| |
| /*--------------------------------------------------------------------*/ |
| /*--- Process-related libc stuff. m_libcproc.c ---*/ |
| /*--------------------------------------------------------------------*/ |
| |
| /* |
| This file is part of Valgrind, a dynamic binary instrumentation |
| framework. |
| |
| Copyright (C) 2000-2008 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_mallocfree.h" |
| #include "pub_core_syscall.h" |
| #include "pub_core_xarray.h" |
| #include "pub_core_clientstate.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) = 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) |
| { |
| 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, "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); |
| 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) |
| { |
| # if defined(VGO_linux) |
| SysRes res = VG_(do_syscall4)(__NR_wait4, pid, (UWord)status, options, 0); |
| return res.isError ? -1 : 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", res.res, res.err); |
| return res.isError ? -1 : 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; |
| } |
| |
| /* 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.res; |
| 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 ir, zzz; |
| /* 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.) |
| */ |
| struct vki_sigaction sa, saved_sa; |
| VG_(memset)( &sa, 0, sizeof(struct vki_sigaction) ); |
| 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); |
| |
| ir = VG_(sigaction)(VKI_SIGCHLD, &saved_sa, 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 (res.isError && res.err == VKI_ENOSYS) |
| res = VG_(do_syscall2)(__NR_getrlimit, resource, (UWord)rlim); |
| return res.isError ? -1 : 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 res.isError ? -1 : res.res; |
| } |
| |
| /* --------------------------------------------------------------------- |
| pids, etc |
| ------------------------------------------------------------------ */ |
| |
| Int VG_(gettid)(void) |
| { |
| # if 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 = res.res; |
| return r; |
| |
| # else |
| SysRes res = VG_(do_syscall0)(__NR_gettid); |
| |
| if (res.isError && 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 (!res.isError && res.res > 0) { |
| pid[res.res] = '\0'; |
| res.res = VG_(atoll)(pid); |
| } |
| } |
| |
| return res.res; |
| # endif |
| } |
| |
| /* 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) . res; |
| } |
| |
| Int VG_(getpgrp) ( void ) |
| { |
| /* ASSUMES SYSCALL ALWAYS SUCCEEDS */ |
| return VG_(do_syscall0)(__NR_getpgrp) . res; |
| } |
| |
| Int VG_(getppid) ( void ) |
| { |
| /* ASSUMES SYSCALL ALWAYS SUCCEEDS */ |
| return VG_(do_syscall0)(__NR_getppid) . res; |
| } |
| |
| Int VG_(geteuid) ( void ) |
| { |
| /* ASSUMES SYSCALL ALWAYS SUCCEEDS */ |
| # if defined(VGP_ppc32_aix5) || defined(VGP_ppc64_aix5) |
| return VG_(do_syscall1)(__NR_AIX5_getuidx, 1) . res; |
| # 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 VG_(do_syscall0)(__NR_geteuid32) . res; |
| # else |
| return VG_(do_syscall0)(__NR_geteuid) . res; |
| # endif |
| } |
| |
| Int VG_(getegid) ( void ) |
| { |
| /* ASSUMES SYSCALL ALWAYS SUCCEEDS */ |
| # if defined(VGP_ppc32_aix5) || defined(VGP_ppc64_aix5) |
| return VG_(do_syscall1)(__NR_AIX5_getgidx, 1) . res; |
| # 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 VG_(do_syscall0)(__NR_getegid32) . res; |
| # else |
| return VG_(do_syscall0)(__NR_getegid) . res; |
| # 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 (sres.isError) |
| return -1; |
| if (sres.res > size) |
| return -1; |
| for (i = 0; i < sres.res; i++) |
| list[i] = (UInt)list16[i]; |
| return sres.res; |
| |
| # elif defined(VGP_amd64_linux) || defined(VGP_ppc64_linux) \ |
| || defined(VGP_ppc32_aix5) || defined(VGP_ppc64_aix5) |
| SysRes sres; |
| sres = VG_(do_syscall2)(__NR_getgroups, size, (Addr)list); |
| if (sres.isError) |
| return -1; |
| return sres.res; |
| |
| # 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.res; |
| } |
| |
| /* --------------------------------------------------------------------- |
| Fork |
| ------------------------------------------------------------------ */ |
| |
| Int VG_(fork) ( void ) |
| { |
| SysRes res; |
| res = VG_(do_syscall0)(__NR_fork); |
| if (res.isError) |
| return -1; |
| return res.res; |
| } |
| |
| /* --------------------------------------------------------------------- |
| Timing stuff |
| ------------------------------------------------------------------ */ |
| |
| UInt VG_(read_millisecond_timer) ( void ) |
| { |
| /* 'now' and 'base' are in microseconds */ |
| static ULong base = 0; |
| ULong now; |
| |
| # if defined(VGP_ppc32_aix5) || defined(VGP_ppc64_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); |
| # else |
| |
| struct vki_timespec ts_now; |
| SysRes res; |
| res = VG_(do_syscall2)(__NR_clock_gettime, VKI_CLOCK_MONOTONIC, |
| (UWord)&ts_now); |
| if (res.isError == 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(! res.isError); |
| now = tv_now.tv_sec * 1000000ULL + tv_now.tv_usec; |
| } |
| # endif |
| |
| if (base == 0) |
| base = now; |
| |
| return (now - base) / 1000; |
| } |
| |
| /* --------------------------------------------------------------------- |
| 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 ---*/ |
| /*--------------------------------------------------------------------*/ |