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[PATCH 2/3] Fix arm process record for some instructions
- From: Yao Qi <qiyaoltc at gmail dot com>
- To: gdb-patches at sourceware dot org
- Date: Fri, 3 Mar 2017 22:06:35 +0000
- Subject: [PATCH 2/3] Fix arm process record for some instructions
- Authentication-results: sourceware.org; auth=none
- References: <1488578796-4481-1-git-send-email-yao.qi@linaro.org>
I look at some fails in gdb.reverse/solib-precsave.exp in -mthumb,
they are caused by some bugs on decoding these three instructions,
uxtb, ldr and mrc. This patch adds unit tests against these three
instructions, and fix these bugs by re-organizing the code to match
the table in ARM ARM.
gdb:
2017-03-03 Yao Qi <yao.qi@linaro.org>
* arm-tdep.c [GDB_SELF_TEST]: include "selftests.h".
(arm_record_test): Declare.
(_initialize_arm_tdep) [GDB_SELF_TEST]: call register_self_test.
(thumb_record_ld_st_reg_offset): Rewrite the opcode matching to
align with the manual.
(thumb_record_misc): Adjust the code order to align with the
manual.
(thumb2_record_decode_insn_handler): Fix instruction matching.
(instruction_reader_thumb): New class.
(arm_record_test): New function.
---
gdb/arm-tdep.c | 305 ++++++++++++++++++++++++++++++++++++++++++---------------
1 file changed, 228 insertions(+), 77 deletions(-)
diff --git a/gdb/arm-tdep.c b/gdb/arm-tdep.c
index b43368e..8135c84 100644
--- a/gdb/arm-tdep.c
+++ b/gdb/arm-tdep.c
@@ -69,6 +69,10 @@
#include "features/arm/arm-with-vfpv3.c"
#include "features/arm/arm-with-neon.c"
+#if GDB_SELF_TEST
+#include "selftest.h"
+#endif
+
static int arm_debug;
/* Macros for setting and testing a bit in a minimal symbol that marks
@@ -9584,6 +9588,11 @@ arm_dump_tdep (struct gdbarch *gdbarch, struct ui_file *file)
(unsigned long) tdep->lowest_pc);
}
+namespace selftests
+{
+static void arm_record_test (void);
+}
+
extern initialize_file_ftype _initialize_arm_tdep; /* -Wmissing-prototypes */
void
@@ -9720,6 +9729,11 @@ vfp - VFP co-processor."),
NULL,
NULL, /* FIXME: i18n: "ARM debugging is %s. */
&setdebuglist, &showdebuglist);
+
+#if GDB_SELF_TEST
+ register_self_test (selftests::arm_record_test);
+#endif
+
}
/* ARM-reversible process record data structures. */
@@ -11749,26 +11763,27 @@ thumb_record_ld_st_reg_offset (insn_decode_record *thumb_insn_r)
if (bit (thumb_insn_r->arm_insn, 12))
{
/* Handle load/store register offset. */
- opcode2 = bits (thumb_insn_r->arm_insn, 9, 10);
- if (opcode2 >= 12 && opcode2 <= 15)
+ uint32_t opB = bits (thumb_insn_r->arm_insn, 9, 11);
+
+ if (opB >= 4 && opB <= 7)
{
/* LDR(2), LDRB(2) , LDRH(2), LDRSB, LDRSH. */
reg_src1 = bits (thumb_insn_r->arm_insn,0, 2);
record_buf[0] = reg_src1;
thumb_insn_r->reg_rec_count = 1;
}
- else if (opcode2 >= 8 && opcode2 <= 10)
+ else if (opB >= 0 && opB <= 2)
{
/* STR(2), STRB(2), STRH(2) . */
reg_src1 = bits (thumb_insn_r->arm_insn, 3, 5);
reg_src2 = bits (thumb_insn_r->arm_insn, 6, 8);
regcache_raw_read_unsigned (reg_cache, reg_src1, &u_regval[0]);
regcache_raw_read_unsigned (reg_cache, reg_src2, &u_regval[1]);
- if (8 == opcode2)
+ if (0 == opB)
record_buf_mem[0] = 4; /* STR (2). */
- else if (10 == opcode2)
+ else if (2 == opB)
record_buf_mem[0] = 1; /* STRB (2). */
- else if (9 == opcode2)
+ else if (1 == opB)
record_buf_mem[0] = 2; /* STRH (2). */
record_buf_mem[1] = u_regval[0] + u_regval[1];
thumb_insn_r->mem_rec_count = 1;
@@ -11784,6 +11799,7 @@ thumb_record_ld_st_reg_offset (insn_decode_record *thumb_insn_r)
}
else if (opcode1)
{
+ /* Special data instructions and branch and exchange */
opcode2 = bits (thumb_insn_r->arm_insn, 8, 9);
opcode3 = bits (thumb_insn_r->arm_insn, 0, 2);
if ((3 == opcode2) && (!opcode3))
@@ -11924,7 +11940,7 @@ thumb_record_misc (insn_decode_record *thumb_insn_r)
{
struct regcache *reg_cache = thumb_insn_r->regcache;
- uint32_t opcode = 0, opcode1 = 0, opcode2 = 0;
+ uint32_t opcode = 0;
uint32_t register_bits = 0, register_count = 0;
uint32_t index = 0, start_address = 0;
uint32_t record_buf[24], record_buf_mem[48];
@@ -11933,81 +11949,111 @@ thumb_record_misc (insn_decode_record *thumb_insn_r)
ULONGEST u_regval = 0;
opcode = bits (thumb_insn_r->arm_insn, 11, 12);
- opcode1 = bits (thumb_insn_r->arm_insn, 8, 12);
- opcode2 = bits (thumb_insn_r->arm_insn, 9, 12);
- if (14 == opcode2)
- {
- /* POP. */
- register_bits = bits (thumb_insn_r->arm_insn, 0, 7);
- while (register_bits)
- {
- if (register_bits & 0x00000001)
- record_buf[index++] = register_count;
- register_bits = register_bits >> 1;
- register_count++;
- }
- record_buf[index++] = ARM_PS_REGNUM;
- record_buf[index++] = ARM_SP_REGNUM;
- thumb_insn_r->reg_rec_count = index;
- }
- else if (10 == opcode2)
- {
- /* PUSH. */
- register_bits = bits (thumb_insn_r->arm_insn, 0, 7);
- regcache_raw_read_unsigned (reg_cache, ARM_SP_REGNUM, &u_regval);
- while (register_bits)
- {
- if (register_bits & 0x00000001)
- register_count++;
- register_bits = register_bits >> 1;
- }
- start_address = u_regval - \
- (4 * (bit (thumb_insn_r->arm_insn, 8) + register_count));
- thumb_insn_r->mem_rec_count = register_count;
- while (register_count)
- {
- record_buf_mem[(register_count * 2) - 1] = start_address;
- record_buf_mem[(register_count * 2) - 2] = 4;
- start_address = start_address + 4;
- register_count--;
- }
- record_buf[0] = ARM_SP_REGNUM;
- thumb_insn_r->reg_rec_count = 1;
- }
- else if (0x1E == opcode1)
+ if (opcode == 0 || opcode == 1)
{
- /* BKPT insn. */
- /* Handle enhanced software breakpoint insn, BKPT. */
- /* CPSR is changed to be executed in ARM state, disabling normal
- interrupts, entering abort mode. */
- /* According to high vector configuration PC is set. */
- /* User hits breakpoint and type reverse, in that case, we need to go back with
- previous CPSR and Program Counter. */
- record_buf[0] = ARM_PS_REGNUM;
- record_buf[1] = ARM_LR_REGNUM;
- thumb_insn_r->reg_rec_count = 2;
- /* We need to save SPSR value, which is not yet done. */
- printf_unfiltered (_("Process record does not support instruction "
- "0x%0x at address %s.\n"),
- thumb_insn_r->arm_insn,
- paddress (thumb_insn_r->gdbarch,
- thumb_insn_r->this_addr));
- return -1;
- }
- else if ((0 == opcode) || (1 == opcode))
- {
- /* ADD(5), ADD(6). */
+ /* ADR and ADD (SP plus immediate) */
+
reg_src1 = bits (thumb_insn_r->arm_insn, 8, 10);
record_buf[0] = reg_src1;
thumb_insn_r->reg_rec_count = 1;
}
- else if (2 == opcode)
+ else
{
- /* ADD(7), SUB(4). */
- reg_src1 = bits (thumb_insn_r->arm_insn, 8, 10);
- record_buf[0] = ARM_SP_REGNUM;
- thumb_insn_r->reg_rec_count = 1;
+ /* Miscellaneous 16-bit instructions */
+ uint32_t opcode2 = bits (thumb_insn_r->arm_insn, 8, 11);
+
+ switch (opcode2)
+ {
+ case 6:
+ /* SETEND and CPS */
+ break;
+ case 0:
+ /* ADD/SUB (SP plus immediate) */
+ reg_src1 = bits (thumb_insn_r->arm_insn, 8, 10);
+ record_buf[0] = ARM_SP_REGNUM;
+ thumb_insn_r->reg_rec_count = 1;
+ break;
+ case 1: /* fall through */
+ case 3: /* fall through */
+ case 9: /* fall through */
+ case 11:
+ /* CBNZ, CBZ */
+ return -1;
+ break;
+ case 2:
+ /* SXTH, SXTB, UXTH, UXTB */
+ record_buf[0] = bits (thumb_insn_r->arm_insn, 0, 2);
+ thumb_insn_r->reg_rec_count = 1;
+ break;
+ case 4: /* fall through */
+ case 5:
+ /* PUSH. */
+ register_bits = bits (thumb_insn_r->arm_insn, 0, 7);
+ regcache_raw_read_unsigned (reg_cache, ARM_SP_REGNUM, &u_regval);
+ while (register_bits)
+ {
+ if (register_bits & 0x00000001)
+ register_count++;
+ register_bits = register_bits >> 1;
+ }
+ start_address = u_regval - \
+ (4 * (bit (thumb_insn_r->arm_insn, 8) + register_count));
+ thumb_insn_r->mem_rec_count = register_count;
+ while (register_count)
+ {
+ record_buf_mem[(register_count * 2) - 1] = start_address;
+ record_buf_mem[(register_count * 2) - 2] = 4;
+ start_address = start_address + 4;
+ register_count--;
+ }
+ record_buf[0] = ARM_SP_REGNUM;
+ thumb_insn_r->reg_rec_count = 1;
+ break;
+ case 10:
+ /* REV, REV16, REVSH */
+ return -1;
+ break;
+ case 12: /* fall through */
+ case 13:
+ /* POP. */
+ register_bits = bits (thumb_insn_r->arm_insn, 0, 7);
+ while (register_bits)
+ {
+ if (register_bits & 0x00000001)
+ record_buf[index++] = register_count;
+ register_bits = register_bits >> 1;
+ register_count++;
+ }
+ record_buf[index++] = ARM_PS_REGNUM;
+ record_buf[index++] = ARM_SP_REGNUM;
+ thumb_insn_r->reg_rec_count = index;
+ break;
+ case 0xe:
+ /* BKPT insn. */
+ /* Handle enhanced software breakpoint insn, BKPT. */
+ /* CPSR is changed to be executed in ARM state, disabling normal
+ interrupts, entering abort mode. */
+ /* According to high vector configuration PC is set. */
+ /* User hits breakpoint and type reverse, in that case, we need to go back with
+ previous CPSR and Program Counter. */
+ record_buf[0] = ARM_PS_REGNUM;
+ record_buf[1] = ARM_LR_REGNUM;
+ thumb_insn_r->reg_rec_count = 2;
+ /* We need to save SPSR value, which is not yet done. */
+ printf_unfiltered (_("Process record does not support instruction "
+ "0x%0x at address %s.\n"),
+ thumb_insn_r->arm_insn,
+ paddress (thumb_insn_r->gdbarch,
+ thumb_insn_r->this_addr));
+ return -1;
+
+ case 0xf:
+ /* If-Then, and hints */
+ break;
+ default:
+ return -1;
+ };
}
REG_ALLOC (thumb_insn_r->arm_regs, thumb_insn_r->reg_rec_count, record_buf);
@@ -12819,12 +12865,12 @@ thumb2_record_decode_insn_handler (insn_decode_record *thumb2_insn_r)
/* Load/store multiple instruction. */
return thumb2_record_ld_st_multiple (thumb2_insn_r);
}
- else if (!((op2 & 0x64) ^ 0x04))
+ else if ((op2 & 0x64) == 0x4)
{
/* Load/store (dual/exclusive) and table branch instruction. */
return thumb2_record_ld_st_dual_ex_tbb (thumb2_insn_r);
}
- else if (!((op2 & 0x20) ^ 0x20))
+ else if ((op2 & 0x60) == 0x20)
{
/* Data-processing (shifted register). */
return thumb2_record_data_proc_sreg_mimm (thumb2_insn_r);
@@ -13058,6 +13104,111 @@ decode_insn (abstract_memory_reader &reader, insn_decode_record *arm_record,
return ret;
}
+#if GDB_SELF_TEST
+namespace selftests {
+
+/* Provide both 16-bit and 32-bit thumb instructions. */
+
+class instruction_reader_thumb : public abstract_memory_reader
+{
+public:
+ template<size_t SIZE>
+ instruction_reader_thumb (enum bfd_endian endian,
+ const uint16_t (&insns)[SIZE])
+ : m_endian (endian), m_insns (insns), m_insns_size (SIZE)
+ {}
+
+ bool read (CORE_ADDR memaddr, gdb_byte *buf, const size_t len)
+ {
+ SELF_CHECK (len == 4 || len == 2);
+ SELF_CHECK (memaddr % 2 == 0);
+ SELF_CHECK ((memaddr / 2) < m_insns_size);
+
+ store_unsigned_integer (buf, 2, m_endian, m_insns[memaddr / 2]);
+ if (len == 4)
+ {
+ store_unsigned_integer (&buf[2], 2, m_endian,
+ m_insns[memaddr / 2 + 1]);
+ }
+ return true;
+ }
+
+private:
+ enum bfd_endian m_endian;
+ const uint16_t *m_insns;
+ size_t m_insns_size;
+};
+
+static void
+arm_record_test (void)
+{
+ struct gdbarch_info info;
+ gdbarch_info_init (&info);
+ info.bfd_arch_info = bfd_scan_arch ("arm");
+
+ struct gdbarch *gdbarch = gdbarch_find_by_info (info);
+
+ SELF_CHECK (gdbarch != NULL);
+
+ /* 16-bit Thumb instructions. */
+ {
+ insn_decode_record arm_record;
+
+ memset (&arm_record, 0, sizeof (insn_decode_record));
+ arm_record.gdbarch = gdbarch;
+
+ static const uint16_t insns[] = {
+ /* db b2 uxtb r3, r3 */
+ 0xb2db,
+ /* cd 58 ldr r5, [r1, r3] */
+ 0x58cd,
+ };
+
+ enum bfd_endian endian = gdbarch_byte_order_for_code (arm_record.gdbarch);
+ instruction_reader_thumb reader (endian, insns);
+ int ret = decode_insn (reader, &arm_record, THUMB_RECORD,
+ THUMB_INSN_SIZE_BYTES);
+
+ SELF_CHECK (ret == 0);
+ SELF_CHECK (arm_record.mem_rec_count == 0);
+ SELF_CHECK (arm_record.reg_rec_count == 1);
+ SELF_CHECK (arm_record.arm_regs[0] == 3);
+
+ arm_record.this_addr += 2;
+ ret = decode_insn (reader, &arm_record, THUMB_RECORD,
+ THUMB_INSN_SIZE_BYTES);
+
+ SELF_CHECK (ret == 0);
+ SELF_CHECK (arm_record.mem_rec_count == 0);
+ SELF_CHECK (arm_record.reg_rec_count == 1);
+ SELF_CHECK (arm_record.arm_regs[0] == 5);
+ }
+
+ /* 32-bit Thumb-2 instructions. */
+ {
+ insn_decode_record arm_record;
+
+ memset (&arm_record, 0, sizeof (insn_decode_record));
+ arm_record.gdbarch = gdbarch;
+
+ static const uint16_t insns[] = {
+ /* 1d ee 70 7f mrc 15, 0, r7, cr13, cr0, {3} */
+ 0xee1d, 0x7f70,
+ };
+
+ enum bfd_endian endian = gdbarch_byte_order_for_code (arm_record.gdbarch);
+ instruction_reader_thumb reader (endian, insns);
+ int ret = decode_insn (reader, &arm_record, THUMB2_RECORD,
+ THUMB2_INSN_SIZE_BYTES);
+
+ SELF_CHECK (ret == 0);
+ SELF_CHECK (arm_record.mem_rec_count == 0);
+ SELF_CHECK (arm_record.reg_rec_count == 1);
+ SELF_CHECK (arm_record.arm_regs[0] == 7);
+ }
+}
+} // namespace selftests
+#endif /* GDB_SELF_TEST */
/* Cleans up local record registers and memory allocations. */
--
1.9.1