#include "unwind.h"
#include <mono/utils/mono-counters.h>
+#include <mono/metadata/threads-types.h>
typedef enum {
LOC_SAME,
static CRITICAL_SECTION unwind_mutex;
-static GPtrArray *cached_info;
-static int cached_info_size;
+static MonoUnwindInfo **cached_info;
+static int cached_info_next, cached_info_size;
+/* Statistics */
+static int unwind_info_size;
#define unwind_lock() EnterCriticalSection (&unwind_mutex)
#define unwind_unlock() LeaveCriticalSection (&unwind_mutex)
-#ifdef __x86_64__
+#ifdef TARGET_AMD64
static int map_hw_reg_to_dwarf_reg [] = { 0, 2, 1, 3, 7, 6, 4, 5, 8, 9, 10, 11, 12, 13, 14, 15, 16 };
#define NUM_REGS AMD64_NREG
+#define DWARF_DATA_ALIGN (-8)
+#define DWARF_PC_REG (mono_hw_reg_to_dwarf_reg (AMD64_RIP))
+#elif defined(TARGET_ARM)
+// http://infocenter.arm.com/help/topic/com.arm.doc.ihi0040a/IHI0040A_aadwarf.pdf
+static int map_hw_reg_to_dwarf_reg [] = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 };
+#define NUM_REGS 16
+#define DWARF_DATA_ALIGN (-4)
+#define DWARF_PC_REG (mono_hw_reg_to_dwarf_reg (ARMREG_LR))
+#elif defined (TARGET_X86)
+static int map_hw_reg_to_dwarf_reg [] = { 0, 1, 2, 3, 4, 5, 6, 7, 8 };
+/* + 1 is for IP */
+#define NUM_REGS X86_NREG + 1
+#define DWARF_DATA_ALIGN (-4)
+#define DWARF_PC_REG (mono_hw_reg_to_dwarf_reg (X86_NREG))
+#elif defined (TARGET_POWERPC)
+// http://refspecs.linuxfoundation.org/ELF/ppc64/PPC-elf64abi-1.9.html
+static int map_hw_reg_to_dwarf_reg [] = { 0, 1, 2, 3, 4, 5, 6, 7, 8,
+ 9, 10, 11, 12, 13, 14, 15, 16,
+ 17, 18, 19, 20, 21, 22, 23, 24,
+ 25, 26, 27, 28, 29, 30, 31 };
+#define NUM_REGS 110
+#define DWARF_DATA_ALIGN (-(gint32)sizeof (mgreg_t))
+#define DWARF_PC_REG 108
#else
-static int map_hw_reg_to_dwarf_reg [0];
-#define NUM_REGS 0
+static int map_hw_reg_to_dwarf_reg [16];
+#define NUM_REGS 16
+#define DWARF_DATA_ALIGN 0
+#define DWARF_PC_REG -1
#endif
static gboolean dwarf_reg_to_hw_reg_inited;
int
mono_hw_reg_to_dwarf_reg (int reg)
{
-#ifdef __x86_64__
- return map_hw_reg_to_dwarf_reg [reg];
-#else
- g_assert_not_reached ();
- return -1;
+#ifdef TARGET_POWERPC
+ if (reg == ppc_lr)
+ return 108;
+ else
+ g_assert (reg < NUM_REGS);
#endif
+
+ if (NUM_REGS == 0) {
+ g_assert_not_reached ();
+ return -1;
+ } else {
+ return map_hw_reg_to_dwarf_reg [reg];
+ }
}
static void
*endbuf = p;
}
+static G_GNUC_UNUSED void
+encode_sleb128 (gint32 value, guint8 *buf, guint8 **endbuf)
+{
+ gboolean more = 1;
+ gboolean negative = (value < 0);
+ guint32 size = 32;
+ guint8 byte;
+ guint8 *p = buf;
+
+ while (more) {
+ byte = value & 0x7f;
+ value >>= 7;
+ /* the following is unnecessary if the
+ * implementation of >>= uses an arithmetic rather
+ * than logical shift for a signed left operand
+ */
+ if (negative)
+ /* sign extend */
+ value |= - (1 <<(size - 7));
+ /* sign bit of byte is second high order bit (0x40) */
+ if ((value == 0 && !(byte & 0x40)) ||
+ (value == -1 && (byte & 0x40)))
+ more = 0;
+ else
+ byte |= 0x80;
+ *p ++= byte;
+ }
+
+ *endbuf = p;
+}
+
static inline guint32
decode_uleb128 (guint8 *buf, guint8 **endbuf)
{
return res;
}
+static inline gint32
+decode_sleb128 (guint8 *buf, guint8 **endbuf)
+{
+ guint8 *p = buf;
+ gint32 res = 0;
+ int shift = 0;
+
+ while (TRUE) {
+ guint8 b = *p;
+ p ++;
+
+ res = res | (((int)(b & 0x7f)) << shift);
+ shift += 7;
+ if (!(b & 0x80)) {
+ if (shift < 32 && (b & 0x40))
+ res |= - (1 << shift);
+ break;
+ }
+ }
+
+ *endbuf = p;
+
+ return res;
+}
+
/*
* mono_unwind_ops_encode:
*
int loc;
guint8 *buf, *p, *res;
- p = buf = g_malloc0 (256);
+ p = buf = g_malloc0 (4096);
loc = 0;
l = unwind_ops;
reg = mono_hw_reg_to_dwarf_reg (op->reg);
/* Emit an advance_loc if neccesary */
- if (op->when > loc) {
- g_assert (op->when - loc < 32);
- *p ++ = DW_CFA_advance_loc | (op->when - loc);
+ while (op->when > loc) {
+ if (op->when - loc < 32) {
+ *p ++ = DW_CFA_advance_loc | (op->when - loc);
+ loc = op->when;
+ } else {
+ *p ++ = DW_CFA_advance_loc | (30);
+ loc += 30;
+ }
}
switch (op->op) {
encode_uleb128 (reg, p, &p);
break;
case DW_CFA_offset:
- *p ++ = DW_CFA_offset | reg;
- encode_uleb128 (op->val / - 8, p, &p);
+ if (reg > 63) {
+ *p ++ = DW_CFA_offset_extended_sf;
+ encode_uleb128 (reg, p, &p);
+ encode_sleb128 (op->val / DWARF_DATA_ALIGN, p, &p);
+ } else {
+ *p ++ = DW_CFA_offset | reg;
+ encode_uleb128 (op->val / DWARF_DATA_ALIGN, p, &p);
+ }
break;
default:
g_assert_not_reached ();
break;
}
-
- loc = op->when;
}
- g_assert (p - buf < 256);
+ g_assert (p - buf < 4096);
*out_len = p - buf;
res = g_malloc (p - buf);
memcpy (res, buf, p - buf);
* Given the state of the current frame as stored in REGS, execute the unwind
* operations in unwind_info until the location counter reaches POS. The result is
* stored back into REGS. OUT_CFA will receive the value of the CFA.
+ * This function is signal safe.
*/
void
mono_unwind_frame (guint8 *unwind_info, guint32 unwind_info_len,
- int data_align_factor,
- guint8 *start_ip, guint8 *end_ip, guint8 *ip, gssize *regs,
+ guint8 *start_ip, guint8 *end_ip, guint8 *ip, mgreg_t *regs,
int nregs, guint8 **out_cfa)
{
Loc locations [NUM_REGS];
- int i, pos, reg, cfa_reg, cfa_offset;
+ int i, pos, reg, cfa_reg, cfa_offset, offset;
guint8 *p;
guint8 *cfa_val;
p = unwind_info;
pos = 0;
+ cfa_reg = -1;
+ cfa_offset = -1;
while (pos <= ip - start_ip && p < unwind_info + unwind_info_len) {
int op = *p & 0xc0;
reg = mono_dwarf_reg_to_hw_reg (*p & 0x3f);
p ++;
locations [reg].loc_type = LOC_OFFSET;
- locations [reg].offset = decode_uleb128 (p, &p) * data_align_factor;
+ locations [reg].offset = decode_uleb128 (p, &p) * DWARF_DATA_ALIGN;
break;
case 0: {
int ext_op = *p;
case DW_CFA_def_cfa_register:
cfa_reg = mono_dwarf_reg_to_hw_reg (decode_uleb128 (p, &p));
break;
+ case DW_CFA_offset_extended_sf:
+ reg = mono_dwarf_reg_to_hw_reg (decode_uleb128 (p, &p));
+ offset = decode_sleb128 (p, &p) * DWARF_DATA_ALIGN;
+ break;
+ case DW_CFA_advance_loc4:
+ pos += *(guint32*)p;
+ p += 4;
+ break;
default:
g_assert_not_reached ();
}
{
InitializeCriticalSection (&unwind_mutex);
- mono_counters_register ("Unwind info size", MONO_COUNTER_JIT | MONO_COUNTER_INT, &cached_info_size);
+ mono_counters_register ("Unwind info size", MONO_COUNTER_JIT | MONO_COUNTER_INT, &unwind_info_size);
}
void
DeleteCriticalSection (&unwind_mutex);
- for (i = 0; i < cached_info->len; ++i) {
- MonoUnwindInfo *cached = g_ptr_array_index (cached_info, i);
+ if (!cached_info)
+ return;
+
+ for (i = 0; i < cached_info_next; ++i) {
+ MonoUnwindInfo *cached = cached_info [i];
g_free (cached);
}
- g_ptr_array_free (cached_info, TRUE);
+ g_free (cached_info);
}
/*
MonoUnwindInfo *info;
unwind_lock ();
- if (cached_info == NULL)
- cached_info = g_ptr_array_new ();
- for (i = 0; i < cached_info->len; ++i) {
- MonoUnwindInfo *cached = g_ptr_array_index (cached_info, i);
+ if (cached_info == NULL) {
+ cached_info_size = 16;
+ cached_info = g_new0 (MonoUnwindInfo*, cached_info_size);
+ }
+
+ for (i = 0; i < cached_info_next; ++i) {
+ MonoUnwindInfo *cached = cached_info [i];
if (cached->len == unwind_info_len && memcmp (cached->info, unwind_info, unwind_info_len) == 0) {
unwind_unlock ();
info->len = unwind_info_len;
memcpy (&info->info, unwind_info, unwind_info_len);
- i = cached_info->len;
- g_ptr_array_add (cached_info, info);
+ i = cached_info_next;
+
+ if (cached_info_next >= cached_info_size) {
+ MonoUnwindInfo **old_table, **new_table;
+
+ /*
+ * Have to resize the table, while synchronizing with
+ * mono_get_cached_unwind_info () using hazard pointers.
+ */
+
+ old_table = cached_info;
+ new_table = g_new0 (MonoUnwindInfo*, cached_info_size * 2);
+
+ memcpy (new_table, cached_info, cached_info_size * sizeof (MonoUnwindInfo*));
- cached_info_size += sizeof (MonoUnwindInfo) + unwind_info_len;
+ mono_memory_barrier ();
+
+ cached_info = new_table;
+
+ mono_memory_barrier ();
+
+ mono_thread_hazardous_free_or_queue (old_table, g_free);
+
+ cached_info_size *= 2;
+ }
+
+ cached_info [cached_info_next ++] = info;
+
+ unwind_info_size += sizeof (MonoUnwindInfo) + unwind_info_len;
unwind_unlock ();
return i;
}
+static gpointer
+get_hazardous_pointer (gpointer volatile *pp, MonoThreadHazardPointers *hp, int hazard_index)
+{
+ gpointer p;
+
+ for (;;) {
+ /* Get the pointer */
+ p = *pp;
+ /* If we don't have hazard pointers just return the
+ pointer. */
+ if (!hp)
+ return p;
+ /* Make it hazardous */
+ mono_hazard_pointer_set (hp, hazard_index, p);
+ /* Check that it's still the same. If not, try
+ again. */
+ if (*pp != p) {
+ mono_hazard_pointer_clear (hp, hazard_index);
+ continue;
+ }
+ break;
+ }
+
+ return p;
+}
+
+/*
+ * This function is signal safe.
+ */
guint8*
mono_get_cached_unwind_info (guint32 index, guint32 *unwind_info_len)
{
+ MonoUnwindInfo **table;
MonoUnwindInfo *info;
+ guint8 *data;
+ MonoThreadHazardPointers *hp = mono_hazard_pointer_get ();
- // FIXME: Get rid of the locking somehow, as this is called a lot during
- // exception handling
- unwind_lock ();
- info = g_ptr_array_index (cached_info, index);
- unwind_unlock ();
+ table = get_hazardous_pointer ((gpointer volatile*)&cached_info, hp, 0);
+
+ info = table [index];
*unwind_info_len = info->len;
+ data = info->info;
+
+ mono_hazard_pointer_clear (hp, 0);
+
+ return data;
+}
+
+/*
+ * mono_unwind_get_dwarf_data_align:
+ *
+ * Return the data alignment used by the encoded unwind information.
+ */
+int
+mono_unwind_get_dwarf_data_align (void)
+{
+ return DWARF_DATA_ALIGN;
+}
+
+/*
+ * mono_unwind_get_dwarf_pc_reg:
+ *
+ * Return the dwarf register number of the register holding the ip of the
+ * previous frame.
+ */
+int
+mono_unwind_get_dwarf_pc_reg (void)
+{
+ return DWARF_PC_REG;
+}
+
+static void
+decode_cie_op (guint8 *p, guint8 **endp)
+{
+ int op = *p & 0xc0;
+
+ switch (op) {
+ case DW_CFA_advance_loc:
+ p ++;
+ break;
+ case DW_CFA_offset:
+ p ++;
+ decode_uleb128 (p, &p);
+ break;
+ case 0: {
+ int ext_op = *p;
+ p ++;
+ switch (ext_op) {
+ case DW_CFA_def_cfa:
+ decode_uleb128 (p, &p);
+ decode_uleb128 (p, &p);
+ break;
+ case DW_CFA_def_cfa_offset:
+ decode_uleb128 (p, &p);
+ break;
+ case DW_CFA_def_cfa_register:
+ decode_uleb128 (p, &p);
+ break;
+ case DW_CFA_advance_loc4:
+ p += 4;
+ break;
+ default:
+ g_assert_not_reached ();
+ }
+ break;
+ }
+ default:
+ g_assert_not_reached ();
+ }
+
+ *endp = p;
+}
+
+/*
+ * mono_unwind_get_ops_from_fde:
+ *
+ * Return the unwind opcodes encoded in a DWARF FDE entry.
+ */
+guint8*
+mono_unwind_get_ops_from_fde (guint8 *fde, guint32 *out_len, guint32 *code_len)
+{
+ guint8 *p, *cie, *code, *fde_cfi, *cie_cfi;
+ gint32 fde_len, cie_offset, pc_begin, pc_range, aug_len, fde_data_len;
+ gint32 cie_len, cie_id, cie_version, code_align, data_align, return_reg;
+ gint32 i, cie_aug_len, buf_len;
+ char *cie_aug_str;
+ guint8 *buf;
+
+ /*
+ * http://refspecs.freestandards.org/LSB_3.0.0/LSB-Core-generic/LSB-Core-generic/ehframechpt.html
+ */
+
+ /* Decode FDE */
+
+ p = fde;
+ // FIXME: Endianess ?
+ fde_len = *(guint32*)p;
+ g_assert (fde_len != 0xffffffff && fde_len != 0);
+ p += 4;
+ cie_offset = *(guint32*)p;
+ cie = p - cie_offset;
+ p += 4;
+ pc_begin = *(gint32*)p;
+ code = p + pc_begin;
+ p += 4;
+ pc_range = *(guint32*)p;
+ p += 4;
+ aug_len = decode_uleb128 (p, &p);
+ g_assert (aug_len == 0);
+ fde_cfi = p;
+ fde_data_len = fde + 4 + fde_len - p;
+
+ if (code_len)
+ *code_len = pc_range;
+
+ /* Decode CIE */
+ p = cie;
+ cie_len = *(guint32*)p;
+ p += 4;
+ cie_id = *(guint32*)p;
+ g_assert (cie_id == 0);
+ p += 4;
+ cie_version = *p;
+ g_assert (cie_version == 1);
+ p += 1;
+ cie_aug_str = (char*)p;
+ p += strlen (cie_aug_str) + 1;
+ code_align = decode_uleb128 (p, &p);
+ data_align = decode_sleb128 (p, &p);
+ return_reg = decode_uleb128 (p, &p);
+ if (strstr (cie_aug_str, "z")) {
+ cie_aug_len = decode_uleb128 (p, &p);
+ p += cie_aug_len;
+ }
+ cie_cfi = p;
+
+ /* Make sure the FDE uses the same constants as we do */
+ g_assert (code_align == 1);
+ g_assert (data_align == DWARF_DATA_ALIGN);
+ g_assert (return_reg == DWARF_PC_REG);
+
+ buf_len = (cie + cie_len + 4 - cie_cfi) + (fde + fde_len + 4 - fde_cfi);
+ buf = g_malloc0 (buf_len);
+
+ i = 0;
+ p = cie_cfi;
+ while (p < cie + cie_len + 4) {
+ if (*p == DW_CFA_nop)
+ break;
+ else
+ decode_cie_op (p, &p);
+ }
+ memcpy (buf + i, cie_cfi, p - cie_cfi);
+ i += p - cie_cfi;
+
+ p = fde_cfi;
+ while (p < fde + fde_len + 4) {
+ if (*p == DW_CFA_nop)
+ break;
+ else
+ decode_cie_op (p, &p);
+ }
+ memcpy (buf + i, fde_cfi, p - fde_cfi);
+ i += p - fde_cfi;
+ g_assert (i <= buf_len);
+
+ *out_len = i;
- return info->info;
+ return g_realloc (buf, i);
}
projects / mono.git / blobdiff