#include "mini-unwind.h"
#include <mono/utils/mono-counters.h>
+#include <mono/utils/freebsd-dwarf.h>
#include <mono/metadata/threads-types.h>
+#include <mono/metadata/mono-endian.h>
typedef enum {
LOC_SAME,
dwarf_reg_to_hw_reg_inited = TRUE;
}
-static inline int
+int
mono_dwarf_reg_to_hw_reg (int reg)
{
if (!dwarf_reg_to_hw_reg_inited)
* 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.
+ * If SAVE_LOCATIONS is non-NULL, it should point to an array of size SAVE_LOCATIONS_LEN.
+ * On return, the nth entry will point to the address of the stack slot where register
+ * N was saved, or NULL, if it was not saved by this frame.
* This function is signal safe.
*/
void
mono_unwind_frame (guint8 *unwind_info, guint32 unwind_info_len,
- guint8 *start_ip, guint8 *end_ip, guint8 *ip, mgreg_t *regs,
- int nregs, guint8 **out_cfa)
+ guint8 *start_ip, guint8 *end_ip, guint8 *ip, mgreg_t *regs, int nregs,
+ mgreg_t **save_locations, int save_locations_len,
+ guint8 **out_cfa)
{
Loc locations [NUM_REGS];
int i, pos, reg, cfa_reg, cfa_offset;
locations [reg].offset = decode_sleb128 (p, &p) * DWARF_DATA_ALIGN;
break;
case DW_CFA_advance_loc4:
- pos += *(guint32*)p;
+ pos += read32 (p);
p += 4;
break;
default:
}
}
+ if (save_locations)
+ memset (save_locations, 0, save_locations_len * sizeof (mgreg_t*));
+
cfa_val = (guint8*)regs [mono_dwarf_reg_to_hw_reg (cfa_reg)] + cfa_offset;
for (i = 0; i < NUM_REGS; ++i) {
if (locations [i].loc_type == LOC_OFFSET) {
int hreg = mono_dwarf_reg_to_hw_reg (i);
g_assert (hreg < nregs);
- regs [hreg] = *(gssize*)(cfa_val + locations [i].offset);
+ regs [hreg] = *(mgreg_t*)(cfa_val + locations [i].offset);
+ if (save_locations && hreg < save_locations_len)
+ save_locations [hreg] = (mgreg_t*)(cfa_val + locations [i].offset);
}
}
/* Pointer Encoding in the .eh_frame */
enum {
- DW_EH_PE_absptr = 0x00,
- DW_EH_PE_omit = 0xff,
+ DW_EH_PE_absptr = 0x00,
+ DW_EH_PE_omit = 0xff,
- DW_EH_PE_udata4 = 0x03,
+ DW_EH_PE_udata4 = 0x03,
DW_EH_PE_sdata4 = 0x0b,
DW_EH_PE_sdata8 = 0x0c,
- DW_EH_PE_pcrel = 0x10
+
+ DW_EH_PE_pcrel = 0x10,
+ DW_EH_PE_textrel = 0x20,
+ DW_EH_PE_datarel = 0x30,
+ DW_EH_PE_funcrel = 0x40,
+ DW_EH_PE_aligned = 0x50,
+
+ DW_EH_PE_indirect = 0x80
};
+static gint64
+read_encoded_val (guint32 encoding, guint8 *p, guint8 **endp)
+{
+ gint64 res;
+
+ switch (encoding & 0xf) {
+ case DW_EH_PE_sdata8:
+ res = *(gint64*)p;
+ p += 8;
+ break;
+ case DW_EH_PE_sdata4:
+ res = *(gint32*)p;
+ p += 4;
+ break;
+ default:
+ g_assert_not_reached ();
+ }
+
+ *endp = p;
+ return res;
+}
+
+/*
+ * decode_lsda:
+ *
+ * Decode the Language Specific Data Area generated by LLVM.
+ */
+static void
+decode_lsda (guint8 *lsda, guint8 *code, MonoJitExceptionInfo **ex_info, guint32 *ex_info_len, gpointer **type_info, int *this_reg, int *this_offset)
+{
+ gint32 ttype_offset, call_site_length;
+ gint32 ttype_encoding, call_site_encoding;
+ guint8 *ttype, *action_table, *call_site, *p;
+ int i, ncall_sites;
+
+ /*
+ * LLVM generates a c++ style LSDA, which can be decoded by looking at
+ * eh_personality.cc in gcc.
+ */
+ p = lsda;
+
+ if (*p == DW_EH_PE_udata4) {
+ /* This is the modified LSDA generated by the LLVM mono branch */
+ guint32 mono_magic, version;
+ gint32 op, reg, offset;
+
+ p ++;
+ mono_magic = decode_uleb128 (p, &p);
+ g_assert (mono_magic == 0x4d4fef4f);
+ version = decode_uleb128 (p, &p);
+ g_assert (version == 1);
+
+ /* 'this' location */
+ op = *p;
+ g_assert (op == DW_OP_bregx);
+ p ++;
+ reg = decode_uleb128 (p, &p);
+ offset = decode_sleb128 (p, &p);
+
+ *this_reg = mono_dwarf_reg_to_hw_reg (reg);
+ *this_offset = offset;
+ } else {
+ /* Read @LPStart */
+ g_assert (*p == DW_EH_PE_omit);
+ p ++;
+
+ *this_reg = -1;
+ *this_offset = -1;
+ }
+
+ /* Read @TType */
+ ttype_encoding = *p;
+ p ++;
+ ttype_offset = decode_uleb128 (p, &p);
+ ttype = p + ttype_offset;
+
+ /* Read call-site table */
+ call_site_encoding = *p;
+ g_assert (call_site_encoding == DW_EH_PE_udata4);
+ p ++;
+ call_site_length = decode_uleb128 (p, &p);
+ call_site = p;
+ p += call_site_length;
+ action_table = p;
+
+ /* Calculate the size of our table */
+ ncall_sites = 0;
+ p = call_site;
+ while (p < action_table) {
+ int block_start_offset, block_size, landing_pad, action_offset;
+
+ block_start_offset = read32 (p);
+ p += sizeof (gint32);
+ block_size = read32 (p);
+ p += sizeof (gint32);
+ landing_pad = read32 (p);
+ p += sizeof (gint32);
+ action_offset = decode_uleb128 (p, &p);
+
+ /* landing_pad == 0 means the region has no landing pad */
+ if (landing_pad)
+ ncall_sites ++;
+ }
+
+ if (ex_info) {
+ *ex_info = g_malloc0 (ncall_sites * sizeof (MonoJitExceptionInfo));
+ *ex_info_len = ncall_sites;
+ }
+
+ if (type_info)
+ *type_info = g_malloc0 (ncall_sites * sizeof (gpointer));
+
+ p = call_site;
+ i = 0;
+ while (p < action_table) {
+ int block_start_offset, block_size, landing_pad, action_offset, type_offset;
+ guint8 *action, *tinfo;
+
+ block_start_offset = read32 (p);
+ p += sizeof (gint32);
+ block_size = read32 (p);
+ p += sizeof (gint32);
+ landing_pad = read32 (p);
+ p += sizeof (gint32);
+ action_offset = decode_uleb128 (p, &p);
+
+ action = action_table + action_offset - 1;
+
+ type_offset = decode_sleb128 (action, &action);
+
+ if (landing_pad) {
+ //printf ("BLOCK: %p-%p %p, %d\n", code + block_start_offset, code + block_start_offset + block_size, code + landing_pad, action_offset);
+
+ g_assert (ttype_offset);
+
+ if (ttype_encoding == DW_EH_PE_absptr) {
+ guint8 *ttype_entry = (ttype - (type_offset * sizeof (gpointer)));
+ tinfo = *(gpointer*)ttype_entry;
+ } else if (ttype_encoding == (DW_EH_PE_indirect | DW_EH_PE_pcrel | DW_EH_PE_sdata4)) {
+ guint8 *ttype_entry = (ttype - (type_offset * 4));
+ gint32 offset = *(gint32*)ttype_entry;
+ guint8 *stub = ttype_entry + offset;
+ tinfo = *(gpointer*)stub;
+ } else if (ttype_encoding == (DW_EH_PE_pcrel | DW_EH_PE_sdata4)) {
+ guint8 *ttype_entry = (ttype - (type_offset * 4));
+ gint32 offset = *(gint32*)ttype_entry;
+ tinfo = ttype_entry + offset;
+ } else if (ttype_encoding == DW_EH_PE_udata4) {
+ /* Embedded directly */
+ guint8 *ttype_entry = (ttype - (type_offset * 4));
+ tinfo = ttype_entry;
+ } else {
+ g_assert_not_reached ();
+ }
+
+ if (ex_info) {
+ if (*type_info)
+ (*type_info) [i] = tinfo;
+ (*ex_info)[i].try_start = code + block_start_offset;
+ (*ex_info)[i].try_end = code + block_start_offset + block_size;
+ (*ex_info)[i].handler_start = code + landing_pad;
+
+ }
+ i ++;
+ }
+ }
+}
+
/*
* mono_unwind_decode_fde:
*
* Decode a DWARF FDE entry, returning the unwind opcodes.
* If not NULL, EX_INFO is set to a malloc-ed array of MonoJitExceptionInfo structures,
* only try_start, try_end and handler_start is set.
+ * If not NULL, TYPE_INFO is set to a malloc-ed array containing the ttype table from the
+ * LSDA.
*/
guint8*
-mono_unwind_decode_fde (guint8 *fde, guint32 *out_len, guint32 *code_len, MonoJitExceptionInfo **ex_info, guint32 *ex_info_len)
+mono_unwind_decode_fde (guint8 *fde, guint32 *out_len, guint32 *code_len, MonoJitExceptionInfo **ex_info, guint32 *ex_info_len, gpointer **type_info, int *this_reg, int *this_offset)
{
- guint8 *p, *cie, *fde_current, *fde_aug, *code, *fde_cfi, *cie_cfi;
+ guint8 *p, *cie, *fde_current, *fde_aug = NULL, *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;
+ gboolean has_fde_augmentation = FALSE;
/*
* http://refspecs.freestandards.org/LSB_3.0.0/LSB-Core-generic/LSB-Core-generic/ehframechpt.html
*/
+ *type_info = NULL;
+ *this_reg = -1;
+ *this_offset = -1;
+
/* Decode FDE */
p = fde;
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);
+ guint8 *cie_aug;
+ guint32 p_encoding;
- g_assert (!strcmp (cie_aug_str, "zR") || !strcmp (cie_aug_str, "zPLR"));
+ cie_aug_len = decode_uleb128 (p, &p);
- /* Check that the augmention is what we expect */
- if (!strcmp (cie_aug_str, "zPLR")) {
- guint8 *cie_aug = p;
+ has_fde_augmentation = TRUE;
- g_assert (cie_aug_len == sizeof (gpointer) + 3);
- /* P */
- /* FIXME: 32 bit */
- g_assert (cie_aug [0] == DW_EH_PE_sdata8);
- /* L */
- g_assert (cie_aug [1 + sizeof (gpointer)] == (DW_EH_PE_sdata4|DW_EH_PE_pcrel));
- /* R */
- g_assert (cie_aug [1 + sizeof (gpointer) + 1] == (DW_EH_PE_sdata4|DW_EH_PE_pcrel));
+ cie_aug = p;
+ for (i = 0; cie_aug_str [i] != '\0'; ++i) {
+ switch (cie_aug_str [i]) {
+ case 'z':
+ break;
+ case 'P':
+ p_encoding = *p;
+ p ++;
+ read_encoded_val (p_encoding, p, &p);
+ break;
+ case 'L':
+ g_assert ((*p == (DW_EH_PE_sdata4|DW_EH_PE_pcrel)) || (*p == (DW_EH_PE_sdata8|DW_EH_PE_pcrel)));
+ p ++;
+ break;
+ case 'R':
+ g_assert (*p == (DW_EH_PE_sdata4|DW_EH_PE_pcrel));
+ p ++;
+ break;
+ default:
+ g_assert_not_reached ();
+ break;
+ }
}
+
+ p = cie_aug;
p += cie_aug_len;
}
cie_cfi = p;
p += 4;
pc_range = *(guint32*)p;
p += 4;
- aug_len = decode_uleb128 (p, &p);
- fde_aug = p;
- p += aug_len;
+ if (has_fde_augmentation) {
+ aug_len = decode_uleb128 (p, &p);
+ fde_aug = p;
+ p += aug_len;
+ } else {
+ aug_len = 0;
+ }
fde_cfi = p;
fde_data_len = fde + 4 + fde_len - p;
/* Decode FDE augmention */
if (aug_len) {
- gint32 lsda_offset, cio_offset, call_site_length;
- gint32 call_site_encoding;
- guint8 *lsda, *class_info, *action_table, *call_site, *p;
- int i, ncall_sites;
-
- /*
- * For some reason, this is 8 bytes long, even through it only includes
- * the offset to the LSDA which is encoded as an sdata4.
- */
- g_assert (aug_len == 8);
+ gint32 lsda_offset;
+ guint8 *lsda;
+
/* sdata|pcrel encoding */
- lsda_offset = *(gint32*)fde_aug;
+ if (aug_len == 4)
+ lsda_offset = read32 (fde_aug);
+ else if (aug_len == 8)
+ lsda_offset = *(gint64*)fde_aug;
+ else
+ g_assert_not_reached ();
if (lsda_offset != 0) {
- lsda = fde_aug + *(gint32*)fde_aug;
-
- /*
- * LLVM generates a c++ style LSDA, which can be decoded by looking at
- * eh_personality.cc in gcc.
- */
- p = lsda;
-
- /* Read @LPStart */
- g_assert (*p == DW_EH_PE_omit);
- p ++;
+ lsda = fde_aug + lsda_offset;
- /* Read @TType */
- g_assert (*p == DW_EH_PE_absptr);
- p ++;
- cio_offset = decode_uleb128 (p, &p);
- class_info = lsda + cio_offset;
-
- /* Read call-site table */
- call_site_encoding = *p;
- g_assert (call_site_encoding == DW_EH_PE_udata4);
- p ++;
- call_site_length = decode_uleb128 (p, &p);
- call_site = p;
- p += call_site_length;
- action_table = p;
-
- /* Calculate the size of our table */
- ncall_sites = 0;
- p = call_site;
- while (p < action_table) {
- int block_start_offset, block_size, landing_pad, action_offset;
-
- block_start_offset = ((guint32*)p) [0];
- block_size = ((guint32*)p) [1];
- landing_pad = ((guint32*)p) [2];
- p += 3 * sizeof (guint32);
- action_offset = decode_uleb128 (p, &p);
-
- /* landing_pad == 0 means the region has no landing pad */
- if (landing_pad)
- ncall_sites ++;
- }
-
- if (ex_info) {
- *ex_info = g_malloc0 (ncall_sites * sizeof (MonoJitExceptionInfo));
- *ex_info_len = ncall_sites;
- }
-
- p = call_site;
- i = 0;
- while (p < action_table) {
- int block_start_offset, block_size, landing_pad, action_offset;
-
- block_start_offset = ((guint32*)p) [0];
- block_size = ((guint32*)p) [1];
- landing_pad = ((guint32*)p) [2];
- p += 3 * sizeof (guint32);
- action_offset = decode_uleb128 (p, &p);
-
- if (landing_pad) {
- //printf ("BLOCK: %p-%p %p, %d\n", code + block_start_offset, code + block_start_offset + block_size, code + landing_pad, action_offset);
-
- if (ex_info) {
- (*ex_info)[i].try_start = code + block_start_offset;
- (*ex_info)[i].try_end = code + block_start_offset + block_size;
- (*ex_info)[i].handler_start = code + landing_pad;
- }
- i ++;
- }
- }
+ decode_lsda (lsda, code, ex_info, ex_info_len, type_info, this_reg, this_offset);
}
}
-
/* Make sure the FDE uses the same constants as we do */
g_assert (code_align == 1);
g_assert (data_align == DWARF_DATA_ALIGN);
return g_realloc (buf, i);
}
+
+/*
+ * mono_unwind_decode_mono_fde:
+ *
+ * Decode an FDE entry in the LLVM emitted mono EH frame.
+ * info->ex_info is set to a malloc-ed array of MonoJitExceptionInfo structures,
+ * only try_start, try_end and handler_start is set.
+ * info->type_info is set to a malloc-ed array containing the ttype table from the
+ * LSDA.
+ */
+void
+mono_unwind_decode_llvm_mono_fde (guint8 *fde, int fde_len, guint8 *cie, guint8 *code, MonoLLVMFDEInfo *res)
+{
+ guint8 *p, *fde_aug, *cie_cfi, *fde_cfi, *buf;
+ int has_aug, aug_len, cie_cfi_len, fde_cfi_len;
+ gint32 code_align, data_align, return_reg, pers_encoding;
+
+ memset (res, 0, sizeof (*res));
+ res->this_reg = -1;
+ res->this_offset = -1;
+
+ /* fde points to data emitted by LLVM in DwarfException::EmitMonoEHFrame () */
+ p = fde;
+ has_aug = *p;
+ p ++;
+ if (has_aug) {
+ aug_len = read32 (p);
+ p += 4;
+ } else {
+ aug_len = 0;
+ }
+ fde_aug = p;
+ p += aug_len;
+ fde_cfi = p;
+
+ if (has_aug) {
+ guint8 *lsda;
+
+ /* The LSDA is embedded directly into the FDE */
+ lsda = fde_aug;
+
+ decode_lsda (lsda, code, &res->ex_info, &res->ex_info_len, &res->type_info, &res->this_reg, &res->this_offset);
+ }
+
+ /* Decode CIE */
+ p = cie;
+ code_align = decode_uleb128 (p, &p);
+ data_align = decode_sleb128 (p, &p);
+ return_reg = decode_uleb128 (p, &p);
+ pers_encoding = *p;
+ p ++;
+ if (pers_encoding != DW_EH_PE_omit)
+ read_encoded_val (pers_encoding, p, &p);
+
+ 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);
+
+ /* Compute size of CIE unwind info it is DW_CFA_nop terminated */
+ p = cie_cfi;
+ while (TRUE) {
+ if (*p == DW_CFA_nop)
+ break;
+ else
+ decode_cie_op (p, &p);
+ }
+ cie_cfi_len = p - cie_cfi;
+ fde_cfi_len = (fde + fde_len - fde_cfi);
+
+ buf = g_malloc0 (cie_cfi_len + fde_cfi_len);
+ memcpy (buf, cie_cfi, cie_cfi_len);
+ memcpy (buf + cie_cfi_len, fde_cfi, fde_cfi_len);
+
+ res->unw_info_len = cie_cfi_len + fde_cfi_len;
+ res->unw_info = buf;
+}
+
+/*
+ * mono_unwind_get_cie_program:
+ *
+ * Get the unwind bytecode for the DWARF CIE.
+ */
+GSList*
+mono_unwind_get_cie_program (void)
+{
+#if defined(TARGET_AMD64) || defined(TARGET_X86) || defined(TARGET_POWERPC)
+ return mono_arch_get_cie_program ();
+#else
+ return NULL;
+#endif
+}
projects / mono.git / blobdiff