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Diffstat (limited to 'elf/sotruss-lib.c')
| -rw-r--r-- | elf/sotruss-lib.c | 333 |
1 files changed, 333 insertions, 0 deletions
diff --git a/elf/sotruss-lib.c b/elf/sotruss-lib.c new file mode 100644 index 0000000000..b01011d08e --- /dev/null +++ b/elf/sotruss-lib.c @@ -0,0 +1,333 @@ +/* Trace calls through PLTs and show caller, callee, and parameters. + Copyright (C) 2011 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Ulrich Drepper <drepper@gmail.com>, 2011. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library 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 + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + +#include <error.h> +#include <fcntl.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> +#include <sys/param.h> +#include <sys/uio.h> + +#include <ldsodefs.h> + + +extern const char *__progname; +extern const char *__progname_full; + + +/* List of objects to trace calls from. */ +static const char *fromlist; +/* List of objects to trace calls to. */ +static const char *tolist; + +/* If non-zero, also trace returns of the calls. */ +static int do_exit; +/* If non-zero print PID for each line. */ +static int print_pid; + +/* The output stream to use. */ +static FILE *out_file; + + +static int +match_pid (pid_t pid, const char *which) +{ + if (which == NULL || which[0] == '\0') + { + print_pid = 1; + return 1; + } + + char *endp; + unsigned long n = strtoul (which, &endp, 0); + return *endp == '\0' && n == pid; +} + + +static void +init (void) +{ + fromlist = getenv ("SOTRUSS_FROMLIST"); + if (fromlist != NULL && fromlist[0] == '\0') + fromlist = NULL; + tolist = getenv ("SOTRUSS_TOLIST"); + if (tolist != NULL && tolist[0] == '\0') + tolist = NULL; + do_exit = (getenv ("SOTRUSS_EXIT") ?: "")[0] != '\0'; + + /* Determine whether this process is supposed to be traced and if + yes, whether we should print into a file. */ + const char *which_process = getenv ("SOTRUSS_WHICH"); + pid_t pid = getpid (); + int out_fd = -1; + if (match_pid (pid, which_process)) + { + const char *out_filename = getenv ("SOTRUSS_OUTNAME"); + + if (out_filename != NULL && out_filename[0] != 0) + { + size_t out_filename_len = strlen (out_filename) + 12; + char fullname[out_filename_len]; + char *endp = stpcpy (fullname, out_filename); + if (which_process == NULL || which_process[0] == '\0') + snprintf (endp, 12, ".%lu", (unsigned long int) pid); + + out_fd = open (fullname, O_RDWR | O_CREAT | O_TRUNC, 0666); + if (out_fd != -1) + print_pid = 0; + } + } + + /* If we do not write into a file write to stderr. Duplicate the + descriptor so that we can keep printing in case the program + closes stderr. Try first to allocate a descriptor with a value + usually not used as to minimize interference with the + program. */ + if (out_fd == -1) + { + out_fd = fcntl (STDERR_FILENO, F_DUPFD, 1000); + if (out_fd == -1) + out_fd = dup (STDERR_FILENO); + } + + if (out_fd != -1) + { + /* Convert file descriptor into a stream. */ + out_file = fdopen (out_fd, "w"); + if (out_file != NULL) + setlinebuf (out_file); + } +} + + +/* Audit interface verification. We also initialize everything if + everything checks out OK. */ +unsigned int +la_version (unsigned int v) +{ + if (v != LAV_CURRENT) + error (1, 0, "cannot handle interface version %u", v); + + init (); + + return v; +} + + +/* Check whether a file name is on the colon-separated list of file + names. */ +static unsigned int +match_file (const char *list, const char *name, size_t name_len, + unsigned int mask) +{ + if (list[0] == '\0') + return 0; + + const char *cp = list; + while (1) + { + if (strncmp (cp, name, name_len) == 0 + && (cp[name_len] == ':' || cp[name_len] == '\0')) + return mask; + + cp = strchr (cp, ':'); + if (cp == NULL) + return 0; + ++cp; + } +} + + +unsigned int +la_objopen (struct link_map *map, Lmid_t lmid, uintptr_t *cookie) +{ + if (out_file == NULL) + return 0; + + const char *full_name = map->l_name ?: ""; + if (full_name[0] == '\0') + full_name = __progname_full; + size_t full_name_len = strlen (full_name); + const char *base_name = basename (full_name); + if (base_name[0] == '\0') + base_name = __progname; + size_t base_name_len = strlen (base_name); + + int result = 0; + const char *print_name = NULL; + for (struct libname_list *l = map->l_libname; l != NULL; l = l->next) + { + if (print_name == NULL || (print_name[0] == '/' && l->name[0] != '/')) + print_name = l->name; + + if (fromlist != NULL) + result |= match_file (fromlist, l->name, strlen (l->name), + LA_FLG_BINDFROM); + + if (tolist != NULL) + result |= match_file (tolist, l->name, strlen (l->name),LA_FLG_BINDTO); + } + + if (print_name == NULL) + print_name = base_name; + if (print_name[0] == '\0') + print_name = __progname; + + /* We cannot easily get to the object name in the PLT handling + functions. Use the cookie to get the string pointer passed back + to us. */ + *cookie = (uintptr_t) print_name; + + /* The object name has to be on the list of objects to trace calls + from or that list must be empty. In the latter case we trace + only calls from the main binary. */ + if (fromlist == NULL) + result |= map->l_name[0] == '\0' ? LA_FLG_BINDFROM : 0; + else + result |= (match_file (fromlist, full_name, full_name_len, + LA_FLG_BINDFROM) + | match_file (fromlist, base_name, base_name_len, + LA_FLG_BINDFROM)); + + /* The object name has to be on the list of objects to trace calls + to or that list must be empty. In the latter case we trace + calls toall objects. */ + if (tolist == NULL) + result |= LA_FLG_BINDTO; + else + result |= (match_file (tolist, full_name, full_name_len, LA_FLG_BINDTO) + | match_file (tolist, base_name, base_name_len, LA_FLG_BINDTO)); + + return result; +} + + +#if __ELF_NATIVE_CLASS == 32 +# define la_symbind la_symbind32 +typedef Elf32_Sym Elf_Sym; +#else +# define la_symbind la_symbind64 +typedef Elf64_Sym Elf_Sym; +#endif + +uintptr_t +la_symbind (Elf_Sym *sym, unsigned int ndx, uintptr_t *refcook, + uintptr_t *defcook, unsigned int *flags, const char *symname) +{ + if (!do_exit) + *flags = LA_SYMB_NOPLTEXIT; + + return sym->st_value; +} + + +static void +print_enter (uintptr_t *refcook, uintptr_t *defcook, const char *symname, + unsigned long int reg1, unsigned long int reg2, + unsigned long int reg3, unsigned int flags) +{ + char buf[3 * sizeof (pid_t) + 3]; + buf[0] = '\0'; + if (print_pid) + snprintf (buf, sizeof (buf), "%5ld: ", (long int) getpid ()); + + fprintf (out_file, "%s%15s -> %-15s:%s%s(0x%lx, 0x%lx, 0x%lx)\n", + buf, (char *) *refcook, (char *) *defcook, + (flags & LA_SYMB_NOPLTEXIT) ? "*" : " ", symname, reg1, reg2, reg3); +} + + +#ifdef __i386__ +Elf32_Addr +la_i86_gnu_pltenter (Elf32_Sym *sym __attribute__ ((unused)), + unsigned int ndx __attribute__ ((unused)), + uintptr_t *refcook, uintptr_t *defcook, + La_i86_regs *regs, unsigned int *flags, + const char *symname, long int *framesizep) +{ + unsigned long int *sp = (unsigned long int *) regs->lr_esp; + + print_enter (refcook, defcook, symname, sp[1], sp[2], sp[3], *flags); + + /* No need to copy anything, we will not need the parameters in any case. */ + *framesizep = 0; + + return sym->st_value; +} +#elif defined __x86_64__ +Elf64_Addr +la_x86_64_gnu_pltenter (Elf64_Sym *sym __attribute__ ((unused)), + unsigned int ndx __attribute__ ((unused)), + uintptr_t *refcook, uintptr_t *defcook, + La_x86_64_regs *regs, unsigned int *flags, + const char *symname, long int *framesizep) +{ + print_enter (refcook, defcook, symname, + regs->lr_rdi, regs->lr_rsi, regs->lr_rdx, *flags); + + /* No need to copy anything, we will not need the parameters in any case. */ + *framesizep = 0; + + return sym->st_value; +} +#elif !defined HAVE_ARCH_PLTENTER +# warning "pltenter for architecture not supported" +#endif + + +static void +print_exit (uintptr_t *refcook, uintptr_t *defcook, const char *symname, + unsigned long int reg) +{ + char buf[3 * sizeof (pid_t) + 3]; + buf[0] = '\0'; + if (print_pid) + snprintf (buf, sizeof (buf), "%5ld: ", (long int) getpid ()); + + fprintf (out_file, "%s%15s -> %-15s:%s%s - 0x%lu\n", + buf, (char *) *refcook, (char *) *defcook, " ", symname, reg); +} + + +#ifdef __i386__ +unsigned int +la_i86_gnu_pltexit (Elf32_Sym *sym, unsigned int ndx, uintptr_t *refcook, + uintptr_t *defcook, const struct La_i86_regs *inregs, + struct La_i86_retval *outregs, const char *symname) +{ + print_exit (refcook, defcook, symname, outregs->lrv_eax); + + return 0; +} +#elif defined __x86_64__ +unsigned int +la_x86_64_gnu_pltexit (Elf64_Sym *sym, unsigned int ndx, uintptr_t *refcook, + uintptr_t *defcook, const struct La_x86_64_regs *inregs, + struct La_x86_64_retval *outregs, const char *symname) +{ + print_exit (refcook, defcook, symname, outregs->lrv_rax); + + return 0; +} +#elif !defined HAVE_ARCH_PLTEXIT +# warning "pltexit for architecture not supported" +#endif |