From: John Baldwin <jhb@FreeBSD.org>
To: Simon Marchi <simon.marchi@polymtl.ca>, gdb-patches@sourceware.org
Subject: Re: [PATCH 00/24] Fix reading and writing pseudo registers in non-current frames
Date: Sat, 11 Nov 2023 12:26:24 -0800 [thread overview]
Message-ID: <f3714134-93e1-4654-b53a-1dd03bce7e50@FreeBSD.org> (raw)
In-Reply-To: <20231108051222.1275306-1-simon.marchi@polymtl.ca>
On 11/7/23 9:00 PM, Simon Marchi wrote:
> This series fixes reading/writing pseudo registers from/to non-current
> frames (that is, frames other than frame 0). Currently, we get this:
>
> (gdb) frame 0
> #0 break_here_asm () at /home/smarchi/src/binutils-gdb/gdb/testsuite/gdb.arch/amd64-pseudo-unwind-asm.S:38
> 38 pop %rbx
> (gdb) p/x $rbx
> $1 = 0x2021222324252627
> (gdb) p/x $ebx
> $2 = 0x24252627
> (gdb) frame 1
> #1 0x000055555555517d in caller () at /home/smarchi/src/binutils-gdb/gdb/testsuite/gdb.arch/amd64-pseudo-unwind-asm.S:58
> 58 call callee
> (gdb) p/x $rbx
> $3 = 0x1011121314151617
> (gdb) p/x $ebx
> $4 = 0x24252627
>
> This is a bit surprising, we would expect the last value to be
> 0x14151617, the bottom half of the rbx value from frame 1 (the currently
> selected frame at that point). Instead, we got the bottom half of the
> rbx value from frame 0. This is because pseudo registers are always
> read/written from/to the current thread's regcache.
>
> This series fixes this (as well as writing to pseudo registers) by
> making it so pseudo registers are read/written using a frame.
>
> Simon Marchi (24):
> gdb: don't handle i386 k registers as pseudo registers
> gdb: use reg_buffer_common throughout gdbsupport/common-regcache.h
> gdb: make store_integer take an array_view
> gdb: simplify conditions in
> regcache::{read,write,raw_collect,raw_supply}_part
> gdb: change regcache interface to use array_view
> gdb: fix bugs in {get,put}_frame_register_bytes
> gdb: make put_frame_register take an array_view
> gdb: change value_of_register and value_of_register_lazy to take the
> next frame
> gdb: remove frame_register
> gdb: make put_frame_register take the next frame
> gdb: make put_frame_register_bytes take the next frame
> gdb: make get_frame_register_bytes take the next frame
> gdb: add value::allocate_register
> gdb: read pseudo register through frame
> gdb: change parameter name in frame_unwind_register_unsigned
> declaration
> gdb: rename gdbarch_pseudo_register_write to
> gdbarch_deprecated_pseudo_register_write
> gdb: add gdbarch_pseudo_register_write that takes a frame
> gdb: migrate i386 and amd64 to the new gdbarch_pseudo_register_write
> gdb: make aarch64_za_offsets_from_regnum return za_offsets
> gdb: add missing raw register read in
> aarch64_sme_pseudo_register_write
> gdb: migrate aarch64 to new gdbarch_pseudo_register_write
> gdb: migrate arm to gdbarch_pseudo_register_read_value
> gdb: migrate arm to new gdbarch_pseudo_register_write
> gdb/testsuite: add tests for unwinding of pseudo registers
>
> gdb/aarch64-tdep.c | 297 +++++-----
> gdb/alpha-tdep.c | 11 +-
> gdb/amd64-tdep.c | 82 +--
> gdb/arch/arm-get-next-pcs.c | 6 +-
> gdb/arch/arm-get-next-pcs.h | 5 +-
> gdb/arch/arm.c | 2 +-
> gdb/arch/arm.h | 4 +-
> gdb/arm-linux-tdep.c | 11 +-
> gdb/arm-tdep.c | 145 +++--
> gdb/avr-tdep.c | 3 +-
> gdb/bfin-tdep.c | 3 +-
> gdb/csky-tdep.c | 4 +-
> gdb/defs.h | 39 +-
> gdb/dwarf2/expr.c | 22 +-
> gdb/dwarf2/frame.c | 5 +-
> gdb/eval.c | 3 +-
> gdb/findvar.c | 50 +-
> gdb/frame-unwind.c | 3 +-
> gdb/frame.c | 174 +++---
> gdb/frame.h | 28 +-
> gdb/frv-tdep.c | 3 +-
> gdb/gdbarch-gen.h | 28 +-
> gdb/gdbarch.c | 40 +-
> gdb/gdbarch_components.py | 29 +-
> gdb/guile/scm-frame.c | 3 +-
> gdb/h8300-tdep.c | 3 +-
> gdb/i386-tdep.c | 380 ++++--------
> gdb/i386-tdep.h | 15 +-
> gdb/i387-tdep.c | 16 +-
> gdb/ia64-tdep.c | 18 +-
> gdb/infcmd.c | 6 +-
> gdb/loongarch-tdep.c | 3 +-
> gdb/m32c-tdep.c | 3 +-
> gdb/m68hc11-tdep.c | 3 +-
> gdb/m68k-tdep.c | 17 +-
> gdb/mep-tdep.c | 3 +-
> gdb/mi/mi-main.c | 3 +-
> gdb/mips-tdep.c | 29 +-
> gdb/msp430-tdep.c | 3 +-
> gdb/nat/aarch64-hw-point.c | 3 +-
> gdb/nat/aarch64-scalable-linux-ptrace.c | 20 +-
> gdb/nat/linux-btrace.c | 3 +-
> gdb/nds32-tdep.c | 8 +-
> gdb/python/py-frame.c | 3 +-
> gdb/python/py-unwind.c | 4 +-
> gdb/regcache.c | 548 +++++++++++-------
> gdb/regcache.h | 113 +++-
> gdb/riscv-tdep.c | 13 +-
> gdb/rl78-tdep.c | 3 +-
> gdb/rs6000-tdep.c | 21 +-
> gdb/s12z-tdep.c | 2 +-
> gdb/s390-tdep.c | 3 +-
> gdb/sh-tdep.c | 9 +-
> gdb/sparc-tdep.c | 3 +-
> gdb/sparc64-tdep.c | 3 +-
> gdb/std-regs.c | 11 +-
> .../gdb.arch/aarch64-pseudo-unwind-asm.S | 82 +++
> .../gdb.arch/aarch64-pseudo-unwind.c | 33 ++
> .../gdb.arch/aarch64-pseudo-unwind.exp | 90 +++
> .../gdb.arch/amd64-pseudo-unwind-asm.S | 66 +++
> gdb/testsuite/gdb.arch/amd64-pseudo-unwind.c | 33 ++
> .../gdb.arch/amd64-pseudo-unwind.exp | 91 +++
> .../gdb.arch/arm-pseudo-unwind-asm.S | 81 +++
> .../gdb.arch/arm-pseudo-unwind-legacy-asm.S | 84 +++
> .../gdb.arch/arm-pseudo-unwind-legacy.c | 33 ++
> .../gdb.arch/arm-pseudo-unwind-legacy.exp | 86 +++
> gdb/testsuite/gdb.arch/arm-pseudo-unwind.c | 33 ++
> gdb/testsuite/gdb.arch/arm-pseudo-unwind.exp | 88 +++
> gdb/valops.c | 31 +-
> gdb/value.c | 149 +++++
> gdb/value.h | 64 +-
> gdb/xtensa-tdep.c | 3 +-
> gdbserver/linux-arm-low.cc | 4 +-
> gdbserver/regcache.cc | 69 ++-
> gdbserver/regcache.h | 6 +-
> gdbsupport/common-regcache.cc | 2 +-
> gdbsupport/common-regcache.h | 58 +-
> gdbsupport/rsp-low.cc | 8 +
> gdbsupport/rsp-low.h | 2 +
> 79 files changed, 2324 insertions(+), 1144 deletions(-)
> create mode 100644 gdb/testsuite/gdb.arch/aarch64-pseudo-unwind-asm.S
> create mode 100644 gdb/testsuite/gdb.arch/aarch64-pseudo-unwind.c
> create mode 100644 gdb/testsuite/gdb.arch/aarch64-pseudo-unwind.exp
> create mode 100644 gdb/testsuite/gdb.arch/amd64-pseudo-unwind-asm.S
> create mode 100644 gdb/testsuite/gdb.arch/amd64-pseudo-unwind.c
> create mode 100644 gdb/testsuite/gdb.arch/amd64-pseudo-unwind.exp
> create mode 100644 gdb/testsuite/gdb.arch/arm-pseudo-unwind-asm.S
> create mode 100644 gdb/testsuite/gdb.arch/arm-pseudo-unwind-legacy-asm.S
> create mode 100644 gdb/testsuite/gdb.arch/arm-pseudo-unwind-legacy.c
> create mode 100644 gdb/testsuite/gdb.arch/arm-pseudo-unwind-legacy.exp
> create mode 100644 gdb/testsuite/gdb.arch/arm-pseudo-unwind.c
> create mode 100644 gdb/testsuite/gdb.arch/arm-pseudo-unwind.exp
>
>
> base-commit: 1185b5b79a12ba67eb60bee3f75babf7a222fde0
I did not review the aarch64/arm changes very thoroughly (patches 19-23),
but the rest all look fine to me aside from the one comment I had on
patch 18.
(So to be clear, you can add my Reviewed-by on all of 1-18.) Looks like
Luis is helping to validate the arm changes.
I certainly have a use case for this for CHERI support where GPRs are
also extended (so ideally I'd like to treat the 64-bit GPRs as pseudos
of the 129-bit capability registers), and also for Morello in particular
where the stack pointer is banked in userland and can vary by stack
frame depending on a permission in the PC as to which real register it
maps on to.
--
John Baldwin
next prev parent reply other threads:[~2023-11-11 20:26 UTC|newest]
Thread overview: 54+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-11-08 5:00 Simon Marchi
2023-11-08 5:00 ` [PATCH 01/24] gdb: don't handle i386 k registers as pseudo registers Simon Marchi
2023-11-11 19:29 ` John Baldwin
2023-11-08 5:00 ` [PATCH 02/24] gdb: use reg_buffer_common throughout gdbsupport/common-regcache.h Simon Marchi
2023-11-11 19:42 ` John Baldwin
2023-11-08 5:00 ` [PATCH 03/24] gdb: make store_integer take an array_view Simon Marchi
2023-11-08 5:00 ` [PATCH 04/24] gdb: simplify conditions in regcache::{read,write,raw_collect,raw_supply}_part Simon Marchi
2023-11-08 5:00 ` [PATCH 05/24] gdb: change regcache interface to use array_view Simon Marchi
2023-11-13 13:43 ` Andrew Burgess
2023-11-13 14:00 ` Andrew Burgess
2023-11-13 16:47 ` Simon Marchi
2023-11-08 5:00 ` [PATCH 06/24] gdb: fix bugs in {get,put}_frame_register_bytes Simon Marchi
2023-11-13 15:00 ` Andrew Burgess
2023-11-13 19:51 ` Simon Marchi
2023-11-08 5:00 ` [PATCH 07/24] gdb: make put_frame_register take an array_view Simon Marchi
2023-11-08 5:00 ` [PATCH 08/24] gdb: change value_of_register and value_of_register_lazy to take the next frame Simon Marchi
2023-11-08 5:00 ` [PATCH 09/24] gdb: remove frame_register Simon Marchi
2023-11-08 5:00 ` [PATCH 10/24] gdb: make put_frame_register take the next frame Simon Marchi
2023-11-08 5:00 ` [PATCH 11/24] gdb: make put_frame_register_bytes " Simon Marchi
2023-11-08 5:00 ` [PATCH 12/24] gdb: make get_frame_register_bytes " Simon Marchi
2023-11-08 5:00 ` [PATCH 13/24] gdb: add value::allocate_register Simon Marchi
2023-11-08 5:00 ` [PATCH 14/24] gdb: read pseudo register through frame Simon Marchi
2023-11-11 20:11 ` John Baldwin
2023-11-08 5:00 ` [PATCH 15/24] gdb: change parameter name in frame_unwind_register_unsigned declaration Simon Marchi
2023-11-08 5:01 ` [PATCH 16/24] gdb: rename gdbarch_pseudo_register_write to gdbarch_deprecated_pseudo_register_write Simon Marchi
2023-11-14 12:12 ` Andrew Burgess
2023-11-14 15:16 ` Simon Marchi
2023-11-08 5:01 ` [PATCH 17/24] gdb: add gdbarch_pseudo_register_write that takes a frame Simon Marchi
2023-11-14 12:20 ` Andrew Burgess
2023-11-14 15:20 ` Simon Marchi
2023-11-08 5:01 ` [PATCH 18/24] gdb: migrate i386 and amd64 to the new gdbarch_pseudo_register_write Simon Marchi
2023-11-11 20:16 ` John Baldwin
2023-11-13 2:59 ` Simon Marchi
2023-11-08 5:01 ` [PATCH 19/24] gdb: make aarch64_za_offsets_from_regnum return za_offsets Simon Marchi
2023-11-08 5:01 ` [PATCH 20/24] gdb: add missing raw register read in aarch64_sme_pseudo_register_write Simon Marchi
2023-11-08 5:01 ` [PATCH 21/24] gdb: migrate aarch64 to new gdbarch_pseudo_register_write Simon Marchi
2023-11-08 5:01 ` [PATCH 22/24] gdb: migrate arm to gdbarch_pseudo_register_read_value Simon Marchi
2023-11-08 5:01 ` [PATCH 23/24] gdb: migrate arm to new gdbarch_pseudo_register_write Simon Marchi
2023-11-08 5:01 ` [PATCH 24/24] gdb/testsuite: add tests for unwinding of pseudo registers Simon Marchi
2023-11-08 5:16 ` [PATCH 00/24] Fix reading and writing pseudo registers in non-current frames Simon Marchi
2023-11-09 3:05 ` Simon Marchi
2023-11-08 11:57 ` Luis Machado
2023-11-08 15:47 ` Simon Marchi
2023-11-08 17:08 ` Luis Machado
2023-11-08 19:34 ` Simon Marchi
2023-11-09 19:04 ` Simon Marchi
2023-11-13 13:10 ` Luis Machado
2023-11-13 15:08 ` Luis Machado
2023-11-11 20:26 ` John Baldwin [this message]
2023-11-13 3:03 ` Simon Marchi
2023-12-01 16:27 Simon Marchi
2023-12-01 16:56 ` Simon Marchi
2023-12-14 14:51 ` Luis Machado
2023-12-14 16:20 ` Simon Marchi
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