Mercurial > hg > truffle
diff src/os/aix/vm/porting_aix.cpp @ 14415:666e6ce3976c
8023038: PPC64 (part 15): Platform files for AIX/PPC64 support
Reviewed-by: kvn
author | simonis |
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date | Fri, 06 Sep 2013 20:16:09 +0200 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/os/aix/vm/porting_aix.cpp Fri Sep 06 20:16:09 2013 +0200 @@ -0,0 +1,367 @@ +/* + * 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] + +}