/*--------------------------------------------------------------------*/ /*--- Process-related libc stuff. m_libcproc.c ---*/ /*--------------------------------------------------------------------*/ /* This file is part of Valgrind, a dynamic binary instrumentation framework. Copyright (C) 2000-2017 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_machine.h" // For VG_(machine_get_VexArchInfo) #include "pub_core_vki.h" #include "pub_core_vkiscnums.h" #include "pub_core_libcbase.h" #include "pub_core_libcassert.h" #include "pub_core_libcfile.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. */ HChar** VG_(client_envp) = NULL; /* Path to library directory */ const HChar *VG_(libdir) = VG_LIBDIR; const HChar *VG_(LD_PRELOAD_var_name) = #if defined(VGO_linux) || defined(VGO_solaris) "LD_PRELOAD"; #elif defined(VGO_darwin) "DYLD_INSERT_LIBRARIES"; #else # error Unknown OS #endif /* We do getenv without libc's help by snooping around in VG_(client_envp) as determined at startup time. */ HChar *VG_(getenv)(const HChar *varname) { Int i, n; vg_assert( VG_(client_envp) ); n = VG_(strlen)(varname); for (i = 0; VG_(client_envp)[i] != NULL; i++) { HChar* s = VG_(client_envp)[i]; if (VG_(strncmp)(varname, s, n) == 0 && s[n] == '=') { return & s[n+1]; } } return NULL; } /* If free_fn is not NULL, it is called on "unset" environment variable. */ void VG_(env_unsetenv) ( HChar **env, const HChar *varname, void (*free_fn) (void *) ) { HChar **from, **to; vg_assert(env); vg_assert(varname); 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++; } else if (free_fn != NULL) { free_fn(*from); } } *to = *from; } /* set the environment; returns the old env if a new one was allocated */ HChar **VG_(env_setenv) ( HChar ***envp, const HChar* varname, const HChar *val ) { HChar **env = (*envp); HChar **cpp; Int len = VG_(strlen)(varname); HChar *valstr = VG_(malloc)("libcproc.es.1", len + VG_(strlen)(val) + 2); HChar **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_(malloc)("libcproc.es.2", sizeof(HChar *) * 2); env[0] = valstr; env[1] = NULL; *envp = env; } else { Int envlen = (cpp-env) + 2; HChar **newenv = VG_(malloc)("libcproc.es.3", envlen * sizeof(HChar *)); 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(HChar *varp, const HChar *remove_pattern) { HChar *const start = varp; HChar *entry_start = varp; HChar *output = varp; if (varp == NULL) return; while(*varp) { if (*varp == ':') { HChar 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 ':' */ } if (*varp) *output++ = *varp++; } /* make sure last entry is nul terminated */ *output = '\0'; /* 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. If the ro_strings option is set to True then all strings referenced by envp are considered read-only, which means they will be duplicated before they are modified. If free_fn is not NULL, it is called on "unset" environment variables. */ void VG_(env_remove_valgrind_env_stuff)(HChar** envp, Bool ro_strings, void (*free_fn) (void *) ) { Int i; HChar* ld_preload_str = NULL; HChar* ld_library_path_str = NULL; HChar* dyld_insert_libraries_str = NULL; HChar* 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) { if (ro_strings) envp[i] = VG_(strdup)("libcproc.erves.1", envp[i]); ld_preload_str = &envp[i][11]; } if (VG_(strncmp)(envp[i], "LD_LIBRARY_PATH=", 16) == 0) { if (ro_strings) envp[i] = VG_(strdup)("libcproc.erves.2", envp[i]); ld_library_path_str = &envp[i][16]; } if (VG_(strncmp)(envp[i], "DYLD_INSERT_LIBRARIES=", 22) == 0) { if (ro_strings) envp[i] = VG_(strdup)("libcproc.erves.3", envp[i]); dyld_insert_libraries_str = &envp[i][22]; } } buf = VG_(malloc)("libcproc.erves.4", 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, free_fn); // Remove DYLD_SHARED_REGION variable. VG_(env_unsetenv)(envp, "DYLD_SHARED_REGION", free_fn); // XXX if variable becomes empty, remove it completely? VG_(free)(buf); } /* Resolves filename of VG_(cl_exec_fd) and copies it to the buffer. Buffer must not be NULL and buf_size must be at least 1. If buffer is not large enough it is terminated with '\0' only when 'terminate_with_NUL == True'. */ void VG_(client_fname)(HChar *buffer, SizeT buf_size, Bool terminate_with_NUL) { vg_assert(buffer != NULL); vg_assert(buf_size >= 1); const HChar *name; if (VG_(resolve_filename)(VG_(cl_exec_fd), &name)) { const HChar *n = name + VG_(strlen)(name) - 1; while (n > name && *n != '/') n--; if (n != name) n++; VG_(strncpy)(buffer, n, buf_size); if (terminate_with_NUL) buffer[buf_size - 1] = '\0'; } else { buffer[0] = '\0'; } } static Bool add_string(HChar *buffer, SizeT *buf_size, const HChar *string) { SizeT len = VG_(strlen)(string); VG_(strncat)(buffer, string, *buf_size); if (len >= *buf_size - 1) { *buf_size = 0; return False; } else { *buf_size -= len; return True; } } /* Concatenates client exename and command line arguments into the buffer. Buffer must not be NULL and buf_size must be at least 1. Buffer is always terminated with '\0'. */ void VG_(client_cmd_and_args)(HChar *buffer, SizeT buf_size) { vg_assert(buffer != NULL); vg_assert(buf_size >= 1); buffer[0] = '\0'; if (add_string(buffer, &buf_size, VG_(args_the_exename)) == False) return; Int i; for (i = 0; i < VG_(sizeXA)(VG_(args_for_client)); i++) { if (add_string(buffer, &buf_size, " ") == False) return; HChar *arg = *(HChar **) VG_(indexXA)(VG_(args_for_client), i); if (add_string(buffer, &buf_size, arg) == False) return; } } /* --------------------------------------------------------------------- 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_solaris) SysRes res; vki_idtype_t idtype; vki_id_t id; vki_siginfo_t info; /* We need to do a lot of work here. */ if (pid > 0) { idtype = VKI_P_PID; id = pid; } else if (pid < -1) { idtype = VKI_P_PGID; id = -pid; } else if (pid == -1) { idtype = VKI_P_ALL; id = 0; } else { idtype = VKI_P_PGID; res = VG_(do_syscall0)(__NR_getpid); id = sr_ResHI(res); } options |= VKI_WEXITED | VKI_WTRAPPED; res = VG_(do_syscall4)(__NR_waitsys, idtype, id, (UWord)&info, options); if (sr_isError(res)) return -1; if (status) { Int s = info.si_status & 0xff; switch (info.si_code) { case VKI_CLD_EXITED: s <<= 8; break; case VKI_CLD_DUMPED: s |= VKI_WCOREFLG; break; case VKI_CLD_KILLED: break; case VKI_CLD_TRAPPED: case VKI_CLD_STOPPED: s <<= 8; s |= VKI_WSTOPFLG; break; case VKI_CLD_CONTINUED: s = VKI_WCONTFLG; break; } *status = s; } return info.si_pid; # else # error Unknown OS # endif } /* clone the environment */ HChar **VG_(env_clone) ( HChar **oldenv ) { HChar **oldenvp; HChar **newenvp; HChar **newenv; Int envlen; vg_assert(oldenv); for (oldenvp = oldenv; oldenvp && *oldenvp; oldenvp++); envlen = oldenvp - oldenv + 1; newenv = VG_(malloc)("libcproc.ec.1", envlen * sizeof(HChar *)); oldenvp = oldenv; newenvp = newenv; while (oldenvp && *oldenvp) { *newenvp++ = *oldenvp++; } *newenvp = *oldenvp; return newenv; } void VG_(execv) ( const HChar* filename, const HChar** argv ) { HChar** envp; SysRes res; envp = VG_(env_clone)(VG_(client_envp)); VG_(env_remove_valgrind_env_stuff)( envp, True /*ro_strings*/, NULL ); res = VG_(do_syscall3)(__NR_execve, (UWord)filename, (UWord)argv, (UWord)envp); VG_(printf)("EXEC failed, errno = %lld\n", (Long)sr_Err(res)); } /* Spawns a new child. Uses either spawn syscall or fork+execv combo. */ Int VG_(spawn) ( const HChar *filename, const HChar **argv ) { vg_assert(filename != NULL); vg_assert(argv != NULL); # if defined(VGO_solaris) && defined(SOLARIS_SPAWN_SYSCALL) HChar **envp = VG_(env_clone)(VG_(client_envp)); for (HChar **p = envp; *p != NULL; p++) { *p = VG_(strdup)("libcproc.s.1", *p); } VG_(env_remove_valgrind_env_stuff)(envp, /* ro_strings */ False, VG_(free)); /* Now combine argv and argp into argenv. */ SizeT argenv_size = 1 + 1; for (const HChar **p = argv; *p != NULL; p++) { argenv_size += VG_(strlen)(*p) + 2; } for (HChar **p = envp; *p != NULL; p++) { argenv_size += VG_(strlen)(*p) + 2; } HChar *argenv = VG_(malloc)("libcproc.s.2", argenv_size); HChar *current = argenv; # define COPY_CHAR_TO_ARGENV(dst, character) \ do { \ *(dst) = character; \ (dst) += 1; \ } while (0) # define COPY_STRING_TO_ARGENV(dst, src) \ do { \ COPY_CHAR_TO_ARGENV(dst, '\1'); \ SizeT src_len = VG_(strlen)((src)) + 1; \ VG_(memcpy)((dst), (src), src_len); \ (dst) += src_len; \ } while (0) for (const HChar **p = argv; *p != NULL; p++) { COPY_STRING_TO_ARGENV(current, *p); } COPY_CHAR_TO_ARGENV(current, '\0'); for (HChar **p = envp; *p != NULL; p++) { COPY_STRING_TO_ARGENV(current, *p); } COPY_CHAR_TO_ARGENV(current, '\0'); vg_assert(current == argenv + argenv_size); # undef COPY_CHAR_TO_ARGENV # undef COPY_STRING_TOARGENV SysRes res = VG_(do_syscall5)(__NR_spawn, (UWord) filename, (UWord) NULL, 0, (UWord) argenv, argenv_size); VG_(free)(argenv); for (HChar **p = envp; *p != NULL; p++) { VG_(free)(*p); } VG_(free)(envp); if (sr_isError(res)) return -1; return sr_Res(res); # else Int pid = VG_(fork)(); if (pid < 0) return -1; if (pid == 0) { /* child */ VG_(execv)(argv[0], argv); /* If we're still alive here, execv failed. */ VG_(exit)(1); } else { return pid; } # endif /* VGO_solaris && SOLARIS_SPAWN_SYSCALL */ } /* Return -1 if error, else 0. NOTE does not indicate return code of child! */ Int VG_(system) ( const HChar* cmd ) { Int pid; if (cmd == NULL) return 1; const HChar *argv[4] = { "/bin/sh", "-c", cmd, 0 }; pid = VG_(spawn)(argv[0], argv); if (pid < 0) return -1; vg_assert(pid > 0); /* 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; } Int VG_(sysctl)(Int *name, UInt namelen, void *oldp, SizeT *oldlenp, void *newp, SizeT newlen) { SysRes res; # if defined(VGO_darwin) res = VG_(do_syscall6)(__NR___sysctl, (UWord)name, namelen, (UWord)oldp, (UWord)oldlenp, (UWord)newp, newlen); # else res = VG_(mk_SysRes_Error)(VKI_ENOSYS); # endif return sr_isError(res) ? -1 : sr_Res(res); } /* --------------------------------------------------------------------- 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); } /* Support for prctl. */ Int VG_(prctl) (Int option, ULong arg2, ULong arg3, ULong arg4, ULong arg5) { SysRes res = VG_(mk_SysRes_Error)(VKI_ENOSYS); # if defined(VGO_linux) /* res = prctl( option, arg2, arg3, arg4, arg5 ); */ res = VG_(do_syscall5)(__NR_prctl, (UWord) option, (UWord) arg2, (UWord) arg3, (UWord) arg4, (UWord) arg5); # endif 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) { HChar 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... */ # if defined(VGP_arm64_linux) res = VG_(do_syscall4)(__NR_readlinkat, VKI_AT_FDCWD, (UWord)"/proc/self", (UWord)pid, sizeof(pid)); # else res = VG_(do_syscall3)(__NR_readlink, (UWord)"/proc/self", (UWord)pid, sizeof(pid)); # endif if (!sr_isError(res) && sr_Res(res) > 0) { HChar* 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\n", pid); } } } return sr_Res(res); # elif defined(VGO_darwin) // Darwin's gettid syscall is something else. // Use Mach thread ports for lwpid instead. return mach_thread_self(); # elif defined(VGO_solaris) SysRes res = VG_(do_syscall0)(__NR_lwp_self); return sr_Res(res); # 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 */ # if defined(VGP_arm64_linux) return sr_Res( VG_(do_syscall1)(__NR_getpgid, 0) ); # elif defined(VGO_linux) || defined(VGO_darwin) return sr_Res( VG_(do_syscall0)(__NR_getpgrp) ); # elif defined(VGO_solaris) /* Uses the shared pgrpsys syscall, 0 for the getpgrp variant. */ return sr_Res( VG_(do_syscall1)(__NR_pgrpsys, 0) ); # else # error Unknown OS # endif } Int VG_(getppid) ( void ) { /* ASSUMES SYSCALL ALWAYS SUCCEEDS */ # if defined(VGO_linux) || defined(VGO_darwin) return sr_Res( VG_(do_syscall0)(__NR_getppid) ); # elif defined(VGO_solaris) /* Uses the shared getpid/getppid syscall, val2 contains a parent pid. */ return sr_ResHI( VG_(do_syscall0)(__NR_getpid) ); # else # error Unknown OS # endif } Int VG_(geteuid) ( void ) { /* ASSUMES SYSCALL ALWAYS SUCCEEDS */ # if defined(VGO_linux) || defined(VGO_darwin) { # if 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 } # elif defined(VGO_solaris) /* Uses the shared getuid/geteuid syscall, val2 contains the effective uid. */ return sr_ResHI( VG_(do_syscall0)(__NR_getuid) ); # else # error Unknown OS # endif } Int VG_(getegid) ( void ) { # if defined(VGO_linux) || defined(VGO_darwin) /* ASSUMES SYSCALL ALWAYS SUCCEEDS */ # if 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 # elif defined(VGO_solaris) /* Uses the shared getgid/getegid syscall, val2 contains the effective gid. */ return sr_ResHI( VG_(do_syscall0)(__NR_getgid) ); # else # error Unknown OS # 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. As a special case, if size == 0 the function returns the number of groups leaving list untouched. */ Int VG_(getgroups)( Int size, UInt* list ) { if (size < 0) return -1; # if defined(VGP_x86_linux) || defined(VGP_ppc32_linux) \ || defined(VGP_mips64_linux) Int i; SysRes sres; UShort list16[size]; sres = VG_(do_syscall2)(__NR_getgroups, size, (Addr)list16); if (sr_isError(sres)) return -1; if (size != 0) { for (i = 0; i < sr_Res(sres); i++) list[i] = (UInt)list16[i]; } return sr_Res(sres); # elif defined(VGP_amd64_linux) || defined(VGP_arm_linux) \ || defined(VGP_ppc64be_linux) || defined(VGP_ppc64le_linux) \ || defined(VGO_darwin) || defined(VGP_s390x_linux) \ || defined(VGP_mips32_linux) || defined(VGP_arm64_linux) \ || defined(VGO_solaris) 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; # if defined(VGO_linux) || defined(VGO_darwin) res = VG_(do_syscall4)(__NR_ptrace, request, pid, (UWord)addr, (UWord)data); # elif defined(VGO_solaris) /* There is no ptrace syscall on Solaris. Such requests has to be implemented using the /proc interface. Callers of VG_(ptrace) should ensure that this function is not reached on Solaris, i.e. they must provide a special code for Solaris for whatever feature they provide. */ I_die_here; # else # error Unknown OS # endif if (sr_isError(res)) return -1; return sr_Res(res); } /* --------------------------------------------------------------------- Fork ------------------------------------------------------------------ */ Int VG_(fork) ( void ) { # if defined(VGP_arm64_linux) SysRes res; res = VG_(do_syscall5)(__NR_clone, VKI_SIGCHLD, (UWord)NULL, (UWord)NULL, (UWord)NULL, (UWord)NULL); if (sr_isError(res)) return -1; return sr_Res(res); # elif defined(VGO_linux) 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); # elif defined(VGO_solaris) /* Using fork() on Solaris is not really the best thing to do. Solaris does not do memory overcommitment so fork() can fail if there is not enough memory to copy the current process into a new one. Prefer to use VG_(spawn)() over VG_(fork)() + VG_(execv)(). */ SysRes res; res = VG_(do_syscall2)(__NR_forksys, 0 /*subcode (fork)*/, 0 /*flags*/); if (sr_isError(res)) return -1; /* On success: val = a pid of the child in the parent, a pid of the parent in the child, val2 = 0 in the parent process, 1 in the child process. */ if (sr_ResHI(res) != 0) { return 0; } 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) || defined(VGO_solaris) { 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; /* Note: On Solaris, this syscall takes only one parameter but the extra dummy one does not cause any harm. */ 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_darwin) // Weird: it seems that gettimeofday() doesn't fill in the timeval, but // rather returns the tv_sec as the low 32 bits of the result and the // tv_usec as the high 32 bits of the result. (But the timeval cannot be // NULL!) See bug 200990. { SysRes res; struct vki_timeval tv_now = { 0, 0 }; res = VG_(do_syscall2)(__NR_gettimeofday, (UWord)&tv_now, (UWord)NULL); vg_assert(! sr_isError(res)); now = sr_Res(res) * 1000000ULL + sr_ResHI(res); } # else # error "Unknown OS" # endif /* COMMON CODE */ if (base == 0) base = now; return (now - base) / 1000; } Int VG_(gettimeofday)(struct vki_timeval *tv, struct vki_timezone *tz) { SysRes res; res = VG_(do_syscall2)(__NR_gettimeofday, (UWord)tv, (UWord)tz); if (! sr_isError(res)) return 0; /* Make sure, argument values are deterministic upon failure */ if (tv) *tv = (struct vki_timeval){ .tv_sec = 0, .tv_usec = 0 }; if (tz) *tz = (struct vki_timezone){ .tz_minuteswest = 0, .tz_dsttime = 0 }; return -1; } /* --------------------------------------------------------------------- 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); } /* --------------------------------------------------------------------- icache invalidation ------------------------------------------------------------------ */ void VG_(invalidate_icache) ( void *ptr, SizeT nbytes ) { if (nbytes == 0) return; // nothing to do // Get cache info VexArchInfo vai; VG_(machine_get_VexArchInfo)(NULL, &vai); // If I-caches are coherent, nothing needs to be done here if (vai.hwcache_info.icaches_maintain_coherence) return; # if defined(VGA_ppc32) || defined(VGA_ppc64be) || defined(VGA_ppc64le) Addr startaddr = (Addr) ptr; Addr endaddr = startaddr + nbytes; Addr cls; Addr addr; cls = vai.ppc_icache_line_szB; /* Stay sane .. */ vg_assert(cls == 16 || cls == 32 || cls == 64 || cls == 128); startaddr &= ~(cls - 1); for (addr = startaddr; addr < endaddr; addr += cls) { __asm__ __volatile__("dcbst 0,%0" : : "r" (addr)); } __asm__ __volatile__("sync"); for (addr = startaddr; addr < endaddr; addr += cls) { __asm__ __volatile__("icbi 0,%0" : : "r" (addr)); } __asm__ __volatile__("sync; isync"); # elif defined(VGP_arm_linux) /* ARM cache flushes are privileged, so we must defer to the kernel. */ Addr startaddr = (Addr) ptr; Addr endaddr = startaddr + nbytes; VG_(do_syscall2)(__NR_ARM_cacheflush, startaddr, endaddr); # elif defined(VGP_arm64_linux) // This arm64_linux section of this function VG_(invalidate_icache) // is copied from // https://github.com/armvixl/vixl/blob/master/src/a64/cpu-a64.cc // which has the following copyright notice: /* Copyright 2013, ARM Limited All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: * Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. * Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. * Neither the name of ARM Limited nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ // Ask what the I and D line sizes are UInt cache_type_register; // Copy the content of the cache type register to a core register. __asm__ __volatile__ ("mrs %[ctr], ctr_el0" // NOLINT : [ctr] "=r" (cache_type_register)); const Int kDCacheLineSizeShift = 16; const Int kICacheLineSizeShift = 0; const UInt kDCacheLineSizeMask = 0xf << kDCacheLineSizeShift; const UInt kICacheLineSizeMask = 0xf << kICacheLineSizeShift; // The cache type register holds the size of the I and D caches as a power of // two. const UInt dcache_line_size_power_of_two = (cache_type_register & kDCacheLineSizeMask) >> kDCacheLineSizeShift; const UInt icache_line_size_power_of_two = (cache_type_register & kICacheLineSizeMask) >> kICacheLineSizeShift; const UInt dcache_line_size_ = 4 * (1 << dcache_line_size_power_of_two); const UInt icache_line_size_ = 4 * (1 << icache_line_size_power_of_two); Addr start = (Addr)ptr; // Sizes will be used to generate a mask big enough to cover a pointer. Addr dsize = (Addr)dcache_line_size_; Addr isize = (Addr)icache_line_size_; // Cache line sizes are always a power of 2. Addr dstart = start & ~(dsize - 1); Addr istart = start & ~(isize - 1); Addr end = start + nbytes; __asm__ __volatile__ ( // Clean every line of the D cache containing the target data. "0: \n\t" // dc : Data Cache maintenance // c : Clean // va : by (Virtual) Address // u : to the point of Unification // The point of unification for a processor is the point by which the // instruction and data caches are guaranteed to see the same copy of a // memory location. See ARM DDI 0406B page B2-12 for more information. "dc cvau, %[dline] \n\t" "add %[dline], %[dline], %[dsize] \n\t" "cmp %[dline], %[end] \n\t" "b.lt 0b \n\t" // Barrier to make sure the effect of the code above is visible to the rest // of the world. // dsb : Data Synchronisation Barrier // ish : Inner SHareable domain // The point of unification for an Inner Shareable shareability domain is // the point by which the instruction and data caches of all the processors // in that Inner Shareable shareability domain are guaranteed to see the // same copy of a memory location. See ARM DDI 0406B page B2-12 for more // information. "dsb ish \n\t" // Invalidate every line of the I cache containing the target data. "1: \n\t" // ic : instruction cache maintenance // i : invalidate // va : by address // u : to the point of unification "ic ivau, %[iline] \n\t" "add %[iline], %[iline], %[isize] \n\t" "cmp %[iline], %[end] \n\t" "b.lt 1b \n\t" // Barrier to make sure the effect of the code above is visible to the rest // of the world. "dsb ish \n\t" // Barrier to ensure any prefetching which happened before this code is // discarded. // isb : Instruction Synchronisation Barrier "isb \n\t" : [dline] "+r" (dstart), [iline] "+r" (istart) : [dsize] "r" (dsize), [isize] "r" (isize), [end] "r" (end) // This code does not write to memory but without the dependency gcc might // move this code before the code is generated. : "cc", "memory" ); # elif defined(VGA_mips32) || defined(VGA_mips64) SysRes sres = VG_(do_syscall3)(__NR_cacheflush, (UWord) ptr, (UWord) nbytes, (UWord) 3); vg_assert( !sr_isError(sres) ); # endif } /* --------------------------------------------------------------------- dcache flushing ------------------------------------------------------------------ */ void VG_(flush_dcache) ( void *ptr, SizeT nbytes ) { /* Currently this is only required on ARM64. */ # if defined(VGA_arm64) Addr startaddr = (Addr) ptr; Addr endaddr = startaddr + nbytes; Addr cls; Addr addr; ULong ctr_el0; __asm__ __volatile__ ("mrs %0, ctr_el0" : "=r"(ctr_el0)); cls = 4 * (1ULL << (0xF & (ctr_el0 >> 16))); /* Stay sane .. */ vg_assert(cls == 64 || cls == 128); startaddr &= ~(cls - 1); for (addr = startaddr; addr < endaddr; addr += cls) { __asm__ __volatile__("dc cvau, %0" : : "r" (addr)); } __asm__ __volatile__("dsb ish"); # endif } /*--------------------------------------------------------------------*/ /*--- end ---*/ /*--------------------------------------------------------------------*/