提交 7b9854d2 编写于 作者: Z zgu

7186778: MachO decoder implementation for MacOSX

Summary: Implementation of decoder for Apple's MacOSX. The implementation is based on the patch provided by Kevin Walls.
Reviewed-by: coleenp, kamg, kevinw
上级 b6ac67b7
...@@ -26,6 +26,139 @@ ...@@ -26,6 +26,139 @@
#ifdef __APPLE__ #ifdef __APPLE__
#include "decoder_machO.hpp" #include "decoder_machO.hpp"
#include <cxxabi.h>
#include <mach-o/loader.h>
#include <mach-o/nlist.h>
bool MachODecoder::demangle(const char* symbol, char *buf, int buflen) {
int status;
char* result;
size_t size = (size_t)buflen;
// Don't pass buf to __cxa_demangle. In case of the 'buf' is too small,
// __cxa_demangle will call system "realloc" for additional memory, which
// may use different malloc/realloc mechanism that allocates 'buf'.
if ((result = abi::__cxa_demangle(symbol, NULL, NULL, &status)) != NULL) {
jio_snprintf(buf, buflen, "%s", result);
// call c library's free
::free(result);
return true;
}
return false;
}
bool MachODecoder::decode(address addr, char *buf,
int buflen, int *offset, const void *mach_base) {
struct symtab_command * symt = (struct symtab_command *)
mach_find_command((struct mach_header_64 *)mach_base, LC_SYMTAB);
if (symt == NULL) {
DEBUG_ONLY(tty->print_cr("no symtab in mach file at 0x%lx", mach_base));
return false;
}
uint32_t off = symt->symoff; /* symbol table offset (within this mach file) */
uint32_t nsyms = symt->nsyms; /* number of symbol table entries */
uint32_t stroff = symt->stroff; /* string table offset */
uint32_t strsize = symt->strsize; /* string table size in bytes */
// iterate through symbol table trying to match our offset
uint32_t addr_relative = (uintptr_t) mach_base - (uintptr_t) addr; // offset we seek in the symtab
void * symtab_addr = (void*) ((uintptr_t) mach_base + off);
struct nlist_64 *cur_nlist = (struct nlist_64 *) symtab_addr;
struct nlist_64 *last_nlist = cur_nlist; // no size stored in an entry, so keep previously seen nlist
int32_t found_strx = 0;
int32_t found_symval = 0;
for (uint32_t i=0; i < nsyms; i++) {
uint32_t this_value = cur_nlist->n_value;
if (addr_relative == this_value) {
found_strx = cur_nlist->n_un.n_strx;
found_symval = this_value;
break;
} else if (addr_relative > this_value) {
// gone past it, use previously seen nlist:
found_strx = last_nlist->n_un.n_strx;
found_symval = last_nlist->n_value;
break;
}
last_nlist = cur_nlist;
cur_nlist = cur_nlist + sizeof(struct nlist_64);
}
if (found_strx == 0) {
return false;
}
// write the offset:
*offset = addr_relative - found_symval;
// lookup found_strx in the string table
char * symname = mach_find_in_stringtable((char*) ((uintptr_t)mach_base + stroff), strsize, found_strx);
if (symname) {
strncpy(buf, symname, buflen);
return true;
}
DEBUG_ONLY(tty->print_cr("no string or null string found."));
return false;
}
void* MachODecoder::mach_find_command(struct mach_header_64 * mach_base, uint32_t command_wanted) {
// possibly verify it is a mach_header, use magic number.
// commands begin immediately after the header.
struct load_command *pos = (struct load_command *) mach_base + sizeof(struct mach_header_64);
for (uint32_t i = 0; i < mach_base->ncmds; i++) {
struct load_command *this_cmd = (struct load_command *) pos;
if (this_cmd->cmd == command_wanted) {
return pos;
}
int cmdsize = this_cmd->cmdsize;
pos += cmdsize;
}
return NULL;
}
char* MachODecoder::mach_find_in_stringtable(char *strtab, uint32_t tablesize, int strx_wanted) {
if (strx_wanted == 0) {
return NULL;
}
char *strtab_end = strtab + tablesize;
// find the first string, skip over the space char
// (or the four zero bytes we see e.g. in libclient)
if (*strtab == ' ') {
strtab++;
if (*strtab != 0) {
DEBUG_ONLY(tty->print_cr("string table has leading space but no following zero."));
return NULL;
}
strtab++;
} else {
if ((uint32_t) *strtab != 0) {
DEBUG_ONLY(tty->print_cr("string table without leading space or leading int of zero."));
return NULL;
}
strtab+=4;
}
// read the real strings starting at index 1
int cur_strx = 1;
while (strtab < strtab_end) {
if (cur_strx == strx_wanted) {
return strtab;
}
// find start of next string
while (*strtab != 0) {
strtab++;
}
strtab++; // skip the terminating zero
cur_strx++;
}
DEBUG_ONLY(tty->print_cr("string number %d not found.", strx_wanted));
return NULL;
}
#endif #endif
...@@ -31,10 +31,25 @@ ...@@ -31,10 +31,25 @@
// Just a placehold for now, a real implementation should derive // Just a placehold for now, a real implementation should derive
// from AbstractDecoder // from AbstractDecoder
class MachODecoder : public NullDecoder { class MachODecoder : public AbstractDecoder {
public: public:
MachODecoder() { } MachODecoder() { }
~MachODecoder() { } ~MachODecoder() { }
virtual bool can_decode_C_frame_in_vm() const {
return true;
}
virtual bool demangle(const char* symbol, char* buf, int buflen);
virtual bool decode(address pc, char* buf, int buflen, int* offset,
const void* base);
virtual bool decode(address pc, char* buf, int buflen, int* offset,
const char* module_path = NULL) {
ShouldNotReachHere();
return false;
}
private:
void * mach_find_command(struct mach_header_64 * mach_base, uint32_t command_wanted);
char * mach_find_in_stringtable(char *strtab, uint32_t tablesize, int strx_wanted);
}; };
#endif #endif
......
...@@ -1946,10 +1946,16 @@ bool os::address_is_in_vm(address addr) { ...@@ -1946,10 +1946,16 @@ bool os::address_is_in_vm(address addr) {
return false; return false;
} }
#define MACH_MAXSYMLEN 256
bool os::dll_address_to_function_name(address addr, char *buf, bool os::dll_address_to_function_name(address addr, char *buf,
int buflen, int *offset) { int buflen, int *offset) {
Dl_info dlinfo; Dl_info dlinfo;
char localbuf[MACH_MAXSYMLEN];
// dladdr will find names of dynamic functions only, but does
// it set dli_fbase with mach_header address when it "fails" ?
if (dladdr((void*)addr, &dlinfo) && dlinfo.dli_sname != NULL) { if (dladdr((void*)addr, &dlinfo) && dlinfo.dli_sname != NULL) {
if (buf != NULL) { if (buf != NULL) {
if(!Decoder::demangle(dlinfo.dli_sname, buf, buflen)) { if(!Decoder::demangle(dlinfo.dli_sname, buf, buflen)) {
...@@ -1965,6 +1971,14 @@ bool os::dll_address_to_function_name(address addr, char *buf, ...@@ -1965,6 +1971,14 @@ bool os::dll_address_to_function_name(address addr, char *buf,
} }
} }
// Handle non-dymanic manually:
if (dlinfo.dli_fbase != NULL &&
Decoder::decode(addr, localbuf, MACH_MAXSYMLEN, offset, dlinfo.dli_fbase)) {
if(!Decoder::demangle(localbuf, buf, buflen)) {
jio_snprintf(buf, buflen, "%s", localbuf);
}
return true;
}
if (buf != NULL) buf[0] = '\0'; if (buf != NULL) buf[0] = '\0';
if (offset != NULL) *offset = -1; if (offset != NULL) *offset = -1;
return false; return false;
......
...@@ -72,10 +72,10 @@ void WindowsDecoder::initialize() { ...@@ -72,10 +72,10 @@ void WindowsDecoder::initialize() {
// find out if jvm.dll contains private symbols, by decoding // find out if jvm.dll contains private symbols, by decoding
// current function and comparing the result // current function and comparing the result
address addr = (address)Decoder::decode; address addr = (address)Decoder::demangle;
char buf[MAX_PATH]; char buf[MAX_PATH];
if (decode(addr, buf, sizeof(buf), NULL)) { if (decode(addr, buf, sizeof(buf), NULL)) {
_can_decode_in_vm = !strcmp(buf, "Decoder::decode"); _can_decode_in_vm = !strcmp(buf, "Decoder::demangle");
} }
} }
} }
......
...@@ -45,6 +45,10 @@ public: ...@@ -45,6 +45,10 @@ public:
bool can_decode_C_frame_in_vm() const; bool can_decode_C_frame_in_vm() const;
bool demangle(const char* symbol, char *buf, int buflen); bool demangle(const char* symbol, char *buf, int buflen);
bool decode(address addr, char *buf, int buflen, int* offset, const char* modulepath = NULL); bool decode(address addr, char *buf, int buflen, int* offset, const char* modulepath = NULL);
bool decode(address addr, char *buf, int buflen, int* offset, const void* base) {
ShouldNotReachHere();
return false;
}
private: private:
void initialize(); void initialize();
......
...@@ -91,6 +91,18 @@ bool Decoder::decode(address addr, char* buf, int buflen, int* offset, const cha ...@@ -91,6 +91,18 @@ bool Decoder::decode(address addr, char* buf, int buflen, int* offset, const cha
return decoder->decode(addr, buf, buflen, offset, modulepath); return decoder->decode(addr, buf, buflen, offset, modulepath);
} }
bool Decoder::decode(address addr, char* buf, int buflen, int* offset, const void* base) {
assert(_shared_decoder_lock != NULL, "Just check");
bool error_handling_thread = os::current_thread_id() == VMError::first_error_tid;
MutexLockerEx locker(error_handling_thread ? NULL : _shared_decoder_lock, true);
AbstractDecoder* decoder = error_handling_thread ?
get_error_handler_instance(): get_shared_instance();
assert(decoder != NULL, "null decoder");
return decoder->decode(addr, buf, buflen, offset, base);
}
bool Decoder::demangle(const char* symbol, char* buf, int buflen) { bool Decoder::demangle(const char* symbol, char* buf, int buflen) {
assert(_shared_decoder_lock != NULL, "Just check"); assert(_shared_decoder_lock != NULL, "Just check");
bool error_handling_thread = os::current_thread_id() == VMError::first_error_tid; bool error_handling_thread = os::current_thread_id() == VMError::first_error_tid;
......
...@@ -47,6 +47,8 @@ public: ...@@ -47,6 +47,8 @@ public:
// the function // the function
virtual bool decode(address pc, char* buf, int buflen, int* offset, virtual bool decode(address pc, char* buf, int buflen, int* offset,
const char* modulepath = NULL) = 0; const char* modulepath = NULL) = 0;
virtual bool decode(address pc, char* buf, int buflen, int* offset, const void* base) = 0;
// demangle a C++ symbol // demangle a C++ symbol
virtual bool demangle(const char* symbol, char* buf, int buflen) = 0; virtual bool demangle(const char* symbol, char* buf, int buflen) = 0;
// if the decoder can decode symbols in vm // if the decoder can decode symbols in vm
...@@ -82,6 +84,10 @@ public: ...@@ -82,6 +84,10 @@ public:
return false; return false;
} }
virtual bool decode(address pc, char* buf, int buflen, int* offset, const void* base) {
return false;
}
virtual bool demangle(const char* symbol, char* buf, int buflen) { virtual bool demangle(const char* symbol, char* buf, int buflen) {
return false; return false;
} }
...@@ -95,6 +101,7 @@ public: ...@@ -95,6 +101,7 @@ public:
class Decoder : AllStatic { class Decoder : AllStatic {
public: public:
static bool decode(address pc, char* buf, int buflen, int* offset, const char* modulepath = NULL); static bool decode(address pc, char* buf, int buflen, int* offset, const char* modulepath = NULL);
static bool decode(address pc, char* buf, int buflen, int* offset, const void* base);
static bool demangle(const char* symbol, char* buf, int buflen); static bool demangle(const char* symbol, char* buf, int buflen);
static bool can_decode_C_frame_in_vm(); static bool can_decode_C_frame_in_vm();
......
...@@ -43,6 +43,10 @@ public: ...@@ -43,6 +43,10 @@ public:
bool demangle(const char* symbol, char *buf, int buflen); bool demangle(const char* symbol, char *buf, int buflen);
bool decode(address addr, char *buf, int buflen, int* offset, const char* filepath = NULL); bool decode(address addr, char *buf, int buflen, int* offset, const char* filepath = NULL);
bool decode(address addr, char *buf, int buflen, int* offset, const void *base) {
ShouldNotReachHere();
return false;
}
private: private:
ElfFile* get_elf_file(const char* filepath); ElfFile* get_elf_file(const char* filepath);
......
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