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 #define modify_ldt sbcl_modify_ldt
  53 static inline int modify_ldt (int func, void *ptr, unsigned long bytecount)
  54 {
  55   return syscall (SYS_modify_ldt, func, ptr, bytecount);
  56 }
  57
  58 #include "validate.h"
  59 size_t os_vm_page_size;
  60
  61 u32 local_ldt_copy[LDT_ENTRIES*LDT_ENTRY_SIZE/sizeof(u32)];
  62
  63 /* This is never actually called, but it's great for calling from gdb when
  64  * users have thread-related problems that maintainers can't duplicate */
  65
  66 void debug_get_ldt()
  67 {
  68     int n=modify_ldt (0, local_ldt_copy, sizeof local_ldt_copy);
  69     printf("%d bytes in ldt: print/x local_ldt_copy\n", n);
  70 }
  71
  72 #ifdef LISP_FEATURE_SB_THREAD
  73 pthread_mutex_t modify_ldt_lock = PTHREAD_MUTEX_INITIALIZER;
  74 #endif
  75
  76 int arch_os_thread_init(struct thread *thread) {
  77     stack_t sigstack;
  78 #ifdef LISP_FEATURE_SB_THREAD
  79     struct user_desc ldt_entry = {
  80         1, 0, 0, /* index, address, length filled in later */
  81         1, MODIFY_LDT_CONTENTS_DATA, 0, 0, 0, 1
  82     };
  83     int n;
  84     thread_mutex_lock(&modify_ldt_lock);
  85     n=modify_ldt(0,local_ldt_copy,sizeof local_ldt_copy);
  86     /* get next free ldt entry */
  87
  88     if(n) {
  89         u32 *p;
  90         for(n=0,p=local_ldt_copy;*p;p+=LDT_ENTRY_SIZE/sizeof(u32))
  91             n++;
  92     }
  93     ldt_entry.entry_number=n;
  94     ldt_entry.base_addr=(unsigned long) thread;
  95     ldt_entry.limit=dynamic_values_bytes;
  96     ldt_entry.limit_in_pages=0;
  97     if (modify_ldt (1, &ldt_entry, sizeof (ldt_entry)) != 0) {
  98         thread_mutex_unlock(&modify_ldt_lock);
  99         /* modify_ldt call failed: something magical is not happening */
 100         return 0;
 101     }
 102     __asm__ __volatile__ ("movw %w0, %%fs" : : "q"
 103                           ((n << 3) /* selector number */
 104                            + (1 << 2) /* TI set = LDT */
 105                            + 3)); /* privilege level */
 106     thread->tls_cookie=n;
 107     pthread_mutex_unlock(&modify_ldt_lock);
 108
 109     if(n<0) return 0;
 110 #ifdef LISP_FEATURE_GCC_TLS
 111     current_thread = thread;
 112 #else
 113     pthread_setspecific(specials,thread);
 114 #endif
 115 #endif
 116 #ifdef LISP_FEATURE_C_STACK_IS_CONTROL_STACK
 117     /* Signal handlers are run on the control stack, so if it is exhausted
 118      * we had better use an alternate stack for whatever signal tells us
 119      * we've exhausted it */
 120     sigstack.ss_sp=((void *) thread)+dynamic_values_bytes;
 121     sigstack.ss_flags=0;
 122     sigstack.ss_size = 32*SIGSTKSZ;
 123     if(sigaltstack(&sigstack,0)<0)
 124         lose("Cannot sigaltstack: %s\n",strerror(errno));
 125 #endif
 126     return 1;
 127 }
 128
 129 struct thread *debug_get_fs() {
 130     register u32 fs;
 131     __asm__ __volatile__ ("movl %%fs,%0" : "=r" (fs)  : );
 132     return (struct thread *)fs;
 133 }
 134
 135 /* free any arch/os-specific resources used by thread, which is now
 136  * defunct.  Not called on live threads
 137  */
 138
 139 int arch_os_thread_cleanup(struct thread *thread) {
 140     struct user_desc ldt_entry = {
 141         0, 0, 0,
 142         0, MODIFY_LDT_CONTENTS_DATA, 0, 0, 0, 0
 143     };
 144     int result;
 145
 146     ldt_entry.entry_number=thread->tls_cookie;
 147     thread_mutex_lock(&modify_ldt_lock);
 148     result = modify_ldt(1, &ldt_entry, sizeof (ldt_entry));
 149     thread_mutex_unlock(&modify_ldt_lock);
 150     return result;
 151 }
 152
 153
 154
 155 /* KLUDGE: As of kernel 2.2.14 on Red Hat 6.2, there's code in the
 156  * <sys/ucontext.h> file to define symbolic names for offsets into
 157  * gregs[], but it's conditional on __USE_GNU and not defined, so
 158  * we need to do this nasty absolute index magic number thing
 159  * instead. */
 160 os_context_register_t *
 161 os_context_register_addr(os_context_t *context, int offset)
 162 {
 163     switch(offset) {
 164     case reg_EAX: return &context->uc_mcontext.gregs[11];
 165     case reg_ECX: return &context->uc_mcontext.gregs[10];
 166     case reg_EDX: return &context->uc_mcontext.gregs[9];
 167     case reg_EBX: return &context->uc_mcontext.gregs[8];
 168     case reg_ESP: return &context->uc_mcontext.gregs[7];
 169     case reg_EBP: return &context->uc_mcontext.gregs[6];
 170     case reg_ESI: return &context->uc_mcontext.gregs[5];
 171     case reg_EDI: return &context->uc_mcontext.gregs[4];
 172     default: return 0;
 173     }
 174     return &context->uc_mcontext.gregs[offset];
 175 }
 176
 177 os_context_register_t *
 178 os_context_pc_addr(os_context_t *context)
 179 {
 180     return &context->uc_mcontext.gregs[14]; /*  REG_EIP */
 181 }
 182
 183 os_context_register_t *
 184 os_context_sp_addr(os_context_t *context)
 185 {
 186     return &context->uc_mcontext.gregs[17]; /* REG_UESP */
 187 }
 188
 189 os_context_register_t *
 190 os_context_fp_addr(os_context_t *context)
 191 {
 192     return &context->uc_mcontext.gregs[6]; /* REG_EBP */
 193 }
 194
 195 unsigned long
 196 os_context_fp_control(os_context_t *context)
 197 {
 198     return ((((context->uc_mcontext.fpregs->cw) & 0xffff) ^ 0x3f) |
 199             (((context->uc_mcontext.fpregs->sw) & 0xffff) << 16));
 200 }
 201
 202 sigset_t *
 203 os_context_sigmask_addr(os_context_t *context)
 204 {
 205     return &context->uc_sigmask;
 206 }
 207
 208 void
 209 os_restore_fp_control(os_context_t *context)
 210 {
 211     asm ("fldcw %0" : : "m" (context->uc_mcontext.fpregs->cw));
 212 }
 213
 214 void
 215 os_flush_icache(os_vm_address_t address, os_vm_size_t length)
 216 {
 217 }