/*--------------------------------------------------------------------*/ /*--- Process-related libc stuff. m_libcproc.c ---*/ /*--------------------------------------------------------------------*/ /* This file is part of Valgrind, a dynamic binary instrumentation framework. Copyright (C) 2000-2009 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_vki.h" #include "pub_core_vkiscnums.h" #include "pub_core_libcbase.h" #include "pub_core_libcassert.h" #include "pub_core_libcprint.h" #include "pub_core_libcproc.h" #include "pub_core_libcsignal.h" #include "pub_core_seqmatch.h" #include "pub_core_mallocfree.h" #include "pub_core_syscall.h" #include "pub_core_xarray.h" #include "pub_core_clientstate.h" #if defined(VGO_darwin) /* --- !!! --- EXTERNAL HEADERS start --- !!! --- */ #include /* mach_thread_self */ /* --- !!! --- EXTERNAL HEADERS end --- !!! --- */ #endif /* IMPORTANT: on Darwin it is essential to use the _nocancel versions of syscalls rather than the vanilla version, if a _nocancel version is available. See docs/internals/Darwin-notes.txt for the reason why. */ /* --------------------------------------------------------------------- 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) = NULL; /* 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; vg_assert( VG_(client_envp) ); 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, "libcproc.es.1", 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, "libcproc.es.2", 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, "libcproc.es.3", 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) { #if defined(VGO_darwin) // Environment cleanup is also handled during parent launch // in vg_preloaded.c:vg_cleanup_env(). #endif Int i; Char* ld_preload_str = NULL; Char* ld_library_path_str = NULL; Char* dyld_insert_libraries_str = NULL; Char* buf; // Find LD_* variables // DDD: should probably conditionally compiled some of this: // - LD_LIBRARY_PATH is universal? // - LD_PRELOAD is on Linux, not on Darwin, not sure about AIX // - DYLD_INSERT_LIBRARIES and DYLD_SHARED_REGION are Darwin-only 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]; if (VG_(strncmp)(envp[i], "DYLD_INSERT_LIBRARIES=", 22) == 0) dyld_insert_libraries_str = &envp[i][22]; } buf = VG_(arena_malloc)(VG_AR_CORE, "libcproc.erves.1", 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); mash_colon_env(dyld_insert_libraries_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); // Remove DYLD_SHARED_REGION variable. VG_(env_unsetenv)(envp, "DYLD_SHARED_REGION"); // 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) { # if defined(VGO_linux) SysRes res = VG_(do_syscall4)(__NR_wait4, pid, (UWord)status, options, 0); return sr_isError(res) ? -1 : sr_Res(res); # elif defined(VGO_darwin) SysRes res = VG_(do_syscall4)(__NR_wait4_nocancel, pid, (UWord)status, options, 0); return sr_isError(res) ? -1 : sr_Res(res); # elif defined(VGO_aix5) /* magic number 4 obtained by truss-ing a C program doing 'waitpid'. Note status and pid args opposite way round from POSIX. */ SysRes res = VG_(do_syscall5)(__NR_AIX5_kwaitpid, (UWord)status, pid, 4 | options,0,0); if (0) VG_(printf)("waitpid: got 0x%lx 0x%lx\n", sr_Res(res), res.err); return sr_isError(res) ? -1 : sr_Res(res); # else # error Unknown OS # endif } /* 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, "libcproc.ec.1", envlen * sizeof(Char **)); oldenvp = oldenv; newenvp = newenv; while (oldenvp && *oldenvp) { *newenvp++ = *oldenvp++; } *newenvp = *oldenvp; return newenv; } void VG_(execv) ( Char* filename, Char** argv ) { Char** envp; SysRes res; /* 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 ); res = VG_(do_syscall3)(__NR_execve, (UWord)filename, (UWord)argv, (UWord)envp); VG_(printf)("EXEC failed, errno = %lld\n", (Long)sr_Err(res)); } /* Return -1 if error, else 0. NOTE does not indicate return code of child! */ Int VG_(system) ( Char* cmd ) { Int pid; if (cmd == NULL) return 1; pid = VG_(fork)(); if (pid < 0) return -1; if (pid == 0) { /* child */ Char* argv[4] = { "/bin/sh", "-c", cmd, 0 }; VG_(execv)(argv[0], argv); /* If we're still alive here, execve failed. */ VG_(exit)(1); } else { /* parent */ /* We have to set SIGCHLD to its default behaviour in order that VG_(waitpid) works (at least on AIX). According to the Linux man page for waitpid: POSIX.1-2001 specifies that if the disposition of SIGCHLD is set to SIG_IGN or the SA_NOCLDWAIT flag is set for SIGCHLD (see sigaction(2)), then children that terminate do not become zombies and a call to wait() or waitpid() will block until all children have terminated, and then fail with errno set to ECHILD. (The original POSIX standard left the behaviour of setting SIGCHLD to SIG_IGN unspecified.) */ Int ir, zzz; vki_sigaction_toK_t sa, sa2; vki_sigaction_fromK_t saved_sa; VG_(memset)( &sa, 0, sizeof(sa) ); VG_(sigemptyset)(&sa.sa_mask); sa.ksa_handler = VKI_SIG_DFL; sa.sa_flags = 0; ir = VG_(sigaction)(VKI_SIGCHLD, &sa, &saved_sa); vg_assert(ir == 0); zzz = VG_(waitpid)(pid, NULL, 0); VG_(convert_sigaction_fromK_to_toK)( &saved_sa, &sa2 ); ir = VG_(sigaction)(VKI_SIGCHLD, &sa2, NULL); vg_assert(ir == 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 (sr_isError(res) && sr_Err(res) == VKI_ENOSYS) res = VG_(do_syscall2)(__NR_getrlimit, resource, (UWord)rlim); return sr_isError(res) ? -1 : sr_Res(res); } /* 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 sr_isError(res) ? -1 : sr_Res(res); } /* --------------------------------------------------------------------- pids, etc ------------------------------------------------------------------ */ Int VG_(gettid)(void) { # if defined(VGO_linux) SysRes res = VG_(do_syscall0)(__NR_gettid); if (sr_isError(res) && sr_Res(res) == 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 (!sr_isError(res) && sr_Res(res) > 0) { Char* s; pid[sr_Res(res)] = '\0'; res = VG_(mk_SysRes_Success)( VG_(strtoll10)(pid, &s) ); if (*s != '\0') { VG_(message)(Vg_DebugMsg, "Warning: invalid file name linked to by /proc/self: %s", pid); } } } return sr_Res(res); # elif defined(VGO_aix5) SysRes res; Int r; vg_assert(__NR_AIX5__thread_self != __NR_AIX5_UNKNOWN); res = VG_(do_syscall0)(__NR_AIX5__thread_self); r = sr_Res(res); return r; # elif defined(VGO_darwin) // Darwin's gettid syscall is something else. // Use Mach thread ports for lwpid instead. return mach_thread_self(); # else # error "Unknown OS" # endif } /* You'd be amazed how many places need to know the current pid. */ Int VG_(getpid) ( void ) { /* ASSUMES SYSCALL ALWAYS SUCCEEDS */ return sr_Res( VG_(do_syscall0)(__NR_getpid) ); } Int VG_(getpgrp) ( void ) { /* ASSUMES SYSCALL ALWAYS SUCCEEDS */ return sr_Res( VG_(do_syscall0)(__NR_getpgrp) ); } Int VG_(getppid) ( void ) { /* ASSUMES SYSCALL ALWAYS SUCCEEDS */ return sr_Res( VG_(do_syscall0)(__NR_getppid) ); } Int VG_(geteuid) ( void ) { /* ASSUMES SYSCALL ALWAYS SUCCEEDS */ # if defined(VGP_ppc32_aix5) || defined(VGP_ppc64_aix5) return sr_Res( VG_(do_syscall1)(__NR_AIX5_getuidx, 1) ); # elif defined(__NR_geteuid32) // We use the 32-bit version if it's supported. Otherwise, IDs greater // than 65536 cause problems, as bug #151209 showed. return sr_Res( VG_(do_syscall0)(__NR_geteuid32) ); # else return sr_Res( VG_(do_syscall0)(__NR_geteuid) ); # endif } Int VG_(getegid) ( void ) { /* ASSUMES SYSCALL ALWAYS SUCCEEDS */ # if defined(VGP_ppc32_aix5) || defined(VGP_ppc64_aix5) return sr_Res( VG_(do_syscall1)(__NR_AIX5_getgidx, 1) ); # elif defined(__NR_getegid32) // We use the 32-bit version if it's supported. Otherwise, IDs greater // than 65536 cause problems, as bug #151209 showed. return sr_Res( VG_(do_syscall0)(__NR_getegid32) ); # else return sr_Res( VG_(do_syscall0)(__NR_getegid) ); # endif } /* 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[64]; if (size < 0) return -1; if (size > 64) size = 64; sres = VG_(do_syscall2)(__NR_getgroups, size, (Addr)list16); if (sr_isError(sres)) return -1; if (sr_Res(sres) > size) return -1; for (i = 0; i < sr_Res(sres); i++) list[i] = (UInt)list16[i]; return sr_Res(sres); # elif defined(VGP_amd64_linux) || defined(VGP_ppc64_linux) \ || defined(VGP_ppc32_aix5) || defined(VGP_ppc64_aix5) \ || defined(VGO_darwin) SysRes sres; sres = VG_(do_syscall2)(__NR_getgroups, size, (Addr)list); if (sr_isError(sres)) return -1; return sr_Res(sres); # 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 (sr_isError(res)) return -1; return sr_Res(res); } /* --------------------------------------------------------------------- Fork ------------------------------------------------------------------ */ Int VG_(fork) ( void ) { # if defined(VGO_linux) || defined(VGO_aix5) SysRes res; res = VG_(do_syscall0)(__NR_fork); if (sr_isError(res)) return -1; return sr_Res(res); # elif defined(VGO_darwin) SysRes res; res = VG_(do_syscall0)(__NR_fork); /* __NR_fork is UX64 */ if (sr_isError(res)) return -1; /* on success: wLO = child pid; wHI = 1 for child, 0 for parent */ if (sr_ResHI(res) != 0) { return 0; /* this is child: return 0 instead of child pid */ } return sr_Res(res); # else # error "Unknown OS" # endif } /* --------------------------------------------------------------------- Timing stuff ------------------------------------------------------------------ */ UInt VG_(read_millisecond_timer) ( void ) { /* 'now' and 'base' are in microseconds */ static ULong base = 0; ULong now; # if defined(VGO_linux) { SysRes res; struct vki_timespec ts_now; res = VG_(do_syscall2)(__NR_clock_gettime, VKI_CLOCK_MONOTONIC, (UWord)&ts_now); if (sr_isError(res) == 0) { now = ts_now.tv_sec * 1000000ULL + ts_now.tv_nsec / 1000; } else { struct vki_timeval tv_now; res = VG_(do_syscall2)(__NR_gettimeofday, (UWord)&tv_now, (UWord)NULL); vg_assert(! sr_isError(res)); now = tv_now.tv_sec * 1000000ULL + tv_now.tv_usec; } } # elif defined(VGO_aix5) /* AIX requires a totally different implementation since sys_gettimeofday doesn't exist. We use the POWER real-time register facility. This will SIGILL on PowerPC 970 on AIX, since PowerPC doesn't support these instructions. */ UWord nsec, sec1, sec2; while (1) { __asm__ __volatile__ ("\n" "\tmfspr %0,4\n" /* 4==RTCU */ "\tmfspr %1,5\n" /* 5==RTCL */ "\tmfspr %2,4\n" /* 4==RTCU */ : "=b" (sec1), "=b" (nsec), "=b" (sec2) ); if (sec1 == sec2) break; } vg_assert(nsec < 1000*1000*1000); now = ((ULong)sec1) * 1000000ULL; now += (ULong)(nsec / 1000); # elif defined(VGO_darwin) { SysRes res; struct vki_timeval tv_now; res = VG_(do_syscall2)(__NR_gettimeofday, (UWord)&tv_now, (UWord)NULL); vg_assert(! sr_isError(res)); now = tv_now.tv_sec * 1000000ULL + tv_now.tv_usec; } # else # error "Unknown OS" # endif /* COMMON CODE */ if (base == 0) base = now; return (now - base) / 1000; } /* --------------------------------------------------------------------- atfork() ------------------------------------------------------------------ */ struct atfork { vg_atfork_t pre; vg_atfork_t parent; vg_atfork_t child; }; #define VG_MAX_ATFORK 10 static struct atfork atforks[VG_MAX_ATFORK]; static Int n_atfork = 0; void VG_(atfork)(vg_atfork_t pre, vg_atfork_t parent, vg_atfork_t child) { Int i; for (i = 0; i < n_atfork; i++) { if (atforks[i].pre == pre && atforks[i].parent == parent && atforks[i].child == child) return; } if (n_atfork >= VG_MAX_ATFORK) VG_(core_panic)( "Too many VG_(atfork) handlers requested: raise VG_MAX_ATFORK"); atforks[n_atfork].pre = pre; atforks[n_atfork].parent = parent; atforks[n_atfork].child = child; n_atfork++; } void VG_(do_atfork_pre)(ThreadId tid) { Int i; for (i = 0; i < n_atfork; i++) if (atforks[i].pre != NULL) (*atforks[i].pre)(tid); } void VG_(do_atfork_parent)(ThreadId tid) { Int i; for (i = 0; i < n_atfork; i++) if (atforks[i].parent != NULL) (*atforks[i].parent)(tid); } void VG_(do_atfork_child)(ThreadId tid) { Int i; for (i = 0; i < n_atfork; i++) if (atforks[i].child != NULL) (*atforks[i].child)(tid); } /*--------------------------------------------------------------------*/ /*--- end ---*/ /*--------------------------------------------------------------------*/