    && (context->regs.r64[3] < pstack_end)) {

+			context->greg++;

+			context->stack_pointer += 8;

+		}

+#else

 		context->greg++;

+#endif

+	}

 	return context;

 }

@@ -144,7 +167,8 @@ arch_fetch_arg_clone(struct process *proc,

 static int

 allocate_stack_slot(struct fetch_context *ctx, struct process *proc,

-		    struct arg_type_info *info, struct value *valuep)

+		    struct arg_type_info *info, struct value *valuep,

+		    bool is_hfa_type)

 {

 	size_t sz = type_sizeof(proc, info);

 	if (sz == (size_t)-1)

@@ -154,7 +178,14 @@ allocate_stack_slot(struct fetch_context *ctx, struct process *proc,

 	size_t off = 0;

 	if (proc->e_machine == EM_PPC && a < 4)

 		a = 4;

+#if _CALL_ELF == 2

+	else if (proc->e_machine == EM_PPC64 && sz == 4 && is_hfa_type)

+		a = 4;

+	else

+		a = 8;

+#else

 	else if (proc->e_machine == EM_PPC64 && a < 8)

+#endif

 		a = 8;

 	/* XXX Remove the two double casts when arch_addr_t

@@ -164,7 +195,7 @@ allocate_stack_slot(struct fetch_context *ctx, struct process *proc,

 	if (valuep != NULL)

 		value_in_inferior(valuep, ctx->stack_pointer + off);

-	ctx->stack_pointer += sz;

+	ctx->stack_pointer += a;

 	return 0;

 }

@@ -216,19 +247,34 @@ align_small_int(unsigned char *buf, size_t w, size_t sz)

 static int

 allocate_gpr(struct fetch_context *ctx, struct process *proc,

-	     struct arg_type_info *info, struct value *valuep)

+	     struct arg_type_info *info, struct value *valuep,

+	     size_t off, bool is_hfa_type)

 {

 	if (ctx->greg > 10)

-		return allocate_stack_slot(ctx, proc, info, valuep);

+		return allocate_stack_slot(ctx, proc, info, valuep, is_hfa_type);

-	int reg_num = ctx->greg++;

-	if (valuep == NULL)

-		return 0;

+	int reg_num = ctx->greg;

 	size_t sz = type_sizeof(proc, info);

 	if (sz == (size_t)-1)

 		return -1;

 	assert(sz == 1 || sz == 2 || sz == 4 || sz == 8);

+#if _CALL_ELF == 2

+	/* Consume the stack slot corresponding to this arg.  */

+	if ((sz + off) >= 8)

+		ctx->greg++;

+

+	if (is_hfa_type)

+		ctx->stack_pointer += sz;

+	else

+		ctx->stack_pointer += 8;

+#else

+	ctx->greg++;

+#endif

+

+	if (valuep == NULL)

+		return 0;

+

 	if (value_reserve(valuep, sz) == NULL)

 		return -1;

@@ -240,13 +286,14 @@ allocate_gpr(struct fetch_context *ctx, struct process *proc,

 	u.i64 = read_gpr(ctx, proc, reg_num);

 	if (proc->e_machine == EM_PPC)

 		align_small_int(u.buf, 8, sz);

-	memcpy(value_get_raw_data(valuep), u.buf, sz);

+	memcpy(value_get_raw_data(valuep), u.buf + off, sz);

 	return 0;

 }

 static int

 allocate_float(struct fetch_context *ctx, struct process *proc,

-	       struct arg_type_info *info, struct value *valuep)

+	       struct arg_type_info *info, struct value *valuep,

+	       size_t off, bool is_hfa_type)

 {

 	int pool = proc->e_machine == EM_PPC64 ? 13 : 8;

 	if (ctx->freg <= pool) {

@@ -257,8 +304,12 @@ allocate_float(struct fetch_context *ctx, struct process *proc,

 		} u = { .d = ctx->fpregs.fpregs[ctx->freg] };

 		ctx->freg++;

+

+		if (!is_hfa_type)

+			ctx->vgreg++;

+

 		if (proc->e_machine == EM_PPC64)

-			allocate_gpr(ctx, proc, info, NULL);

+			allocate_gpr(ctx, proc, info, NULL, off, is_hfa_type);

 		size_t sz = sizeof(double);

 		if (info->type == ARGTYPE_FLOAT) {

@@ -272,8 +323,128 @@ allocate_float(struct fetch_context *ctx, struct process *proc,

 		memcpy(value_get_raw_data(valuep), u.buf, sz);

 		return 0;

 	}

-	return allocate_stack_slot(ctx, proc, info, valuep);

+	return allocate_stack_slot(ctx, proc, info, valuep, is_hfa_type);

+}

+

+#if _CALL_ELF == 2

+static int

+allocate_hfa(struct fetch_context *ctx, struct process *proc,

+	     struct arg_type_info *info, struct value *valuep,

+	     enum arg_type hfa_type, size_t hfa_count)

+{

+	size_t sz = type_sizeof(proc, info);

+	if (sz == (size_t)-1)

+		return -1;

+

+	ctx->struct_hfa_size += sz;

+

+	/* There are two changes regarding structure return types:

+	 * * heterogeneous float/vector structs are returned

+	 *   in (multiple) FP/vector registers,

+	 *   instead of via implicit reference.

+	 * * small structs (up to 16 bytes) are return

+	 *   in one or two GPRs, instead of via implicit reference.

+	 *

+	 * Other structures (larger than 16 bytes, not heterogeneous)

+	 * are still returned via implicit reference (i.e. a pointer

+	 * to memory where to return the struct being passed in r3).

+	 * Of course, whether or not an implicit reference pointer

+	 * is present will shift the remaining arguments,

+	 * so you need to get this right for ELFv2 in order

+	 * to get the arguments correct.

+	 * If an actual parameter is known to correspond to an HFA

+	 * formal parameter, each element is passed in the next

+	 * available floating-point argument register starting at fp1

+	 * until the fp13. The remaining elements of the aggregate are

+	 * passed on the stack.  */

+	size_t slot_off = 0;

+

+	unsigned char *buf = value_reserve(valuep, sz);

+	if (buf == NULL)

+		return -1;

+

+	struct arg_type_info *hfa_info = type_get_simple(hfa_type);

+	size_t hfa_sz = type_sizeof(proc, hfa_info);

+

+	if (hfa_count > 8)

+		ctx->struct_hfa_count += hfa_count;

+

+	while (hfa_count > 0 && ctx->freg <= 13) {

+		int rc;

+		struct value tmp;

+

+		value_init(&tmp, proc, NULL, hfa_info, 0);

+

+		/* Hetereogeneous struct - get value on GPR or stack.  */

+		if (((hfa_type == ARGTYPE_FLOAT

+		    || hfa_type == ARGTYPE_DOUBLE)

+		      && hfa_count <= 8))

+			rc = allocate_float(ctx, proc, hfa_info, &tmp,

+						slot_off, true);

+		else

+			rc = allocate_gpr(ctx, proc, hfa_info, &tmp,

+						slot_off, true);

+

+		memcpy(buf, value_get_data(&tmp, NULL), hfa_sz);

+

+		slot_off += hfa_sz;

+		buf += hfa_sz;

+		hfa_count--;

+		if (slot_off == 8) {

+			slot_off = 0;

+			ctx->vgreg++;

+		}

+

+		value_destroy(&tmp);

+		if (rc < 0)

+			return -1;

+	}

+	if (hfa_count == 0)

+		return 0;

+

+	/* if no remaining FP, GPR corresponding to slot is used

+	* Mostly it is in part of r10.  */

+	if (ctx->struct_hfa_size <= 64 && ctx->vgreg == 10) {

+		while (ctx->vgreg <= 10) {

+			struct value tmp;

+			value_init(&tmp, proc, NULL, hfa_info, 0);

+			union {

+				uint64_t i64;

+				unsigned char buf[0];

+			} u;

+

+			u.i64 = read_gpr(ctx, proc, ctx->vgreg);

+

+			memcpy(buf, u.buf + slot_off, hfa_sz);

+			slot_off += hfa_sz;

+			buf += hfa_sz;

+			hfa_count--;

+			ctx->stack_pointer += hfa_sz;

+			if (slot_off >= 8 ) {

+				slot_off = 0;

+				ctx->vgreg++;

+			}

+			value_destroy(&tmp);

+		}

+	}

+

+	if (hfa_count == 0)

+		return 0;

+

+	/* Remaining values are on stack */

+	while (hfa_count) {

+		struct value tmp;

+		value_init(&tmp, proc, NULL, hfa_info, 0);

+

+		value_in_inferior(&tmp, ctx->stack_pointer);

+		memcpy(buf, value_get_data(&tmp, NULL), hfa_sz);

+		ctx->stack_pointer += hfa_sz;

+		buf += hfa_sz;

+		hfa_count--;

+	}

+	return 0;

 }

+#endif

 static int

 allocate_argument(struct fetch_context *ctx, struct process *proc,

@@ -287,13 +458,25 @@ allocate_argument(struct fetch_context *ctx, struct process *proc,

 	case ARGTYPE_FLOAT:

 	case ARGTYPE_DOUBLE:

-		return allocate_float(ctx, proc, info, valuep);

+		return allocate_float(ctx, proc, info, valuep,

+					8 - type_sizeof(proc,info), false);

 	case ARGTYPE_STRUCT:

 		if (proc->e_machine == EM_PPC) {

 			if (value_pass_by_reference(valuep) < 0)

 				return -1;

 		} else {

+#if _CALL_ELF == 2

+			struct arg_type_info *hfa_info;

+			size_t hfa_size;

+			hfa_info = type_get_hfa_type(info, &hfa_size);

+			if (hfa_info != NULL ) {

+				size_t sz = type_sizeof(proc, info);

+				ctx->struct_size += sz;

+				return allocate_hfa(ctx, proc, info, valuep,

+						hfa_info->type, hfa_size);

+			}

+#endif

 			/* PPC64: Fixed size aggregates and unions passed by

 			 * value are mapped to as many doublewords of the

 			 * parameter save area as the value uses in memory.

@@ -326,6 +509,10 @@ allocate_argument(struct fetch_context *ctx, struct process *proc,

 	size_t sz = type_sizeof(proc, valuep->type);

 	if (sz == (size_t)-1)

 		return -1;

+

+	if (ctx->ret_struct)

+		ctx->struct_size += sz;

+

 	size_t slots = (sz + width - 1) / width;  /* Round up.  */

 	unsigned char *buf = value_reserve(valuep, slots * width);

 	if (buf == NULL)

@@ -346,9 +533,11 @@ allocate_argument(struct fetch_context *ctx, struct process *proc,

 		struct arg_type_info *fp_info

 			= type_get_fp_equivalent(valuep->type);

 		if (fp_info != NULL)

-			rc = allocate_float(ctx, proc, fp_info, &val;;

+			rc = allocate_float(ctx, proc, fp_info, &val,

+					8-type_sizeof(proc,info), false);

 		else

-			rc = allocate_gpr(ctx, proc, long_info, &val;;

+			rc = allocate_gpr(ctx, proc, long_info, &val,

+					0, false);

 		if (rc >= 0) {

 			memcpy(ptr, value_get_data(&val, NULL), width);

@@ -363,6 +552,7 @@ allocate_argument(struct fetch_context *ctx, struct process *proc,

 			return rc;

 	}

+#ifndef __LITTLE_ENDIAN__

 	/* Small values need post-processing.  */

 	if (sz < width) {

 		switch (info->type) {

@@ -394,6 +584,7 @@ allocate_argument(struct fetch_context *ctx, struct process *proc,

 			break;

 		}

 	}

+#endif

 	return 0;

 }

@@ -411,7 +602,22 @@ arch_fetch_retval(struct fetch_context *ctx, enum tof type,

 		  struct process *proc, struct arg_type_info *info,

 		  struct value *valuep)

 {

+	if (fetch_context_init(proc, ctx) < 0)

+		return -1;

+

+#if _CALL_ELF == 2

+	void *ptr = (void *)(ctx->regs.r64[1]+32);

+	uint64_t val = ptrace(PTRACE_PEEKTEXT, proc->pid, ptr, 0);

+

+	if (ctx->ret_struct

+	   && ((ctx->struct_size > 64

+	      || ctx->struct_hfa_count > 8

+	      || (ctx->struct_hfa_size == 0 && ctx->struct_size > 56)

+	      || (ctx->regs.r64[3] == ctx->regs.r64[1]+32)

+	      || (ctx->regs.r64[3] == val )))) {

+#else

 	if (ctx->ret_struct) {

+#endif

 		assert(info->type == ARGTYPE_STRUCT);

 		uint64_t addr = read_gpr(ctx, proc, 3);

@@ -424,8 +630,6 @@ arch_fetch_retval(struct fetch_context *ctx, enum tof type,

 		return 0;

 	}

-	if (fetch_context_init(proc, ctx) < 0)

-		return -1;

 	return allocate_argument(ctx, proc, info, valuep);

 }

diff --git a/sysdeps/linux-gnu/ppc/plt.c b/sysdeps/linux-gnu/ppc/plt.c

index 332daa8..45ed7fb 100644

--- a/sysdeps/linux-gnu/ppc/plt.c

+++ b/sysdeps/linux-gnu/ppc/plt.c

@@ -136,7 +136,11 @@

  */

 #define PPC_PLT_STUB_SIZE 16

-#define PPC64_PLT_STUB_SIZE 8 //xxx

+#if _CALL_ELF != 2

+#define PPC64_PLT_STUB_SIZE 8

+#else

+#define PPC64_PLT_STUB_SIZE 4

+#endif

 static inline int

 host_powerpc64()

@@ -186,8 +190,13 @@ ppc32_delayed_symbol(struct library_symbol *libsym)

 	if ((insn1 & BRANCH_MASK) == B_INSN

 	    || ((insn2 & BRANCH_MASK) == B_INSN

 		/* XXX double cast  */

+#ifdef __LITTLE_ENDIAN__

+		&& (ppc_branch_dest(libsym->enter_addr + 4, insn1)

+		    == (arch_addr_t) (long) libsym->lib->arch.pltgot_addr)))

+#else

 		&& (ppc_branch_dest(libsym->enter_addr + 4, insn2)

 		    == (arch_addr_t) (long) libsym->lib->arch.pltgot_addr)))

+#endif

 	{

 		mark_as_resolved(libsym, libsym->arch.resolved_value);

 	}

@@ -206,7 +215,7 @@ arch_dynlink_done(struct process *proc)

 				"couldn't read PLT value for %s(%p): %s\n",

 				libsym->name, libsym->enter_addr,

 				strerror(errno));

-			return;

+				return;

 		}

 		if (proc->e_machine == EM_PPC)

@@ -227,8 +236,14 @@ reloc_is_irelative(int machine, GElf_Rela *rela)

 {

 	bool irelative = false;

 	if (machine == EM_PPC64) {

-#ifdef R_PPC64_JMP_IREL

+#ifdef __LITTLE_ENDIAN__

+# ifdef R_PPC64_IRELATIVE

+		irelative = GELF_R_TYPE(rela->r_info) == R_PPC64_IRELATIVE;

+# endif

+#else

+# ifdef R_PPC64_JMP_IREL

 		irelative = GELF_R_TYPE(rela->r_info) == R_PPC64_JMP_IREL;

+# endif

 #endif

 	} else {

 		assert(machine == EM_PPC);

@@ -285,6 +300,7 @@ arch_translate_address_dyn(struct process *proc,

 			   arch_addr_t addr, arch_addr_t *ret)

 {

 	if (proc->e_machine == EM_PPC64) {

+#if _CALL_ELF != 2

 		uint64_t value;

 		if (proc_read_64(proc, addr, &value) < 0) {

 			fprintf(stderr,

@@ -296,6 +312,7 @@ arch_translate_address_dyn(struct process *proc,

 		 * arch_addr_t becomes integral type.  */

 		*ret = (arch_addr_t)(uintptr_t)value;

 		return 0;

+#endif

 	}

 	*ret = addr;

@@ -306,7 +323,8 @@ int

 arch_translate_address(struct ltelf *lte,

 		       arch_addr_t addr, arch_addr_t *ret)

 {

-	if (lte->ehdr.e_machine == EM_PPC64) {

+	if (lte->ehdr.e_machine == EM_PPC64

+	    && !lte->arch.elfv2_abi) {

 		/* XXX The double cast should be removed when

 		 * arch_addr_t becomes integral type.  */

 		GElf_Xword offset

@@ -430,7 +448,16 @@ reloc_copy_if_irelative(GElf_Rela *rela, void *data)

 int

 arch_elf_init(struct ltelf *lte, struct library *lib)

 {

+

+	/* Check for ABIv2 in ELF header processor specific flag.  */

+#ifndef EF_PPC64_ABI

+	assert (! (lte->ehdr.e_flags & 3 ) == 2)

+#else

+	lte->arch.elfv2_abi=((lte->ehdr.e_flags & EF_PPC64_ABI) == 2) ;

+#endif

+

 	if (lte->ehdr.e_machine == EM_PPC64

+	    && !lte->arch.elfv2_abi

 	    && load_opd_data(lte, lib) < 0)

 		return -1;

@@ -599,7 +626,7 @@ read_plt_slot_value(struct process *proc, GElf_Addr addr, GElf_Addr *valp)

 	uint64_t l;

 	/* XXX double cast.  */

 	if (proc_read_64(proc, (arch_addr_t)(uintptr_t)addr, &l) < 0) {

-		fprintf(stderr, "ptrace .plt slot value @%#" PRIx64": %s\n",

+		debug(DEBUG_EVENT, "ptrace .plt slot value @%#" PRIx64": %s",

 			addr, strerror(errno));

 		return -1;

 	}

@@ -616,7 +643,7 @@ unresolve_plt_slot(struct process *proc, GElf_Addr addr, GElf_Addr value)

 	 * pointers intact.  Hence the only adjustment that we need to

 	 * do is to IP.  */

 	if (ptrace(PTRACE_POKETEXT, proc->pid, addr, value) < 0) {

-		fprintf(stderr, "failed to unresolve .plt slot: %s\n",

+		debug(DEBUG_EVENT, "failed to unresolve .plt slot: %s",

 			strerror(errno));

 		return -1;

 	}

@@ -629,9 +656,48 @@ arch_elf_add_func_entry(struct process *proc, struct ltelf *lte,

 			arch_addr_t addr, const char *name,

 			struct library_symbol **ret)

 {

-	if (lte->ehdr.e_machine != EM_PPC || lte->ehdr.e_type == ET_DYN)

+#ifndef PPC64_LOCAL_ENTRY_OFFSET

+	assert(! lte->arch.elfv2_abi);

+#else

+	/* With ABIv2 st_other field contains an offset.  */

+	 if (lte->arch.elfv2_abi)

+		addr += PPC64_LOCAL_ENTRY_OFFSET(sym->st_other);

+#endif

+

+	int st_info = GELF_ST_TYPE(sym->st_info);

+

+	if ((lte->ehdr.e_machine != EM_PPC && sym->st_other == 0)

+	    || lte->ehdr.e_type == ET_DYN

+	    || (st_info == STT_FUNC && ! sym->st_other))

 		return PLT_DEFAULT;

+	if (st_info == STT_FUNC) {

+		/* Put the default symbol to the chain.

+		 * The addr has already been updated with

+		 * symbol offset  */

+		char *full_name = strdup(name);

+		if (full_name == NULL) {

+			fprintf(stderr, "couldn't copy name of %s: %s\n",

+			name, strerror(errno));

+			free(full_name);

+			return PLT_FAIL;

+		}

+		struct library_symbol *libsym = malloc(sizeof *libsym);

+		if (libsym == NULL

+		    || library_symbol_init(libsym, addr, full_name, 1,

+					   LS_TOPLT_NONE) < 0) {

+			free(libsym);

+			delete_symbol_chain(libsym);

+			libsym = NULL;

+			fprintf(stderr, "Couldn't add symbol %s"

+				"for tracing.\n", name);

+		}

+		full_name = NULL;

+		libsym->next = *ret;

+		*ret = libsym;

+		return PLT_OK;

+	}

+

 	bool ifunc = false;

 #ifdef STT_GNU_IFUNC

 	ifunc = GELF_ST_TYPE(sym->st_info) == STT_GNU_IFUNC;

@@ -761,9 +827,15 @@ arch_elf_add_plt_entry(struct process *proc, struct ltelf *lte,

 	assert(plt_slot_addr >= lte->plt_addr

 	       || plt_slot_addr < lte->plt_addr + lte->plt_size);

+	/* Should avoid to do read if dynamic linker hasn't run yet

+	 * or allow -1 a valid return code.  */

 	GElf_Addr plt_slot_value;

-	if (read_plt_slot_value(proc, plt_slot_addr, &plt_slot_value) < 0)

-		goto fail;

+	if (read_plt_slot_value(proc, plt_slot_addr, &plt_slot_value) < 0) {

+		if (!lte->arch.elfv2_abi)

+			goto fail;

+		else

+			return PPC_PLT_UNRESOLVED;

+	}

 	struct library_symbol *libsym = malloc(sizeof(*libsym));

 	if (libsym == NULL) {

@@ -997,8 +1069,12 @@ ppc_plt_bp_continue(struct breakpoint *bp, struct process *proc)

 			return;

 		}

+#if _CALL_ELF == 2

+		continue_after_breakpoint(proc, bp);

+#else

 		jump_to_entry_point(proc, bp);

 		continue_process(proc->pid);

+#endif

 		return;

 	case PPC64_PLT_STUB:

@@ -1123,7 +1199,11 @@ arch_library_symbol_init(struct library_symbol *libsym)

 	/* We set type explicitly in the code above, where we have the