struct trad_frame_saved_reg *saved_regs;
};
-static CORE_ADDR arm_analyze_prologue (struct gdbarch *gdbarch,
- CORE_ADDR prologue_start,
- CORE_ADDR prologue_end,
- struct arm_prologue_cache *cache);
+namespace {
+
+/* Abstract class to read ARM instructions from memory. */
+
+class arm_instruction_reader
+{
+public:
+ /* Read a 4 bytes instruction bytes from memory using the BYTE_ORDER
+ endianness. */
+ virtual uint32_t read (CORE_ADDR memaddr, bfd_endian byte_order) const = 0;
+};
+
+/* Read instructions from target memory. */
+
+class target_arm_instruction_reader : public arm_instruction_reader
+{
+public:
+ uint32_t read (CORE_ADDR memaddr, bfd_endian byte_order) const override
+ {
+ return read_code_unsigned_integer (memaddr, 4, byte_order);
+ }
+};
+
+} /* namespace */
+
+static CORE_ADDR arm_analyze_prologue
+ (struct gdbarch *gdbarch, CORE_ADDR prologue_start, CORE_ADDR prologue_end,
+ struct arm_prologue_cache *cache, const arm_instruction_reader &insn_reader);
/* Architecture version for displaced stepping. This effects the behaviour of
certain instructions, and really should not be hard-wired. */
analyzed_limit = thumb_analyze_prologue (gdbarch, func_addr,
post_prologue_pc, NULL);
else
- analyzed_limit = arm_analyze_prologue (gdbarch, func_addr,
- post_prologue_pc, NULL);
+ analyzed_limit
+ = arm_analyze_prologue (gdbarch, func_addr, post_prologue_pc,
+ NULL, target_arm_instruction_reader ());
if (analyzed_limit != post_prologue_pc)
return func_addr;
if (arm_pc_is_thumb (gdbarch, pc))
return thumb_analyze_prologue (gdbarch, pc, limit_pc, NULL);
else
- return arm_analyze_prologue (gdbarch, pc, limit_pc, NULL);
+ return arm_analyze_prologue (gdbarch, pc, limit_pc, NULL,
+ target_arm_instruction_reader ());
}
/* *INDENT-OFF* */
return 0;
}
+/* Implement immediate value decoding, as described in section A5.2.4
+ (Modified immediate constants in ARM instructions) of the ARM Architecture
+ Reference Manual (ARMv7-A and ARMv7-R edition). */
+
+static uint32_t
+arm_expand_immediate (uint32_t imm)
+{
+ /* Immediate values are 12 bits long. */
+ gdb_assert ((imm & 0xfffff000) == 0);
+
+ uint32_t unrotated_value = imm & 0xff;
+ uint32_t rotate_amount = (imm & 0xf00) >> 7;
+
+ if (rotate_amount == 0)
+ return unrotated_value;
+
+ return ((unrotated_value >> rotate_amount)
+ | (unrotated_value << (32 - rotate_amount)));
+}
+
/* Analyze an ARM mode prologue starting at PROLOGUE_START and
continuing no further than PROLOGUE_END. If CACHE is non-NULL,
fill it in. Return the first address not recognized as a prologue
static CORE_ADDR
arm_analyze_prologue (struct gdbarch *gdbarch,
CORE_ADDR prologue_start, CORE_ADDR prologue_end,
- struct arm_prologue_cache *cache)
+ struct arm_prologue_cache *cache,
+ const arm_instruction_reader &insn_reader)
{
enum bfd_endian byte_order_for_code = gdbarch_byte_order_for_code (gdbarch);
int regno;
current_pc < prologue_end;
current_pc += 4)
{
- unsigned int insn
- = read_code_unsigned_integer (current_pc, 4, byte_order_for_code);
+ uint32_t insn = insn_reader.read (current_pc, byte_order_for_code);
if (insn == 0xe1a0c00d) /* mov ip, sp */
{
else if ((insn & 0xfff00000) == 0xe2800000 /* add Rd, Rn, #n */
&& pv_is_register (regs[bits (insn, 16, 19)], ARM_SP_REGNUM))
{
- unsigned imm = insn & 0xff; /* immediate value */
- unsigned rot = (insn & 0xf00) >> 7; /* rotate amount */
+ uint32_t imm = arm_expand_immediate (insn & 0xfff);
int rd = bits (insn, 12, 15);
- imm = (imm >> rot) | (imm << (32 - rot));
regs[rd] = pv_add_constant (regs[bits (insn, 16, 19)], imm);
continue;
}
else if ((insn & 0xfff00000) == 0xe2400000 /* sub Rd, Rn, #n */
&& pv_is_register (regs[bits (insn, 16, 19)], ARM_SP_REGNUM))
{
- unsigned imm = insn & 0xff; /* immediate value */
- unsigned rot = (insn & 0xf00) >> 7; /* rotate amount */
+ uint32_t imm = arm_expand_immediate (insn & 0xfff);
int rd = bits (insn, 12, 15);
- imm = (imm >> rot) | (imm << (32 - rot));
regs[rd] = pv_add_constant (regs[bits (insn, 16, 19)], -imm);
continue;
}
}
else if ((insn & 0xfffff000) == 0xe24cb000) /* sub fp, ip #n */
{
- unsigned imm = insn & 0xff; /* immediate value */
- unsigned rot = (insn & 0xf00) >> 7; /* rotate amount */
- imm = (imm >> rot) | (imm << (32 - rot));
+ uint32_t imm = arm_expand_immediate (insn & 0xfff);
regs[ARM_FP_REGNUM] = pv_add_constant (regs[ARM_IP_REGNUM], -imm);
}
else if ((insn & 0xfffff000) == 0xe24dd000) /* sub sp, sp #n */
{
- unsigned imm = insn & 0xff; /* immediate value */
- unsigned rot = (insn & 0xf00) >> 7; /* rotate amount */
- imm = (imm >> rot) | (imm << (32 - rot));
+ uint32_t imm = arm_expand_immediate(insn & 0xfff);
regs[ARM_SP_REGNUM] = pv_add_constant (regs[ARM_SP_REGNUM], -imm);
}
else if ((insn & 0xffff7fff) == 0xed6d0103 /* stfe f?,
if (prev_pc < prologue_end)
prologue_end = prev_pc;
- arm_analyze_prologue (gdbarch, prologue_start, prologue_end, cache);
+ arm_analyze_prologue (gdbarch, prologue_start, prologue_end, cache,
+ target_arm_instruction_reader ());
}
static struct arm_prologue_cache *
namespace selftests
{
static void arm_record_test (void);
+static void arm_analyze_prologue_test ();
}
#endif
#if GDB_SELF_TEST
selftests::register_test ("arm-record", selftests::arm_record_test);
+ selftests::register_test ("arm_analyze_prologue", selftests::arm_analyze_prologue_test);
#endif
}
SELF_CHECK (arm_record.arm_regs[0] == 7);
}
}
+
+/* Instruction reader from manually cooked instruction sequences. */
+
+class test_arm_instruction_reader : public arm_instruction_reader
+{
+public:
+ explicit test_arm_instruction_reader (gdb::array_view<const uint32_t> insns)
+ : m_insns (insns)
+ {}
+
+ uint32_t read (CORE_ADDR memaddr, enum bfd_endian byte_order) const override
+ {
+ SELF_CHECK (memaddr % 4 == 0);
+ SELF_CHECK (memaddr / 4 < m_insns.size ());
+
+ return m_insns[memaddr / 4];
+ }
+
+private:
+ const gdb::array_view<const uint32_t> m_insns;
+};
+
+static void
+arm_analyze_prologue_test ()
+{
+ for (bfd_endian endianness : {BFD_ENDIAN_LITTLE, BFD_ENDIAN_BIG})
+ {
+ struct gdbarch_info info;
+ gdbarch_info_init (&info);
+ info.byte_order = endianness;
+ info.byte_order_for_code = endianness;
+ info.bfd_arch_info = bfd_scan_arch ("arm");
+
+ struct gdbarch *gdbarch = gdbarch_find_by_info (info);
+
+ SELF_CHECK (gdbarch != NULL);
+
+ /* The "sub" instruction contains an immediate value rotate count of 0,
+ which resulted in a 32-bit shift of a 32-bit value, caught by
+ UBSan. */
+ const uint32_t insns[] = {
+ 0xe92d4ff0, /* push {r4, r5, r6, r7, r8, r9, sl, fp, lr} */
+ 0xe1a05000, /* mov r5, r0 */
+ 0xe5903020, /* ldr r3, [r0, #32] */
+ 0xe24dd044, /* sub sp, sp, #68 ; 0x44 */
+ };
+
+ test_arm_instruction_reader mem_reader (insns);
+ arm_prologue_cache cache;
+ cache.saved_regs = trad_frame_alloc_saved_regs (gdbarch);
+
+ arm_analyze_prologue (gdbarch, 0, sizeof (insns) - 1, &cache, mem_reader);
+ }
+}
+
} // namespace selftests
#endif /* GDB_SELF_TEST */
projects / binutils-gdb.git / commitdiff