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| author | Tamar Christina <tamar.christina@arm.com> | 2019-03-25 12:08:53 +0000 |
|---|---|---|
| committer | Tamar Christina <tamar.christina@arm.com> | 2019-03-25 15:05:53 +0000 |
| commit | 53b2f36bf6aa939feab6f82f05d7dad52f82660d (patch) | |
| tree | 3ea5018d4dee6a17be4eae4bacbcb70f0bbbbb51 /opcodes/aarch64-dis.c | |
| parent | 9a93502fa81734d39f213ccb33b497bc40e1423d (diff) | |
| download | gdb-53b2f36bf6aa939feab6f82f05d7dad52f82660d.zip gdb-53b2f36bf6aa939feab6f82f05d7dad52f82660d.tar.gz gdb-53b2f36bf6aa939feab6f82f05d7dad52f82660d.tar.bz2 | |
AArch64: Fix disassembler bug with out-of-order sections
The AArch64 disassembler has an optimization that it uses to reduce the amount
it has to search for mapping symbols during disassembly. This optimization
assumes that sections are listed in the section header in monotonic increasing
VMAs. However this is not a requirement for the ELF specification.
Because of this when such "out of order" sections occur the disassembler would
pick the wrong mapping symbol to disassemble the section with.
This fixes it by explicitly passing along the stop offset for the current
disassembly glob and when this changes compared to the previous one we've seen
the optimization won't be performed. In effect this restarts the search from
a well defined starting point. Usually the symbol's address.
The existing stop_vma can't be used for this as it is allowed to be unset and
setting this unconditionally would change the semantics of this field.
binutils/ChangeLog:
* objdump.c (disassemble_bytes): Pass stop_offset.
* testsuite/binutils-all/aarch64/out-of-order.T: New test.
* testsuite/binutils-all/aarch64/out-of-order.d: New test.
* testsuite/binutils-all/aarch64/out-of-order.s: New test.
include/ChangeLog:
* dis-asm.h (struct disassemble_info): Add stop_offset.
opcodes/ChangeLog:
* aarch64-dis.c (last_stop_offset): New.
(print_insn_aarch64): Use stop_offset.
Diffstat (limited to 'opcodes/aarch64-dis.c')
| -rw-r--r-- | opcodes/aarch64-dis.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/opcodes/aarch64-dis.c b/opcodes/aarch64-dis.c index 4c31f57..fc7e95d 100644 --- a/opcodes/aarch64-dis.c +++ b/opcodes/aarch64-dis.c @@ -37,6 +37,7 @@ enum map_type static enum map_type last_type; static int last_mapping_sym = -1; +static bfd_vma last_stop_offset = 0; static bfd_vma last_mapping_addr = 0; /* Other options */ @@ -3333,7 +3334,10 @@ print_insn_aarch64 (bfd_vma pc, /* Start scanning at the start of the function, or wherever we finished last time. */ n = info->symtab_pos + 1; - if (n < last_mapping_sym) + /* If the last stop offset is different from the current one it means we + are disassembling a different glob of bytes. As such the optimization + would not be safe and we should start over. */ + if (n < last_mapping_sym && info->stop_offset == last_stop_offset) n = last_mapping_sym; /* Scan up to the location being disassembled. */ @@ -3370,6 +3374,7 @@ print_insn_aarch64 (bfd_vma pc, last_mapping_sym = last_sym; last_type = type; + last_stop_offset = info->stop_offset; /* Look a little bit ahead to see if we should print out less than four bytes of data. If there's a symbol, |