original development tree for Linux kernel GTP module; now long in mainline.
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include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
12 years ago
Sanitize the type of struct user.u_ar0 struct user.u_ar0 is defined to contain a pointer offset on all architectures in which it is defined (all architectures which define an a.out format except SPARC.) However, it has a pointer type in the headers, which is pointless -- <asm/user.h> is not exported to userspace, and it just makes the code messy. Redefine the field as "unsigned long" (which is the same size as a pointer on all Linux architectures) and change the setting code to user offsetof() instead of hand-coded arithmetic. Cc: Linux Arch Mailing List <linux-arch@vger.kernel.org> Cc: Bryan Wu <bryan.wu@analog.com> Cc: Roman Zippel <zippel@linux-m68k.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Lennert Buytenhek <kernel@wantstofly.org> Cc: Håvard Skinnemoen <hskinnemoen@atmel.com> Cc: Mikael Starvik <starvik@axis.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Tony Luck <tony.luck@intel.com> Cc: Hirokazu Takata <takata@linux-m32r.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Paul Mundt <lethal@linux-sh.org> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
14 years ago
coredump: unify dump_seek() implementations for each binfmt_*.c The current ELF dumper can produce broken corefiles if program headers exceed 65535. In particular, the program in 64-bit environment often demands more than 65535 mmaps. If you google max_map_count, then you can find many users facing this problem. Solaris has already dealt with this issue, and other OSes have also adopted the same method as in Solaris. Currently, Sun's document and AMD 64 ABI include the description for the extension, where they call the extension Extended Numbering. See Reference for further information. I believe that linux kernel should adopt the same way as they did, so I've written this patch. I am also preparing for patches of GDB and binutils. How to fix ========== In new dumping process, there are two cases according to weather or not the number of program headers is equal to or more than 65535. - if less than 65535, the produced corefile format is exactly the same as the ordinary one. - if equal to or more than 65535, then e_phnum field is set to newly introduced constant PN_XNUM(0xffff) and the actual number of program headers is set to sh_info field of the section header at index 0. Compatibility Concern ===================== * As already mentioned in Summary, Sun and AMD64 has already adopted this. See Reference. * There are four combinations according to whether kernel and userland tools are respectively modified or not. The next table summarizes shortly for each combination. --------------------------------------------- Original Kernel | Modified Kernel --------------------------------------------- < 65535 | >= 65535 | < 65535 | >= 65535 ------------------------------------------------------------- Original Tools | OK | broken | OK | broken (#) ------------------------------------------------------------- Modified Tools | OK | broken | OK | OK ------------------------------------------------------------- Note that there is no case that `OK' changes to `broken'. (#) Although this case remains broken, O-M behaves better than O-O. That is, while in O-O case e_phnum field would be extremely small due to integer overflow, in O-M case it is guaranteed to be at least 65535 by being set to PN_XNUM(0xFFFF), much closer to the actual correct value than the O-O case. Test Program ============ Here is a test program mkmmaps.c that is useful to produce the corefile with many mmaps. To use this, please take the following steps: $ ulimit -c unlimited $ sysctl vm.max_map_count=70000 # default 65530 is too small $ sysctl fs.file-max=70000 $ mkmmaps 65535 Then, the program will abort and a corefile will be generated. If failed, there are two cases according to the error message displayed. * ``out of memory'' means vm.max_map_count is still smaller * ``too many open files'' means fs.file-max is still smaller So, please change it to a larger value, and then retry it. mkmmaps.c == #include <stdio.h> #include <stdlib.h> #include <sys/mman.h> #include <fcntl.h> #include <unistd.h> int main(int argc, char **argv) { int maps_num; if (argc < 2) { fprintf(stderr, "mkmmaps [number of maps to be created]\n"); exit(1); } if (sscanf(argv[1], "%d", &maps_num) == EOF) { perror("sscanf"); exit(2); } if (maps_num < 0) { fprintf(stderr, "%d is invalid\n", maps_num); exit(3); } for (; maps_num > 0; --maps_num) { if (MAP_FAILED == mmap((void *)NULL, (size_t) 1, PROT_READ, MAP_SHARED | MAP_ANONYMOUS, (int) -1, (off_t) NULL)) { perror("mmap"); exit(4); } } abort(); { char buffer[128]; sprintf(buffer, "wc -l /proc/%u/maps", getpid()); system(buffer); } return 0; } Tested on i386, ia64 and um/sys-i386. Built on sh4 (which covers fs/binfmt_elf_fdpic.c) References ========== - Sun microsystems: Linker and Libraries. Part No: 817-1984-17, September 2008. URL: http://docs.sun.com/app/docs/doc/817-1984 - System V ABI AMD64 Architecture Processor Supplement Draft Version 0.99., May 11, 2009. URL: http://www.x86-64.org/ This patch: There are three different definitions for dump_seek() functions in binfmt_aout.c, binfmt_elf.c and binfmt_elf_fdpic.c, respectively. The only for binfmt_elf.c. My next patch will move dump_seek() into a header file in order to share the same implementations for dump_write() and dump_seek(). As the first step, this patch unify these three definitions for dump_seek() by applying the past commits that have been applied only for binfmt_elf.c. Specifically, the modification made here is part of the following commits: * d025c9db7f31fc0554ce7fb2dfc78d35a77f3487 * 7f14daa19ea36b200d237ad3ac5826ae25360461 This patch does not change a shape of corefiles. Signed-off-by: Daisuke HATAYAMA <d.hatayama@jp.fujitsu.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Jeff Dike <jdike@addtoit.com> Cc: David Howells <dhowells@redhat.com> Cc: Greg Ungerer <gerg@snapgear.com> Cc: Roland McGrath <roland@redhat.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Andi Kleen <andi@firstfloor.org> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
12 years ago
CRED: Make execve() take advantage of copy-on-write credentials Make execve() take advantage of copy-on-write credentials, allowing it to set up the credentials in advance, and then commit the whole lot after the point of no return. This patch and the preceding patches have been tested with the LTP SELinux testsuite. This patch makes several logical sets of alteration: (1) execve(). The credential bits from struct linux_binprm are, for the most part, replaced with a single credentials pointer (bprm->cred). This means that all the creds can be calculated in advance and then applied at the point of no return with no possibility of failure. I would like to replace bprm->cap_effective with: cap_isclear(bprm->cap_effective) but this seems impossible due to special behaviour for processes of pid 1 (they always retain their parent's capability masks where normally they'd be changed - see cap_bprm_set_creds()). The following sequence of events now happens: (a) At the start of do_execve, the current task's cred_exec_mutex is locked to prevent PTRACE_ATTACH from obsoleting the calculation of creds that we make. (a) prepare_exec_creds() is then called to make a copy of the current task's credentials and prepare it. This copy is then assigned to bprm->cred. This renders security_bprm_alloc() and security_bprm_free() unnecessary, and so they've been removed. (b) The determination of unsafe execution is now performed immediately after (a) rather than later on in the code. The result is stored in bprm->unsafe for future reference. (c) prepare_binprm() is called, possibly multiple times. (i) This applies the result of set[ug]id binaries to the new creds attached to bprm->cred. Personality bit clearance is recorded, but now deferred on the basis that the exec procedure may yet fail. (ii) This then calls the new security_bprm_set_creds(). This should calculate the new LSM and capability credentials into *bprm->cred. This folds together security_bprm_set() and parts of security_bprm_apply_creds() (these two have been removed). Anything that might fail must be done at this point. (iii) bprm->cred_prepared is set to 1. bprm->cred_prepared is 0 on the first pass of the security calculations, and 1 on all subsequent passes. This allows SELinux in (ii) to base its calculations only on the initial script and not on the interpreter. (d) flush_old_exec() is called to commit the task to execution. This performs the following steps with regard to credentials: (i) Clear pdeath_signal and set dumpable on certain circumstances that may not be covered by commit_creds(). (ii) Clear any bits in current->personality that were deferred from (c.i). (e) install_exec_creds() [compute_creds() as was] is called to install the new credentials. This performs the following steps with regard to credentials: (i) Calls security_bprm_committing_creds() to apply any security requirements, such as flushing unauthorised files in SELinux, that must be done before the credentials are changed. This is made up of bits of security_bprm_apply_creds() and security_bprm_post_apply_creds(), both of which have been removed. This function is not allowed to fail; anything that might fail must have been done in (c.ii). (ii) Calls commit_creds() to apply the new credentials in a single assignment (more or less). Possibly pdeath_signal and dumpable should be part of struct creds. (iii) Unlocks the task's cred_replace_mutex, thus allowing PTRACE_ATTACH to take place. (iv) Clears The bprm->cred pointer as the credentials it was holding are now immutable. (v) Calls security_bprm_committed_creds() to apply any security alterations that must be done after the creds have been changed. SELinux uses this to flush signals and signal handlers. (f) If an error occurs before (d.i), bprm_free() will call abort_creds() to destroy the proposed new credentials and will then unlock cred_replace_mutex. No changes to the credentials will have been made. (2) LSM interface. A number of functions have been changed, added or removed: (*) security_bprm_alloc(), ->bprm_alloc_security() (*) security_bprm_free(), ->bprm_free_security() Removed in favour of preparing new credentials and modifying those. (*) security_bprm_apply_creds(), ->bprm_apply_creds() (*) security_bprm_post_apply_creds(), ->bprm_post_apply_creds() Removed; split between security_bprm_set_creds(), security_bprm_committing_creds() and security_bprm_committed_creds(). (*) security_bprm_set(), ->bprm_set_security() Removed; folded into security_bprm_set_creds(). (*) security_bprm_set_creds(), ->bprm_set_creds() New. The new credentials in bprm->creds should be checked and set up as appropriate. bprm->cred_prepared is 0 on the first call, 1 on the second and subsequent calls. (*) security_bprm_committing_creds(), ->bprm_committing_creds() (*) security_bprm_committed_creds(), ->bprm_committed_creds() New. Apply the security effects of the new credentials. This includes closing unauthorised files in SELinux. This function may not fail. When the former is called, the creds haven't yet been applied to the process; when the latter is called, they have. The former may access bprm->cred, the latter may not. (3) SELinux. SELinux has a number of changes, in addition to those to support the LSM interface changes mentioned above: (a) The bprm_security_struct struct has been removed in favour of using the credentials-under-construction approach. (c) flush_unauthorized_files() now takes a cred pointer and passes it on to inode_has_perm(), file_has_perm() and dentry_open(). Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: James Morris <jmorris@namei.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: James Morris <jmorris@namei.org>
13 years ago
  1. /*
  2. * linux/fs/binfmt_aout.c
  3. *
  4. * Copyright (C) 1991, 1992, 1996 Linus Torvalds
  5. */
  6. #include <linux/module.h>
  7. #include <linux/time.h>
  8. #include <linux/kernel.h>
  9. #include <linux/mm.h>
  10. #include <linux/mman.h>
  11. #include <linux/a.out.h>
  12. #include <linux/errno.h>
  13. #include <linux/signal.h>
  14. #include <linux/string.h>
  15. #include <linux/fs.h>
  16. #include <linux/file.h>
  17. #include <linux/stat.h>
  18. #include <linux/fcntl.h>
  19. #include <linux/ptrace.h>
  20. #include <linux/user.h>
  21. #include <linux/binfmts.h>
  22. #include <linux/personality.h>
  23. #include <linux/init.h>
  24. #include <linux/coredump.h>
  25. #include <linux/slab.h>
  26. #include <asm/uaccess.h>
  27. #include <asm/cacheflush.h>
  28. #include <asm/a.out-core.h>
  29. static int load_aout_binary(struct linux_binprm *);
  30. static int load_aout_library(struct file*);
  31. #ifdef CONFIG_COREDUMP
  32. /*
  33. * Routine writes a core dump image in the current directory.
  34. * Currently only a stub-function.
  35. *
  36. * Note that setuid/setgid files won't make a core-dump if the uid/gid
  37. * changed due to the set[u|g]id. It's enforced by the "current->mm->dumpable"
  38. * field, which also makes sure the core-dumps won't be recursive if the
  39. * dumping of the process results in another error..
  40. */
  41. static int aout_core_dump(struct coredump_params *cprm)
  42. {
  43. mm_segment_t fs;
  44. int has_dumped = 0;
  45. void __user *dump_start;
  46. int dump_size;
  47. struct user dump;
  48. #ifdef __alpha__
  49. # define START_DATA(u) ((void __user *)u.start_data)
  50. #else
  51. # define START_DATA(u) ((void __user *)((u.u_tsize << PAGE_SHIFT) + \
  52. u.start_code))
  53. #endif
  54. # define START_STACK(u) ((void __user *)u.start_stack)
  55. fs = get_fs();
  56. set_fs(KERNEL_DS);
  57. has_dumped = 1;
  58. strncpy(dump.u_comm, current->comm, sizeof(dump.u_comm));
  59. dump.u_ar0 = offsetof(struct user, regs);
  60. dump.signal = cprm->siginfo->si_signo;
  61. aout_dump_thread(cprm->regs, &dump);
  62. /* If the size of the dump file exceeds the rlimit, then see what would happen
  63. if we wrote the stack, but not the data area. */
  64. if ((dump.u_dsize + dump.u_ssize+1) * PAGE_SIZE > cprm->limit)
  65. dump.u_dsize = 0;
  66. /* Make sure we have enough room to write the stack and data areas. */
  67. if ((dump.u_ssize + 1) * PAGE_SIZE > cprm->limit)
  68. dump.u_ssize = 0;
  69. /* make sure we actually have a data and stack area to dump */
  70. set_fs(USER_DS);
  71. if (!access_ok(VERIFY_READ, START_DATA(dump), dump.u_dsize << PAGE_SHIFT))
  72. dump.u_dsize = 0;
  73. if (!access_ok(VERIFY_READ, START_STACK(dump), dump.u_ssize << PAGE_SHIFT))
  74. dump.u_ssize = 0;
  75. set_fs(KERNEL_DS);
  76. /* struct user */
  77. if (!dump_emit(cprm, &dump, sizeof(dump)))
  78. goto end_coredump;
  79. /* Now dump all of the user data. Include malloced stuff as well */
  80. if (!dump_skip(cprm, PAGE_SIZE - sizeof(dump)))
  81. goto end_coredump;
  82. /* now we start writing out the user space info */
  83. set_fs(USER_DS);
  84. /* Dump the data area */
  85. if (dump.u_dsize != 0) {
  86. dump_start = START_DATA(dump);
  87. dump_size = dump.u_dsize << PAGE_SHIFT;
  88. if (!dump_emit(cprm, dump_start, dump_size))
  89. goto end_coredump;
  90. }
  91. /* Now prepare to dump the stack area */
  92. if (dump.u_ssize != 0) {
  93. dump_start = START_STACK(dump);
  94. dump_size = dump.u_ssize << PAGE_SHIFT;
  95. if (!dump_emit(cprm, dump_start, dump_size))
  96. goto end_coredump;
  97. }
  98. end_coredump:
  99. set_fs(fs);
  100. return has_dumped;
  101. }
  102. #else
  103. #define aout_core_dump NULL
  104. #endif
  105. static struct linux_binfmt aout_format = {
  106. .module = THIS_MODULE,
  107. .load_binary = load_aout_binary,
  108. .load_shlib = load_aout_library,
  109. .core_dump = aout_core_dump,
  110. .min_coredump = PAGE_SIZE
  111. };
  112. #define BAD_ADDR(x) ((unsigned long)(x) >= TASK_SIZE)
  113. static int set_brk(unsigned long start, unsigned long end)
  114. {
  115. start = PAGE_ALIGN(start);
  116. end = PAGE_ALIGN(end);
  117. if (end > start) {
  118. unsigned long addr;
  119. addr = vm_brk(start, end - start);
  120. if (BAD_ADDR(addr))
  121. return addr;
  122. }
  123. return 0;
  124. }
  125. /*
  126. * create_aout_tables() parses the env- and arg-strings in new user
  127. * memory and creates the pointer tables from them, and puts their
  128. * addresses on the "stack", returning the new stack pointer value.
  129. */
  130. static unsigned long __user *create_aout_tables(char __user *p, struct linux_binprm * bprm)
  131. {
  132. char __user * __user *argv;
  133. char __user * __user *envp;
  134. unsigned long __user *sp;
  135. int argc = bprm->argc;
  136. int envc = bprm->envc;
  137. sp = (void __user *)((-(unsigned long)sizeof(char *)) & (unsigned long) p);
  138. #ifdef __alpha__
  139. /* whee.. test-programs are so much fun. */
  140. put_user(0, --sp);
  141. put_user(0, --sp);
  142. if (bprm->loader) {
  143. put_user(0, --sp);
  144. put_user(1003, --sp);
  145. put_user(bprm->loader, --sp);
  146. put_user(1002, --sp);
  147. }
  148. put_user(bprm->exec, --sp);
  149. put_user(1001, --sp);
  150. #endif
  151. sp -= envc+1;
  152. envp = (char __user * __user *) sp;
  153. sp -= argc+1;
  154. argv = (char __user * __user *) sp;
  155. #ifndef __alpha__
  156. put_user((unsigned long) envp,--sp);
  157. put_user((unsigned long) argv,--sp);
  158. #endif
  159. put_user(argc,--sp);
  160. current->mm->arg_start = (unsigned long) p;
  161. while (argc-->0) {
  162. char c;
  163. put_user(p,argv++);
  164. do {
  165. get_user(c,p++);
  166. } while (c);
  167. }
  168. put_user(NULL,argv);
  169. current->mm->arg_end = current->mm->env_start = (unsigned long) p;
  170. while (envc-->0) {
  171. char c;
  172. put_user(p,envp++);
  173. do {
  174. get_user(c,p++);
  175. } while (c);
  176. }
  177. put_user(NULL,envp);
  178. current->mm->env_end = (unsigned long) p;
  179. return sp;
  180. }
  181. /*
  182. * These are the functions used to load a.out style executables and shared
  183. * libraries. There is no binary dependent code anywhere else.
  184. */
  185. static int load_aout_binary(struct linux_binprm * bprm)
  186. {
  187. struct pt_regs *regs = current_pt_regs();
  188. struct exec ex;
  189. unsigned long error;
  190. unsigned long fd_offset;
  191. unsigned long rlim;
  192. int retval;
  193. ex = *((struct exec *) bprm->buf); /* exec-header */
  194. if ((N_MAGIC(ex) != ZMAGIC && N_MAGIC(ex) != OMAGIC &&
  195. N_MAGIC(ex) != QMAGIC && N_MAGIC(ex) != NMAGIC) ||
  196. N_TRSIZE(ex) || N_DRSIZE(ex) ||
  197. i_size_read(file_inode(bprm->file)) < ex.a_text+ex.a_data+N_SYMSIZE(ex)+N_TXTOFF(ex)) {
  198. return -ENOEXEC;
  199. }
  200. /*
  201. * Requires a mmap handler. This prevents people from using a.out
  202. * as part of an exploit attack against /proc-related vulnerabilities.
  203. */
  204. if (!bprm->file->f_op->mmap)
  205. return -ENOEXEC;
  206. fd_offset = N_TXTOFF(ex);
  207. /* Check initial limits. This avoids letting people circumvent
  208. * size limits imposed on them by creating programs with large
  209. * arrays in the data or bss.
  210. */
  211. rlim = rlimit(RLIMIT_DATA);
  212. if (rlim >= RLIM_INFINITY)
  213. rlim = ~0;
  214. if (ex.a_data + ex.a_bss > rlim)
  215. return -ENOMEM;
  216. /* Flush all traces of the currently running executable */
  217. retval = flush_old_exec(bprm);
  218. if (retval)
  219. return retval;
  220. /* OK, This is the point of no return */
  221. #ifdef __alpha__
  222. SET_AOUT_PERSONALITY(bprm, ex);
  223. #else
  224. set_personality(PER_LINUX);
  225. #endif
  226. setup_new_exec(bprm);
  227. current->mm->end_code = ex.a_text +
  228. (current->mm->start_code = N_TXTADDR(ex));
  229. current->mm->end_data = ex.a_data +
  230. (current->mm->start_data = N_DATADDR(ex));
  231. current->mm->brk = ex.a_bss +
  232. (current->mm->start_brk = N_BSSADDR(ex));
  233. retval = setup_arg_pages(bprm, STACK_TOP, EXSTACK_DEFAULT);
  234. if (retval < 0) {
  235. /* Someone check-me: is this error path enough? */
  236. send_sig(SIGKILL, current, 0);
  237. return retval;
  238. }
  239. install_exec_creds(bprm);
  240. if (N_MAGIC(ex) == OMAGIC) {
  241. unsigned long text_addr, map_size;
  242. loff_t pos;
  243. text_addr = N_TXTADDR(ex);
  244. #ifdef __alpha__
  245. pos = fd_offset;
  246. map_size = ex.a_text+ex.a_data + PAGE_SIZE - 1;
  247. #else
  248. pos = 32;
  249. map_size = ex.a_text+ex.a_data;
  250. #endif
  251. error = vm_brk(text_addr & PAGE_MASK, map_size);
  252. if (error != (text_addr & PAGE_MASK)) {
  253. send_sig(SIGKILL, current, 0);
  254. return error;
  255. }
  256. error = read_code(bprm->file, text_addr, pos,
  257. ex.a_text+ex.a_data);
  258. if ((signed long)error < 0) {
  259. send_sig(SIGKILL, current, 0);
  260. return error;
  261. }
  262. } else {
  263. if ((ex.a_text & 0xfff || ex.a_data & 0xfff) &&
  264. (N_MAGIC(ex) != NMAGIC) && printk_ratelimit())
  265. {
  266. printk(KERN_NOTICE "executable not page aligned\n");
  267. }
  268. if ((fd_offset & ~PAGE_MASK) != 0 && printk_ratelimit())
  269. {
  270. printk(KERN_WARNING
  271. "fd_offset is not page aligned. Please convert program: %s\n",
  272. bprm->file->f_path.dentry->d_name.name);
  273. }
  274. if (!bprm->file->f_op->mmap||((fd_offset & ~PAGE_MASK) != 0)) {
  275. vm_brk(N_TXTADDR(ex), ex.a_text+ex.a_data);
  276. read_code(bprm->file, N_TXTADDR(ex), fd_offset,
  277. ex.a_text + ex.a_data);
  278. goto beyond_if;
  279. }
  280. error = vm_mmap(bprm->file, N_TXTADDR(ex), ex.a_text,
  281. PROT_READ | PROT_EXEC,
  282. MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE,
  283. fd_offset);
  284. if (error != N_TXTADDR(ex)) {
  285. send_sig(SIGKILL, current, 0);
  286. return error;
  287. }
  288. error = vm_mmap(bprm->file, N_DATADDR(ex), ex.a_data,
  289. PROT_READ | PROT_WRITE | PROT_EXEC,
  290. MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE,
  291. fd_offset + ex.a_text);
  292. if (error != N_DATADDR(ex)) {
  293. send_sig(SIGKILL, current, 0);
  294. return error;
  295. }
  296. }
  297. beyond_if:
  298. set_binfmt(&aout_format);
  299. retval = set_brk(current->mm->start_brk, current->mm->brk);
  300. if (retval < 0) {
  301. send_sig(SIGKILL, current, 0);
  302. return retval;
  303. }
  304. current->mm->start_stack =
  305. (unsigned long) create_aout_tables((char __user *) bprm->p, bprm);
  306. #ifdef __alpha__
  307. regs->gp = ex.a_gpvalue;
  308. #endif
  309. start_thread(regs, ex.a_entry, current->mm->start_stack);
  310. return 0;
  311. }
  312. static int load_aout_library(struct file *file)
  313. {
  314. struct inode * inode;
  315. unsigned long bss, start_addr, len;
  316. unsigned long error;
  317. int retval;
  318. struct exec ex;
  319. inode = file_inode(file);
  320. retval = -ENOEXEC;
  321. error = kernel_read(file, 0, (char *) &ex, sizeof(ex));
  322. if (error != sizeof(ex))
  323. goto out;
  324. /* We come in here for the regular a.out style of shared libraries */
  325. if ((N_MAGIC(ex) != ZMAGIC && N_MAGIC(ex) != QMAGIC) || N_TRSIZE(ex) ||
  326. N_DRSIZE(ex) || ((ex.a_entry & 0xfff) && N_MAGIC(ex) == ZMAGIC) ||
  327. i_size_read(inode) < ex.a_text+ex.a_data+N_SYMSIZE(ex)+N_TXTOFF(ex)) {
  328. goto out;
  329. }
  330. /*
  331. * Requires a mmap handler. This prevents people from using a.out
  332. * as part of an exploit attack against /proc-related vulnerabilities.
  333. */
  334. if (!file->f_op->mmap)
  335. goto out;
  336. if (N_FLAGS(ex))
  337. goto out;
  338. /* For QMAGIC, the starting address is 0x20 into the page. We mask
  339. this off to get the starting address for the page */
  340. start_addr = ex.a_entry & 0xfffff000;
  341. if ((N_TXTOFF(ex) & ~PAGE_MASK) != 0) {
  342. if (printk_ratelimit())
  343. {
  344. printk(KERN_WARNING
  345. "N_TXTOFF is not page aligned. Please convert library: %s\n",
  346. file->f_path.dentry->d_name.name);
  347. }
  348. vm_brk(start_addr, ex.a_text + ex.a_data + ex.a_bss);
  349. read_code(file, start_addr, N_TXTOFF(ex),
  350. ex.a_text + ex.a_data);
  351. retval = 0;
  352. goto out;
  353. }
  354. /* Now use mmap to map the library into memory. */
  355. error = vm_mmap(file, start_addr, ex.a_text + ex.a_data,
  356. PROT_READ | PROT_WRITE | PROT_EXEC,
  357. MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE,
  358. N_TXTOFF(ex));
  359. retval = error;
  360. if (error != start_addr)
  361. goto out;
  362. len = PAGE_ALIGN(ex.a_text + ex.a_data);
  363. bss = ex.a_text + ex.a_data + ex.a_bss;
  364. if (bss > len) {
  365. error = vm_brk(start_addr + len, bss - len);
  366. retval = error;
  367. if (error != start_addr + len)
  368. goto out;
  369. }
  370. retval = 0;
  371. out:
  372. return retval;
  373. }
  374. static int __init init_aout_binfmt(void)
  375. {
  376. register_binfmt(&aout_format);
  377. return 0;
  378. }
  379. static void __exit exit_aout_binfmt(void)
  380. {
  381. unregister_binfmt(&aout_format);
  382. }
  383. core_initcall(init_aout_binfmt);
  384. module_exit(exit_aout_binfmt);
  385. MODULE_LICENSE("GPL");