#include "frame-base.h"
#include "trad-frame.h"
#include "objfiles.h"
+#include "dwarf2.h"
#include "dwarf2/frame.h"
#include "gdbtypes.h"
#include "prologue-value.h"
/* The register used to hold the frame pointer for this frame. */
int framereg;
+ /* True if the return address is signed, false otherwise. */
+ gdb::optional<bool> ra_signed_state;
+
/* Saved register offsets. */
trad_frame_saved_reg *saved_regs;
};
while (start < limit)
{
unsigned short insn;
+ gdb::optional<bool> ra_signed_state;
insn = read_code_unsigned_integer (start, 2, byte_order_for_code);
inst2 = read_code_unsigned_integer (start + 2, 2,
byte_order_for_code);
+ uint32_t whole_insn = (insn << 16) | inst2;
if ((insn & 0xf800) == 0xf000 && (inst2 & 0xe800) == 0xe800)
{
constant = read_memory_unsigned_integer (loc + 4, 4, byte_order);
regs[bits (inst2, 8, 11)] = pv_constant (constant);
}
-
+ /* Start of ARMv8.1-m PACBTI extension instructions. */
+ else if (IS_PAC (whole_insn))
+ {
+ /* LR and SP are input registers. PAC is in R12. LR is
+ signed from this point onwards. NOP space. */
+ ra_signed_state = true;
+ }
+ else if (IS_PACBTI (whole_insn))
+ {
+ /* LR and SP are input registers. PAC is in R12 and PC is a
+ valid BTI landing pad. LR is signed from this point onwards.
+ NOP space. */
+ ra_signed_state = true;
+ }
+ else if (IS_BTI (whole_insn))
+ {
+ /* Valid BTI landing pad. NOP space. */
+ }
+ else if (IS_PACG (whole_insn))
+ {
+ /* Sign Rn using Rm and store the PAC in Rd. Rd is signed from
+ this point onwards. */
+ ra_signed_state = true;
+ }
+ else if (IS_AUT (whole_insn) || IS_AUTG (whole_insn))
+ {
+ /* These instructions appear close to the epilogue, when signed
+ pointers are getting authenticated. */
+ ra_signed_state = false;
+ }
+ /* End of ARMv8.1-m PACBTI extension instructions */
else if (thumb2_instruction_changes_pc (insn, inst2))
{
/* Don't scan past anything that might change control flow. */
unrecognized_pc = start;
}
+ arm_gdbarch_tdep *tdep
+ = (arm_gdbarch_tdep *) gdbarch_tdep (gdbarch);
+
+ /* Make sure we are dealing with a target that supports ARMv8.1-m
+ PACBTI. */
+ if (cache != nullptr && tdep->have_pacbti
+ && ra_signed_state.has_value ())
+ {
+ arm_debug_printf ("Found pacbti instruction at %s",
+ paddress (gdbarch, start));
+ arm_debug_printf ("RA is %s",
+ *ra_signed_state? "signed" : "not signed");
+ cache->ra_signed_state = ra_signed_state;
+ }
+
start += 2;
}
else if (thumb_instruction_changes_pc (insn))
*this_cache = arm_make_prologue_cache (this_frame);
cache = (struct arm_prologue_cache *) *this_cache;
+ arm_gdbarch_tdep *tdep = (arm_gdbarch_tdep *) gdbarch_tdep (gdbarch);
+
+ /* If this frame has signed the return address, mark it as so. */
+ if (tdep->have_pacbti && cache->ra_signed_state.has_value ()
+ && *cache->ra_signed_state)
+ set_frame_previous_pc_masked (this_frame);
+
/* If we are asked to unwind the PC, then we need to return the LR
instead. The prologue may save PC, but it will point into this
frame's prologue, not the next frame's resume location. Also
int regnum)
{
struct gdbarch * gdbarch = get_frame_arch (this_frame);
+ arm_gdbarch_tdep *tdep = (arm_gdbarch_tdep *) gdbarch_tdep (gdbarch);
CORE_ADDR lr, cpsr;
ULONGEST t_bit = arm_psr_thumb_bit (gdbarch);
describes saves of LR. However, that version may have an
extra bit set to indicate Thumb state. The bit is not
part of the PC. */
+
+ /* Record in the frame whether the return address was signed. */
+ if (tdep->have_pacbti)
+ {
+ CORE_ADDR ra_auth_code
+ = frame_unwind_register_unsigned (this_frame,
+ tdep->pacbti_pseudo_base);
+
+ if (ra_auth_code != 0)
+ set_frame_previous_pc_masked (this_frame);
+ }
+
lr = frame_unwind_register_unsigned (this_frame, ARM_LR_REGNUM);
return frame_unwind_got_constant (this_frame, regnum,
arm_addr_bits_remove (gdbarch, lr));
}
}
-static void
-arm_dwarf2_frame_init_reg (struct gdbarch *gdbarch, int regnum,
- struct dwarf2_frame_state_reg *reg,
- struct frame_info *this_frame)
-{
- switch (regnum)
- {
- case ARM_PC_REGNUM:
- case ARM_PS_REGNUM:
- reg->how = DWARF2_FRAME_REG_FN;
- reg->loc.fn = arm_dwarf2_prev_register;
- break;
- case ARM_SP_REGNUM:
- reg->how = DWARF2_FRAME_REG_CFA;
- break;
- }
-}
-
/* Implement the stack_frame_destroyed_p gdbarch method. */
static int
return false;
}
+/* Return true if REGNUM is a PACBTI pseudo register (ra_auth_code). Return
+ false otherwise.
+
+ REGNUM is the raw register number and not a pseudo-relative register
+ number. */
+
+static bool
+is_pacbti_pseudo (struct gdbarch *gdbarch, int regnum)
+{
+ arm_gdbarch_tdep *tdep = (arm_gdbarch_tdep *) gdbarch_tdep (gdbarch);
+
+ if (tdep->have_pacbti
+ && regnum >= tdep->pacbti_pseudo_base
+ && regnum < tdep->pacbti_pseudo_base + tdep->pacbti_pseudo_count)
+ return true;
+
+ return false;
+}
+
/* Return the GDB type object for the "standard" data type of data in
register N. */
if (is_mve_pseudo (gdbarch, regnum))
return builtin_type (gdbarch)->builtin_int16;
+ if (is_pacbti_pseudo (gdbarch, regnum))
+ return builtin_type (gdbarch)->builtin_uint32;
+
/* If the target description has register information, we are only
in this function so that we can override the types of
double-precision registers for NEON. */
if (reg >= 112 && reg <= 127)
return ARM_WR0_REGNUM + reg - 112;
+ /* PACBTI register containing the Pointer Authentication Code. */
+ if (reg == ARM_DWARF_RA_AUTH_CODE)
+ {
+ arm_gdbarch_tdep *tdep = (arm_gdbarch_tdep *) gdbarch_tdep (gdbarch);
+
+ if (tdep->have_pacbti)
+ return tdep->pacbti_pseudo_base;
+
+ return -1;
+ }
+
if (reg >= 192 && reg <= 199)
return ARM_WC0_REGNUM + reg - 192;
internal_error (__FILE__, __LINE__, _("Bad REGNUM %d"), regnum);
}
+static const unsigned char op_lit0 = DW_OP_lit0;
+
+static void
+arm_dwarf2_frame_init_reg (struct gdbarch *gdbarch, int regnum,
+ struct dwarf2_frame_state_reg *reg,
+ struct frame_info *this_frame)
+{
+ if (is_pacbti_pseudo (gdbarch, regnum))
+ {
+ /* Initialize RA_AUTH_CODE to zero. */
+ reg->how = DWARF2_FRAME_REG_SAVED_VAL_EXP;
+ reg->loc.exp.start = &op_lit0;
+ reg->loc.exp.len = 1;
+ return;
+ }
+
+ switch (regnum)
+ {
+ case ARM_PC_REGNUM:
+ case ARM_PS_REGNUM:
+ reg->how = DWARF2_FRAME_REG_FN;
+ reg->loc.fn = arm_dwarf2_prev_register;
+ break;
+ case ARM_SP_REGNUM:
+ reg->how = DWARF2_FRAME_REG_CFA;
+ break;
+ }
+}
+
/* Given BUF, which is OLD_LEN bytes ending at ENDADDR, expand
the buffer to be NEW_LEN bytes ending at ENDADDR. Return
NULL if an error occurs. BUF is freed. */
if (is_mve_pseudo (gdbarch, i))
return "p0";
+ /* RA_AUTH_CODE is used for unwinding only. Do not assign it a name. */
+ if (is_pacbti_pseudo (gdbarch, i))
+ return "";
+
if (i >= ARRAY_SIZE (arm_register_names))
/* These registers are only supported on targets which supply
an XML description. */
return gdbarch_bfd_arch_info (gdbarch)->arch_name;
}
+/* Implement the "get_pc_address_flags" gdbarch method. */
+
+static std::string
+arm_get_pc_address_flags (frame_info *frame, CORE_ADDR pc)
+{
+ if (get_frame_pc_masked (frame))
+ return "PAC";
+
+ return "";
+}
+
/* Initialize the current architecture based on INFO. If possible,
re-use an architecture from ARCHES, which is a list of
architectures already created during this debugging session.
const struct target_desc *tdesc = info.target_desc;
bool have_vfp = false;
bool have_mve = false;
+ bool have_pacbti = false;
int mve_vpr_regnum = -1;
int register_count = ARM_NUM_REGS;
|| attr_arch == TAG_CPU_ARCH_V8_1M_MAIN
|| attr_profile == 'M'))
is_m = true;
+
+ /* Look for attributes that indicate support for ARMv8.1-m
+ PACBTI. */
+ if (!tdesc_has_registers (tdesc) && is_m)
+ {
+ int attr_pac_extension
+ = bfd_elf_get_obj_attr_int (info.abfd, OBJ_ATTR_PROC,
+ Tag_PAC_extension);
+
+ int attr_bti_extension
+ = bfd_elf_get_obj_attr_int (info.abfd, OBJ_ATTR_PROC,
+ Tag_BTI_extension);
+
+ int attr_pacret_use
+ = bfd_elf_get_obj_attr_int (info.abfd, OBJ_ATTR_PROC,
+ Tag_PACRET_use);
+
+ int attr_bti_use
+ = bfd_elf_get_obj_attr_int (info.abfd, OBJ_ATTR_PROC,
+ Tag_BTI_use);
+
+ if (attr_pac_extension != 0 || attr_bti_extension != 0
+ || attr_pacret_use != 0 || attr_bti_use != 0)
+ have_pacbti = true;
+ }
#endif
}
if (have_vfp)
have_q_pseudos = true;
}
+
+ /* Do we have the ARMv8.1-m PACBTI feature? */
+ feature = tdesc_find_feature (tdesc,
+ "org.gnu.gdb.arm.m-profile-pacbti");
+ if (feature != nullptr)
+ {
+ /* By advertising this feature, the target acknowledges the
+ presence of the ARMv8.1-m PACBTI extensions.
+
+ We don't care for any particular registers in this group, so
+ the target is free to include whatever it deems appropriate.
+
+ The expectation is for this feature to include the PAC
+ keys. */
+ have_pacbti = true;
+ }
}
}
if (is_m != tdep->is_m)
continue;
+ /* Also check for ARMv8.1-m PACBTI support, since it might come from
+ the binary. */
+ if (have_pacbti != tdep->have_pacbti)
+ continue;
+
/* Found a match. */
break;
}
tdep->mve_vpr_regnum = mve_vpr_regnum;
}
+ /* Adjust the PACBTI feature settings. */
+ tdep->have_pacbti = have_pacbti;
+
arm_register_g_packet_guesses (gdbarch);
/* Breakpoints. */
set_gdbarch_long_double_format (gdbarch, floatformats_ieee_double);
}
+ /* Hook used to decorate frames with signed return addresses, only available
+ for ARMv8.1-m PACBTI. */
+ if (is_m && have_pacbti)
+ set_gdbarch_get_pc_address_flags (gdbarch, arm_get_pc_address_flags);
+
if (tdesc_data != nullptr)
{
set_tdesc_pseudo_register_name (gdbarch, arm_register_name);
num_pseudos += tdep->mve_pseudo_count;
}
+ /* Do we have any ARMv8.1-m PACBTI pseudo registers. */
+ if (have_pacbti)
+ {
+ tdep->pacbti_pseudo_base = register_count + num_pseudos;
+ tdep->pacbti_pseudo_count = 1;
+ num_pseudos += tdep->pacbti_pseudo_count;
+ }
+
/* Set some pseudo register hooks, if we have pseudo registers. */
- if (tdep->have_s_pseudos || have_mve)
+ if (tdep->have_s_pseudos || have_mve || have_pacbti)
{
set_gdbarch_num_pseudo_regs (gdbarch, num_pseudos);
set_gdbarch_pseudo_register_read (gdbarch, arm_pseudo_read);
tdep->mve_pseudo_count);
gdb_printf (file, _("arm_dump_tdep: Lowest pc = 0x%lx\n"),
(unsigned long) tdep->lowest_pc);
+ gdb_printf (file, _("arm_dump_tdep: have_pacbti = %s\n"),
+ tdep->have_pacbti? "yes" : "no");
+ gdb_printf (file, _("arm_dump_tdep: pacbti_pseudo_base = %i\n"),
+ tdep->pacbti_pseudo_base);
+ gdb_printf (file, _("arm_dump_tdep: pacbti_pseudo_count = %i\n"),
+ tdep->pacbti_pseudo_count);
+ gdb_printf (file, _("arm_dump_tdep: is_m = %s\n"),
+ tdep->is_m? "yes" : "no");
}
#if GDB_SELF_TEST
projects / binutils-gdb.git / commitdiff