| /* Trace calls through PLTs and show caller, callee, and parameters. |
| Copyright (C) 2011-2018 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, see |
| <http://www.gnu.org/licenses/>. */ |
| |
| #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) + 13; |
| char fullname[out_filename_len]; |
| char *endp = stpcpy (fullname, out_filename); |
| if (which_process == NULL || which_process[0] == '\0') |
| snprintf (endp, 13, ".%ld", (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 __sparc__ && !defined __arch64__ |
| Elf32_Addr |
| la_sparc32_gnu_pltenter (Elf32_Sym *sym __attribute__ ((unused)), |
| unsigned int ndx __attribute__ ((unused)), |
| uintptr_t *refcook, uintptr_t *defcook, |
| La_sparc32_regs *regs, unsigned int *flags, |
| const char *symname, long int *framesizep) |
| { |
| print_enter (refcook, defcook, symname, |
| regs->lr_reg[0], regs->lr_reg[1], regs->lr_reg[2], |
| *flags); |
| |
| /* No need to copy anything, we will not need the parameters in any case. */ |
| *framesizep = 0; |
| |
| return sym->st_value; |
| } |
| #elif defined __sparc__ && defined __arch64__ |
| Elf64_Addr |
| la_sparc64_gnu_pltenter (Elf64_Sym *sym __attribute__ ((unused)), |
| unsigned int ndx __attribute__ ((unused)), |
| uintptr_t *refcook, uintptr_t *defcook, |
| La_sparc64_regs *regs, unsigned int *flags, |
| const char *symname, long int *framesizep) |
| { |
| print_enter (refcook, defcook, symname, |
| regs->lr_reg[0], regs->lr_reg[1], regs->lr_reg[2], |
| *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%lx\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 __sparc__ && !defined __arch64__ |
| unsigned int |
| la_sparc32_gnu_pltexit (Elf32_Sym *sym, unsigned int ndx, uintptr_t *refcook, |
| uintptr_t *defcook, const struct La_sparc32_regs *inregs, |
| struct La_sparc32_retval *outregs, const char *symname) |
| { |
| print_exit (refcook, defcook, symname, outregs->lrv_reg[0]); |
| |
| return 0; |
| } |
| #elif defined __sparc__ && defined __arch64__ |
| unsigned int |
| la_sparc64_gnu_pltexit (Elf64_Sym *sym, unsigned int ndx, uintptr_t *refcook, |
| uintptr_t *defcook, const struct La_sparc64_regs *inregs, |
| struct La_sparc64_retval *outregs, const char *symname) |
| { |
| print_exit (refcook, defcook, symname, outregs->lrv_reg[0]); |
| |
| return 0; |
| } |
| #elif !defined HAVE_ARCH_PLTEXIT |
| # warning "pltexit for architecture not supported" |
| #endif |
