/*--------------------------------------------------------------------*/ /*--- Process-related libc stuff. m_libcproc.c ---*/ /*--------------------------------------------------------------------*/ /* This file is part of Valgrind, a dynamic binary instrumentation framework. Copyright (C) 2000-2005 Julian Seward jseward@acm.org This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program 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 for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA. The GNU General Public License is contained in the file COPYING. */ #include "pub_core_basics.h" #include "pub_core_libcbase.h" #include "pub_core_libcassert.h" #include "pub_core_libcprint.h" #include "pub_core_libcproc.h" #include "pub_core_mallocfree.h" #include "pub_core_syscall.h" #include "pub_core_clientstate.h" #include "vki_unistd.h" /* --------------------------------------------------------------------- Command line and environment stuff ------------------------------------------------------------------ */ /* As deduced from sp_at_startup, the client's argc, argv[] and envp[] as extracted from the client's stack at startup-time. */ Char** VG_(client_envp); /* Path to library directory */ const Char *VG_(libdir) = VG_LIBDIR; /* We do getenv without libc's help by snooping around in VG_(client_envp) as determined at startup time. */ Char *VG_(getenv)(Char *varname) { Int i, n; n = VG_(strlen)(varname); for (i = 0; VG_(client_envp)[i] != NULL; i++) { Char* s = VG_(client_envp)[i]; if (VG_(strncmp)(varname, s, n) == 0 && s[n] == '=') { return & s[n+1]; } } return NULL; } void VG_(env_unsetenv) ( Char **env, const Char *varname ) { Char **from; Char **to = NULL; Int len = VG_(strlen)(varname); for (from = to = env; from && *from; from++) { if (!(VG_(strncmp)(varname, *from, len) == 0 && (*from)[len] == '=')) { *to = *from; to++; } } *to = *from; } /* set the environment; returns the old env if a new one was allocated */ Char **VG_(env_setenv) ( Char ***envp, const Char* varname, const Char *val ) { Char **env = (*envp); Char **cpp; Int len = VG_(strlen)(varname); Char *valstr = VG_(arena_malloc)(VG_AR_CORE, len + VG_(strlen)(val) + 2); Char **oldenv = NULL; VG_(sprintf)(valstr, "%s=%s", varname, val); for (cpp = env; cpp && *cpp; cpp++) { if (VG_(strncmp)(varname, *cpp, len) == 0 && (*cpp)[len] == '=') { *cpp = valstr; return oldenv; } } if (env == NULL) { env = VG_(arena_malloc)(VG_AR_CORE, sizeof(Char **) * 2); env[0] = valstr; env[1] = NULL; *envp = env; } else { Int envlen = (cpp-env) + 2; Char **newenv = VG_(arena_malloc)(VG_AR_CORE, envlen * sizeof(Char **)); for (cpp = newenv; *env; ) *cpp++ = *env++; *cpp++ = valstr; *cpp++ = NULL; oldenv = *envp; *envp = newenv; } return oldenv; } /* Walk through a colon-separated environment variable, and remove the entries which match remove_pattern. It slides everything down over the removed entries, and pads the remaining space with '\0'. It modifies the entries in place (in the client address space), but it shouldn't matter too much, since we only do this just before an execve(). This is also careful to mop up any excess ':'s, since empty strings delimited by ':' are considered to be '.' in a path. */ static void mash_colon_env(Char *varp, const Char *remove_pattern) { Char *const start = varp; Char *entry_start = varp; Char *output = varp; if (varp == NULL) return; while(*varp) { if (*varp == ':') { Char prev; Bool match; /* This is a bit subtle: we want to match against the entry we just copied, because it may have overlapped with itself, junking the original. */ prev = *output; *output = '\0'; match = VG_(string_match)(remove_pattern, entry_start); *output = prev; if (match) { output = entry_start; varp++; /* skip ':' after removed entry */ } else entry_start = output+1; /* entry starts after ':' */ } *output++ = *varp++; } /* match against the last entry */ if (VG_(string_match)(remove_pattern, entry_start)) { output = entry_start; if (output > start) { /* remove trailing ':' */ output--; vg_assert(*output == ':'); } } /* pad out the left-overs with '\0' */ while(output < varp) *output++ = '\0'; } // Removes all the Valgrind-added stuff from the passed environment. Used // when starting child processes, so they don't see that added stuff. void VG_(env_remove_valgrind_env_stuff)(Char** envp) { Int i; Char* ld_preload_str = NULL; Char* ld_library_path_str = NULL; Char* buf; // Find LD_* variables for (i = 0; envp[i] != NULL; i++) { if (VG_(strncmp)(envp[i], "LD_PRELOAD=", 11) == 0) ld_preload_str = &envp[i][11]; if (VG_(strncmp)(envp[i], "LD_LIBRARY_PATH=", 16) == 0) ld_library_path_str = &envp[i][16]; } buf = VG_(arena_malloc)(VG_AR_CORE, VG_(strlen)(VG_(libdir)) + 20); // Remove Valgrind-specific entries from LD_*. VG_(sprintf)(buf, "%s*/vgpreload_*.so", VG_(libdir)); mash_colon_env(ld_preload_str, buf); VG_(sprintf)(buf, "%s*", VG_(libdir)); mash_colon_env(ld_library_path_str, buf); // Remove VALGRIND_LAUNCHER variable. VG_(env_unsetenv)(envp, VALGRIND_LAUNCHER); // XXX if variable becomes empty, remove it completely? VG_(arena_free)(VG_AR_CORE, buf); } /* --------------------------------------------------------------------- Various important syscall wrappers ------------------------------------------------------------------ */ Int VG_(waitpid)(Int pid, Int *status, Int options) { SysRes res = VG_(do_syscall4)(__NR_wait4, pid, (UWord)status, options, 0); return res.isError ? -1 : res.val; } Int VG_(poll)( struct vki_pollfd *ufds, UInt nfds, Int timeout) { SysRes res = VG_(do_syscall3)(__NR_poll, (UWord)ufds, nfds, timeout); /* ASSUMES SYSCALL ALWAYS SUCCEEDS */ return res.val; } /* clone the environment */ Char **VG_(env_clone) ( Char **oldenv ) { Char **oldenvp; Char **newenvp; Char **newenv; Int envlen; for (oldenvp = oldenv; oldenvp && *oldenvp; oldenvp++); envlen = oldenvp - oldenv + 1; newenv = VG_(arena_malloc)(VG_AR_CORE, envlen * sizeof(Char **)); oldenvp = oldenv; newenvp = newenv; while (oldenvp && *oldenvp) { *newenvp++ = *oldenvp++; } *newenvp = *oldenvp; return newenv; } /* Return -1 if error, else 0. NOTE does not indicate return code of child! */ Int VG_(system) ( Char* cmd ) { Int pid; SysRes res; if (cmd == NULL) return 1; res = VG_(do_syscall0)(__NR_fork); if (res.isError) return -1; pid = res.val; if (pid == 0) { /* child */ static Char** envp = NULL; Char* argv[4]; /* restore the DATA rlimit for the child */ VG_(setrlimit)(VKI_RLIMIT_DATA, &VG_(client_rlimit_data)); envp = VG_(env_clone)(VG_(client_envp)); VG_(env_remove_valgrind_env_stuff)( envp ); argv[0] = "/bin/sh"; argv[1] = "-c"; argv[2] = cmd; argv[3] = 0; (void)VG_(do_syscall3)(__NR_execve, (UWord)"/bin/sh", (UWord)argv, (UWord)envp); /* If we're still alive here, execve failed. */ VG_(exit)(1); } else { /* parent */ Int zzz = VG_(waitpid)(pid, NULL, 0); return zzz == -1 ? -1 : 0; } } /* --------------------------------------------------------------------- Resource limits ------------------------------------------------------------------ */ /* Support for getrlimit. */ Int VG_(getrlimit) (Int resource, struct vki_rlimit *rlim) { SysRes res = VG_(mk_SysRes_Error)(VKI_ENOSYS); /* res = getrlimit( resource, rlim ); */ # ifdef __NR_ugetrlimit res = VG_(do_syscall2)(__NR_ugetrlimit, resource, (UWord)rlim); # endif if (res.isError && res.val == VKI_ENOSYS) res = VG_(do_syscall2)(__NR_getrlimit, resource, (UWord)rlim); return res.isError ? -1 : res.val; } /* Support for setrlimit. */ Int VG_(setrlimit) (Int resource, const struct vki_rlimit *rlim) { SysRes res; /* res = setrlimit( resource, rlim ); */ res = VG_(do_syscall2)(__NR_setrlimit, resource, (UWord)rlim); return res.isError ? -1 : res.val; } /* --------------------------------------------------------------------- pids, etc ------------------------------------------------------------------ */ Int VG_(gettid)(void) { SysRes res = VG_(do_syscall0)(__NR_gettid); if (res.isError && res.val == VKI_ENOSYS) { Char pid[16]; /* * The gettid system call does not exist. The obvious assumption * to make at this point would be that we are running on an older * system where the getpid system call actually returns the ID of * the current thread. * * Unfortunately it seems that there are some systems with a kernel * where getpid has been changed to return the ID of the thread group * leader but where the gettid system call has not yet been added. * * So instead of calling getpid here we use readlink to see where * the /proc/self link is pointing... */ res = VG_(do_syscall3)(__NR_readlink, (UWord)"/proc/self", (UWord)pid, sizeof(pid)); if (!res.isError && res.val > 0) { pid[res.val] = '\0'; res.val = VG_(atoll)(pid); } } return res.val; } /* You'd be amazed how many places need to know the current pid. */ Int VG_(getpid) ( void ) { /* ASSUMES SYSCALL ALWAYS SUCCEEDS */ return VG_(do_syscall0)(__NR_getpid) . val; } Int VG_(getpgrp) ( void ) { /* ASSUMES SYSCALL ALWAYS SUCCEEDS */ return VG_(do_syscall0)(__NR_getpgrp) . val; } Int VG_(getppid) ( void ) { /* ASSUMES SYSCALL ALWAYS SUCCEEDS */ return VG_(do_syscall0)(__NR_getppid) . val; } Int VG_(geteuid) ( void ) { /* ASSUMES SYSCALL ALWAYS SUCCEEDS */ return VG_(do_syscall0)(__NR_geteuid) . val; } Int VG_(getegid) ( void ) { /* ASSUMES SYSCALL ALWAYS SUCCEEDS */ return VG_(do_syscall0)(__NR_getegid) . val; } /* Get supplementary groups into list[0 .. size-1]. Returns the number of groups written, or -1 if error. Note that in order to be portable, the groups are 32-bit unsigned ints regardless of the platform. */ Int VG_(getgroups)( Int size, UInt* list ) { # if defined(VGP_x86_linux) || defined(VGP_ppc32_linux) Int i; SysRes sres; UShort list16[32]; if (size < 0) return -1; if (size > 32) size = 32; sres = VG_(do_syscall2)(__NR_getgroups, size, (Addr)list16); if (sres.isError) return -1; if (sres.val != size) return -1; for (i = 0; i < size; i++) list[i] = (UInt)list16[i]; return size; # elif defined(VGP_amd64_linux) SysRes sres; sres = VG_(do_syscall2)(__NR_getgroups, size, (Addr)list); if (sres.isError) return -1; return sres.val; # else # error "VG_(getgroups): needs implementation on this platform" # endif } /* --------------------------------------------------------------------- Process tracing ------------------------------------------------------------------ */ Int VG_(ptrace) ( Int request, Int pid, void *addr, void *data ) { SysRes res; res = VG_(do_syscall4)(__NR_ptrace, request, pid, (UWord)addr, (UWord)data); if (res.isError) return -1; return res.val; } /* --------------------------------------------------------------------- Fork ------------------------------------------------------------------ */ Int VG_(fork) ( void ) { SysRes res; res = VG_(do_syscall0)(__NR_fork); if (res.isError) return -1; return res.val; } /* --------------------------------------------------------------------- Timing stuff ------------------------------------------------------------------ */ UInt VG_(read_millisecond_timer) ( void ) { static ULong base = 0; struct vki_timeval tv_now; ULong now; SysRes res; res = VG_(do_syscall2)(__NR_gettimeofday, (UWord)&tv_now, (UWord)NULL); now = tv_now.tv_sec * 1000000ULL + tv_now.tv_usec; if (base == 0) base = now; return (now - base) / 1000; } void VG_(nanosleep)(struct vki_timespec *ts) { (void)VG_(do_syscall2)(__NR_nanosleep, (UWord)ts, (UWord)NULL); } /* --------------------------------------------------------------------- A trivial atfork() facility for Valgrind's internal use ------------------------------------------------------------------ */ // Trivial because it only supports a single post-fork child action, which // is all we need. static vg_atfork_t atfork_child = NULL; void VG_(atfork_child)(vg_atfork_t child) { if (NULL != atfork_child) VG_(core_panic)("More than one atfork_child handler requested"); atfork_child = child; } void VG_(do_atfork_child)(ThreadId tid) { if (NULL != atfork_child) (*atfork_child)(tid); } /*--------------------------------------------------------------------*/ /*--- end ---*/ /*--------------------------------------------------------------------*/