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author | William Joye <wjoye@cfa.harvard.edu> | 2016-12-21 22:56:22 (GMT) |
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committer | William Joye <wjoye@cfa.harvard.edu> | 2016-12-21 22:56:22 (GMT) |
commit | d1a6de55efc90f190dee42ab8c4fa9070834e77d (patch) | |
tree | ec633f5608ef498bee52a5f42c12c49493ec8bf8 /tcl8.6/unix/tclLoadAix.c | |
parent | 5514e37335c012cc70f5b9aee3cedfe3d57f583f (diff) | |
parent | 98acd3f494b28ddd8c345a2bb9311e41e2d56ddd (diff) | |
download | blt-d1a6de55efc90f190dee42ab8c4fa9070834e77d.zip blt-d1a6de55efc90f190dee42ab8c4fa9070834e77d.tar.gz blt-d1a6de55efc90f190dee42ab8c4fa9070834e77d.tar.bz2 |
Merge commit '98acd3f494b28ddd8c345a2bb9311e41e2d56ddd' as 'tcl8.6'
Diffstat (limited to 'tcl8.6/unix/tclLoadAix.c')
-rw-r--r-- | tcl8.6/unix/tclLoadAix.c | 630 |
1 files changed, 630 insertions, 0 deletions
diff --git a/tcl8.6/unix/tclLoadAix.c b/tcl8.6/unix/tclLoadAix.c new file mode 100644 index 0000000..88e6b50 --- /dev/null +++ b/tcl8.6/unix/tclLoadAix.c @@ -0,0 +1,630 @@ +/* + * tclLoadAix.c -- + * + * This file implements the dlopen and dlsym APIs under the AIX operating + * system, to enable the Tcl "load" command to work. This code was + * provided by Jens-Uwe Mager. + * + * This file is subject to the following copyright notice, which is + * different from the notice used elsewhere in Tcl. The file has been + * modified to incorporate the file dlfcn.h in-line. + * + * Copyright (c) 1992,1993,1995,1996, Jens-Uwe Mager, Helios Software GmbH + * Not derived from licensed software. + * + * Permission is granted to freely use, copy, modify, and redistribute + * this software, provided that the author is not construed to be liable + * for any results of using the software, alterations are clearly marked + * as such, and this notice is not modified. + * + * Note: this file has been altered from the original in a few ways in order + * to work properly with Tcl. + */ + +/* + * @(#)dlfcn.c 1.7 revision of 95/08/14 19:08:38 + * This is an unpublished work copyright (c) 1992 HELIOS Software GmbH + * 30159 Hannover, Germany + */ + +#include <stdio.h> +#include <errno.h> +#include <string.h> +#include <stdlib.h> +#include <sys/types.h> +#include <sys/ldr.h> +#include <a.out.h> +#include <ldfcn.h> +#include "../compat/dlfcn.h" + +/* + * We simulate dlopen() et al. through a call to load. Because AIX has no call + * to find an exported symbol we read the loader section of the loaded module + * and build a list of exported symbols and their virtual address. + */ + +typedef struct { + char *name; /* The symbols's name. */ + void *addr; /* Its relocated virtual address. */ +} Export, *ExportPtr; + +/* + * xlC uses the following structure to list its constructors and destructors. + * This is gleaned from the output of munch. + */ + +typedef struct { + void (*init)(void); /* call static constructors */ + void (*term)(void); /* call static destructors */ +} Cdtor, *CdtorPtr; + +/* + * The void * handle returned from dlopen is actually a ModulePtr. + */ + +typedef struct Module { + struct Module *next; + char *name; /* module name for refcounting */ + int refCnt; /* the number of references */ + void *entry; /* entry point from load */ + struct dl_info *info; /* optional init/terminate functions */ + CdtorPtr cdtors; /* optional C++ constructors */ + int nExports; /* the number of exports found */ + ExportPtr exports; /* the array of exports */ +} Module, *ModulePtr; + +/* + * We keep a list of all loaded modules to be able to call the fini handlers + * and destructors at atexit() time. + */ + +static ModulePtr modList; + +/* + * The last error from one of the dl* routines is kept in static variables + * here. Each error is returned only once to the caller. + */ + +static char errbuf[BUFSIZ]; +static int errvalid; + +static void caterr(char *); +static int readExports(ModulePtr); +static void terminate(void); +static void *findMain(void); + +void * +dlopen( + const char *path, + int mode) +{ + register ModulePtr mp; + static void *mainModule; + + /* + * Upon the first call register a terminate handler that will close all + * libraries. Also get a reference to the main module for use with + * loadbind. + */ + + if (!mainModule) { + mainModule = findMain(); + if (mainModule == NULL) { + return NULL; + } + atexit(terminate); + } + + /* + * Scan the list of modules if we have the module already loaded. + */ + + for (mp = modList; mp; mp = mp->next) { + if (strcmp(mp->name, path) == 0) { + mp->refCnt++; + return (void *) mp; + } + } + + mp = (ModulePtr) calloc(1, sizeof(*mp)); + if (mp == NULL) { + errvalid++; + strcpy(errbuf, "calloc: "); + strcat(errbuf, strerror(errno)); + return NULL; + } + + mp->name = malloc((unsigned) (strlen(path) + 1)); + strcpy(mp->name, path); + + /* + * load should be declared load(const char *...). Thus we cast the path to + * a normal char *. Ugly. + */ + + mp->entry = (void *) load((char *)path, L_NOAUTODEFER, NULL); + if (mp->entry == NULL) { + free(mp->name); + free(mp); + errvalid++; + strcpy(errbuf, "dlopen: "); + strcat(errbuf, path); + strcat(errbuf, ": "); + + /* + * If AIX says the file is not executable, the error can be further + * described by querying the loader about the last error. + */ + + if (errno == ENOEXEC) { + char *tmp[BUFSIZ/sizeof(char *)], **p; + + if (loadquery(L_GETMESSAGES, tmp, sizeof(tmp)) == -1) { + strcpy(errbuf, strerror(errno)); + } else { + for (p=tmp ; *p ; p++) { + caterr(*p); + } + } + } else { + strcat(errbuf, strerror(errno)); + } + return NULL; + } + + mp->refCnt = 1; + mp->next = modList; + modList = mp; + + if (loadbind(0, mainModule, mp->entry) == -1) { + loadbindFailure: + dlclose(mp); + errvalid++; + strcpy(errbuf, "loadbind: "); + strcat(errbuf, strerror(errno)); + return NULL; + } + + /* + * If the user wants global binding, loadbind against all other loaded + * modules. + */ + + if (mode & RTLD_GLOBAL) { + register ModulePtr mp1; + + for (mp1 = mp->next; mp1; mp1 = mp1->next) { + if (loadbind(0, mp1->entry, mp->entry) == -1) { + goto loadbindFailure; + } + } + } + + if (readExports(mp) == -1) { + dlclose(mp); + return NULL; + } + + /* + * If there is a dl_info structure, call the init function. + */ + + if (mp->info = (struct dl_info *)dlsym(mp, "dl_info")) { + if (mp->info->init) { + mp->info->init(); + } + } else { + errvalid = 0; + } + + /* + * If the shared object was compiled using xlC we will need to call static + * constructors (and later on dlclose destructors). + */ + + if (mp->cdtors = (CdtorPtr) dlsym(mp, "__cdtors")) { + while (mp->cdtors->init) { + mp->cdtors->init(); + mp->cdtors++; + } + } else { + errvalid = 0; + } + + return (void *) mp; +} + +/* + * Attempt to decipher an AIX loader error message and append it to our static + * error message buffer. + */ + +static void +caterr( + char *s) +{ + register char *p = s; + + while (*p >= '0' && *p <= '9') { + p++; + } + switch (atoi(s)) { /* INTL: "C", UTF safe. */ + case L_ERROR_TOOMANY: + strcat(errbuf, "to many errors"); + break; + case L_ERROR_NOLIB: + strcat(errbuf, "can't load library"); + strcat(errbuf, p); + break; + case L_ERROR_UNDEF: + strcat(errbuf, "can't find symbol"); + strcat(errbuf, p); + break; + case L_ERROR_RLDBAD: + strcat(errbuf, "bad RLD"); + strcat(errbuf, p); + break; + case L_ERROR_FORMAT: + strcat(errbuf, "bad exec format in"); + strcat(errbuf, p); + break; + case L_ERROR_ERRNO: + strcat(errbuf, strerror(atoi(++p))); /* INTL: "C", UTF safe. */ + break; + default: + strcat(errbuf, s); + break; + } +} + +void * +dlsym( + void *handle, + const char *symbol) +{ + register ModulePtr mp = (ModulePtr)handle; + register ExportPtr ep; + register int i; + + /* + * Could speed up the search, but I assume that one assigns the result to + * function pointers anyways. + */ + + for (ep = mp->exports, i = mp->nExports; i; i--, ep++) { + if (strcmp(ep->name, symbol) == 0) { + return ep->addr; + } + } + + errvalid++; + strcpy(errbuf, "dlsym: undefined symbol "); + strcat(errbuf, symbol); + return NULL; +} + +char * +dlerror(void) +{ + if (errvalid) { + errvalid = 0; + return errbuf; + } + return NULL; +} + +int +dlclose( + void *handle) +{ + register ModulePtr mp = (ModulePtr)handle; + int result; + register ModulePtr mp1; + + if (--mp->refCnt > 0) { + return 0; + } + + if (mp->info && mp->info->fini) { + mp->info->fini(); + } + + if (mp->cdtors) { + while (mp->cdtors->term) { + mp->cdtors->term(); + mp->cdtors++; + } + } + + result = unload(mp->entry); + if (result == -1) { + errvalid++; + strcpy(errbuf, strerror(errno)); + } + + if (mp->exports) { + register ExportPtr ep; + register int i; + for (ep = mp->exports, i = mp->nExports; i; i--, ep++) { + if (ep->name) { + free(ep->name); + } + } + free(mp->exports); + } + + if (mp == modList) { + modList = mp->next; + } else { + for (mp1 = modList; mp1; mp1 = mp1->next) { + if (mp1->next == mp) { + mp1->next = mp->next; + break; + } + } + } + + free(mp->name); + free(mp); + return result; +} + +static void +terminate(void) +{ + while (modList) { + dlclose(modList); + } +} + +/* + * Build the export table from the XCOFF .loader section. + */ + +static int +readExports( + ModulePtr mp) +{ + LDFILE *ldp = NULL; + SCNHDR sh, shdata; + LDHDR *lhp; + char *ldbuf; + LDSYM *ls; + int i; + ExportPtr ep; + const char *errMsg; + +#define Error(msg) do{errMsg=(msg);goto error;}while(0) +#define SysErr() Error(strerror(errno)) + + ldp = ldopen(mp->name, ldp); + if (ldp == NULL) { + struct ld_info *lp; + char *buf; + int size = 0; + + if (errno != ENOENT) { + SysErr(); + } + + /* + * The module might be loaded due to the LIBPATH environment variable. + * Search for the loaded module using L_GETINFO. + */ + + while (1) { + size += 4 * 1024; + buf = malloc(size); + if (buf == NULL) { + SysErr(); + } + + i = loadquery(L_GETINFO, buf, size); + + if (i != -1) { + break; + } + free(buf); + if (errno != ENOMEM) { + SysErr(); + } + } + + /* + * Traverse the list of loaded modules. The entry point returned by + * load() does actually point to the data segment origin. + */ + + lp = (struct ld_info *) buf; + while (lp) { + if (lp->ldinfo_dataorg == mp->entry) { + ldp = ldopen(lp->ldinfo_filename, ldp); + break; + } + if (lp->ldinfo_next == 0) { + lp = NULL; + } else { + lp = (struct ld_info *)((char *)lp + lp->ldinfo_next); + } + } + + free(buf); + + if (!ldp) { + SysErr(); + } + } + + if (TYPE(ldp) != U802TOCMAGIC) { + Error("bad magic"); + } + + /* + * Get the padding for the data section. This is needed for AIX 4.1 + * compilers. This is used when building the final function pointer to the + * exported symbol. + */ + + if (ldnshread(ldp, _DATA, &shdata) != SUCCESS) { + Error("cannot read data section header"); + } + + if (ldnshread(ldp, _LOADER, &sh) != SUCCESS) { + Error("cannot read loader section header"); + } + + /* + * We read the complete loader section in one chunk, this makes finding + * long symbol names residing in the string table easier. + */ + + ldbuf = (char *) malloc(sh.s_size); + if (ldbuf == NULL) { + SysErr(); + } + + if (FSEEK(ldp, sh.s_scnptr, BEGINNING) != OKFSEEK) { + free(ldbuf); + Error("cannot seek to loader section"); + } + + if (FREAD(ldbuf, sh.s_size, 1, ldp) != 1) { + free(ldbuf); + Error("cannot read loader section"); + } + + lhp = (LDHDR *) ldbuf; + ls = (LDSYM *)(ldbuf + LDHDRSZ); + + /* + * Count the number of exports to include in our export table. + */ + + for (i = lhp->l_nsyms; i; i--, ls++) { + if (!LDR_EXPORT(*ls)) { + continue; + } + mp->nExports++; + } + + mp->exports = (ExportPtr) calloc(mp->nExports, sizeof(*mp->exports)); + if (mp->exports == NULL) { + free(ldbuf); + SysErr(); + } + + /* + * Fill in the export table. All entries are relative to the entry point + * we got from load. + */ + + ep = mp->exports; + ls = (LDSYM *)(ldbuf + LDHDRSZ); + for (i=lhp->l_nsyms ; i!=0 ; i--,ls++) { + char *symname; + char tmpsym[SYMNMLEN+1]; + + if (!LDR_EXPORT(*ls)) { + continue; + } + + if (ls->l_zeroes == 0) { + symname = ls->l_offset + lhp->l_stoff + ldbuf; + } else { + /* + * The l_name member is not zero terminated, we must copy the + * first SYMNMLEN chars and make sure we have a zero byte at the + * end. + */ + + strncpy(tmpsym, ls->l_name, SYMNMLEN); + tmpsym[SYMNMLEN] = '\0'; + symname = tmpsym; + } + ep->name = malloc((unsigned) (strlen(symname) + 1)); + strcpy(ep->name, symname); + ep->addr = (void *)((unsigned long) + mp->entry + ls->l_value - shdata.s_vaddr); + ep++; + } + free(ldbuf); + while (ldclose(ldp) == FAILURE) { + /* Empty body */ + } + return 0; + + /* + * This is a factoring out of the error-handling code to make the rest of + * the function much simpler to read. + */ + + error: + errvalid++; + strcpy(errbuf, "readExports: "); + strcat(errbuf, errMsg); + + if (ldp != NULL) { + while (ldclose(ldp) == FAILURE) { + /* Empty body */ + } + } + return -1; +} + +/* + * Find the main modules entry point. This is used as export pointer for + * loadbind() to be able to resolve references to the main part. + */ + +static void * +findMain(void) +{ + struct ld_info *lp; + char *buf; + int size = 4*1024; + int i; + void *ret; + + buf = malloc(size); + if (buf == NULL) { + goto error; + } + + while ((i = loadquery(L_GETINFO, buf, size)) == -1 && errno == ENOMEM) { + free(buf); + size += 4*1024; + buf = malloc(size); + if (buf == NULL) { + goto error; + } + } + + if (i == -1) { + free(buf); + goto error; + } + + /* + * The first entry is the main module. The entry point returned by load() + * does actually point to the data segment origin. + */ + + lp = (struct ld_info *) buf; + ret = lp->ldinfo_dataorg; + free(buf); + return ret; + + error: + errvalid++; + strcpy(errbuf, "findMain: "); + strcat(errbuf, strerror(errno)); + return NULL; +} + +/* + * Local Variables: + * mode: c + * c-basic-offset: 4 + * fill-column: 78 + * End: + */ |