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"
38 #include <sys/socket.h>
39 #include <sys/utsname.h>
42 #include <sys/types.h>
44 /* #include <sys/sysinfo.h> */
48 #include <linux/version.h>
53 #if defined LISP_FEATURE_GENCGC
54 #include "gencgc-internal.h"
57 #ifdef LISP_FEATURE_X86
58 /* Prototype for personality(2). Done inline here since the header file
59 * for this isn't available on old versions of glibc. */
60 int personality (unsigned long);
63 size_t os_vm_page_size;
65 #if defined(LISP_FEATURE_SB_THREAD) && !defined(LISP_FEATURE_SB_LUTEX)
66 #include <sys/syscall.h>
70 /* values taken from the kernel's linux/futex.h. This header file
71 doesn't exist in userspace, which is our excuse for not grovelling
73 #define FUTEX_WAIT (0)
74 #define FUTEX_WAKE (1)
76 #define FUTEX_REQUEUE (3)
78 #define sys_futex sbcl_sys_futex
79 static inline int sys_futex (void *futex, int op, int val, struct timespec *rel)
81 return syscall (SYS_futex, futex, op, val, rel);
85 futex_wait(int *lock_word, int oldval)
87 int t= sys_futex(lock_word,FUTEX_WAIT,oldval, 0);
92 futex_wake(int *lock_word, int n)
94 return sys_futex(lock_word,FUTEX_WAKE,n,0);
99 int linux_sparc_siginfo_bug = 0;
101 /* This variable was in real use for a few months, basically for
102 * storing autodetected information about whether the Linux
103 * installation was recent enough to support SBCL threads, and make
104 * some run-time decisions based on that. But this turned out to be
105 * unstable, so now we just flat-out refuse to start on the old installations
106 * when thread support has been compiled in.
108 * Unfortunately, in the meanwhile Slime started depending on this
109 * variable for deciding which communication style to use. So even
110 * though this variable looks unused, it shouldn't be deleted until
111 * it's no longer used in the versions of Slime that people are
112 * likely to download first. -- JES, 2006-06-07
114 int linux_no_threads_p = 0;
116 #ifdef LISP_FEATURE_SB_THREAD
120 size_t n = confstr (_CS_GNU_LIBPTHREAD_VERSION, NULL, 0);
122 char *buf = alloca (n);
123 confstr (_CS_GNU_LIBPTHREAD_VERSION, buf, n);
124 if (strstr (buf, "NPTL")) {
133 os_init(char *argv[], char *envp[])
135 /* Conduct various version checks: do we have enough mmap(), is
136 * this a sparc running 2.2, can we do threads? */
137 #if defined(LISP_FEATURE_SB_THREAD) && !defined(LISP_FEATURE_SB_LUTEX)
147 major_version = atoi(p);
149 minor_version = atoi(p);
151 patch_version = atoi(p);
152 if (major_version<2) {
153 lose("linux kernel version too old: major version=%d (can't run in version < 2.0.0)\n",
156 if (!(major_version>2 || minor_version >= 4)) {
157 #ifdef LISP_FEATURE_SPARC
158 FSHOW((stderr,"linux kernel %d.%d predates 2.4;\n enabling workarounds for SPARC kernel bugs in signal handling.\n", major_version,minor_version));
159 linux_sparc_siginfo_bug = 1;
162 #ifdef LISP_FEATURE_SB_THREAD
163 #if !defined(LISP_FEATURE_SB_LUTEX)
164 futex_wait(futex,-1);
166 lose("This version of SBCL is compiled with threading support, but your kernel\n"
167 "is too old to support this. Please use a more recent kernel or\n"
168 "a version of SBCL without threading support.\n");
172 lose("This version of SBCL only works correctly with the NPTL threading\n"
173 "library. Please use a newer glibc, use an older SBCL, or stop using\n"
174 "LD_ASSUME_KERNEL\n");
177 os_vm_page_size = getpagesize();
179 /* KLUDGE: Disable memory randomization on new Linux kernels
180 * by setting a personality flag and re-executing. (We need
181 * to re-execute, since the memory maps that can conflict with
182 * the SBCL spaces have already been done at this point).
184 * Since randomization is currently implemented only on x86 kernels,
185 * don't do this trick on other platforms.
187 #ifdef LISP_FEATURE_X86
188 if ((major_version == 2
189 /* Some old kernels will apparently lose unsupported personality flags
191 && ((minor_version == 6 && patch_version >= 11)
192 || (minor_version > 6)))
193 || major_version >= 3)
195 int pers = personality(0xffffffffUL);
196 /* 0x40000 aka. ADDR_NO_RANDOMIZE */
197 if (!(pers & 0x40000)) {
198 int retval = personality(pers | 0x40000);
199 /* Allegedly some Linux kernels (the reported case was
200 * "hardened Linux 2.6.7") won't set the new personality,
201 * but nor will they return -1 for an error. So as a
202 * workaround query the new personality...
204 int newpers = personality(0xffffffffUL);
205 /* ... and don't re-execute if either the setting resulted
206 * in an error or if the value didn't change. Otherwise
207 * this might result in an infinite loop.
209 if (retval != -1 && newpers != pers) {
210 /* Use /proc/self/exe instead of trying to figure out
211 * the executable path from PATH and argv[0], since
212 * that's unreliable. We follow the symlink instead of
213 * executing the file directly in order to prevent top
214 * from displaying the name of the process as "exe". */
215 char runtime[PATH_MAX+1];
216 int i = readlink("/proc/self/exe", runtime, PATH_MAX);
219 execve(runtime, argv, envp);
222 /* Either changing the personality or execve() failed. Either
223 * way we might as well continue, and hope that the random
224 * memory maps are ok this time around.
226 fprintf(stderr, "WARNING: Couldn't re-execute SBCL with the proper personality flags (maybe /proc isn't mounted?). Trying to continue anyway.\n");
229 /* Use SSE detector. Recent versions of Linux enable SSE support
230 * on SSE capable CPUs. */
231 /* FIXME: Are there any old versions that does not support SSE? */
232 fast_bzero_pointer = fast_bzero_detect;
237 #ifdef LISP_FEATURE_ALPHA
238 /* The Alpha is a 64 bit CPU. SBCL is a 32 bit application. Due to all
239 * the places that assume we can get a pointer into a fixnum with no
240 * information loss, we have to make sure it allocates all its ram in the
243 static void * under_2gb_free_pointer=DYNAMIC_1_SPACE_END;
247 os_validate(os_vm_address_t addr, os_vm_size_t len)
249 int flags = MAP_PRIVATE | MAP_ANONYMOUS | MAP_NORESERVE;
250 os_vm_address_t actual;
252 #ifdef LISP_FEATURE_ALPHA
254 addr=under_2gb_free_pointer;
257 actual = mmap(addr, len, OS_VM_PROT_ALL, flags, -1, 0);
258 if (actual == MAP_FAILED) {
260 return 0; /* caller should check this */
263 if (addr && (addr!=actual)) {
264 fprintf(stderr, "mmap: wanted %lu bytes at %p, actually mapped at %p\n",
265 (unsigned long) len, addr, actual);
269 #ifdef LISP_FEATURE_ALPHA
271 len=(len+(os_vm_page_size-1))&(~(os_vm_page_size-1));
272 under_2gb_free_pointer+=len;
279 os_invalidate(os_vm_address_t addr, os_vm_size_t len)
281 if (munmap(addr,len) == -1) {
287 os_map(int fd, int offset, os_vm_address_t addr, os_vm_size_t len)
289 os_vm_address_t actual;
291 actual = mmap(addr, len, OS_VM_PROT_ALL, MAP_PRIVATE | MAP_FIXED,
293 if (actual == MAP_FAILED || (addr && (addr != actual))) {
295 lose("unexpected mmap(..) failure\n");
302 os_protect(os_vm_address_t address, os_vm_size_t length, os_vm_prot_t prot)
304 if (mprotect(address, length, prot) == -1) {
305 if (errno == ENOMEM) {
306 lose("An mprotect call failed with ENOMEM. This probably means that the maximum amount\n"
307 "of separate memory mappings was exceeded. To fix the problem, either increase\n"
308 "the maximum with e.g. 'echo 262144 > /proc/sys/vm/max_map_count' or recompile\n"
309 "SBCL with a larger value for GENCGC-PAGE-SIZE in 'src/target/parms.lisp'.");
317 is_valid_lisp_addr(os_vm_address_t addr)
320 size_t ad = (size_t) addr;
322 if ((READ_ONLY_SPACE_START <= ad && ad < READ_ONLY_SPACE_END)
323 || (STATIC_SPACE_START <= ad && ad < STATIC_SPACE_END)
324 #if defined LISP_FEATURE_GENCGC
325 || (DYNAMIC_SPACE_START <= ad && ad < DYNAMIC_SPACE_END)
327 || (DYNAMIC_0_SPACE_START <= ad && ad < DYNAMIC_0_SPACE_END)
328 || (DYNAMIC_1_SPACE_START <= ad && ad < DYNAMIC_1_SPACE_END)
332 for_each_thread(th) {
333 if((size_t)(th->control_stack_start) <= ad
334 && ad < (size_t)(th->control_stack_end))
336 if((size_t)(th->binding_stack_start) <= ad
337 && ad < (size_t)(th->binding_stack_start + BINDING_STACK_SIZE))
344 * any OS-dependent special low-level handling for signals
348 * The GC needs to be hooked into whatever signal is raised for
349 * page fault on this OS.
352 sigsegv_handler(int signal, siginfo_t *info, void* void_context)
354 os_context_t *context = arch_os_get_context(&void_context);
355 os_vm_address_t addr = arch_get_bad_addr(signal, info, context);
357 #ifdef LISP_FEATURE_ALPHA
358 /* Alpha stuff: This is the end of a pseudo-atomic section during
359 which a signal was received. We must deal with the pending
360 interrupt (see also interrupt.c, ../code/interrupt.lisp)
362 (how we got here: when interrupting, we set bit 63 in reg_ALLOC.
363 At the end of the atomic section we tried to write to reg_ALLOC,
364 got a SIGSEGV (there's nothing mapped there) so ended up here. */
366 *os_context_register_addr(context, reg_ALLOC) & (1L<<63)) {
367 *os_context_register_addr(context, reg_ALLOC) -= (1L<<63);
368 interrupt_handle_pending(context);
373 #ifdef LISP_FEATURE_GENCGC
374 if (!gencgc_handle_wp_violation(addr))
376 if (!interrupt_maybe_gc(signal, info, context))
378 if (!handle_guard_page_triggered(context, addr))
379 #ifdef LISP_FEATURE_C_STACK_IS_CONTROL_STACK
380 arrange_return_to_lisp_function(context, SymbolFunction(MEMORY_FAULT_ERROR));
382 interrupt_handle_now(signal, info, context);
387 os_install_interrupt_handlers(void)
389 undoably_install_low_level_interrupt_handler(SIG_MEMORY_FAULT,
391 #ifdef LISP_FEATURE_SB_THREAD
392 undoably_install_low_level_interrupt_handler(SIG_INTERRUPT_THREAD,
393 interrupt_thread_handler);
394 undoably_install_low_level_interrupt_handler(SIG_STOP_FOR_GC,
395 sig_stop_for_gc_handler);
400 os_get_runtime_executable_path()
402 char path[PATH_MAX + 1];
405 size = readlink("/proc/self/exe", path, sizeof(path)-1);
411 return copied_string(path);