Commit be9fa663 authored by Will Deacon's avatar Will Deacon Committed by Linus Torvalds
Browse files

scripts/decodecode: fix decoding for AArch64 (arm64) instructions

There are a couple of problems with the decodecode script and arm64:

1. AArch64 objdump refuses to disassemble .4byte directives as instructions,
   insisting that they are data values and displaying them as:

	a94153f3	.word	0xa94153f3		<-- trapping instruction

   This is resolved by using the .inst directive instead.

2. Disassembly of branch instructions attempts to provide the target as
   an offset from a symbol, e.g.:

   0:	34000082	cbz	w2, 10 <.text+0x10>

  however this falls foul of the grep -v, which matches lines containing
  ".text" and ends up removing all branch instructions from the dump.

This patch resolves both issues by using the .inst directive for 4-byte
quantities on arm64 and stripping the resulting binaries (as is done on
arm already) to remove the mapping symbols.

Link: http://lkml.kernel.org/r/1506596147-23630-1-git-send-email-will.deacon@arm.com

Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
Reviewed-by: default avatarDave Martin <Dave.Martin@arm.com>
Cc: Michal Marek <mmarek@suse.cz>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 6bec6ad7
......@@ -59,6 +59,14 @@ disas() {
${CROSS_COMPILE}strip $1.o
fi
if [ "$ARCH" = "arm64" ]; then
if [ $width -eq 4 ]; then
type=inst
fi
${CROSS_COMPILE}strip $1.o
fi
${CROSS_COMPILE}objdump $OBJDUMPFLAGS -S $1.o | \
grep -v "/tmp\|Disassembly\|\.text\|^$" > $1.dis 2>&1
}
......
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