binutils-gdb/binutils/testsuite/binutils-all/aarch64/in-order.d

#PROG: objcopy
#source: out-of-order.s
#ld: -e v1 -Ttext-segment=0x400000
#objdump: -d
#name: Check if disassembler can handle sections in default order

.*: +file format .*aarch64.*

Disassembly of section \.func1:

0000000000400000 <v1>:
  400000:	8b010000 	add	x0, x0, x1
  400004:	00000000 	\.word	0x00000000

Disassembly of section .func2:

0000000000400008 <\.func2>:
  400008:	8b010000 	add	x0, x0, x1

Disassembly of section \.func3:

000000000040000c <\.func3>:
  40000c:	8b010000 	add	x0, x0, x1
  400010:	8b010000 	add	x0, x0, x1
  400014:	8b010000 	add	x0, x0, x1
  400018:	8b010000 	add	x0, x0, x1
  40001c:	8b010000 	add	x0, x0, x1
  400020:	00000000 	\.word	0x00000000
AArch64: Fix AArch64 disassembler mapping symbol search My previous patch for AArch64 was not enough to catch all the cases where disassembling an out-of-order section could go wrong. It had missed the case DATA sections could be incorrectly disassembled as TEXT. Out of order here refers to an object file where sections are not listed in a monotonic increasing VMA order. The ELF ABI for AArch64 [1] specifies the following for mapping symbols: 1) A text section must always have a corresponding mapping symbol at it's start. 2) Data sections do not require any mapping symbols. 3) The range of a mapping symbol extends from the address it starts on up to the next mapping symbol (exclusive) or section end (inclusive). However there is no defined order between a symbol and it's corresponding mapping symbol in the symbol table. This means that while in general we look up for a corresponding mapping symbol, we have to make at least one check of the symbol below the address being disassembled. When disassembling different PCs within the same section, the search for mapping symbol can be cached somewhat. We know that the mapping symbol corresponding to the current PC is either the previous one used, or one at the same address as the current PC. However this optimization and mapping symbol search must stop as soon as we reach the end or start of the section. Furthermore if we're only disassembling a part of a section, the search is a allowed to search further than the current chunk, but is not allowed to search past it (The mapping symbol if there, must be at the same address, so in practice we usually stop at PC+4). lastly, since only data sections don't require a mapping symbol the default mapping type should be DATA and not INSN as previously defined, however if the binary has had all its symbols stripped than this isn't very useful. To fix this we determine the default based on the section flags. This will allow the disassembler to be more useful on stripped binaries. If there is no section than we assume you to be disassembling INSN. [1] https://developer.arm.com/docs/ihi0056/latest/elf-for-the-arm-64-bit-architecture-aarch64-abi-2018q4#aaelf64-section4-5-4 binutils/ChangeLog: * testsuite/binutils-all/aarch64/in-order.d: New test. * testsuite/binutils-all/aarch64/out-of-order.d: Disassemble data as well. opcodes/ChangeLog: * aarch64-dis.c (print_insn_aarch64): Update the mapping symbol search order. 2019-03-25 20:12:03 +08:00			`#PROG: objcopy`
			`#source: out-of-order.s`
			`#ld: -e v1 -Ttext-segment=0x400000`
			`#objdump: -d`
			`#name: Check if disassembler can handle sections in default order`

			`.: +file format .aarch64.*`

			`Disassembly of section \.func1:`

			`0000000000400000 <v1>:`
			`400000: 8b010000 add x0, x0, x1`
			`400004: 00000000 \.word 0x00000000`

			`Disassembly of section .func2:`

			`0000000000400008 <\.func2>:`
			`400008: 8b010000 add x0, x0, x1`

			`Disassembly of section \.func3:`

			`000000000040000c <\.func3>:`
			`40000c: 8b010000 add x0, x0, x1`
			`400010: 8b010000 add x0, x0, x1`
			`400014: 8b010000 add x0, x0, x1`
			`400018: 8b010000 add x0, x0, x1`
			`40001c: 8b010000 add x0, x0, x1`
			`400020: 00000000 \.word 0x00000000`