2 * the Linux incarnation of OS-dependent routines. See also
3 * $(sbcl_arch)-linux-os.c
5 * This file (along with os.h) exports an OS-independent interface to
6 * the operating system VM facilities. Surprise surprise, this
7 * interface looks a lot like the Mach interface (but simpler in some
8 * places). For some operating systems, a subset of these functions
9 * will have to be emulated.
13 * This software is part of the SBCL system. See the README file for
16 * This software is derived from the CMU CL system, which was
17 * written at Carnegie Mellon University and released into the
18 * public domain. The software is in the public domain and is
19 * provided with absolutely no warranty. See the COPYING and CREDITS
20 * files for more information.
24 #include <sys/param.h>
31 #include "interrupt.h"
35 #include "genesis/static-symbols.h"
36 #include "genesis/fdefn.h"
37 #include <sys/socket.h>
38 #include <sys/utsname.h>
40 #include <sys/types.h>
42 /* #include <sys/sysinfo.h> */
46 #include <linux/version.h>
51 #if defined LISP_FEATURE_GENCGC
52 #include "gencgc-internal.h"
55 #ifdef LISP_FEATURE_X86
56 /* Prototype for personality(2). Done inline here since the header file
57 * for this isn't available on old versions of glibc. */
58 int personality (unsigned long);
61 size_t os_vm_page_size;
63 #ifdef LISP_FEATURE_SB_THREAD
64 #include <sys/syscall.h>
68 /* values taken from the kernel's linux/futex.h. This header file
69 doesn't exist in userspace, which is our excuse for not grovelling
71 #define FUTEX_WAIT (0)
72 #define FUTEX_WAKE (1)
74 #define FUTEX_REQUEUE (3)
76 #define sys_futex sbcl_sys_futex
77 static inline int sys_futex (void *futex, int op, int val, struct timespec *rel)
79 return syscall (SYS_futex, futex, op, val, rel);
83 futex_wait(int *lock_word, int oldval)
85 int t= sys_futex(lock_word,FUTEX_WAIT,oldval, 0);
90 futex_wake(int *lock_word, int n)
92 return sys_futex(lock_word,FUTEX_WAKE,n,0);
97 int linux_sparc_siginfo_bug = 0;
98 int linux_no_threads_p = 0;
100 #ifdef LISP_FEATURE_SB_THREAD
104 size_t n = confstr (_CS_GNU_LIBPTHREAD_VERSION, NULL, 0);
106 char *buf = alloca (n);
107 confstr (_CS_GNU_LIBPTHREAD_VERSION, buf, n);
108 if (strstr (buf, "NPTL")) {
117 os_init(char *argv[], char *envp[])
119 /* Conduct various version checks: do we have enough mmap(), is
120 * this a sparc running 2.2, can we do threads? */
121 #ifdef LISP_FEATURE_SB_THREAD
131 major_version = atoi(p);
133 minor_version = atoi(p);
135 patch_version = atoi(p);
136 if (major_version<2) {
137 lose("linux kernel version too old: major version=%d (can't run in version < 2.0.0)\n",
140 if (!(major_version>2 || minor_version >= 4)) {
141 #ifdef LISP_FEATURE_SPARC
142 FSHOW((stderr,"linux kernel %d.%d predates 2.4;\n enabling workarounds for SPARC kernel bugs in signal handling.\n", major_version,minor_version));
143 linux_sparc_siginfo_bug = 1;
146 #ifdef LISP_FEATURE_SB_THREAD
147 futex_wait(futex,-1);
149 lose("This version of SBCL is compiled with threading support, but your kernel\n"
150 "is too old to support this. Please use a more recent kernel or\n"
151 "a version of SBCL without threading support.\n");
154 lose("This version of SBCL only works correctly with the NPTL threading\n"
155 "library. Please use a newer glibc, use an older SBCL, or stop using\n"
156 "LD_ASSUME_KERNEL\n");
159 os_vm_page_size = getpagesize();
161 /* KLUDGE: Disable memory randomization on new Linux kernels
162 * by setting a personality flag and re-executing. (We need
163 * to re-execute, since the memory maps that can conflict with
164 * the SBCL spaces have already been done at this point).
166 * Since randomization is currently implemented only on x86 kernels,
167 * don't do this trick on other platforms.
169 #ifdef LISP_FEATURE_X86
170 if ((major_version == 2
171 /* Some old kernels will apparently lose unsupported personality flags
173 && ((minor_version == 6 && patch_version >= 11)
174 || (minor_version > 6)))
175 || major_version >= 3)
177 int pers = personality(0xffffffffUL);
178 /* 0x40000 aka. ADDR_NO_RANDOMIZE */
179 if (!(pers & 0x40000)) {
180 int retval = personality(pers | 0x40000);
181 /* Allegedly some Linux kernels (the reported case was
182 * "hardened Linux 2.6.7") won't set the new personality,
183 * but nor will they return -1 for an error. So as a
184 * workaround query the new personality...
186 int newpers = personality(0xffffffffUL);
187 /* ... and don't re-execute if either the setting resulted
188 * in an error or if the value didn't change. Otherwise
189 * this might result in an infinite loop.
191 if (retval != -1 && newpers != pers) {
192 /* Use /proc/self/exe instead of trying to figure out
193 * the executable path from PATH and argv[0], since
194 * that's unreliable. We follow the symlink instead of
195 * executing the file directly in order to prevent top
196 * from displaying the name of the process as "exe". */
197 char runtime[PATH_MAX+1];
198 int i = readlink("/proc/self/exe", runtime, PATH_MAX);
201 execve(runtime, argv, envp);
204 /* Either changing the personality or execve() failed. Either
205 * way we might as well continue, and hope that the random
206 * memory maps are ok this time around.
208 fprintf(stderr, "WARNING: Couldn't re-execute SBCL with the proper personality flags (maybe /proc isn't mounted?). Trying to continue anyway.\n");
211 /* Use SSE detector. Recent versions of Linux enable SSE support
212 * on SSE capable CPUs. */
213 /* FIXME: Are there any old versions that does not support SSE? */
214 fast_bzero_pointer = fast_bzero_detect;
219 #ifdef LISP_FEATURE_ALPHA
220 /* The Alpha is a 64 bit CPU. SBCL is a 32 bit application. Due to all
221 * the places that assume we can get a pointer into a fixnum with no
222 * information loss, we have to make sure it allocates all its ram in the
225 static void * under_2gb_free_pointer=DYNAMIC_1_SPACE_END;
229 os_validate(os_vm_address_t addr, os_vm_size_t len)
231 int flags = MAP_PRIVATE | MAP_ANONYMOUS | MAP_NORESERVE;
232 os_vm_address_t actual;
234 #ifdef LISP_FEATURE_ALPHA
236 addr=under_2gb_free_pointer;
239 actual = mmap(addr, len, OS_VM_PROT_ALL, flags, -1, 0);
240 if (actual == MAP_FAILED) {
242 return 0; /* caller should check this */
245 if (addr && (addr!=actual)) {
246 fprintf(stderr, "mmap: wanted %lu bytes at %p, actually mapped at %p\n",
247 (unsigned long) len, addr, actual);
251 #ifdef LISP_FEATURE_ALPHA
253 len=(len+(os_vm_page_size-1))&(~(os_vm_page_size-1));
254 under_2gb_free_pointer+=len;
261 os_invalidate(os_vm_address_t addr, os_vm_size_t len)
263 if (munmap(addr,len) == -1) {
269 os_map(int fd, int offset, os_vm_address_t addr, os_vm_size_t len)
271 os_vm_address_t actual;
273 actual = mmap(addr, len, OS_VM_PROT_ALL, MAP_PRIVATE | MAP_FIXED,
275 if (actual == MAP_FAILED || (addr && (addr != actual))) {
277 lose("unexpected mmap(..) failure\n");
284 os_protect(os_vm_address_t address, os_vm_size_t length, os_vm_prot_t prot)
286 if (mprotect(address, length, prot) == -1) {
292 is_valid_lisp_addr(os_vm_address_t addr)
295 size_t ad = (size_t) addr;
297 if ((READ_ONLY_SPACE_START <= ad && ad < READ_ONLY_SPACE_END)
298 || (STATIC_SPACE_START <= ad && ad < STATIC_SPACE_END)
299 #if defined LISP_FEATURE_GENCGC
300 || (DYNAMIC_SPACE_START <= ad && ad < DYNAMIC_SPACE_END)
302 || (DYNAMIC_0_SPACE_START <= ad && ad < DYNAMIC_0_SPACE_END)
303 || (DYNAMIC_1_SPACE_START <= ad && ad < DYNAMIC_1_SPACE_END)
307 for_each_thread(th) {
308 if((size_t)(th->control_stack_start) <= ad
309 && ad < (size_t)(th->control_stack_end))
311 if((size_t)(th->binding_stack_start) <= ad
312 && ad < (size_t)(th->binding_stack_start + BINDING_STACK_SIZE))
319 * any OS-dependent special low-level handling for signals
323 * The GC needs to be hooked into whatever signal is raised for
324 * page fault on this OS.
327 sigsegv_handler(int signal, siginfo_t *info, void* void_context)
329 os_context_t *context = arch_os_get_context(&void_context);
330 os_vm_address_t addr = arch_get_bad_addr(signal, info, context);
332 #ifdef LISP_FEATURE_ALPHA
333 /* Alpha stuff: This is the end of a pseudo-atomic section during
334 which a signal was received. We must deal with the pending
335 interrupt (see also interrupt.c, ../code/interrupt.lisp)
337 (how we got here: when interrupting, we set bit 63 in reg_ALLOC.
338 At the end of the atomic section we tried to write to reg_ALLOC,
339 got a SIGSEGV (there's nothing mapped there) so ended up here. */
341 *os_context_register_addr(context, reg_ALLOC) & (1L<<63)) {
342 *os_context_register_addr(context, reg_ALLOC) -= (1L<<63);
343 interrupt_handle_pending(context);
348 #ifdef LISP_FEATURE_GENCGC
349 if (!gencgc_handle_wp_violation(addr))
351 if (!interrupt_maybe_gc(signal, info, context))
353 if (!handle_guard_page_triggered(context, addr))
354 #ifdef LISP_FEATURE_C_STACK_IS_CONTROL_STACK
355 arrange_return_to_lisp_function(context, SymbolFunction(MEMORY_FAULT_ERROR));
357 interrupt_handle_now(signal, info, context);
362 os_install_interrupt_handlers(void)
364 undoably_install_low_level_interrupt_handler(SIG_MEMORY_FAULT,
366 #ifdef LISP_FEATURE_SB_THREAD
367 undoably_install_low_level_interrupt_handler(SIG_INTERRUPT_THREAD,
368 interrupt_thread_handler);
369 undoably_install_low_level_interrupt_handler(SIG_STOP_FOR_GC,
370 sig_stop_for_gc_handler);
375 os_get_runtime_executable_path()
377 char path[PATH_MAX + 1];
380 size = readlink("/proc/self/exe", path, sizeof(path)-1);
386 return copied_string(path);