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 "./signal.h"
  26 #include "os.h"
  27 #include "arch.h"
  28 #include "globals.h"
  29 #include "interrupt.h"
  30 #include "interr.h"
  31 #include "lispregs.h"
  32 #include "sbcl.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 <linux/unistd.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 _syscall3(int, modify_ldt, int, func, void *, ptr, unsigned long, bytecount );
  53
  54 #include "validate.h"
  55 size_t os_vm_page_size;
  56
  57 u32 local_ldt_copy[LDT_ENTRIES*LDT_ENTRY_SIZE/sizeof(u32)];
  58
  59 /* This is never actually called, but it's great for calling from gdb when
  60  * users have thread-related problems that maintainers can't duplicate */
  61
  62 void debug_get_ldt()
  63 {
  64     int n=modify_ldt (0, local_ldt_copy, sizeof local_ldt_copy);
  65     printf("%d bytes in ldt: print/x local_ldt_copy\n", n);
  66 }
  67
  68 lispobj modify_ldt_lock;        /* protect all calls to modify_ldt */
  69
  70 int arch_os_thread_init(struct thread *thread) {
  71     stack_t sigstack;
  72 #ifdef LISP_FEATURE_SB_THREAD
  73     /* this must be called from a function that has an exclusive lock
  74      * on all_threads
  75      */
  76     struct user_desc ldt_entry = {
  77         1, 0, 0, /* index, address, length filled in later */
  78         1, MODIFY_LDT_CONTENTS_DATA, 0, 0, 0, 1
  79     };
  80     int n;
  81     get_spinlock(&modify_ldt_lock,thread);
  82     n=modify_ldt(0,local_ldt_copy,sizeof local_ldt_copy);
  83     /* get next free ldt entry */
  84
  85     if(n) {
  86         u32 *p;
  87         for(n=0,p=local_ldt_copy;*p;p+=LDT_ENTRY_SIZE/sizeof(u32))
  88             n++;
  89     }
  90     ldt_entry.entry_number=n;
  91     ldt_entry.base_addr=(unsigned long) thread;
  92     ldt_entry.limit=dynamic_values_bytes;
  93     ldt_entry.limit_in_pages=0;
  94     if (modify_ldt (1, &ldt_entry, sizeof (ldt_entry)) != 0) {
  95         modify_ldt_lock=0;
  96         /* modify_ldt call failed: something magical is not happening */
  97         return -1;
  98     }
  99     __asm__ __volatile__ ("movw %w0, %%fs" : : "q"
 100                           ((n << 3) /* selector number */
 101                            + (1 << 2) /* TI set = LDT */
 102                            + 3)); /* privilege level */
 103     thread->tls_cookie=n;
 104     modify_ldt_lock=0;
 105
 106     if(n<0) return 0;
 107 #endif
 108 #ifdef LISP_FEATURE_C_STACK_IS_CONTROL_STACK
 109     /* Signal handlers are run on the control stack, so if it is exhausted
 110      * we had better use an alternate stack for whatever signal tells us
 111      * we've exhausted it */
 112     sigstack.ss_sp=((void *) thread)+dynamic_values_bytes;
 113     sigstack.ss_flags=0;
 114     sigstack.ss_size = 32*SIGSTKSZ;
 115     sigaltstack(&sigstack,0);
 116 #endif
 117     return 1;
 118 }
 119
 120 struct thread *debug_get_fs() {
 121     register u32 fs;
 122     __asm__ __volatile__ ("movl %%fs,%0" : "=r" (fs)  : );
 123     return fs;
 124 }
 125
 126 /* free any arch/os-specific resources used by thread, which is now
 127  * defunct.  Not called on live threads
 128  */
 129
 130 int arch_os_thread_cleanup(struct thread *thread) {
 131     struct user_desc ldt_entry = {
 132         0, 0, 0,
 133         0, MODIFY_LDT_CONTENTS_DATA, 0, 0, 0, 0
 134     };
 135
 136     ldt_entry.entry_number=thread->tls_cookie;
 137     get_spinlock(&modify_ldt_lock,thread);
 138     if (modify_ldt (1, &ldt_entry, sizeof (ldt_entry)) != 0) {
 139         modify_ldt_lock=0;
 140         /* modify_ldt call failed: something magical is not happening */
 141         return 0;
 142     }
 143     modify_ldt_lock=0;
 144     return 1;
 145 }
 146
 147
 148
 149 /* KLUDGE: As of kernel 2.2.14 on Red Hat 6.2, there's code in the
 150  * <sys/ucontext.h> file to define symbolic names for offsets into
 151  * gregs[], but it's conditional on __USE_GNU and not defined, so
 152  * we need to do this nasty absolute index magic number thing
 153  * instead. */
 154 os_context_register_t *
 155 os_context_register_addr(os_context_t *context, int offset)
 156 {
 157     switch(offset) {
 158     case reg_EAX: return &context->uc_mcontext.gregs[11];
 159     case reg_ECX: return &context->uc_mcontext.gregs[10];
 160     case reg_EDX: return &context->uc_mcontext.gregs[9];
 161     case reg_EBX: return &context->uc_mcontext.gregs[8];
 162     case reg_ESP: return &context->uc_mcontext.gregs[7];
 163     case reg_EBP: return &context->uc_mcontext.gregs[6];
 164     case reg_ESI: return &context->uc_mcontext.gregs[5];
 165     case reg_EDI: return &context->uc_mcontext.gregs[4];
 166     default: return 0;
 167     }
 168     return &context->uc_mcontext.gregs[offset];
 169 }
 170
 171 os_context_register_t *
 172 os_context_pc_addr(os_context_t *context)
 173 {
 174     return &context->uc_mcontext.gregs[14]; /*  REG_EIP */
 175 }
 176
 177 os_context_register_t *
 178 os_context_sp_addr(os_context_t *context)
 179 {
 180     return &context->uc_mcontext.gregs[17]; /* REG_UESP */
 181 }
 182
 183 os_context_register_t *
 184 os_context_fp_addr(os_context_t *context)
 185 {
 186     return &context->uc_mcontext.gregs[6]; /* REG_EBP */
 187 }
 188
 189 unsigned long
 190 os_context_fp_control(os_context_t *context)
 191 {
 192     return ((((context->uc_mcontext.fpregs->cw) & 0xffff) ^ 0x3f) |
 193             (((context->uc_mcontext.fpregs->sw) & 0xffff) << 16));
 194 }
 195
 196 sigset_t *
 197 os_context_sigmask_addr(os_context_t *context)
 198 {
 199     return &context->uc_sigmask;
 200 }
 201
 202 void
 203 os_restore_fp_control(os_context_t *context)
 204 {
 205     asm ("fldcw %0" : : "m" (context->uc_mcontext.fpregs->cw));
 206 }
 207
 208 void
 209 os_flush_icache(os_vm_address_t address, os_vm_size_t length)
 210 {
 211 }
 212