From afcf3cd8ebff8fed79238a2d1b95338c4606b1ee Mon Sep 17 00:00:00 2001 From: Adhemerval Zanella Date: Thu, 10 Nov 2016 09:28:00 -0200 Subject: [PATCH] New internal function __access_noerrno Implement an internal version of __access called __access_noerrno that avoids setting errno. This is useful to check accessibility of files very early on in process startup i.e. before TLS setup. This allows tunables to replace MALLOC_CHECK_ safely (i.e. check existence of /etc/suid-debug to enable/disable MALLOC_CHECK) and at the same time initialize very early so that it can override IFUNCs. Checked on x86_64. * hurd/hurd.h (__hurd_fail_noerrno): New function. * include/unistd.h [IS_IN (rtld) || !defined SHARED]: Declare __access_noerrno. * io/access.c (__access_noerrno): New function. * sysdeps/mach/hurd/access.c (hurd_fail_seterrno): New function. (hurd_fail_seterrno): Likewise. (access_common): Likewise. (__access_noerrno): Likewise. * sysdeps/nacl/access.c (__access_noerrno): Likewise. * sysdeps/unix/sysv/linux/access.c (__access_noerrno): Likewise. * sysdeps/nacl/nacl-interfaces.h (NACL_CALL_NOERRNO): New macro. --- ChangeLog | 15 +++++++++++++ hurd/hurd.h | 29 +++++++++++++++++++++++++ include/unistd.h | 6 ++++++ io/access.c | 7 ++++++ sysdeps/mach/hurd/access.c | 37 ++++++++++++++++++++++++++------ sysdeps/nacl/access.c | 7 ++++++ sysdeps/nacl/nacl-interfaces.h | 4 ++++ sysdeps/unix/sysv/linux/access.c | 15 +++++++++++++ 8 files changed, 114 insertions(+), 6 deletions(-) diff --git a/ChangeLog b/ChangeLog index dfa48e4c0a..b2e5b68cf8 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,18 @@ +2016-11-16 Adhemerval Zanella + + * hurd/hurd.h (__hurd_fail_noerrno): New function. + * include/unistd.h [IS_IN (rtld) || !defined SHARED]: Declare + __access_noerrno. + * io/access.c (__access_noerrno): New function. + * sysdeps/mach/hurd/access.c (hurd_fail_seterrno): New function. + (hurd_fail_seterrno): Likewise. + (access_common): Likewise. + (__access_noerrno): Likewise. + * sysdeps/nacl/access.c (__access_noerrno): Likewise. + * sysdeps/unix/sysv/linux/access.c (__access_noerrno): Likewise. + * sysdeps/nacl/nacl-interfaces.h (NACL_CALL_NOERRNO): New + macro. + 2016-11-16 Joseph Myers * sysdeps/unix/sysv/linux/sh/sh4/register-dump.h (register_dump): diff --git a/hurd/hurd.h b/hurd/hurd.h index ec0782797d..c089d4c445 100644 --- a/hurd/hurd.h +++ b/hurd/hurd.h @@ -75,6 +75,35 @@ __hurd_fail (error_t err) errno = err; return -1; } + +_HURD_H_EXTERN_INLINE int +__hurd_fail_noerrno (error_t err) +{ + switch (err) + { + case EMACH_SEND_INVALID_DEST: + case EMIG_SERVER_DIED: + /* The server has disappeared! */ + err = EIEIO; + break; + + case KERN_NO_SPACE: + err = ENOMEM; + break; + + case KERN_INVALID_ARGUMENT: + err = EINVAL; + break; + + case 0: + return 0; + + default: + break; + } + + return -1; +} /* Basic ports and info, initialized by startup. */ diff --git a/include/unistd.h b/include/unistd.h index d2802b2b3e..6144f411aa 100644 --- a/include/unistd.h +++ b/include/unistd.h @@ -181,6 +181,12 @@ extern int __getlogin_r_loginuid (char *name, size_t namesize) # include # endif +# if IS_IN (rtld) || !defined SHARED +/* __access variant that does not set errno. Used in very early initialization + code in libc.a and ld.so. */ +extern __typeof (__access) __access_noerrno attribute_hidden; +# endif + __END_DECLS # endif diff --git a/io/access.c b/io/access.c index 45347048af..859cf75e30 100644 --- a/io/access.c +++ b/io/access.c @@ -19,6 +19,13 @@ #include #include +/* Test for access to FILE without setting errno. */ +int +__access_noerrno (const char *file, int type) +{ + return -1; +} + /* Test for access to FILE. */ int __access (const char *file, int type) diff --git a/sysdeps/mach/hurd/access.c b/sysdeps/mach/hurd/access.c index c308340329..93e21666f8 100644 --- a/sysdeps/mach/hurd/access.c +++ b/sysdeps/mach/hurd/access.c @@ -22,9 +22,20 @@ #include #include -/* Test for access to FILE by our real user and group IDs. */ -int -__access (const char *file, int type) +static int +hurd_fail_seterrno (error_t err) +{ + return __hurd_fail (err); +} + +static int +hurd_fail_noerrno (error_t err) +{ + return __hurd_fail_noerrno (err); +} + +static int +access_common (const char *file, int type, int (*errfunc) (error_t)) { error_t err; file_t rcrdir, rcwdir, io; @@ -120,13 +131,13 @@ __access (const char *file, int type) if (rcwdir != MACH_PORT_NULL) __mach_port_deallocate (__mach_task_self (), rcwdir); if (err) - return __hurd_fail (err); + return errfunc (err); /* Find out what types of access we are allowed to this file. */ err = __file_check_access (io, &allowed); __mach_port_deallocate (__mach_task_self (), io); if (err) - return __hurd_fail (err); + return errfunc (err); flags = 0; if (type & R_OK) @@ -138,9 +149,23 @@ __access (const char *file, int type) if (flags & ~allowed) /* We are not allowed all the requested types of access. */ - return __hurd_fail (EACCES); + return errfunc (EACESS); return 0; } +/* Test for access to FILE by our real user and group IDs without setting + errno. */ +int +__access_noerrno (const char *file, int type) +{ + return access_common (file, type, hurd_fail_noerrno); +} + +/* Test for access to FILE by our real user and group IDs. */ +int +__access (const char *file, int type) +{ + return access_common (file, type, hurd_fail_seterrno); +} weak_alias (__access, access) diff --git a/sysdeps/nacl/access.c b/sysdeps/nacl/access.c index 95a0fb726b..e07d5582d6 100644 --- a/sysdeps/nacl/access.c +++ b/sysdeps/nacl/access.c @@ -19,6 +19,13 @@ #include #include +/* Test for access to FILE without setting errno. */ +int +__access_noerrno (const char *file, int type) +{ + return NACL_CALL_NOERRNO (__nacl_irt_dev_filename.access (file, type), 0); +} + /* Test for access to FILE. */ int __access (const char *file, int type) diff --git a/sysdeps/nacl/nacl-interfaces.h b/sysdeps/nacl/nacl-interfaces.h index b7b45bbf38..edd3217489 100644 --- a/sysdeps/nacl/nacl-interfaces.h +++ b/sysdeps/nacl/nacl-interfaces.h @@ -113,4 +113,8 @@ __nacl_fail (int err) #define NACL_CALL(err, val) \ ({ int _err = (err); _err ? __nacl_fail (_err) : (val); }) +/* Same as NACL_CALL but without setting errno. */ +#define NACL_CALL_NOERRNO(err, val) \ + ({ int _err = (err); _err ? _err : (val); }) + #endif /* nacl-interfaces.h */ diff --git a/sysdeps/unix/sysv/linux/access.c b/sysdeps/unix/sysv/linux/access.c index 8f003df27c..adefbcaac6 100644 --- a/sysdeps/unix/sysv/linux/access.c +++ b/sysdeps/unix/sysv/linux/access.c @@ -20,6 +20,21 @@ #include #include +int +__access_noerrno (const char *file, int type) +{ + int res; + INTERNAL_SYSCALL_DECL (err); +#ifdef __NR_access + res = INTERNAL_SYSCALL_CALL (access, err, file, type); +#else + res = INTERNAL_SYSCALL_CALL (faccessat, err, AT_FDCWD, file, type); +#endif + if (INTERNAL_SYSCALL_ERROR_P (res, err)) + return INTERNAL_SYSCALL_ERRNO (res, err); + return 0; +} + int __access (const char *file, int type) { -- 2.43.5