[PATCH] Patch 2 of 2 for aarch64 ILP32 support in gdb

Tue Jan 31 23:16:00 GMT 2017

On Sun, 2017-01-29 at 22:40 +0000, Yao Qi wrote:

> This changes the word size and address size, which is used to determine
> the inferior is arm or aarch64 by checking "bits_per_word == 32" in
> multi-arch debugging.Â Â You can find some instances of such check in
> aarch64-linux-nat.c.Â Â If the bits_per_word is 32 in ILP32, GDB thinks
> the inferior is an ARM one, rather than an AArch64 ILP32 one. which is
> wrong.Â Â We need to tweak the condition above to correctly identify the
> ARM inferior.
>Â 
> Do you compare the ILP32 gdb test result with normal aarch64 one?

OK, I fixed upÂ arch64-linux-nat.c and didn't find any other places were
the bits_per_word was being checked and I fixed the TRUE/true
FALSE/false constants. Â If I run gdb without any changes or with this
patch but debugging 64 bit code I get around 500 failures. Â The number
doesn't seem to be constant, I have gotten anywhere from 488 to 503
failures testing the same code. Â My last run had:

# of expected passesÂ Â Â Â Â Â Â Â Â Â Â Â 30428
# of unexpected failuresÂ Â Â Â Â Â Â Â 503
# of expected failuresÂ Â Â Â Â Â Â Â Â Â 53
# of unknown successesÂ Â Â Â Â Â Â Â Â Â 2
# of known failuresÂ Â Â Â Â Â Â Â Â Â Â Â Â 64
# of untested testcasesÂ Â Â Â Â Â Â Â Â 66
# of unresolved testcasesÂ Â Â Â Â Â Â 6
# of unsupported testsÂ Â Â Â Â Â Â Â Â Â 293

Many of the failures seem to be thread related and I see a lot of
messages about timeouts and 'program is no longer running'. Â When
I run gdb on 32 bit programs with:

	RUNTESTFLAGS="--target_board=unix/-mabi=ilp32"

I get 700+ failures. Â My last run had:

# of expected passesÂ Â Â Â Â Â Â Â Â Â Â Â 29482
# of unexpected failuresÂ Â Â Â Â Â Â Â 740
# of expected failuresÂ Â Â Â Â Â Â Â Â Â 30
# of unknown successesÂ Â Â Â Â Â Â Â Â Â 2
# of known failuresÂ Â Â Â Â Â Â Â Â Â Â Â Â 65
# of untested testcasesÂ Â Â Â Â Â Â Â Â 79
# of unresolved testcasesÂ Â Â Â Â Â Â 4
# of unsupported testsÂ Â Â Â Â Â Â Â Â Â 288

So there are more failures in ILP32 mode but there seem to be enough
passes that I think it still makes sense to check in the patch to get
some gdb functionality working.

Here is the latest patch.

Steve Ellcey
sellcey@cavium.com

gdb ChangeLog:

2017-01-31Â Â Andrew PinskiÂ Â <apinski@cavium.com>
	Â Â Â Â Steve EllceyÂ Â <sellcey@cavium.com>
	Â Â Â Â Yao QiÂ Â <yao.qi@linaro.org>

	* aarch64-linux-nat.c (IS_ARM32): New macro.
	(fetch_gregs_from_thread): Use IS_ARM32 macro.
	(store_gregs_to_thread): Ditto.
	(fetch_fpregs_from_thread): Ditto.
	(store_fpregs_to_thread): Ditto.
	(ps_get_thread_area): Ditto.
	(aarch64_linux_siginfo_fixup): Ditto.
	* aarch64-linux-tdep.c (aarch64_linux_init_abi): Set link
	map offsets to 32 or 64 bits.
	* aarch64-tdep.c (aarch64_ilp32_register_type): New function.
	(aarch64_gdbarch_init): Setup ILP32 support.
	Make sure the gdbarches have compatible ilp32 flags.
	Set long and ptr sizes correctly for ilp32.
	* aarch64-tdep.h (gdbarch_tdep) <ilp32>: New field.

gdbserver ChangeLog:

2017-01-31Â Â Andrew PinskiÂ Â <apinski@cavium.com>
	Â Â Â Â Steve EllceyÂ Â <sellcey@cavium.com>

	* linux-aarch64-low.c (aarch64_linux_read_description): Use
	machine instead of is_elf64 to determine architecture.Â Â Give an
	error when using 32 bit gdbserver on 64 bit program.
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