| /* |
| * Copyright 2012, 2013 SAP AG. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. |
| * |
| * This code 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 |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| * |
| */ |
| |
| #include "asm/assembler.hpp" |
| #include "loadlib_aix.hpp" |
| #include "porting_aix.hpp" |
| #include "utilities/debug.hpp" |
| |
| #include <demangle.h> |
| #include <sys/debug.h> |
| |
| ////////////////////////////////// |
| // Provide implementation for dladdr based on LoadedLibraries pool and |
| // traceback table scan (see getFuncName). |
| |
| // Search traceback table in stack, |
| // return procedure name from trace back table. |
| #define MAX_FUNC_SEARCH_LEN 0x10000 |
| // Any PC below this value is considered toast. |
| #define MINIMUM_VALUE_FOR_PC ((unsigned int*)0x1024) |
| |
| #define PTRDIFF_BYTES(p1,p2) (((ptrdiff_t)p1) - ((ptrdiff_t)p2)) |
| |
| // Align a pointer without having to cast. |
| inline char* align_ptr_up(char* ptr, intptr_t alignment) { |
| return (char*) align_size_up((intptr_t)ptr, alignment); |
| } |
| |
| // Trace if verbose to tty. |
| // I use these now instead of the Xtrace system because the latter is |
| // not available at init time, hence worthless. Until we fix this, all |
| // tracing here is done with -XX:+Verbose. |
| #define trcVerbose(fmt, ...) { \ |
| if (Verbose) { \ |
| fprintf(stderr, fmt, ##__VA_ARGS__); \ |
| fputc('\n', stderr); fflush(stderr); \ |
| } \ |
| } |
| #define ERRBYE(s) { trcVerbose(s); return -1; } |
| |
| // Unfortunately, the interface of dladdr makes the implementator |
| // responsible for maintaining memory for function name/library |
| // name. I guess this is because most OS's keep those values as part |
| // of the mapped executable image ready to use. On AIX, this doesn't |
| // work, so I have to keep the returned strings. For now, I do this in |
| // a primitive string map. Should this turn out to be a performance |
| // problem, a better hashmap has to be used. |
| class fixed_strings { |
| struct node { |
| char* v; |
| node* next; |
| }; |
| |
| node* first; |
| |
| public: |
| |
| fixed_strings() : first(0) {} |
| ~fixed_strings() { |
| node* n = first; |
| while (n) { |
| node* p = n; |
| n = n->next; |
| free(p->v); |
| delete p; |
| } |
| } |
| |
| char* intern(const char* s) { |
| for (node* n = first; n; n = n->next) { |
| if (strcmp(n->v, s) == 0) { |
| return n->v; |
| } |
| } |
| node* p = new node; |
| p->v = strdup(s); |
| p->next = first; |
| first = p; |
| return p->v; |
| } |
| }; |
| |
| static fixed_strings dladdr_fixed_strings; |
| |
| // Given a code pointer, returns the function name and the displacement. |
| // Function looks for the traceback table at the end of the function. |
| extern "C" int getFuncName( |
| codeptr_t pc, // [in] program counter |
| char* p_name, size_t namelen, // [out] optional: function name ("" if not available) |
| int* p_displacement, // [out] optional: displacement (-1 if not available) |
| const struct tbtable** p_tb, // [out] optional: ptr to traceback table to get further |
| // information (NULL if not available) |
| char* p_errmsg, size_t errmsglen // [out] optional: user provided buffer for error messages |
| ) { |
| struct tbtable* tb = 0; |
| unsigned int searchcount = 0; |
| |
| // initialize output parameters |
| if (p_name && namelen > 0) { |
| *p_name = '\0'; |
| } |
| if (p_errmsg && errmsglen > 0) { |
| *p_errmsg = '\0'; |
| } |
| if (p_displacement) { |
| *p_displacement = -1; |
| } |
| if (p_tb) { |
| *p_tb = NULL; |
| } |
| |
| // weed out obvious bogus states |
| if (pc < MINIMUM_VALUE_FOR_PC) { |
| ERRBYE("invalid program counter"); |
| } |
| |
| codeptr_t pc2 = pc; |
| |
| // make sure the pointer is word aligned. |
| pc2 = (codeptr_t) align_ptr_up((char*)pc2, 4); |
| |
| // Find start of traceback table. |
| // (starts after code, is marked by word-aligned (32bit) zeros) |
| while ((*pc2 != NULL) && (searchcount++ < MAX_FUNC_SEARCH_LEN)) { |
| pc2++; |
| } |
| if (*pc2 != 0) { |
| ERRBYE("could not find traceback table within 5000 bytes of program counter"); |
| } |
| // |
| // Set up addressability to the traceback table |
| // |
| tb = (struct tbtable*) (pc2 + 1); |
| |
| // Is this really a traceback table? No way to be sure but |
| // some indicators we can check. |
| if (tb->tb.lang >= 0xf && tb->tb.lang <= 0xfb) { |
| // Language specifiers, go from 0 (C) to 14 (Objective C). |
| // According to spec, 0xf-0xfa reserved, 0xfb-0xff reserved for ibm. |
| ERRBYE("not a traceback table"); |
| } |
| |
| // Existence of fields in the tbtable extension are contingent upon |
| // specific fields in the base table. Check for their existence so |
| // that we can address the function name if it exists. |
| pc2 = (codeptr_t) tb + |
| sizeof(struct tbtable_short)/sizeof(int); |
| if (tb->tb.fixedparms != 0 || tb->tb.floatparms != 0) |
| pc2++; |
| |
| if (tb->tb.has_tboff == TRUE) { |
| |
| // I want to know the displacement |
| const unsigned int tb_offset = *pc2; |
| codeptr_t start_of_procedure = |
| (codeptr_t)(((char*)tb) - 4 - tb_offset); // (-4 to omit leading 0000) |
| |
| // Weed out the cases where we did find the wrong traceback table. |
| if (pc < start_of_procedure) { |
| ERRBYE("could not find (the real) traceback table within 5000 bytes of program counter"); |
| } |
| |
| // return the displacement |
| if (p_displacement) { |
| (*p_displacement) = (int) PTRDIFF_BYTES(pc, start_of_procedure); |
| } |
| |
| pc2++; |
| } else { |
| // return -1 for displacement |
| if (p_displacement) { |
| (*p_displacement) = -1; |
| } |
| } |
| |
| if (tb->tb.int_hndl == TRUE) |
| pc2++; |
| |
| if (tb->tb.has_ctl == TRUE) |
| pc2 += (*pc2) + 1; // don't care |
| |
| // |
| // return function name if it exists. |
| // |
| if (p_name && namelen > 0) { |
| if (tb->tb.name_present) { |
| char buf[256]; |
| const short l = MIN2<short>(*((short*)pc2), sizeof(buf) - 1); |
| memcpy(buf, (char*)pc2 + sizeof(short), l); |
| buf[l] = '\0'; |
| |
| p_name[0] = '\0'; |
| |
| // If it is a C++ name, try and demangle it using the Demangle interface (see demangle.h). |
| char* rest; |
| Name* const name = Demangle(buf, rest); |
| if (name) { |
| const char* const demangled_name = name->Text(); |
| if (demangled_name) { |
| strncpy(p_name, demangled_name, namelen-1); |
| p_name[namelen-1] = '\0'; |
| } |
| delete name; |
| } |
| |
| // Fallback: if demangling did not work, just provide the unmangled name. |
| if (p_name[0] == '\0') { |
| strncpy(p_name, buf, namelen-1); |
| p_name[namelen-1] = '\0'; |
| } |
| |
| } else { |
| strncpy(p_name, "<nameless function>", namelen-1); |
| p_name[namelen-1] = '\0'; |
| } |
| } |
| // Return traceback table, if user wants it. |
| if (p_tb) { |
| (*p_tb) = tb; |
| } |
| |
| return 0; |
| } |
| |
| // Special implementation of dladdr for Aix based on LoadedLibraries |
| // Note: dladdr returns non-zero for ok, 0 for error! |
| // Note: dladdr is not posix, but a non-standard GNU extension. So this tries to |
| // fulfill the contract of dladdr on Linux (see http://linux.die.net/man/3/dladdr) |
| // Note: addr may be both an AIX function descriptor or a real code pointer |
| // to the entry of a function. |
| extern "C" |
| int dladdr(void* addr, Dl_info* info) { |
| |
| if (!addr) { |
| return 0; |
| } |
| |
| assert(info, ""); |
| |
| int rc = 0; |
| |
| const char* const ZEROSTRING = ""; |
| |
| // Always return a string, even if a "" one. Linux dladdr manpage |
| // does not say anything about returning NULL |
| info->dli_fname = ZEROSTRING; |
| info->dli_sname = ZEROSTRING; |
| info->dli_saddr = NULL; |
| |
| address p = (address) addr; |
| const LoadedLibraryModule* lib = NULL; |
| |
| enum { noclue, code, data } type = noclue; |
| |
| trcVerbose("dladdr(%p)...", p); |
| |
| // Note: input address may be a function. I accept both a pointer to |
| // the entry of a function and a pointer to the function decriptor. |
| // (see ppc64 ABI) |
| lib = LoadedLibraries::find_for_text_address(p); |
| if (lib) { |
| type = code; |
| } |
| |
| if (!lib) { |
| // Not a pointer into any text segment. Is it a function descriptor? |
| const FunctionDescriptor* const pfd = (const FunctionDescriptor*) p; |
| p = pfd->entry(); |
| if (p) { |
| lib = LoadedLibraries::find_for_text_address(p); |
| if (lib) { |
| type = code; |
| } |
| } |
| } |
| |
| if (!lib) { |
| // Neither direct code pointer nor function descriptor. A data ptr? |
| p = (address)addr; |
| lib = LoadedLibraries::find_for_data_address(p); |
| if (lib) { |
| type = data; |
| } |
| } |
| |
| // If we did find the shared library this address belongs to (either |
| // code or data segment) resolve library path and, if possible, the |
| // symbol name. |
| if (lib) { |
| const char* const interned_libpath = |
| dladdr_fixed_strings.intern(lib->get_fullpath()); |
| if (interned_libpath) { |
| info->dli_fname = interned_libpath; |
| } |
| |
| if (type == code) { |
| |
| // For code symbols resolve function name and displacement. Use |
| // displacement to calc start of function. |
| char funcname[256] = ""; |
| int displacement = 0; |
| |
| if (getFuncName((codeptr_t) p, funcname, sizeof(funcname), &displacement, |
| NULL, NULL, 0) == 0) { |
| if (funcname[0] != '\0') { |
| const char* const interned = dladdr_fixed_strings.intern(funcname); |
| info->dli_sname = interned; |
| trcVerbose("... function name: %s ...", interned); |
| } |
| |
| // From the displacement calculate the start of the function. |
| if (displacement != -1) { |
| info->dli_saddr = p - displacement; |
| } else { |
| info->dli_saddr = p; |
| } |
| } else { |
| |
| // No traceback table found. Just assume the pointer is it. |
| info->dli_saddr = p; |
| |
| } |
| |
| } else if (type == data) { |
| |
| // For data symbols. |
| info->dli_saddr = p; |
| |
| } else { |
| ShouldNotReachHere(); |
| } |
| |
| rc = 1; // success: return 1 [sic] |
| |
| } |
| |
| // sanity checks. |
| if (rc) { |
| assert(info->dli_fname, ""); |
| assert(info->dli_sname, ""); |
| assert(info->dli_saddr, ""); |
| } |
| |
| return rc; // error: return 0 [sic] |
| |
| } |