From 6ec5f4be052e594dc90b6677fec1c1e7727d9651 Mon Sep 17 00:00:00 2001 From: Pierre Langlois Date: Mon, 21 Sep 2015 15:01:04 +0100 Subject: [PATCH] Make aarch64_decode_adrp handle both ADR and ADRP instructions We will need to decode both ADR and ADRP instructions in GDBserver. This patch makes common code handle both cases, even if GDB only needs to decode the ADRP instruction. gdb/ChangeLog: * aarch64-tdep.c (aarch64_analyze_prologue): New is_adrp variable. Call aarch64_decode_adr instead of aarch64_decode_adrp. * arch/aarch64-insn.h (aarch64_decode_adrp): Delete. (aarch64_decode_adr): New function declaration. * arch/aarch64-insn.c (aarch64_decode_adrp): Delete. (aarch64_decode_adr): New function, factored out from aarch64_decode_adrp to decode both adr and adrp instructions. --- gdb/ChangeLog | 11 +++++++++++ gdb/aarch64-tdep.c | 4 +++- gdb/arch/aarch64-insn.c | 29 ++++++++++++++++++++++++----- gdb/arch/aarch64-insn.h | 3 ++- 4 files changed, 40 insertions(+), 7 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 7d8feeb0ce5..935daf17c68 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,14 @@ +2015-09-21 Pierre Langlois + + * aarch64-tdep.c (aarch64_analyze_prologue): New is_adrp + variable. Call aarch64_decode_adr instead of + aarch64_decode_adrp. + * arch/aarch64-insn.h (aarch64_decode_adrp): Delete. + (aarch64_decode_adr): New function declaration. + * arch/aarch64-insn.c (aarch64_decode_adrp): Delete. + (aarch64_decode_adr): New function, factored out from + aarch64_decode_adrp to decode both adr and adrp instructions. + 2015-09-21 Pierre Langlois * Makefile.in (ALL_64_TARGET_OBS): Add aarch64-insn.o. diff --git a/gdb/aarch64-tdep.c b/gdb/aarch64-tdep.c index 92e24047bb4..da61e546db9 100644 --- a/gdb/aarch64-tdep.c +++ b/gdb/aarch64-tdep.c @@ -551,13 +551,15 @@ aarch64_analyze_prologue (struct gdbarch *gdbarch, int is_cbnz; int is_tbnz; unsigned bit; + int is_adrp; int32_t offset; insn = read_memory_unsigned_integer (start, 4, byte_order_for_code); if (aarch64_decode_add_sub_imm (start, insn, &rd, &rn, &imm)) regs[rd] = pv_add_constant (regs[rn], imm); - else if (aarch64_decode_adrp (start, insn, &rd)) + else if (aarch64_decode_adr (start, insn, &is_adrp, &rd, &offset) + && is_adrp) regs[rd] = pv_unknown (); else if (aarch64_decode_b (start, insn, &is_link, &offset)) { diff --git a/gdb/arch/aarch64-insn.c b/gdb/arch/aarch64-insn.c index 3a289a26da8..13d0013d6e9 100644 --- a/gdb/arch/aarch64-insn.c +++ b/gdb/arch/aarch64-insn.c @@ -55,25 +55,44 @@ decode_masked_match (uint32_t insn, uint32_t mask, uint32_t pattern) return (insn & mask) == pattern; } -/* Decode an opcode if it represents an ADRP instruction. +/* Decode an opcode if it represents an ADR or ADRP instruction. ADDR specifies the address of the opcode. INSN specifies the opcode to test. + IS_ADRP receives the 'op' field from the decoded instruction. RD receives the 'rd' field from the decoded instruction. + OFFSET receives the 'immhi:immlo' field from the decoded instruction. Return 1 if the opcodes matches and is decoded, otherwise 0. */ int -aarch64_decode_adrp (CORE_ADDR addr, uint32_t insn, unsigned *rd) +aarch64_decode_adr (CORE_ADDR addr, uint32_t insn, int *is_adrp, + unsigned *rd, int32_t *offset) { - if (decode_masked_match (insn, 0x9f000000, 0x90000000)) + /* adr 0ii1 0000 iiii iiii iiii iiii iiir rrrr */ + /* adrp 1ii1 0000 iiii iiii iiii iiii iiir rrrr */ + if (decode_masked_match (insn, 0x1f000000, 0x10000000)) { + uint32_t immlo = (insn >> 29) & 0x3; + int32_t immhi = extract_signed_bitfield (insn, 19, 5) << 2; + + *is_adrp = (insn >> 31) & 0x1; *rd = (insn >> 0) & 0x1f; + if (*is_adrp) + { + /* The ADRP instruction has an offset with a -/+ 4GB range, + encoded as (immhi:immlo * 4096). */ + *offset = (immhi | immlo) * 4096; + } + else + *offset = (immhi | immlo); + if (aarch64_debug) { - debug_printf ("decode: 0x%s 0x%x adrp x%u, #?\n", - core_addr_to_string_nz (addr), insn, *rd); + debug_printf ("decode: 0x%s 0x%x %s x%u, #?\n", + core_addr_to_string_nz (addr), insn, + *is_adrp ? "adrp" : "adr", *rd); } return 1; } diff --git a/gdb/arch/aarch64-insn.h b/gdb/arch/aarch64-insn.h index 7775a34e829..2facb44aea8 100644 --- a/gdb/arch/aarch64-insn.h +++ b/gdb/arch/aarch64-insn.h @@ -21,7 +21,8 @@ extern int aarch64_debug; -int aarch64_decode_adrp (CORE_ADDR addr, uint32_t insn, unsigned *rd); +int aarch64_decode_adr (CORE_ADDR addr, uint32_t insn, int *is_adrp, + unsigned *rd, int32_t *offset); int aarch64_decode_b (CORE_ADDR addr, uint32_t insn, int *is_bl, int32_t *offset); -- 2.30.2