src/runtime/x86-bsd-os.c

   1 #include <signal.h>
   2 #include <stdio.h>
   3 #include <errno.h>
   4 #include "genesis/sbcl.h"
   5 #include "interr.h"
   6 #include "runtime.h"
   7 #include "thread.h"
   8
   9
  10 #ifdef LISP_FEATURE_SB_THREAD
  11 #ifdef LISP_FEATURE_DARWIN
  12 #include <architecture/i386/table.h>
  13 #include <i386/user_ldt.h>
  14 #include <mach/mach_init.h>
  15 #else
  16 #include <machine/segments.h>
  17 #include <machine/sysarch.h>
  18 #endif /* LISP_FEATURE_DARWIN */
  19 #endif
  20
  21 #if defined(LISP_FEATURE_FREEBSD) || defined(LISP_FEATURE_DRAGONFLY)
  22 #include "machine/npx.h"
  23 #endif
  24
  25 #if defined(LISP_FEATURE_OPENBSD)
  26 #include <machine/npx.h>
  27 #include <stddef.h>
  28 #include "openbsd-sigcontext.h"
  29 #ifdef OS_OPENBSD_FPSTATE_IN_SIGFRAME
  30 # include <machine/frame.h>
  31 #endif
  32 #endif
  33
  34 /* KLUDGE: There is strong family resemblance in the signal context
  35  * stuff in FreeBSD and OpenBSD, but in detail they're different in
  36  * almost every line of code. It would be nice to find some way to
  37  * factor out the commonality better; failing that, it might be best
  38  * just to split this generic-BSD code into one variant for each BSD.
  39  *
  40  * KLUDGE II: this split has begun with the addition of the Darwin BSD
  41  * flavour, with the cross-architecture complications that this
  42  * entails; unfortunately, currently the situation is worse, not
  43  * better, than in the above paragraph. */
  44
  45 #ifdef LISP_FEATURE_NETBSD
  46 #define _REG_eax _REG_EAX
  47 #define _REG_ecx _REG_ECX
  48 #define _REG_edx _REG_EDX
  49 #define _REG_ebx _REG_EBX
  50 #define _REG_esp _REG_ESP
  51 #define _REG_ebp _REG_EBP
  52 #define _REG_esi _REG_ESI
  53 #define _REG_edi _REG_EDI
  54 #endif
  55
  56 int *
  57 os_context_register_addr(os_context_t *context, int offset)
  58 {
  59     switch(offset) {
  60     case  0:
  61         return (int *)CONTEXT_ADDR_FROM_STEM(eax);
  62     case  2:
  63         return (int *)CONTEXT_ADDR_FROM_STEM(ecx);
  64     case  4:
  65         return (int *)CONTEXT_ADDR_FROM_STEM(edx);
  66     case  6:
  67         return (int *)CONTEXT_ADDR_FROM_STEM(ebx);
  68     case  8:
  69         return (int *)CONTEXT_ADDR_FROM_STEM(esp);
  70     case 10:
  71         return (int *)CONTEXT_ADDR_FROM_STEM(ebp);
  72     case 12:
  73         return (int *)CONTEXT_ADDR_FROM_STEM(esi);
  74     case 14:
  75         return (int *)CONTEXT_ADDR_FROM_STEM(edi);
  76 #ifdef __NetBSD__
  77     /* Arguably the line in interrupt.c which uses reg_UESP could be changed
  78      * to access c->uc_mcontext.__gregs[_REG_UESP] directly since nothing else
  79      * needs this case, but I don't care enough to figure out why x86 + NetBSD
  80      * crashes in cold-init regardless of any recent changes */
  81     case 16:
  82         return CONTEXT_ADDR_FROM_STEM(UESP);
  83 #endif
  84     default:
  85         return 0;
  86     }
  87 }
  88
  89 int *
  90 os_context_fp_addr(os_context_t *context)
  91 {
  92     return (int *)CONTEXT_ADDR_FROM_STEM(ebp);
  93 }
  94
  95 #if defined(LISP_FEATURE_FREEBSD) || defined(__OpenBSD__) || defined(LISP_FEATURE_DARWIN) || defined(__DragonFly__)
  96 int *
  97 os_context_sp_addr(os_context_t *context)
  98 {
  99     return (int *)CONTEXT_ADDR_FROM_STEM(esp);
 100 }
 101 #endif
 102
 103 #ifdef __NetBSD__
 104 int *
 105 os_context_sp_addr(os_context_t *context)
 106 {
 107     // UC_MACHINE_SP refers to _REG_UESP, not _REG_ESP
 108     return &(_UC_MACHINE_SP(context));
 109 }
 110
 111 #endif  /* __NetBSD__ */
 112
 113 /* FIXME: If this can be a no-op on BSD/x86, then it
 114  * deserves a more precise name.
 115  *
 116  * (Perhaps os_prepare_data_area_to_be_executed()?) */
 117 void
 118 os_flush_icache(os_vm_address_t address, os_vm_size_t length)
 119 {
 120 }
 121
 122 /* Note: the Darwin versions of arch_os_thread_init found in
 123  * x86-darwin-os.c
 124 */
 125 #if !defined(LISP_FEATURE_DARWIN)
 126
 127 #ifdef LISP_FEATURE_SB_THREAD
 128
 129 void set_data_desc_size(struct segment_descriptor* desc, unsigned long size)
 130 {
 131     desc->sd_lolimit = (size - 1) & 0xffff;
 132     desc->sd_hilimit = ((size - 1) >> 16) &0xf;
 133 }
 134
 135 void set_data_desc_addr(struct segment_descriptor* desc, void* addr)
 136 {
 137     desc->sd_lobase = (unsigned int)addr & 0xffffff;
 138     desc->sd_hibase = ((unsigned int)addr & 0xff000000) >> 24;
 139 }
 140
 141 #endif
 142
 143 #ifdef LISP_FEATURE_SB_THREAD
 144 void
 145 arch_os_load_ldt(struct thread *thread)
 146 {
 147     int sel = LSEL(thread->tls_cookie, SEL_UPL);
 148     unsigned int fs = rfs();
 149
 150     /* Load FS only if it's necessary.  Modifying a selector
 151      * causes privilege checking and it takes long time. */
 152     if (fs != sel)
 153         load_fs(sel);
 154 }
 155 #endif
 156
 157 int arch_os_thread_init(struct thread *thread) {
 158
 159 #ifdef LISP_FEATURE_SB_THREAD
 160     int n;
 161
 162     struct segment_descriptor ldt_entry = { 0, 0, SDT_MEMRW, SEL_UPL, 1,
 163                                             0, 0, 1, 0, 0 };
 164
 165     set_data_desc_addr(&ldt_entry, thread);
 166     set_data_desc_size(&ldt_entry, dynamic_values_bytes);
 167
 168     n = i386_set_ldt(LDT_AUTO_ALLOC, (union descriptor*) &ldt_entry, 1);
 169     if (n < 0) {
 170         perror("i386_set_ldt");
 171         lose("unexpected i386_set_ldt(..) failure");
 172     }
 173     thread->tls_cookie=n;
 174     arch_os_load_ldt(thread);
 175 #endif
 176
 177 #ifdef LISP_FEATURE_C_STACK_IS_CONTROL_STACK
 178     stack_t sigstack;
 179
 180     /* Signal handlers are run on the control stack, so if it is exhausted
 181      * we had better use an alternate stack for whatever signal tells us
 182      * we've exhausted it */
 183     sigstack.ss_sp    = calc_altstack_base(thread);
 184     sigstack.ss_flags = 0;
 185     sigstack.ss_size  = calc_altstack_size(thread);
 186     if (sigaltstack(&sigstack,0)<0)
 187         lose("Cannot sigaltstack: %s",strerror(errno));
 188 #endif
 189
 190     return 1;                  /* success */
 191 }
 192
 193 int arch_os_thread_cleanup(struct thread *thread) {
 194
 195 #if defined(LISP_FEATURE_SB_THREAD)
 196     int n = thread->tls_cookie;
 197
 198     /* Set the %%fs register back to 0 and free the ldt by setting it
 199      * to NULL.
 200      */
 201     __asm__ __volatile__ ("mov %0, %%fs" : : "r"(0));
 202     i386_set_ldt(n, NULL, 1);
 203 #endif
 204
 205     return 1;                  /* success */
 206 }
 207
 208 #endif /* !LISP_FEATURE_DARWIN */
 209
 210 #if defined(LISP_FEATURE_FREEBSD)
 211 #if defined(LISP_FEATURE_RESTORE_TLS_SEGMENT_REGISTER_FROM_CONTEXT)
 212 void
 213 os_restore_tls_segment_register(os_context_t *context)
 214 {
 215     load_fs(context->uc_mcontext.mc_fs);
 216 }
 217 #endif
 218
 219 void
 220 os_restore_fp_control(os_context_t *context)
 221 {
 222     /* FPU state is saved per context on post-KSE systems.
 223      * On earlier systems, it is shared in a whole process.
 224      */
 225 #if defined(__FreeBSD_version) && __FreeBSD_version >= 500040
 226     struct envxmm *ex = (struct envxmm *)(context->uc_mcontext.mc_fpstate);
 227     __asm__ __volatile__ ("fldcw %0" : : "m" (ex->en_cw));
 228 #endif
 229 #if defined(LISP_FEATURE_RESTORE_TLS_SEGMENT_REGISTER_FROM_CONTEXT)
 230     /* Calling this function here may not be good idea.  Or rename
 231      * function name os_restore_fp_control to os_restore_context or
 232      * so, to match the behavior?  */
 233     os_restore_tls_segment_register(context);
 234 #endif
 235 }
 236 #endif
 237
 238 #if defined(LISP_FEATURE_DRAGONFLY)
 239 void os_restore_fp_control (os_context_t *context)
 240 {
 241     struct envxmm *ex = (struct envxmm *)(context->uc_mcontext.mc_fpregs);
 242     __asm__ __volatile__ ("fldcw %0" : : "m" (ex->en_cw));
 243 }
 244 #endif /* LISP_FEATURE_DRAGONFLY */
 245
 246 #if defined(LISP_FEATURE_OPENBSD)
 247 void
 248 os_restore_fp_control(os_context_t *context)
 249 {
 250 #ifdef OS_OPENBSD_FPSTATE_IN_SIGFRAME
 251     struct sigframe *frame = (struct sigframe *)((char*)context -
 252         offsetof(struct sigframe, sf_sc));
 253     union savefpu *fpu = frame->sf_fpstate;
 254 #elif defined(OS_OPENBSD_FPSTATE_IN_SIGCONTEXT)
 255     union savefpu *fpu = context->sc_fpstate;
 256 #endif
 257
 258     if (openbsd_use_fxsave)
 259         __asm__ __volatile__ ("fldcw %0" : : "m" (fpu->sv_xmm.sv_env.en_cw));
 260     else
 261         __asm__ __volatile__ ("fldcw %0" : : "m" (fpu->sv_87.sv_env.en_cw));
 262 }
 263 #endif