src/runtime/x86-linux-os.c

   1 /*
   2  * The x86 Linux incarnation of arch-dependent OS-dependent routines.
   3  * See also "linux-os.c".
   4  */
   5
   6 /*
   7  * This software is part of the SBCL system. See the README file for
   8  * more information.
   9  *
  10  * This software is derived from the CMU CL system, which was
  11  * written at Carnegie Mellon University and released into the
  12  * public domain. The software is in the public domain and is
  13  * provided with absolutely no warranty. See the COPYING and CREDITS
  14  * files for more information.
  15  */
  16
  17 #include <stdio.h>
  18 #include <stddef.h>
  19 #include <sys/param.h>
  20 #include <sys/file.h>
  21 #include <sys/types.h>
  22 #include <unistd.h>
  23 #include <errno.h>
  24
  25 #include "sbcl.h"
  26 #include "./signal.h"
  27 #include "os.h"
  28 #include "arch.h"
  29 #include "globals.h"
  30 #include "interrupt.h"
  31 #include "interr.h"
  32 #include "lispregs.h"
  33 #include <sys/socket.h>
  34 #include <sys/utsname.h>
  35
  36 #include <sys/types.h>
  37 #include <signal.h>
  38 /* #include <sys/sysinfo.h> */
  39 #include <sys/time.h>
  40 #include <sys/stat.h>
  41 #include <unistd.h>
  42 #include <asm/ldt.h>
  43 #include <sys/syscall.h>
  44 #include <sys/mman.h>
  45 #include <linux/version.h>
  46 #include "thread.h"             /* dynamic_values_bytes */
  47
  48 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
  49 #define user_desc  modify_ldt_ldt_s
  50 #endif
  51
  52 static inline int modify_ldt(int func, void *ptr, unsigned long bytecount)
  53 {
  54   return syscall(SYS_modify_ldt, func, ptr, bytecount);
  55 }
  56
  57 #include "validate.h"
  58 size_t os_vm_page_size;
  59
  60 u32 local_ldt_copy[LDT_ENTRIES*LDT_ENTRY_SIZE/sizeof(u32)];
  61
  62 /* This is never actually called, but it's great for calling from gdb when
  63  * users have thread-related problems that maintainers can't duplicate */
  64
  65 void debug_get_ldt()
  66 {
  67     int n=modify_ldt (0, local_ldt_copy, sizeof local_ldt_copy);
  68     printf("%d bytes in ldt: print/x local_ldt_copy\n", n);
  69 }
  70
  71 #ifdef LISP_FEATURE_SB_THREAD
  72 pthread_mutex_t modify_ldt_lock = PTHREAD_MUTEX_INITIALIZER;
  73 #endif
  74
  75 int arch_os_thread_init(struct thread *thread) {
  76     stack_t sigstack;
  77 #ifdef LISP_FEATURE_SB_THREAD
  78     struct user_desc ldt_entry = {
  79         1, 0, 0, /* index, address, length filled in later */
  80         1, MODIFY_LDT_CONTENTS_DATA, 0, 0, 0, 1
  81     };
  82     int n;
  83     thread_mutex_lock(&modify_ldt_lock);
  84     n=modify_ldt(0,local_ldt_copy,sizeof local_ldt_copy);
  85     /* get next free ldt entry */
  86
  87     if(n) {
  88         u32 *p;
  89         for(n=0,p=local_ldt_copy;*p;p+=LDT_ENTRY_SIZE/sizeof(u32))
  90             n++;
  91     }
  92     ldt_entry.entry_number=n;
  93     ldt_entry.base_addr=(unsigned long) thread;
  94     ldt_entry.limit=dynamic_values_bytes;
  95     ldt_entry.limit_in_pages=0;
  96     if (modify_ldt (1, &ldt_entry, sizeof (ldt_entry)) != 0) {
  97         thread_mutex_unlock(&modify_ldt_lock);
  98         /* modify_ldt call failed: something magical is not happening */
  99         return 0;
 100     }
 101     __asm__ __volatile__ ("movw %w0, %%fs" : : "q"
 102                           ((n << 3) /* selector number */
 103                            + (1 << 2) /* TI set = LDT */
 104                            + 3)); /* privilege level */
 105     thread->tls_cookie=n;
 106     pthread_mutex_unlock(&modify_ldt_lock);
 107
 108     /* now %fs:0 refers to the current thread.  Useful!  Less usefully,
 109      * Linux/x86 isn't capable of reporting a faulting si_addr on a
 110      * segment as defined above (whereas faults on the segment that %gs
 111      * usually points are reported just fine...).  As a special
 112      * workaround, we store each thread structure's absolute address as
 113      * as slot in itself, so that within the thread,
 114      *   movl %fs:SELFPTR_OFFSET,x
 115      * stores the absolute address of %fs:0 into x.
 116      */
 117 #ifdef LISP_FEATURE_SB_SAFEPOINT
 118     thread->selfptr = thread;
 119 #endif
 120
 121     if(n<0) return 0;
 122 #ifdef LISP_FEATURE_GCC_TLS
 123     current_thread = thread;
 124 #else
 125     pthread_setspecific(specials,thread);
 126 #endif
 127 #endif
 128 #ifdef LISP_FEATURE_C_STACK_IS_CONTROL_STACK
 129     /* Signal handlers are run on the control stack, so if it is exhausted
 130      * we had better use an alternate stack for whatever signal tells us
 131      * we've exhausted it */
 132     sigstack.ss_sp=((void *) thread)+dynamic_values_bytes;
 133     sigstack.ss_flags=0;
 134     sigstack.ss_size = 32*SIGSTKSZ;
 135     if(sigaltstack(&sigstack,0)<0)
 136         lose("Cannot sigaltstack: %s\n",strerror(errno));
 137 #endif
 138     return 1;
 139 }
 140
 141 struct thread *debug_get_fs() {
 142     register u32 fs;
 143     __asm__ __volatile__ ("movl %%fs,%0" : "=r" (fs)  : );
 144     return (struct thread *)fs;
 145 }
 146
 147 /* free any arch/os-specific resources used by thread, which is now
 148  * defunct.  Not called on live threads
 149  */
 150
 151 int arch_os_thread_cleanup(struct thread *thread) {
 152     struct user_desc ldt_entry = {
 153         0, 0, 0,
 154         0, MODIFY_LDT_CONTENTS_DATA, 0, 0, 0, 0
 155     };
 156     int result;
 157
 158     ldt_entry.entry_number=thread->tls_cookie;
 159     thread_mutex_lock(&modify_ldt_lock);
 160     result = modify_ldt(1, &ldt_entry, sizeof (ldt_entry));
 161     thread_mutex_unlock(&modify_ldt_lock);
 162     return result;
 163 }
 164
 165
 166
 167 /* KLUDGE: As of kernel 2.2.14 on Red Hat 6.2, there's code in the
 168  * <sys/ucontext.h> file to define symbolic names for offsets into
 169  * gregs[], but it's conditional on __USE_GNU and not defined, so
 170  * we need to do this nasty absolute index magic number thing
 171  * instead. */
 172 os_context_register_t *
 173 os_context_register_addr(os_context_t *context, int offset)
 174 {
 175     switch(offset) {
 176     case reg_EAX: return &context->uc_mcontext.gregs[11];
 177     case reg_ECX: return &context->uc_mcontext.gregs[10];
 178     case reg_EDX: return &context->uc_mcontext.gregs[9];
 179     case reg_EBX: return &context->uc_mcontext.gregs[8];
 180     case reg_ESP: return &context->uc_mcontext.gregs[7];
 181     case reg_EBP: return &context->uc_mcontext.gregs[6];
 182     case reg_ESI: return &context->uc_mcontext.gregs[5];
 183     case reg_EDI: return &context->uc_mcontext.gregs[4];
 184     default: return 0;
 185     }
 186     return &context->uc_mcontext.gregs[offset];
 187 }
 188
 189 os_context_register_t *
 190 os_context_pc_addr(os_context_t *context)
 191 {
 192     return &context->uc_mcontext.gregs[14]; /*  REG_EIP */
 193 }
 194
 195 os_context_register_t *
 196 os_context_sp_addr(os_context_t *context)
 197 {
 198     return &context->uc_mcontext.gregs[17]; /* REG_UESP */
 199 }
 200
 201 os_context_register_t *
 202 os_context_fp_addr(os_context_t *context)
 203 {
 204     return &context->uc_mcontext.gregs[6]; /* REG_EBP */
 205 }
 206
 207 unsigned long
 208 os_context_fp_control(os_context_t *context)
 209 {
 210     return ((((context->uc_mcontext.fpregs->cw) & 0xffff) ^ 0x3f) |
 211             (((context->uc_mcontext.fpregs->sw) & 0xffff) << 16));
 212 }
 213
 214 sigset_t *
 215 os_context_sigmask_addr(os_context_t *context)
 216 {
 217     return &context->uc_sigmask;
 218 }
 219
 220 void
 221 os_restore_fp_control(os_context_t *context)
 222 {
 223     if (context->uc_mcontext.fpregs)
 224         asm ("fldcw %0" : : "m" (context->uc_mcontext.fpregs->cw));
 225 }
 226
 227 void
 228 os_flush_icache(os_vm_address_t address, os_vm_size_t length)
 229 {
 230 }