PPC64 breakpoint support.

Support LocalEntryPoint for PPC64.

Signed-off-by: Xavier Pouyollon <xavier.pouyollon@windriver.com>

7 files changed, 54 insertions, 3 deletions

diff --git a/agent/tcf/services/breakpoints.c b/agent/tcf/services/breakpoints.c
index b74313c6..ed13c22e 100644
--- a/agent/tcf/services/breakpoints.c
+++ b/agent/tcf/services/breakpoints.c
@@ -1421,10 +1421,18 @@ static void plant_at_address_expression(Context * ctx, ContextAddress ip, Breakp
     ContextAddress size = 1;
     int error = 0;
     Value v;
-
+    SymbolProperties props;
+        
     if (evaluate_expression(ctx, STACK_NO_FRAME, ip, bp->location, 1, &v) < 0) error = errno;
     if (!error && value_to_address(&v, &addr) < 0) error = errno;
+    if (v.sym != NULL) {
+        /* We want to add the LocalEntryOffset */
+        get_symbol_props(v.sym, &props);     
+        /* If the symbol is not a PPC64 function, offset should be 0, so it is safe to add */
+        addr += props.local_entry_offset;
+    }
 #if ENABLE_SkipPrologueWhenPlanting
+    /* Even if addr is incremented by local_entry_offset, we still should be on right code area */
     if (!error && bp->skip_prologue && v.sym != NULL && skip_function_prologue(ctx, v.sym, &addr) < 0) error = errno;
 #endif
     if (bp->access_size > 0) {
@@ -1456,8 +1464,13 @@ static void plant_at_address_expression(Context * ctx, ContextAddress ip, Breakp
             unsigned n = 0;
             while (v.sym_list[n] != NULL) {
                 Symbol * sym = v.sym_list[n++];
-                if (get_symbol_address(sym, &addr) == 0) {
+                if (get_symbol_address(sym, &addr) == 0) {     
+                    /* We want to add the LocalEntryOffset */
+                    get_symbol_props(sym, &props);     
+                    /* If the symbol is not a PPC64 function, offset should be 0, so it is safe to add */
+                    addr += props.local_entry_offset;
 #if ENABLE_SkipPrologueWhenPlanting
+                    /* Even if addr is incremented by local_entry_offset, we still should be on right code area */
                     if (bp->skip_prologue) skip_function_prologue(ctx, sym, &addr);
 #endif
                     plant_breakpoint(ctx, bp, addr, size);
diff --git a/agent/tcf/services/symbols.c b/agent/tcf/services/symbols.c
index d146d7cb..edbf834f 100644
--- a/agent/tcf/services/symbols.c
+++ b/agent/tcf/services/symbols.c
@@ -303,6 +303,13 @@ static void command_get_context_cache_client(void * x) {
             write_stream(&c->out, ',');
         }
 
+        if (props.local_entry_offset != 0) {
+            json_write_string(&c->out, "LocalEntryOffset");
+            write_stream(&c->out, ':');
+            json_write_ulong(&c->out, props.local_entry_offset);
+            write_stream(&c->out, ',');
+        }
+        
         if (value != NULL) {
             json_write_string(&c->out, "Value");
             write_stream(&c->out, ':');
diff --git a/agent/tcf/services/symbols.h b/agent/tcf/services/symbols.h
index 143e9ac5..33a39972 100644
--- a/agent/tcf/services/symbols.h
+++ b/agent/tcf/services/symbols.h
@@ -91,7 +91,8 @@ typedef uint32_t SYM_FLAGS;
 typedef struct SymbolProperties {
     int binary_scale;   /* The exponent of the base two scale factor to be applied to an instance of the type */
     int decimal_scale;  /* The exponent of the base ten scale factor to be applied to an instance of the type */
-    unsigned bit_stride;
+    unsigned bit_stride; 
+    unsigned int local_entry_offset; /* Only PPC64 v2 supports it */	   
 } SymbolProperties;
 
 /* Symbol properties update policies */
diff --git a/agent/tcf/services/symbols_elf.c b/agent/tcf/services/symbols_elf.c
index a38655e6..c014961d 100644
--- a/agent/tcf/services/symbols_elf.c
+++ b/agent/tcf/services/symbols_elf.c
@@ -4147,6 +4147,11 @@ int get_symbol_flags(const Symbol * sym, SYM_FLAGS * flags) {
 }
 
 int get_symbol_props(const Symbol * sym, SymbolProperties * props) {
+#define STO_PPC64_LOCAL_BIT	5
+#define STO_PPC64_LOCAL_MASK	(7 << STO_PPC64_LOCAL_BIT)
+#define IS_PPC64_V2(elfsym) ((elfsym->file->machine == EM_PPC64) && (elfsym->file->flags & 0x3) == 2)
+	
+	ELF_SymbolInfo elf_sym_info;
     ObjectInfo * obj = sym->obj;
     assert(sym->magic == SYMBOL_MAGIC);
     memset(props, 0, sizeof(SymbolProperties));
@@ -4162,6 +4167,25 @@ int get_symbol_props(const Symbol * sym, SymbolProperties * props) {
             if (get_num_prop(obj, AT_stride_size, &n)) props->bit_stride = (unsigned)n;
         }
     }
+    
+    /* PowerPC64 ABIv2 computes local offset from st_other */
+    if (sym->tbl != NULL) {
+    	/* Only do that on PPC64 v2 */
+    	if (!IS_PPC64_V2(sym->tbl))
+    		return 0;
+    	unpack_elf_symbol_info(sym->tbl, sym->index, &elf_sym_info);
+    } else {
+    	Symbol *elf_symbol;
+    	/* From Dwarf object to Elf symbol */
+    	map_to_sym_table(sym->obj, &elf_symbol);
+    	if (elf_symbol == NULL)
+    		return 0;
+    	if (!IS_PPC64_V2(elf_symbol->tbl))
+    		return 0;
+    	unpack_elf_symbol_info(elf_symbol->tbl, elf_symbol->index, &elf_sym_info);
+    }
+	/* We can compute the offset now */
+	props->local_entry_offset = (((1 << (((elf_sym_info.other) & STO_PPC64_LOCAL_MASK) >> STO_PPC64_LOCAL_BIT)) >> 2) << 2);
     return 0;
 }
 
diff --git a/agent/tcf/services/symbols_proxy.c b/agent/tcf/services/symbols_proxy.c
index bc398e80..22e6bdd8 100644
--- a/agent/tcf/services/symbols_proxy.c
+++ b/agent/tcf/services/symbols_proxy.c
@@ -671,6 +671,7 @@ static void read_context_data(InputStream * inp, const char * name, void * args)
     else if (strcmp(name, "BinaryScale") == 0) s->props.binary_scale = (int)json_read_long(inp);
     else if (strcmp(name, "DecimalScale") == 0) s->props.decimal_scale = (int)json_read_long(inp);
     else if (strcmp(name, "BitStride") == 0) s->props.bit_stride = (unsigned)json_read_ulong(inp);
+    else if (strcmp(name, "LocalEntryOffset") == 0) s->props.local_entry_offset = (unsigned)json_read_ulong(inp);
     else if (strcmp(name, "Flags") == 0) s->flags = json_read_ulong(inp);
     else if (strcmp(name, "Frame") == 0) s->frame = (int)json_read_long(inp);
     else json_skip_object(inp);
diff --git a/agent/tcf/services/tcf_elf.c b/agent/tcf/services/tcf_elf.c
index 481188c0..a10f2c5c 100644
--- a/agent/tcf/services/tcf_elf.c
+++ b/agent/tcf/services/tcf_elf.c
@@ -1679,6 +1679,7 @@ void unpack_elf_symbol_info(ELF_Section * sym_sec, U4_T index, ELF_SymbolInfo *
             SWAP(s.st_shndx);
             SWAP(s.st_size);
             SWAP(s.st_value);
+            SWAP(s.st_other);
         }
         st_name = (size_t)s.st_name;
         info->section_index = s.st_shndx;
@@ -1686,6 +1687,7 @@ void unpack_elf_symbol_info(ELF_Section * sym_sec, U4_T index, ELF_SymbolInfo *
         info->type = ELF64_ST_TYPE(s.st_info);
         info->value = s.st_value;
         info->size = s.st_size;
+        info->other = s.st_other;
     }
     else {
         Elf32_Sym s = *(Elf32_Sym *)((U1_T *)sym_sec->data + sym_sec->entsize * index);
@@ -1694,6 +1696,7 @@ void unpack_elf_symbol_info(ELF_Section * sym_sec, U4_T index, ELF_SymbolInfo *
             SWAP(s.st_shndx);
             SWAP(s.st_size);
             SWAP(s.st_value);
+            SWAP(s.st_other);
         }
         st_name = (size_t)s.st_name;
         info->section_index = s.st_shndx;
@@ -1701,6 +1704,7 @@ void unpack_elf_symbol_info(ELF_Section * sym_sec, U4_T index, ELF_SymbolInfo *
         info->type = ELF32_ST_TYPE(s.st_info);
         info->value = s.st_value;
         info->size = s.st_size;
+        info->other = s.st_other;
     }
 
     if (info->section_index > 0 && info->section_index < file->section_cnt) {
diff --git a/agent/tcf/services/tcf_elf.h b/agent/tcf/services/tcf_elf.h
index a1129aed..8fe8997b 100644
--- a/agent/tcf/services/tcf_elf.h
+++ b/agent/tcf/services/tcf_elf.h
@@ -477,6 +477,7 @@ struct ELF_SymbolInfo {
     U1_T type;
     U8_T value;
     U8_T size;
+    U8_T other;
 };
 
 struct ELF_Section {