--- BasiliskII/src/Unix/sigsegv.cpp 2002/01/15 14:58:37 1.7
+++ BasiliskII/src/Unix/sigsegv.cpp 2003/12/20 07:43:56 1.37
@@ -4,6 +4,12 @@
* Derived from Bruno Haible's work on his SIGSEGV library for clisp
*
*
+ * MacOS X support derived from the post by Timothy J. Wood to the
+ * omnigroup macosx-dev list:
+ * Mach Exception Handlers 101 (Was Re: ptrace, gdb)
+ * tjw@omnigroup.com Sun, 4 Jun 2000
+ * www.omnigroup.com/mailman/archive/macosx-dev/2000-June/002030.html
+ *
* Basilisk II (C) 1997-2002 Christian Bauer
*
* This program is free software; you can redistribute it and/or modify
@@ -29,9 +35,14 @@
#include "config.h"
#endif
+#include
#include
#include "sigsegv.h"
+#ifndef NO_STD_NAMESPACE
+using std::list;
+#endif
+
// Return value type of a signal handler (standard type if not defined)
#ifndef RETSIGTYPE
#define RETSIGTYPE void
@@ -41,29 +52,220 @@
typedef RETSIGTYPE (*signal_handler)(int);
// User's SIGSEGV handler
-static sigsegv_handler_t sigsegv_user_handler = 0;
+static sigsegv_fault_handler_t sigsegv_fault_handler = 0;
+
+// Function called to dump state if we can't handle the fault
+static sigsegv_state_dumper_t sigsegv_state_dumper = 0;
// Actual SIGSEGV handler installer
static bool sigsegv_do_install_handler(int sig);
/*
+ * Instruction decoding aids
+ */
+
+// Transfer size
+enum transfer_size_t {
+ SIZE_UNKNOWN,
+ SIZE_BYTE,
+ SIZE_WORD, // 2 bytes
+ SIZE_LONG, // 4 bytes
+ SIZE_QUAD, // 8 bytes
+};
+
+// Transfer type
+typedef sigsegv_transfer_type_t transfer_type_t;
+
+#if (defined(powerpc) || defined(__powerpc__) || defined(__ppc__))
+// Addressing mode
+enum addressing_mode_t {
+ MODE_UNKNOWN,
+ MODE_NORM,
+ MODE_U,
+ MODE_X,
+ MODE_UX
+};
+
+// Decoded instruction
+struct instruction_t {
+ transfer_type_t transfer_type;
+ transfer_size_t transfer_size;
+ addressing_mode_t addr_mode;
+ unsigned int addr;
+ char ra, rd;
+};
+
+static void powerpc_decode_instruction(instruction_t *instruction, unsigned int nip, unsigned int * gpr)
+{
+ // Get opcode and divide into fields
+ unsigned int opcode = *((unsigned int *)nip);
+ unsigned int primop = opcode >> 26;
+ unsigned int exop = (opcode >> 1) & 0x3ff;
+ unsigned int ra = (opcode >> 16) & 0x1f;
+ unsigned int rb = (opcode >> 11) & 0x1f;
+ unsigned int rd = (opcode >> 21) & 0x1f;
+ signed int imm = (signed short)(opcode & 0xffff);
+
+ // Analyze opcode
+ transfer_type_t transfer_type = SIGSEGV_TRANSFER_UNKNOWN;
+ transfer_size_t transfer_size = SIZE_UNKNOWN;
+ addressing_mode_t addr_mode = MODE_UNKNOWN;
+ switch (primop) {
+ case 31:
+ switch (exop) {
+ case 23: // lwzx
+ transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_LONG; addr_mode = MODE_X; break;
+ case 55: // lwzux
+ transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_LONG; addr_mode = MODE_UX; break;
+ case 87: // lbzx
+ transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_BYTE; addr_mode = MODE_X; break;
+ case 119: // lbzux
+ transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_BYTE; addr_mode = MODE_UX; break;
+ case 151: // stwx
+ transfer_type = SIGSEGV_TRANSFER_STORE; transfer_size = SIZE_LONG; addr_mode = MODE_X; break;
+ case 183: // stwux
+ transfer_type = SIGSEGV_TRANSFER_STORE; transfer_size = SIZE_LONG; addr_mode = MODE_UX; break;
+ case 215: // stbx
+ transfer_type = SIGSEGV_TRANSFER_STORE; transfer_size = SIZE_BYTE; addr_mode = MODE_X; break;
+ case 247: // stbux
+ transfer_type = SIGSEGV_TRANSFER_STORE; transfer_size = SIZE_BYTE; addr_mode = MODE_UX; break;
+ case 279: // lhzx
+ transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_WORD; addr_mode = MODE_X; break;
+ case 311: // lhzux
+ transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_WORD; addr_mode = MODE_UX; break;
+ case 343: // lhax
+ transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_WORD; addr_mode = MODE_X; break;
+ case 375: // lhaux
+ transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_WORD; addr_mode = MODE_UX; break;
+ case 407: // sthx
+ transfer_type = SIGSEGV_TRANSFER_STORE; transfer_size = SIZE_WORD; addr_mode = MODE_X; break;
+ case 439: // sthux
+ transfer_type = SIGSEGV_TRANSFER_STORE; transfer_size = SIZE_WORD; addr_mode = MODE_UX; break;
+ }
+ break;
+
+ case 32: // lwz
+ transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_LONG; addr_mode = MODE_NORM; break;
+ case 33: // lwzu
+ transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_LONG; addr_mode = MODE_U; break;
+ case 34: // lbz
+ transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_BYTE; addr_mode = MODE_NORM; break;
+ case 35: // lbzu
+ transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_BYTE; addr_mode = MODE_U; break;
+ case 36: // stw
+ transfer_type = SIGSEGV_TRANSFER_STORE; transfer_size = SIZE_LONG; addr_mode = MODE_NORM; break;
+ case 37: // stwu
+ transfer_type = SIGSEGV_TRANSFER_STORE; transfer_size = SIZE_LONG; addr_mode = MODE_U; break;
+ case 38: // stb
+ transfer_type = SIGSEGV_TRANSFER_STORE; transfer_size = SIZE_BYTE; addr_mode = MODE_NORM; break;
+ case 39: // stbu
+ transfer_type = SIGSEGV_TRANSFER_STORE; transfer_size = SIZE_BYTE; addr_mode = MODE_U; break;
+ case 40: // lhz
+ transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_WORD; addr_mode = MODE_NORM; break;
+ case 41: // lhzu
+ transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_WORD; addr_mode = MODE_U; break;
+ case 42: // lha
+ transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_WORD; addr_mode = MODE_NORM; break;
+ case 43: // lhau
+ transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_WORD; addr_mode = MODE_U; break;
+ case 44: // sth
+ transfer_type = SIGSEGV_TRANSFER_STORE; transfer_size = SIZE_WORD; addr_mode = MODE_NORM; break;
+ case 45: // sthu
+ transfer_type = SIGSEGV_TRANSFER_STORE; transfer_size = SIZE_WORD; addr_mode = MODE_U; break;
+ }
+
+ // Calculate effective address
+ unsigned int addr = 0;
+ switch (addr_mode) {
+ case MODE_X:
+ case MODE_UX:
+ if (ra == 0)
+ addr = gpr[rb];
+ else
+ addr = gpr[ra] + gpr[rb];
+ break;
+ case MODE_NORM:
+ case MODE_U:
+ if (ra == 0)
+ addr = (signed int)(signed short)imm;
+ else
+ addr = gpr[ra] + (signed int)(signed short)imm;
+ break;
+ default:
+ break;
+ }
+
+ // Commit decoded instruction
+ instruction->addr = addr;
+ instruction->addr_mode = addr_mode;
+ instruction->transfer_type = transfer_type;
+ instruction->transfer_size = transfer_size;
+ instruction->ra = ra;
+ instruction->rd = rd;
+}
+#endif
+
+
+/*
* OS-dependant SIGSEGV signals support section
*/
#if HAVE_SIGINFO_T
// Generic extended signal handler
+#if defined(__NetBSD__) || defined(__FreeBSD__)
+#define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGBUS)
+#else
#define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGSEGV)
+#endif
#define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, siginfo_t *sip, void *scp
+#define SIGSEGV_FAULT_HANDLER_ARGLIST_1 siginfo_t *sip, void *scp
+#define SIGSEGV_FAULT_HANDLER_ARGS sip, scp
#define SIGSEGV_FAULT_ADDRESS sip->si_addr
+#if (defined(sgi) || defined(__sgi))
+#include
+#define SIGSEGV_CONTEXT_REGS (((ucontext_t *)scp)->uc_mcontext.gregs)
+#define SIGSEGV_FAULT_INSTRUCTION (unsigned long)SIGSEGV_CONTEXT_REGS[CTX_EPC]
+#endif
+#if defined(__sun__)
+#if (defined(sparc) || defined(__sparc__))
+#include
+#define SIGSEGV_CONTEXT_REGS (((ucontext_t *)scp)->uc_mcontext.gregs)
+#define SIGSEGV_FAULT_INSTRUCTION SIGSEGV_CONTEXT_REGS[REG_PC]
+#endif
+#endif
+#if defined(__FreeBSD__)
+#if (defined(i386) || defined(__i386__))
+#define SIGSEGV_FAULT_INSTRUCTION (((struct sigcontext *)scp)->sc_eip)
+#define SIGSEGV_REGISTER_FILE ((unsigned long *)&(((struct sigcontext *)scp)->sc_edi)) /* EDI is the first GPR (even below EIP) in sigcontext */
+#define SIGSEGV_SKIP_INSTRUCTION ix86_skip_instruction
+#endif
+#endif
#if defined(__linux__)
#if (defined(i386) || defined(__i386__))
#include
-#define SIGSEGV_FAULT_INSTRUCTION (((ucontext_t *)scp)->uc_mcontext.gregs[14]) /* should use REG_EIP instead */
+#define SIGSEGV_CONTEXT_REGS (((ucontext_t *)scp)->uc_mcontext.gregs)
+#define SIGSEGV_FAULT_INSTRUCTION SIGSEGV_CONTEXT_REGS[14] /* should use REG_EIP instead */
+#define SIGSEGV_REGISTER_FILE (unsigned long *)SIGSEGV_CONTEXT_REGS
+#define SIGSEGV_SKIP_INSTRUCTION ix86_skip_instruction
+#endif
+#if (defined(x86_64) || defined(__x86_64__))
+#include
+#define SIGSEGV_CONTEXT_REGS (((ucontext_t *)scp)->uc_mcontext.gregs)
+#define SIGSEGV_FAULT_INSTRUCTION SIGSEGV_CONTEXT_REGS[16] /* should use REG_RIP instead */
+#define SIGSEGV_REGISTER_FILE (unsigned long *)SIGSEGV_CONTEXT_REGS
+#define SIGSEGV_SKIP_INSTRUCTION ix86_skip_instruction
#endif
#if (defined(ia64) || defined(__ia64__))
#define SIGSEGV_FAULT_INSTRUCTION (((struct sigcontext *)scp)->sc_ip & ~0x3ULL) /* slot number is in bits 0 and 1 */
#endif
+#if (defined(powerpc) || defined(__powerpc__))
+#include
+#define SIGSEGV_CONTEXT_REGS (((ucontext_t *)scp)->uc_mcontext.regs)
+#define SIGSEGV_FAULT_INSTRUCTION (SIGSEGV_CONTEXT_REGS->nip)
+#define SIGSEGV_REGISTER_FILE (unsigned int *)&SIGSEGV_CONTEXT_REGS->nip, (unsigned int *)(SIGSEGV_CONTEXT_REGS->gpr)
+#define SIGSEGV_SKIP_INSTRUCTION powerpc_skip_instruction
+#endif
#endif
#endif
@@ -74,47 +276,60 @@ static bool sigsegv_do_install_handler(i
#if (defined(i386) || defined(__i386__))
#include
#define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, struct sigcontext scs
-#define SIGSEGV_FAULT_ADDRESS scs.cr2
-#define SIGSEGV_FAULT_INSTRUCTION scs.eip
+#define SIGSEGV_FAULT_HANDLER_ARGLIST_1 struct sigcontext *scp
+#define SIGSEGV_FAULT_HANDLER_ARGS &scs
+#define SIGSEGV_FAULT_ADDRESS scp->cr2
+#define SIGSEGV_FAULT_INSTRUCTION scp->eip
+#define SIGSEGV_REGISTER_FILE (unsigned long *)scp
+#define SIGSEGV_SKIP_INSTRUCTION ix86_skip_instruction
#endif
#if (defined(sparc) || defined(__sparc__))
#include
#define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp, char *addr
+#define SIGSEGV_FAULT_HANDLER_ARGS sig, code, scp, addr
#define SIGSEGV_FAULT_ADDRESS addr
#endif
#if (defined(powerpc) || defined(__powerpc__))
#include
#define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, struct sigcontext *scp
+#define SIGSEGV_FAULT_HANDLER_ARGS sig, scp
#define SIGSEGV_FAULT_ADDRESS scp->regs->dar
#define SIGSEGV_FAULT_INSTRUCTION scp->regs->nip
+#define SIGSEGV_REGISTER_FILE (unsigned int *)&scp->regs->nip, (unsigned int *)(scp->regs->gpr)
+#define SIGSEGV_SKIP_INSTRUCTION powerpc_skip_instruction
#endif
#if (defined(alpha) || defined(__alpha__))
#include
#define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp
+#define SIGSEGV_FAULT_HANDLER_ARGS sig, code, scp
#define SIGSEGV_FAULT_ADDRESS get_fault_address(scp)
#define SIGSEGV_FAULT_INSTRUCTION scp->sc_pc
-
-// From Boehm's GC 6.0alpha8
-static sigsegv_address_t get_fault_address(struct sigcontext *scp)
-{
- unsigned int instruction = *((unsigned int *)(scp->sc_pc));
- unsigned long fault_address = scp->sc_regs[(instruction >> 16) & 0x1f];
- fault_address += (signed long)(signed short)(instruction & 0xffff);
- return (sigsegv_address_t)fault_address;
-}
#endif
#endif
// Irix 5 or 6 on MIPS
-#if (defined(sgi) || defined(__sgi)) && (defined(SYSTYPE_SVR4) || defined(__SYSTYPE_SVR4))
+#if (defined(sgi) || defined(__sgi)) && (defined(SYSTYPE_SVR4) || defined(_SYSTYPE_SVR4))
+#include
#define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp
-#define SIGSEGV_FAULT_ADDRESS scp->sc_badvaddr
+#define SIGSEGV_FAULT_HANDLER_ARGS sig, code, scp
+#define SIGSEGV_FAULT_ADDRESS (unsigned long)scp->sc_badvaddr
+#define SIGSEGV_FAULT_INSTRUCTION (unsigned long)scp->sc_pc
#define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGSEGV)
#endif
+// HP-UX
+#if (defined(hpux) || defined(__hpux__))
+#define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp
+#define SIGSEGV_FAULT_HANDLER_ARGS sig, code, scp
+#define SIGSEGV_FAULT_ADDRESS scp->sc_sl.sl_ss.ss_narrow.ss_cr21
+#define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGSEGV) FAULT_HANDLER(SIGBUS)
+#endif
+
// OSF/1 on Alpha
#if defined(__osf__)
+#include
#define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp
+#define SIGSEGV_FAULT_HANDLER_ARGS sig, code, scp
#define SIGSEGV_FAULT_ADDRESS scp->sc_traparg_a0
#define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGSEGV)
#endif
@@ -122,147 +337,592 @@ static sigsegv_address_t get_fault_addre
// AIX
#if defined(_AIX)
#define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp
+#define SIGSEGV_FAULT_HANDLER_ARGS sig, code, scp
#define SIGSEGV_FAULT_ADDRESS scp->sc_jmpbuf.jmp_context.o_vaddr
#define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGSEGV)
#endif
-// NetBSD or FreeBSD
-#if defined(__NetBSD__) || defined(__FreeBSD__)
+// NetBSD
+#if defined(__NetBSD__)
#if (defined(m68k) || defined(__m68k__))
#include
#define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp
-#define SIGSEGV_FAULT_ADDRESS ({ \
- struct sigstate { \
- int ss_flags; \
- struct frame ss_frame; \
- }; \
- struct sigstate *state = (struct sigstate *)scp->sc_ap; \
- char *fault_addr; \
- switch (state->ss_frame.f_format) { \
- case 7: /* 68040 access error */ \
- /* "code" is sometimes unreliable (i.e. contains NULL or a bogus address), reason unknown */ \
- fault_addr = state->ss_frame.f_fmt7.f_fa; \
- break; \
- default: \
- fault_addr = (char *)code; \
- break; \
- } \
- fault_addr; \
-})
+#define SIGSEGV_FAULT_HANDLER_ARGS sig, code, scp
+#define SIGSEGV_FAULT_ADDRESS get_fault_address(scp)
#define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGSEGV)
-#else
-#define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, void *scp, char *addr
-#define SIGSEGV_FAULT_ADDRESS addr
+
+// Use decoding scheme from BasiliskII/m68k native
+static sigsegv_address_t get_fault_address(struct sigcontext *scp)
+{
+ struct sigstate {
+ int ss_flags;
+ struct frame ss_frame;
+ };
+ struct sigstate *state = (struct sigstate *)scp->sc_ap;
+ char *fault_addr;
+ switch (state->ss_frame.f_format) {
+ case 7: /* 68040 access error */
+ /* "code" is sometimes unreliable (i.e. contains NULL or a bogus address), reason unknown */
+ fault_addr = state->ss_frame.f_fmt7.f_fa;
+ break;
+ default:
+ fault_addr = (char *)code;
+ break;
+ }
+ return (sigsegv_address_t)fault_addr;
+}
+#endif
+#if (defined(alpha) || defined(__alpha__))
+#define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp
+#define SIGSEGV_FAULT_HANDLER_ARGS sig, code, scp
+#define SIGSEGV_FAULT_ADDRESS get_fault_address(scp)
#define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGBUS)
#endif
+#if (defined(i386) || defined(__i386__))
+#error "FIXME: need to decode instruction and compute EA"
+#define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp
+#define SIGSEGV_FAULT_HANDLER_ARGS sig, code, scp
+#define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGSEGV)
+#endif
+#endif
+#if defined(__FreeBSD__)
+#define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGBUS)
+#if (defined(i386) || defined(__i386__))
+#define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp, char *addr
+#define SIGSEGV_FAULT_HANDLER_ARGS sig, code, scp, addr
+#define SIGSEGV_FAULT_ADDRESS addr
+#define SIGSEGV_FAULT_INSTRUCTION scp->sc_eip
+#define SIGSEGV_REGISTER_FILE ((unsigned long *)&scp->sc_edi)
+#define SIGSEGV_SKIP_INSTRUCTION ix86_skip_instruction
+#endif
#endif
-// MacOS X
+// Extract fault address out of a sigcontext
+#if (defined(alpha) || defined(__alpha__))
+// From Boehm's GC 6.0alpha8
+static sigsegv_address_t get_fault_address(struct sigcontext *scp)
+{
+ unsigned int instruction = *((unsigned int *)(scp->sc_pc));
+ unsigned long fault_address = scp->sc_regs[(instruction >> 16) & 0x1f];
+ fault_address += (signed long)(signed short)(instruction & 0xffff);
+ return (sigsegv_address_t)fault_address;
+}
+#endif
+
+
+// MacOS X, not sure which version this works in. Under 10.1
+// vm_protect does not appear to work from a signal handler. Under
+// 10.2 signal handlers get siginfo type arguments but the si_addr
+// field is the address of the faulting instruction and not the
+// address that caused the SIGBUS. Maybe this works in 10.0? In any
+// case with Mach exception handlers there is a way to do what this
+// was meant to do.
+#ifndef HAVE_MACH_EXCEPTIONS
#if defined(__APPLE__) && defined(__MACH__)
#if (defined(ppc) || defined(__ppc__))
#define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp
+#define SIGSEGV_FAULT_HANDLER_ARGS sig, code, scp
#define SIGSEGV_FAULT_ADDRESS get_fault_address(scp)
#define SIGSEGV_FAULT_INSTRUCTION scp->sc_ir
#define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGBUS)
+#define SIGSEGV_REGISTER_FILE (unsigned int *)&scp->sc_ir, &((unsigned int *) scp->sc_regs)[2]
+#define SIGSEGV_SKIP_INSTRUCTION powerpc_skip_instruction
-// From Boehm's GC 6.0alpha8
-#define EXTRACT_OP1(iw) (((iw) & 0xFC000000) >> 26)
-#define EXTRACT_OP2(iw) (((iw) & 0x000007FE) >> 1)
-#define EXTRACT_REGA(iw) (((iw) & 0x001F0000) >> 16)
-#define EXTRACT_REGB(iw) (((iw) & 0x03E00000) >> 21)
-#define EXTRACT_REGC(iw) (((iw) & 0x0000F800) >> 11)
-#define EXTRACT_DISP(iw) ((short *) &(iw))[1]
-
+// Use decoding scheme from SheepShaver
static sigsegv_address_t get_fault_address(struct sigcontext *scp)
{
- unsigned int instr = *((unsigned int *) scp->sc_ir);
- unsigned int * regs = &((unsigned int *) scp->sc_regs)[2];
- int disp = 0, tmp;
- unsigned int baseA = 0, baseB = 0;
- unsigned int addr, alignmask = 0xFFFFFFFF;
-
- switch(EXTRACT_OP1(instr)) {
- case 38: /* stb */
- case 39: /* stbu */
- case 54: /* stfd */
- case 55: /* stfdu */
- case 52: /* stfs */
- case 53: /* stfsu */
- case 44: /* sth */
- case 45: /* sthu */
- case 47: /* stmw */
- case 36: /* stw */
- case 37: /* stwu */
- tmp = EXTRACT_REGA(instr);
- if(tmp > 0)
- baseA = regs[tmp];
- disp = EXTRACT_DISP(instr);
+ unsigned int nip = (unsigned int) scp->sc_ir;
+ unsigned int * gpr = &((unsigned int *) scp->sc_regs)[2];
+ instruction_t instr;
+
+ powerpc_decode_instruction(&instr, nip, gpr);
+ return (sigsegv_address_t)instr.addr;
+}
+#endif
+#endif
+#endif
+#endif
+
+#if HAVE_MACH_EXCEPTIONS
+
+// This can easily be extended to other Mach systems, but really who
+// uses HURD (oops GNU/HURD), Darwin/x86, NextStep, Rhapsody, or CMU
+// Mach 2.5/3.0?
+#if defined(__APPLE__) && defined(__MACH__)
+
+#include
+#include
+#include
+#include
+
+/*
+ * If you are familiar with MIG then you will understand the frustration
+ * that was necessary to get these embedded into C++ code by hand.
+ */
+extern "C" {
+#include
+#include
+
+extern boolean_t exc_server(mach_msg_header_t *, mach_msg_header_t *);
+extern kern_return_t catch_exception_raise(mach_port_t, mach_port_t,
+ mach_port_t, exception_type_t, exception_data_t, mach_msg_type_number_t);
+extern kern_return_t exception_raise(mach_port_t, mach_port_t, mach_port_t,
+ exception_type_t, exception_data_t, mach_msg_type_number_t);
+extern kern_return_t exception_raise_state(mach_port_t, exception_type_t,
+ exception_data_t, mach_msg_type_number_t, thread_state_flavor_t *,
+ thread_state_t, mach_msg_type_number_t, thread_state_t, mach_msg_type_number_t *);
+extern kern_return_t exception_raise_state_identity(mach_port_t, mach_port_t, mach_port_t,
+ exception_type_t, exception_data_t, mach_msg_type_number_t, thread_state_flavor_t *,
+ thread_state_t, mach_msg_type_number_t, thread_state_t, mach_msg_type_number_t *);
+}
+
+// Could make this dynamic by looking for a result of MIG_ARRAY_TOO_LARGE
+#define HANDLER_COUNT 64
+
+// structure to tuck away existing exception handlers
+typedef struct _ExceptionPorts {
+ mach_msg_type_number_t maskCount;
+ exception_mask_t masks[HANDLER_COUNT];
+ exception_handler_t handlers[HANDLER_COUNT];
+ exception_behavior_t behaviors[HANDLER_COUNT];
+ thread_state_flavor_t flavors[HANDLER_COUNT];
+} ExceptionPorts;
+
+// exception handler thread
+static pthread_t exc_thread;
+
+// place where old exception handler info is stored
+static ExceptionPorts ports;
+
+// our exception port
+static mach_port_t _exceptionPort = MACH_PORT_NULL;
+
+#define MACH_CHECK_ERROR(name,ret) \
+if (ret != KERN_SUCCESS) { \
+ mach_error(#name, ret); \
+ exit (1); \
+}
+
+#define SIGSEGV_FAULT_ADDRESS code[1]
+#define SIGSEGV_FAULT_INSTRUCTION get_fault_instruction(thread, state)
+#define SIGSEGV_FAULT_HANDLER_INVOKE(ADDR, IP) ((code[0] == KERN_PROTECTION_FAILURE) ? sigsegv_fault_handler(ADDR, IP) : SIGSEGV_RETURN_FAILURE)
+#define SIGSEGV_FAULT_HANDLER_ARGLIST mach_port_t thread, exception_data_t code, ppc_thread_state_t *state
+#define SIGSEGV_FAULT_HANDLER_ARGS thread, code, &state
+#define SIGSEGV_SKIP_INSTRUCTION powerpc_skip_instruction
+#define SIGSEGV_REGISTER_FILE &state->srr0, &state->r0
+
+// Given a suspended thread, stuff the current instruction and
+// registers into state.
+//
+// It would have been nice to have this be ppc/x86 independant which
+// could have been done easily with a thread_state_t instead of
+// ppc_thread_state_t, but because of the way this is called it is
+// easier to do it this way.
+#if (defined(ppc) || defined(__ppc__))
+static inline sigsegv_address_t get_fault_instruction(mach_port_t thread, ppc_thread_state_t *state)
+{
+ kern_return_t krc;
+ mach_msg_type_number_t count;
+
+ count = MACHINE_THREAD_STATE_COUNT;
+ krc = thread_get_state(thread, MACHINE_THREAD_STATE, (thread_state_t)state, &count);
+ MACH_CHECK_ERROR (thread_get_state, krc);
+
+ return (sigsegv_address_t)state->srr0;
+}
+#endif
+
+// Since there can only be one exception thread running at any time
+// this is not a problem.
+#define MSG_SIZE 512
+static char msgbuf[MSG_SIZE];
+static char replybuf[MSG_SIZE];
+
+/*
+ * This is the entry point for the exception handler thread. The job
+ * of this thread is to wait for exception messages on the exception
+ * port that was setup beforehand and to pass them on to exc_server.
+ * exc_server is a MIG generated function that is a part of Mach.
+ * Its job is to decide what to do with the exception message. In our
+ * case exc_server calls catch_exception_raise on our behalf. After
+ * exc_server returns, it is our responsibility to send the reply.
+ */
+static void *
+handleExceptions(void *priv)
+{
+ mach_msg_header_t *msg, *reply;
+ kern_return_t krc;
+
+ msg = (mach_msg_header_t *)msgbuf;
+ reply = (mach_msg_header_t *)replybuf;
+
+ for (;;) {
+ krc = mach_msg(msg, MACH_RCV_MSG, MSG_SIZE, MSG_SIZE,
+ _exceptionPort, 0, MACH_PORT_NULL);
+ MACH_CHECK_ERROR(mach_msg, krc);
+
+ if (!exc_server(msg, reply)) {
+ fprintf(stderr, "exc_server hated the message\n");
+ exit(1);
+ }
+
+ krc = mach_msg(reply, MACH_SEND_MSG, reply->msgh_size, 0,
+ msg->msgh_local_port, 0, MACH_PORT_NULL);
+ if (krc != KERN_SUCCESS) {
+ fprintf(stderr, "Error sending message to original reply port, krc = %d, %s",
+ krc, mach_error_string(krc));
+ exit(1);
+ }
+ }
+}
+#endif
+#endif
+
+
+/*
+ * Instruction skipping
+ */
+
+#ifdef HAVE_SIGSEGV_SKIP_INSTRUCTION
+// Decode and skip X86 instruction
+#if (defined(i386) || defined(__i386__)) || defined(__x86_64__)
+#if defined(__linux__)
+enum {
+#if (defined(i386) || defined(__i386__))
+ X86_REG_EIP = 14,
+ X86_REG_EAX = 11,
+ X86_REG_ECX = 10,
+ X86_REG_EDX = 9,
+ X86_REG_EBX = 8,
+ X86_REG_ESP = 7,
+ X86_REG_EBP = 6,
+ X86_REG_ESI = 5,
+ X86_REG_EDI = 4
+#endif
+#if defined(__x86_64__)
+ X86_REG_R8 = 0,
+ X86_REG_R9 = 1,
+ X86_REG_R10 = 2,
+ X86_REG_R11 = 3,
+ X86_REG_R12 = 4,
+ X86_REG_R13 = 5,
+ X86_REG_R14 = 6,
+ X86_REG_R15 = 7,
+ X86_REG_EDI = 8,
+ X86_REG_ESI = 9,
+ X86_REG_EBP = 10,
+ X86_REG_EBX = 11,
+ X86_REG_EDX = 12,
+ X86_REG_EAX = 13,
+ X86_REG_ECX = 14,
+ X86_REG_ESP = 15,
+ X86_REG_EIP = 16
+#endif
+};
+#endif
+#if defined(__NetBSD__) || defined(__FreeBSD__)
+enum {
+#if (defined(i386) || defined(__i386__))
+ X86_REG_EIP = 10,
+ X86_REG_EAX = 7,
+ X86_REG_ECX = 6,
+ X86_REG_EDX = 5,
+ X86_REG_EBX = 4,
+ X86_REG_ESP = 13,
+ X86_REG_EBP = 2,
+ X86_REG_ESI = 1,
+ X86_REG_EDI = 0
+#endif
+};
+#endif
+// FIXME: this is partly redundant with the instruction decoding phase
+// to discover transfer type and register number
+static inline int ix86_step_over_modrm(unsigned char * p)
+{
+ int mod = (p[0] >> 6) & 3;
+ int rm = p[0] & 7;
+ int offset = 0;
+
+ // ModR/M Byte
+ switch (mod) {
+ case 0: // [reg]
+ if (rm == 5) return 4; // disp32
break;
- case 31:
- switch(EXTRACT_OP2(instr)) {
- case 86: /* dcbf */
- case 54: /* dcbst */
- case 1014: /* dcbz */
- case 247: /* stbux */
- case 215: /* stbx */
- case 759: /* stfdux */
- case 727: /* stfdx */
- case 983: /* stfiwx */
- case 695: /* stfsux */
- case 663: /* stfsx */
- case 918: /* sthbrx */
- case 439: /* sthux */
- case 407: /* sthx */
- case 661: /* stswx */
- case 662: /* stwbrx */
- case 150: /* stwcx. */
- case 183: /* stwux */
- case 151: /* stwx */
- case 135: /* stvebx */
- case 167: /* stvehx */
- case 199: /* stvewx */
- case 231: /* stvx */
- case 487: /* stvxl */
- tmp = EXTRACT_REGA(instr);
- if(tmp > 0)
- baseA = regs[tmp];
- baseB = regs[EXTRACT_REGC(instr)];
- /* determine Altivec alignment mask */
- switch(EXTRACT_OP2(instr)) {
- case 167: /* stvehx */
- alignmask = 0xFFFFFFFE;
- break;
- case 199: /* stvewx */
- alignmask = 0xFFFFFFFC;
- break;
- case 231: /* stvx */
- alignmask = 0xFFFFFFF0;
- break;
- case 487: /* stvxl */
- alignmask = 0xFFFFFFF0;
- break;
- }
+ case 1: // disp8[reg]
+ offset = 1;
+ break;
+ case 2: // disp32[reg]
+ offset = 4;
+ break;
+ case 3: // register
+ return 0;
+ }
+
+ // SIB Byte
+ if (rm == 4) {
+ if (mod == 0 && (p[1] & 7) == 5)
+ offset = 5; // disp32[index]
+ else
+ offset++;
+ }
+
+ return offset;
+}
+
+static bool ix86_skip_instruction(unsigned long * regs)
+{
+ unsigned char * eip = (unsigned char *)regs[X86_REG_EIP];
+
+ if (eip == 0)
+ return false;
+
+ transfer_type_t transfer_type = SIGSEGV_TRANSFER_UNKNOWN;
+ transfer_size_t transfer_size = SIZE_LONG;
+
+ int reg = -1;
+ int len = 0;
+
+#if DEBUG
+ printf("IP: %p [%02x %02x %02x %02x...]\n",
+ eip, eip[0], eip[1], eip[2], eip[3]);
+#endif
+
+ // Operand size prefix
+ if (*eip == 0x66) {
+ eip++;
+ len++;
+ transfer_size = SIZE_WORD;
+ }
+
+ // REX prefix
+#if defined(__x86_64__)
+ struct rex_t {
+ unsigned char W;
+ unsigned char R;
+ unsigned char X;
+ unsigned char B;
+ };
+ rex_t rex = { 0, 0, 0, 0 };
+ bool has_rex = false;
+ if ((*eip & 0xf0) == 0x40) {
+ has_rex = true;
+ const unsigned char b = *eip;
+ rex.W = b & (1 << 3);
+ rex.R = b & (1 << 2);
+ rex.X = b & (1 << 1);
+ rex.B = b & (1 << 0);
+#if DEBUG
+ printf("REX: %c,%c,%c,%c\n",
+ rex.W ? 'W' : '_',
+ rex.R ? 'R' : '_',
+ rex.X ? 'X' : '_',
+ rex.B ? 'B' : '_');
+#endif
+ eip++;
+ len++;
+ if (rex.W)
+ transfer_size = SIZE_QUAD;
+ }
+#else
+ const bool has_rex = false;
+#endif
+
+ // Decode instruction
+ switch (eip[0]) {
+ case 0x0f:
+ switch (eip[1]) {
+ case 0xb6: // MOVZX r32, r/m8
+ case 0xb7: // MOVZX r32, r/m16
+ switch (eip[2] & 0xc0) {
+ case 0x80:
+ reg = (eip[2] >> 3) & 7;
+ transfer_type = SIGSEGV_TRANSFER_LOAD;
+ break;
+ case 0x40:
+ reg = (eip[2] >> 3) & 7;
+ transfer_type = SIGSEGV_TRANSFER_LOAD;
+ break;
+ case 0x00:
+ reg = (eip[2] >> 3) & 7;
+ transfer_type = SIGSEGV_TRANSFER_LOAD;
+ break;
+ }
+ len += 3 + ix86_step_over_modrm(eip + 2);
+ break;
+ }
+ break;
+ case 0x8a: // MOV r8, r/m8
+ transfer_size = SIZE_BYTE;
+ case 0x8b: // MOV r32, r/m32 (or 16-bit operation)
+ switch (eip[1] & 0xc0) {
+ case 0x80:
+ reg = (eip[1] >> 3) & 7;
+ transfer_type = SIGSEGV_TRANSFER_LOAD;
break;
- case 725: /* stswi */
- tmp = EXTRACT_REGA(instr);
- if(tmp > 0)
- baseA = regs[tmp];
+ case 0x40:
+ reg = (eip[1] >> 3) & 7;
+ transfer_type = SIGSEGV_TRANSFER_LOAD;
break;
- default: /* ignore instruction */
- return 0;
+ case 0x00:
+ reg = (eip[1] >> 3) & 7;
+ transfer_type = SIGSEGV_TRANSFER_LOAD;
break;
}
+ len += 2 + ix86_step_over_modrm(eip + 1);
break;
- default: /* ignore instruction */
- return 0;
+ case 0x88: // MOV r/m8, r8
+ transfer_size = SIZE_BYTE;
+ case 0x89: // MOV r/m32, r32 (or 16-bit operation)
+ switch (eip[1] & 0xc0) {
+ case 0x80:
+ reg = (eip[1] >> 3) & 7;
+ transfer_type = SIGSEGV_TRANSFER_STORE;
+ break;
+ case 0x40:
+ reg = (eip[1] >> 3) & 7;
+ transfer_type = SIGSEGV_TRANSFER_STORE;
+ break;
+ case 0x00:
+ reg = (eip[1] >> 3) & 7;
+ transfer_type = SIGSEGV_TRANSFER_STORE;
+ break;
+ }
+ len += 2 + ix86_step_over_modrm(eip + 1);
break;
}
+
+ if (transfer_type == SIGSEGV_TRANSFER_UNKNOWN) {
+ // Unknown machine code, let it crash. Then patch the decoder
+ return false;
+ }
+
+#if defined(__x86_64__)
+ if (rex.R)
+ reg += 8;
+#endif
+
+ if (transfer_type == SIGSEGV_TRANSFER_LOAD && reg != -1) {
+ static const int x86_reg_map[] = {
+ X86_REG_EAX, X86_REG_ECX, X86_REG_EDX, X86_REG_EBX,
+ X86_REG_ESP, X86_REG_EBP, X86_REG_ESI, X86_REG_EDI,
+#if defined(__x86_64__)
+ X86_REG_R8, X86_REG_R9, X86_REG_R10, X86_REG_R11,
+ X86_REG_R12, X86_REG_R13, X86_REG_R14, X86_REG_R15,
+#endif
+ };
+
+ if (reg < 0 || reg >= (sizeof(x86_reg_map)/sizeof(x86_reg_map[0]) - 1))
+ return false;
+
+ // Set 0 to the relevant register part
+ // NOTE: this is only valid for MOV alike instructions
+ int rloc = x86_reg_map[reg];
+ switch (transfer_size) {
+ case SIZE_BYTE:
+ if (has_rex || reg < 4)
+ regs[rloc] = (regs[rloc] & ~0x00ffL);
+ else {
+ rloc = x86_reg_map[reg - 4];
+ regs[rloc] = (regs[rloc] & ~0xff00L);
+ }
+ break;
+ case SIZE_WORD:
+ regs[rloc] = (regs[rloc] & ~0xffffL);
+ break;
+ case SIZE_LONG:
+ case SIZE_QUAD: // zero-extension
+ regs[rloc] = 0;
+ break;
+ }
+ }
+
+#if DEBUG
+ printf("%08x: %s %s access", regs[X86_REG_EIP],
+ transfer_size == SIZE_BYTE ? "byte" :
+ transfer_size == SIZE_WORD ? "word" :
+ transfer_size == SIZE_LONG ? "long" :
+ transfer_size == SIZE_QUAD ? "quad" : "unknown",
+ transfer_type == SIGSEGV_TRANSFER_LOAD ? "read" : "write");
- addr = (baseA + baseB) + disp;
- addr &= alignmask;
- return (sigsegv_address_t)addr;
+ if (reg != -1) {
+ static const char * x86_byte_reg_str_map[] = {
+ "al", "cl", "dl", "bl",
+ "spl", "bpl", "sil", "dil",
+ "r8b", "r9b", "r10b", "r11b",
+ "r12b", "r13b", "r14b", "r15b",
+ "ah", "ch", "dh", "bh",
+ };
+ static const char * x86_word_reg_str_map[] = {
+ "ax", "cx", "dx", "bx",
+ "sp", "bp", "si", "di",
+ "r8w", "r9w", "r10w", "r11w",
+ "r12w", "r13w", "r14w", "r15w",
+ };
+ static const char *x86_long_reg_str_map[] = {
+ "eax", "ecx", "edx", "ebx",
+ "esp", "ebp", "esi", "edi",
+ "r8d", "r9d", "r10d", "r11d",
+ "r12d", "r13d", "r14d", "r15d",
+ };
+ static const char *x86_quad_reg_str_map[] = {
+ "rax", "rcx", "rdx", "rbx",
+ "rsp", "rbp", "rsi", "rdi",
+ "r8", "r9", "r10", "r11",
+ "r12", "r13", "r14", "r15",
+ };
+ const char * reg_str = NULL;
+ switch (transfer_size) {
+ case SIZE_BYTE:
+ reg_str = x86_byte_reg_str_map[(!has_rex && reg >= 4 ? 12 : 0) + reg];
+ break;
+ case SIZE_WORD: reg_str = x86_word_reg_str_map[reg]; break;
+ case SIZE_LONG: reg_str = x86_long_reg_str_map[reg]; break;
+ case SIZE_QUAD: reg_str = x86_quad_reg_str_map[reg]; break;
+ }
+ if (reg_str)
+ printf(" %s register %%%s",
+ transfer_type == SIGSEGV_TRANSFER_LOAD ? "to" : "from",
+ reg_str);
+ }
+ printf(", %d bytes instruction\n", len);
+#endif
+
+ regs[X86_REG_EIP] += len;
+ return true;
}
#endif
+
+// Decode and skip PPC instruction
+#if (defined(powerpc) || defined(__powerpc__) || defined(__ppc__))
+static bool powerpc_skip_instruction(unsigned int * nip_p, unsigned int * regs)
+{
+ instruction_t instr;
+ powerpc_decode_instruction(&instr, *nip_p, regs);
+
+ if (instr.transfer_type == SIGSEGV_TRANSFER_UNKNOWN) {
+ // Unknown machine code, let it crash. Then patch the decoder
+ return false;
+ }
+
+#if DEBUG
+ printf("%08x: %s %s access", *nip_p,
+ instr.transfer_size == SIZE_BYTE ? "byte" : instr.transfer_size == SIZE_WORD ? "word" : "long",
+ instr.transfer_type == SIGSEGV_TRANSFER_LOAD ? "read" : "write");
+
+ if (instr.addr_mode == MODE_U || instr.addr_mode == MODE_UX)
+ printf(" r%d (ra = %08x)\n", instr.ra, instr.addr);
+ if (instr.transfer_type == SIGSEGV_TRANSFER_LOAD)
+ printf(" r%d (rd = 0)\n", instr.rd);
+#endif
+
+ if (instr.addr_mode == MODE_U || instr.addr_mode == MODE_UX)
+ regs[instr.ra] = instr.addr;
+ if (instr.transfer_type == SIGSEGV_TRANSFER_LOAD)
+ regs[instr.rd] = 0;
+
+ *nip_p += 4;
+ return true;
+}
#endif
#endif
@@ -270,6 +930,12 @@ static sigsegv_address_t get_fault_addre
#ifndef SIGSEGV_FAULT_INSTRUCTION
#define SIGSEGV_FAULT_INSTRUCTION SIGSEGV_INVALID_PC
#endif
+#ifndef SIGSEGV_FAULT_HANDLER_ARGLIST_1
+#define SIGSEGV_FAULT_HANDLER_ARGLIST_1 SIGSEGV_FAULT_HANDLER_ARGLIST
+#endif
+#ifndef SIGSEGV_FAULT_HANDLER_INVOKE
+#define SIGSEGV_FAULT_HANDLER_INVOKE(ADDR, IP) sigsegv_fault_handler(ADDR, IP)
+#endif
// SIGSEGV recovery supported ?
#if defined(SIGSEGV_ALL_SIGNALS) && defined(SIGSEGV_FAULT_HANDLER_ARGLIST) && defined(SIGSEGV_FAULT_ADDRESS)
@@ -281,21 +947,213 @@ static sigsegv_address_t get_fault_addre
* SIGSEGV global handler
*/
+#if defined(HAVE_SIGSEGV_RECOVERY) || defined(HAVE_MACH_EXCEPTIONS)
+// This function handles the badaccess to memory.
+// It is called from the signal handler or the exception handler.
+static bool handle_badaccess(SIGSEGV_FAULT_HANDLER_ARGLIST_1)
+{
+ sigsegv_address_t fault_address = (sigsegv_address_t)SIGSEGV_FAULT_ADDRESS;
+ sigsegv_address_t fault_instruction = (sigsegv_address_t)SIGSEGV_FAULT_INSTRUCTION;
+
+ // Call user's handler and reinstall the global handler, if required
+ switch (SIGSEGV_FAULT_HANDLER_INVOKE(fault_address, fault_instruction)) {
+ case SIGSEGV_RETURN_SUCCESS:
+ return true;
+
+#if HAVE_SIGSEGV_SKIP_INSTRUCTION
+ case SIGSEGV_RETURN_SKIP_INSTRUCTION:
+ // Call the instruction skipper with the register file
+ // available
+ if (SIGSEGV_SKIP_INSTRUCTION(SIGSEGV_REGISTER_FILE)) {
+#ifdef HAVE_MACH_EXCEPTIONS
+ // Unlike UNIX signals where the thread state
+ // is modified off of the stack, in Mach we
+ // need to actually call thread_set_state to
+ // have the register values updated.
+ kern_return_t krc;
+
+ krc = thread_set_state(thread,
+ MACHINE_THREAD_STATE, (thread_state_t)state,
+ MACHINE_THREAD_STATE_COUNT);
+ MACH_CHECK_ERROR (thread_get_state, krc);
+#endif
+ return true;
+ }
+ break;
+#endif
+ }
+
+ // We can't do anything with the fault_address, dump state?
+ if (sigsegv_state_dumper != 0)
+ sigsegv_state_dumper(fault_address, fault_instruction);
+
+ return false;
+}
+#endif
+
+
+/*
+ * There are two mechanisms for handling a bad memory access,
+ * Mach exceptions and UNIX signals. The implementation specific
+ * code appears below. Its reponsibility is to call handle_badaccess
+ * which is the routine that handles the fault in an implementation
+ * agnostic manner. The implementation specific code below is then
+ * reponsible for checking whether handle_badaccess was able
+ * to handle the memory access error and perform any implementation
+ * specific tasks necessary afterwards.
+ */
+
+#ifdef HAVE_MACH_EXCEPTIONS
+/*
+ * We need to forward all exceptions that we do not handle.
+ * This is important, there are many exceptions that may be
+ * handled by other exception handlers. For example debuggers
+ * use exceptions and the exception hander is in another
+ * process in such a case. (Timothy J. Wood states in his
+ * message to the list that he based this code on that from
+ * gdb for Darwin.)
+ */
+static inline kern_return_t
+forward_exception(mach_port_t thread_port,
+ mach_port_t task_port,
+ exception_type_t exception_type,
+ exception_data_t exception_data,
+ mach_msg_type_number_t data_count,
+ ExceptionPorts *oldExceptionPorts)
+{
+ kern_return_t kret;
+ unsigned int portIndex;
+ mach_port_t port;
+ exception_behavior_t behavior;
+ thread_state_flavor_t flavor;
+ thread_state_t thread_state;
+ mach_msg_type_number_t thread_state_count;
+
+ for (portIndex = 0; portIndex < oldExceptionPorts->maskCount; portIndex++) {
+ if (oldExceptionPorts->masks[portIndex] & (1 << exception_type)) {
+ // This handler wants the exception
+ break;
+ }
+ }
+
+ if (portIndex >= oldExceptionPorts->maskCount) {
+ fprintf(stderr, "No handler for exception_type = %d. Not fowarding\n", exception_type);
+ return KERN_FAILURE;
+ }
+
+ port = oldExceptionPorts->handlers[portIndex];
+ behavior = oldExceptionPorts->behaviors[portIndex];
+ flavor = oldExceptionPorts->flavors[portIndex];
+
+ /*
+ fprintf(stderr, "forwarding exception, port = 0x%x, behaviour = %d, flavor = %d\n", port, behavior, flavor);
+ */
+
+ if (behavior != EXCEPTION_DEFAULT) {
+ thread_state_count = THREAD_STATE_MAX;
+ kret = thread_get_state (thread_port, flavor, thread_state,
+ &thread_state_count);
+ MACH_CHECK_ERROR (thread_get_state, kret);
+ }
+
+ switch (behavior) {
+ case EXCEPTION_DEFAULT:
+ // fprintf(stderr, "forwarding to exception_raise\n");
+ kret = exception_raise(port, thread_port, task_port, exception_type,
+ exception_data, data_count);
+ MACH_CHECK_ERROR (exception_raise, kret);
+ break;
+ case EXCEPTION_STATE:
+ // fprintf(stderr, "forwarding to exception_raise_state\n");
+ kret = exception_raise_state(port, exception_type, exception_data,
+ data_count, &flavor,
+ thread_state, thread_state_count,
+ thread_state, &thread_state_count);
+ MACH_CHECK_ERROR (exception_raise_state, kret);
+ break;
+ case EXCEPTION_STATE_IDENTITY:
+ // fprintf(stderr, "forwarding to exception_raise_state_identity\n");
+ kret = exception_raise_state_identity(port, thread_port, task_port,
+ exception_type, exception_data,
+ data_count, &flavor,
+ thread_state, thread_state_count,
+ thread_state, &thread_state_count);
+ MACH_CHECK_ERROR (exception_raise_state_identity, kret);
+ break;
+ default:
+ fprintf(stderr, "forward_exception got unknown behavior\n");
+ break;
+ }
+
+ if (behavior != EXCEPTION_DEFAULT) {
+ kret = thread_set_state (thread_port, flavor, thread_state,
+ thread_state_count);
+ MACH_CHECK_ERROR (thread_set_state, kret);
+ }
+
+ return KERN_SUCCESS;
+}
+
+/*
+ * This is the code that actually handles the exception.
+ * It is called by exc_server. For Darwin 5 Apple changed
+ * this a bit from how this family of functions worked in
+ * Mach. If you are familiar with that it is a little
+ * different. The main variation that concerns us here is
+ * that code is an array of exception specific codes and
+ * codeCount is a count of the number of codes in the code
+ * array. In typical Mach all exceptions have a code
+ * and sub-code. It happens to be the case that for a
+ * EXC_BAD_ACCESS exception the first entry is the type of
+ * bad access that occurred and the second entry is the
+ * faulting address so these entries correspond exactly to
+ * how the code and sub-code are used on Mach.
+ *
+ * This is a MIG interface. No code in Basilisk II should
+ * call this directley. This has to have external C
+ * linkage because that is what exc_server expects.
+ */
+kern_return_t
+catch_exception_raise(mach_port_t exception_port,
+ mach_port_t thread,
+ mach_port_t task,
+ exception_type_t exception,
+ exception_data_t code,
+ mach_msg_type_number_t codeCount)
+{
+ ppc_thread_state_t state;
+ kern_return_t krc;
+
+ if ((exception == EXC_BAD_ACCESS) && (codeCount >= 2)) {
+ if (handle_badaccess(SIGSEGV_FAULT_HANDLER_ARGS))
+ return KERN_SUCCESS;
+ }
+
+ // In Mach we do not need to remove the exception handler.
+ // If we forward the exception, eventually some exception handler
+ // will take care of this exception.
+ krc = forward_exception(thread, task, exception, code, codeCount, &ports);
+
+ return krc;
+}
+#endif
+
#ifdef HAVE_SIGSEGV_RECOVERY
+// Handle bad memory accesses with signal handler
static void sigsegv_handler(SIGSEGV_FAULT_HANDLER_ARGLIST)
{
- // Call user's handler and reinstall the global handler, if required
- if (sigsegv_user_handler((sigsegv_address_t)SIGSEGV_FAULT_ADDRESS, (sigsegv_address_t)SIGSEGV_FAULT_INSTRUCTION)) {
+ // Call handler and reinstall the global handler, if required
+ if (handle_badaccess(SIGSEGV_FAULT_HANDLER_ARGS)) {
#if (defined(HAVE_SIGACTION) ? defined(SIGACTION_NEED_REINSTALL) : defined(SIGNAL_NEED_REINSTALL))
sigsegv_do_install_handler(sig);
#endif
+ return;
}
- else {
- // FAIL: reinstall default handler for "safe" crash
+
+ // Failure: reinstall default handler for "safe" crash
#define FAULT_HANDLER(sig) signal(sig, SIG_DFL);
- SIGSEGV_ALL_SIGNALS
+ SIGSEGV_ALL_SIGNALS
#undef FAULT_HANDLER
- }
}
#endif
@@ -309,11 +1167,11 @@ static bool sigsegv_do_install_handler(i
{
// Setup SIGSEGV handler to process writes to frame buffer
#ifdef HAVE_SIGACTION
- struct sigaction vosf_sa;
- sigemptyset(&vosf_sa.sa_mask);
- vosf_sa.sa_sigaction = sigsegv_handler;
- vosf_sa.sa_flags = SA_SIGINFO;
- return (sigaction(sig, &vosf_sa, 0) == 0);
+ struct sigaction sigsegv_sa;
+ sigemptyset(&sigsegv_sa.sa_mask);
+ sigsegv_sa.sa_sigaction = sigsegv_handler;
+ sigsegv_sa.sa_flags = SA_SIGINFO;
+ return (sigaction(sig, &sigsegv_sa, 0) == 0);
#else
return (signal(sig, (signal_handler)sigsegv_handler) != SIG_ERR);
#endif
@@ -325,31 +1183,118 @@ static bool sigsegv_do_install_handler(i
{
// Setup SIGSEGV handler to process writes to frame buffer
#ifdef HAVE_SIGACTION
- struct sigaction vosf_sa;
- sigemptyset(&vosf_sa.sa_mask);
- vosf_sa.sa_handler = (signal_handler)sigsegv_handler;
+ struct sigaction sigsegv_sa;
+ sigemptyset(&sigsegv_sa.sa_mask);
+ sigsegv_sa.sa_handler = (signal_handler)sigsegv_handler;
+ sigsegv_sa.sa_flags = 0;
#if !EMULATED_68K && defined(__NetBSD__)
- sigaddset(&vosf_sa.sa_mask, SIGALRM);
- vosf_sa.sa_flags = SA_ONSTACK;
-#else
- vosf_sa.sa_flags = 0;
+ sigaddset(&sigsegv_sa.sa_mask, SIGALRM);
+ sigsegv_sa.sa_flags |= SA_ONSTACK;
#endif
- return (sigaction(sig, &vosf_sa, 0) == 0);
+ return (sigaction(sig, &sigsegv_sa, 0) == 0);
#else
return (signal(sig, (signal_handler)sigsegv_handler) != SIG_ERR);
#endif
}
#endif
-bool sigsegv_install_handler(sigsegv_handler_t handler)
+#if defined(HAVE_MACH_EXCEPTIONS)
+static bool sigsegv_do_install_handler(sigsegv_fault_handler_t handler)
{
-#ifdef HAVE_SIGSEGV_RECOVERY
- sigsegv_user_handler = handler;
+ /*
+ * Except for the exception port functions, this should be
+ * pretty much stock Mach. If later you choose to support
+ * other Mach's besides Darwin, just check for __MACH__
+ * here and __APPLE__ where the actual differences are.
+ */
+#if defined(__APPLE__) && defined(__MACH__)
+ if (sigsegv_fault_handler != NULL) {
+ sigsegv_fault_handler = handler;
+ return true;
+ }
+
+ kern_return_t krc;
+
+ // create the the exception port
+ krc = mach_port_allocate(mach_task_self(),
+ MACH_PORT_RIGHT_RECEIVE, &_exceptionPort);
+ if (krc != KERN_SUCCESS) {
+ mach_error("mach_port_allocate", krc);
+ return false;
+ }
+
+ // add a port send right
+ krc = mach_port_insert_right(mach_task_self(),
+ _exceptionPort, _exceptionPort,
+ MACH_MSG_TYPE_MAKE_SEND);
+ if (krc != KERN_SUCCESS) {
+ mach_error("mach_port_insert_right", krc);
+ return false;
+ }
+
+ // get the old exception ports
+ ports.maskCount = sizeof (ports.masks) / sizeof (ports.masks[0]);
+ krc = thread_get_exception_ports(mach_thread_self(), EXC_MASK_BAD_ACCESS, ports.masks,
+ &ports.maskCount, ports.handlers, ports.behaviors, ports.flavors);
+ if (krc != KERN_SUCCESS) {
+ mach_error("thread_get_exception_ports", krc);
+ return false;
+ }
+
+ // set the new exception port
+ //
+ // We could have used EXCEPTION_STATE_IDENTITY instead of
+ // EXCEPTION_DEFAULT to get the thread state in the initial
+ // message, but it turns out that in the common case this is not
+ // neccessary. If we need it we can later ask for it from the
+ // suspended thread.
+ //
+ // Even with THREAD_STATE_NONE, Darwin provides the program
+ // counter in the thread state. The comments in the header file
+ // seem to imply that you can count on the GPR's on an exception
+ // as well but just to be safe I use MACHINE_THREAD_STATE because
+ // you have to ask for all of the GPR's anyway just to get the
+ // program counter. In any case because of update effective
+ // address from immediate and update address from effective
+ // addresses of ra and rb modes (as good an name as any for these
+ // addressing modes) used in PPC instructions, you will need the
+ // GPR state anyway.
+ krc = thread_set_exception_ports(mach_thread_self(), EXC_MASK_BAD_ACCESS, _exceptionPort,
+ EXCEPTION_DEFAULT, MACHINE_THREAD_STATE);
+ if (krc != KERN_SUCCESS) {
+ mach_error("thread_set_exception_ports", krc);
+ return false;
+ }
+
+ // create the exception handler thread
+ if (pthread_create(&exc_thread, NULL, &handleExceptions, NULL) != 0) {
+ (void)fprintf(stderr, "creation of exception thread failed\n");
+ return false;
+ }
+
+ // do not care about the exception thread any longer, let is run standalone
+ (void)pthread_detach(exc_thread);
+
+ sigsegv_fault_handler = handler;
+ return true;
+#else
+ return false;
+#endif
+}
+#endif
+
+bool sigsegv_install_handler(sigsegv_fault_handler_t handler)
+{
+#if defined(HAVE_SIGSEGV_RECOVERY)
bool success = true;
#define FAULT_HANDLER(sig) success = success && sigsegv_do_install_handler(sig);
SIGSEGV_ALL_SIGNALS
#undef FAULT_HANDLER
+ if (success)
+ sigsegv_fault_handler = handler;
return success;
+#elif defined(HAVE_MACH_EXCEPTIONS)
+ return sigsegv_do_install_handler(handler);
#else
// FAIL: no siginfo_t nor sigcontext subterfuge is available
return false;
@@ -363,14 +1308,30 @@ bool sigsegv_install_handler(sigsegv_han
void sigsegv_deinstall_handler(void)
{
+ // We do nothing for Mach exceptions, the thread would need to be
+ // suspended if not already so, and we might mess with other
+ // exception handlers that came after we registered ours. There is
+ // no need to remove the exception handler, in fact this function is
+ // not called anywhere in Basilisk II.
#ifdef HAVE_SIGSEGV_RECOVERY
- sigsegv_user_handler = 0;
+ sigsegv_fault_handler = 0;
#define FAULT_HANDLER(sig) signal(sig, SIG_DFL);
SIGSEGV_ALL_SIGNALS
#undef FAULT_HANDLER
#endif
}
+
+/*
+ * Set callback function when we cannot handle the fault
+ */
+
+void sigsegv_set_dump_state(sigsegv_state_dumper_t handler)
+{
+ sigsegv_state_dumper = handler;
+}
+
+
/*
* Test program used for configure/test
*/
@@ -382,19 +1343,111 @@ void sigsegv_deinstall_handler(void)
#include
#include "vm_alloc.h"
+const int REF_INDEX = 123;
+const int REF_VALUE = 45;
+
static int page_size;
static volatile char * page = 0;
static volatile int handler_called = 0;
-static bool sigsegv_test_handler(sigsegv_address_t fault_address, sigsegv_address_t instruction_address)
+#ifdef __GNUC__
+// Code range where we expect the fault to come from
+static void *b_region, *e_region;
+#endif
+
+static sigsegv_return_t sigsegv_test_handler(sigsegv_address_t fault_address, sigsegv_address_t instruction_address)
{
handler_called++;
- if ((fault_address - 123) != page)
- exit(1);
+ if ((fault_address - REF_INDEX) != page)
+ exit(10);
+#ifdef __GNUC__
+ // Make sure reported fault instruction address falls into
+ // expected code range
+ if (instruction_address != SIGSEGV_INVALID_PC
+ && ((instruction_address < (sigsegv_address_t)b_region) ||
+ (instruction_address >= (sigsegv_address_t)e_region)))
+ exit(11);
+#endif
if (vm_protect((char *)((unsigned long)fault_address & -page_size), page_size, VM_PAGE_READ | VM_PAGE_WRITE) != 0)
- exit(1);
+ exit(12);
+ return SIGSEGV_RETURN_SUCCESS;
+}
+
+#ifdef HAVE_SIGSEGV_SKIP_INSTRUCTION
+static sigsegv_return_t sigsegv_insn_handler(sigsegv_address_t fault_address, sigsegv_address_t instruction_address)
+{
+ if (((unsigned long)fault_address - (unsigned long)page) < page_size) {
+#ifdef __GNUC__
+ // Make sure reported fault instruction address falls into
+ // expected code range
+ if (instruction_address != SIGSEGV_INVALID_PC
+ && ((instruction_address < (sigsegv_address_t)b_region) ||
+ (instruction_address >= (sigsegv_address_t)e_region)))
+ return SIGSEGV_RETURN_FAILURE;
+#endif
+ return SIGSEGV_RETURN_SKIP_INSTRUCTION;
+ }
+
+ return SIGSEGV_RETURN_FAILURE;
+}
+
+// More sophisticated tests for instruction skipper
+static bool arch_insn_skipper_tests()
+{
+#if (defined(i386) || defined(__i386__)) || defined(__x86_64__)
+ static const unsigned char code[] = {
+ 0x8a, 0x00, // mov (%eax),%al
+ 0x8a, 0x2c, 0x18, // mov (%eax,%ebx,1),%ch
+ 0x88, 0x20, // mov %ah,(%eax)
+ 0x88, 0x08, // mov %cl,(%eax)
+ 0x66, 0x8b, 0x00, // mov (%eax),%ax
+ 0x66, 0x8b, 0x0c, 0x18, // mov (%eax,%ebx,1),%cx
+ 0x66, 0x89, 0x00, // mov %ax,(%eax)
+ 0x66, 0x89, 0x0c, 0x18, // mov %cx,(%eax,%ebx,1)
+ 0x8b, 0x00, // mov (%eax),%eax
+ 0x8b, 0x0c, 0x18, // mov (%eax,%ebx,1),%ecx
+ 0x89, 0x00, // mov %eax,(%eax)
+ 0x89, 0x0c, 0x18, // mov %ecx,(%eax,%ebx,1)
+#if defined(__x86_64__)
+ 0x44, 0x8a, 0x00, // mov (%rax),%r8b
+ 0x44, 0x8a, 0x20, // mov (%rax),%r12b
+ 0x42, 0x8a, 0x3c, 0x10, // mov (%rax,%r10,1),%dil
+ 0x44, 0x88, 0x00, // mov %r8b,(%rax)
+ 0x44, 0x88, 0x20, // mov %r12b,(%rax)
+ 0x42, 0x88, 0x3c, 0x10, // mov %dil,(%rax,%r10,1)
+ 0x66, 0x44, 0x8b, 0x00, // mov (%rax),%r8w
+ 0x66, 0x42, 0x8b, 0x0c, 0x10, // mov (%rax,%r10,1),%cx
+ 0x66, 0x44, 0x89, 0x00, // mov %r8w,(%rax)
+ 0x66, 0x42, 0x89, 0x0c, 0x10, // mov %cx,(%rax,%r10,1)
+ 0x44, 0x8b, 0x00, // mov (%rax),%r8d
+ 0x42, 0x8b, 0x0c, 0x10, // mov (%rax,%r10,1),%ecx
+ 0x44, 0x89, 0x00, // mov %r8d,(%rax)
+ 0x42, 0x89, 0x0c, 0x10, // mov %ecx,(%rax,%r10,1)
+ 0x48, 0x8b, 0x08, // mov (%rax),%rcx
+ 0x4c, 0x8b, 0x18, // mov (%rax),%r11
+ 0x4a, 0x8b, 0x0c, 0x10, // mov (%rax,%r10,1),%rcx
+ 0x4e, 0x8b, 0x1c, 0x10, // mov (%rax,%r10,1),%r11
+ 0x48, 0x89, 0x08, // mov %rcx,(%rax)
+ 0x4c, 0x89, 0x18, // mov %r11,(%rax)
+ 0x4a, 0x89, 0x0c, 0x10, // mov %rcx,(%rax,%r10,1)
+ 0x4e, 0x89, 0x1c, 0x10, // mov %r11,(%rax,%r10,1)
+#endif
+ 0 // end
+ };
+ const int N_REGS = 20;
+ unsigned long regs[N_REGS];
+ for (int i = 0; i < N_REGS; i++)
+ regs[i] = i;
+ const unsigned long start_code = (unsigned long)&code;
+ regs[X86_REG_EIP] = start_code;
+ while ((regs[X86_REG_EIP] - start_code) < (sizeof(code) - 1)
+ && ix86_skip_instruction(regs))
+ ; /* simply iterate */
+ return (regs[X86_REG_EIP] - start_code) == (sizeof(code) - 1);
+#endif
return true;
}
+#endif
int main(void)
{
@@ -403,19 +1456,65 @@ int main(void)
page_size = getpagesize();
if ((page = (char *)vm_acquire(page_size)) == VM_MAP_FAILED)
- return 1;
+ return 2;
+ memset((void *)page, 0, page_size);
if (vm_protect((char *)page, page_size, VM_PAGE_READ) < 0)
- return 1;
+ return 3;
if (!sigsegv_install_handler(sigsegv_test_handler))
- return 1;
-
- page[123] = 45;
- page[123] = 45;
+ return 4;
+#ifdef __GNUC__
+ b_region = &&L_b_region1;
+ e_region = &&L_e_region1;
+#endif
+ L_b_region1:
+ page[REF_INDEX] = REF_VALUE;
+ if (page[REF_INDEX] != REF_VALUE)
+ exit(20);
+ page[REF_INDEX] = REF_VALUE;
+ L_e_region1:
+
if (handler_called != 1)
- return 1;
+ return 5;
+
+#ifdef HAVE_SIGSEGV_SKIP_INSTRUCTION
+ if (!sigsegv_install_handler(sigsegv_insn_handler))
+ return 6;
+
+ if (vm_protect((char *)page, page_size, VM_PAGE_READ | VM_PAGE_WRITE) < 0)
+ return 7;
+
+ for (int i = 0; i < page_size; i++)
+ page[i] = (i + 1) % page_size;
+
+ if (vm_protect((char *)page, page_size, VM_PAGE_NOACCESS) < 0)
+ return 8;
+
+#define TEST_SKIP_INSTRUCTION(TYPE) do { \
+ const unsigned long TAG = 0x12345678 | \
+ (sizeof(long) == 8 ? 0x9abcdef0UL << 31 : 0); \
+ TYPE data = *((TYPE *)(page + sizeof(TYPE))); \
+ volatile unsigned long effect = data + TAG; \
+ if (effect != TAG) \
+ return 9; \
+ } while (0)
+
+#ifdef __GNUC__
+ b_region = &&L_b_region2;
+ e_region = &&L_e_region2;
+#endif
+ L_b_region2:
+ TEST_SKIP_INSTRUCTION(unsigned char);
+ TEST_SKIP_INSTRUCTION(unsigned short);
+ TEST_SKIP_INSTRUCTION(unsigned int);
+ TEST_SKIP_INSTRUCTION(unsigned long);
+ L_e_region2:
+
+ if (!arch_insn_skipper_tests())
+ return 20;
+#endif
vm_exit();
return 0;