From: Luis Machado <luis.machado@arm.com>
To: Koudai Iwahori <koudai@google.com>, gdb-patches@sourceware.org
Subject: Re: [PATCH] AArch64 pauth: Fix internal error when target supports extra regs
Date: Tue, 4 Oct 2022 10:27:30 +0100 [thread overview]
Message-ID: <5f2703cf-c2f3-493a-e756-e0546f117aed@arm.com> (raw)
In-Reply-To: <20220928025057.188075-1-koudai@google.com>
Hi,
This should be addressed by https://sourceware.org/pipermail/gdb-patches/2022-October/192272.html.
Could you please give it a try? It was pushed yesterday.
Out of curiosity, are you using user-mode QEMU? You mentioned extra registers, and those are usually
provided by emulators.
On 9/28/22 03:50, Koudai Iwahori via Gdb-patches wrote:
> GDB crashes in aarch64_pseudo_register_type() when target supports pauth
> and extra registers.
> When the target supports pauth, GDB keeps a pseudo register `RA_STATE`
> and aarch64_gdbarch_tdep::ra_sign_state_regnum has the integer index of
> the register.
> aarch64_gdbarch_tdep::ra_sign_state_regnum is initialized to
> (# of reg) + (# of pseudo reg) right after GDB checking if the target
> supports the core/fpu/sve registers.
> However, the number of registers is updated in tdesc_use_registers() if
> the target can provide extra registers.
> In such cases, ra_sign_state_regnum does not have the right value and
> internal_error() in aarch64_pseudo_register_type() fires.
> I added ra_sign_state_pseudo_regnum field to aarch64_gdbarch_tdep for
> storing the pseudo register number and added get_ra_sign_state_regnum
> member function.
> ---
> gdb/aarch64-tdep.c | 23 ++++++++++++-----------
> gdb/aarch64-tdep.h | 8 +++++++-
> 2 files changed, 19 insertions(+), 12 deletions(-)
>
> diff --git a/gdb/aarch64-tdep.c b/gdb/aarch64-tdep.c
> index 7229b53838e..87335ad22ae 100644
> --- a/gdb/aarch64-tdep.c
> +++ b/gdb/aarch64-tdep.c
> @@ -254,7 +254,8 @@ aarch64_frame_unmask_lr (aarch64_gdbarch_tdep *tdep,
> {
> if (tdep->has_pauth ()
> && frame_unwind_register_unsigned (this_frame,
> - tdep->ra_sign_state_regnum))
> + tdep->get_ra_sign_state_regnum (
> + get_frame_arch (this_frame))))
> {
> int cmask_num = AARCH64_PAUTH_CMASK_REGNUM (tdep->pauth_reg_base);
> CORE_ADDR cmask = frame_unwind_register_unsigned (this_frame, cmask_num);
> @@ -542,7 +543,7 @@ aarch64_analyze_prologue (struct gdbarch *gdbarch,
>
> if (tdep->has_pauth () && cache != nullptr)
> {
> - int regnum = tdep->ra_sign_state_regnum;
> + int regnum = tdep->get_ra_sign_state_regnum (gdbarch);
> cache->saved_regs[regnum].set_value (ra_state_val);
> }
> }
> @@ -882,7 +883,7 @@ aarch64_analyze_prologue_test (void)
>
> if (tdep->has_pauth ())
> {
> - int regnum = tdep->ra_sign_state_regnum;
> + int regnum = tdep->get_ra_sign_state_regnum (gdbarch);
> SELF_CHECK (cache.saved_regs[regnum].is_value ());
> }
> }
> @@ -1137,7 +1138,8 @@ aarch64_prologue_prev_register (struct frame_info *this_frame,
> lr = frame_unwind_register_unsigned (this_frame, AARCH64_LR_REGNUM);
>
> if (tdep->has_pauth ()
> - && cache->saved_regs[tdep->ra_sign_state_regnum].is_value ())
> + && cache->saved_regs[tdep->get_ra_sign_state_regnum (gdbarch)]
> + .is_value ())
> lr = aarch64_frame_unmask_lr (tdep, this_frame, lr);
>
> return frame_unwind_got_constant (this_frame, prev_regnum, lr);
> @@ -1344,7 +1346,7 @@ aarch64_dwarf2_frame_init_reg (struct gdbarch *gdbarch, int regnum,
> /* Init pauth registers. */
> if (tdep->has_pauth ())
> {
> - if (regnum == tdep->ra_sign_state_regnum)
> + if (regnum == tdep->get_ra_sign_state_regnum (gdbarch))
> {
> /* Initialize RA_STATE to zero. */
> reg->how = DWARF2_FRAME_REG_SAVED_VAL_EXP;
> @@ -2255,7 +2257,7 @@ aarch64_dwarf_reg_to_regnum (struct gdbarch *gdbarch, int reg)
> if (tdep->has_pauth ())
> {
> if (reg == AARCH64_DWARF_RA_SIGN_STATE)
> - return tdep->ra_sign_state_regnum;
> + return tdep->get_ra_sign_state_regnum (gdbarch);
> }
>
> return -1;
> @@ -2662,7 +2664,7 @@ aarch64_pseudo_register_name (struct gdbarch *gdbarch, int regnum)
> /* RA_STATE is used for unwinding only. Do not assign it a name - this
> prevents it from being read by methods such as
> mi_cmd_trace_frame_collected. */
> - if (tdep->has_pauth () && regnum == tdep->ra_sign_state_regnum)
> + if (tdep->has_pauth () && p_regnum == tdep->ra_sign_state_pseudo_regnum)
> return "";
>
> internal_error (__FILE__, __LINE__,
> @@ -2698,7 +2700,7 @@ aarch64_pseudo_register_type (struct gdbarch *gdbarch, int regnum)
> && p_regnum < AARCH64_SVE_V0_REGNUM + AARCH64_V_REGS_NUM)
> return aarch64_vnv_type (gdbarch);
>
> - if (tdep->has_pauth () && regnum == tdep->ra_sign_state_regnum)
> + if (tdep->has_pauth () && p_regnum == tdep->ra_sign_state_pseudo_regnum)
> return builtin_type (gdbarch)->builtin_uint64;
>
> internal_error (__FILE__, __LINE__,
> @@ -2732,7 +2734,7 @@ aarch64_pseudo_register_reggroup_p (struct gdbarch *gdbarch, int regnum,
> && p_regnum < AARCH64_SVE_V0_REGNUM + AARCH64_V_REGS_NUM)
> return group == all_reggroup || group == vector_reggroup;
> /* RA_STATE is used for unwinding only. Do not assign it to any groups. */
> - if (tdep->has_pauth () && regnum == tdep->ra_sign_state_regnum)
> + if (tdep->has_pauth () && p_regnum == tdep->ra_sign_state_pseudo_regnum)
> return 0;
>
> return group == all_reggroup;
> @@ -3598,8 +3600,7 @@ aarch64_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
> tdep->jb_elt_size = 8;
> tdep->vq = vq;
> tdep->pauth_reg_base = first_pauth_regnum;
> - tdep->ra_sign_state_regnum = (feature_pauth == NULL) ? -1
> - : ra_sign_state_offset + num_regs;
> + tdep->ra_sign_state_pseudo_regnum = ra_sign_state_offset;
> tdep->mte_reg_base = first_mte_regnum;
> tdep->tls_regnum = tls_regnum;
>
> diff --git a/gdb/aarch64-tdep.h b/gdb/aarch64-tdep.h
> index d8513023c37..acb69b2dc40 100644
> --- a/gdb/aarch64-tdep.h
> +++ b/gdb/aarch64-tdep.h
> @@ -94,7 +94,13 @@ struct aarch64_gdbarch_tdep : gdbarch_tdep_base
> }
>
> int pauth_reg_base = 0;
> - int ra_sign_state_regnum = 0;
> + int ra_sign_state_pseudo_regnum = -1;
> +
> + int get_ra_sign_state_regnum (gdbarch *gdbarch) const
> + {
> + gdb_assert (ra_sign_state_pseudo_regnum >= 0);
> + return ra_sign_state_pseudo_regnum + gdbarch_num_regs (gdbarch);
> + }
>
> /* Returns true if the target supports pauth. */
> bool has_pauth () const
next prev parent reply other threads:[~2022-10-04 9:27 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-28 2:50 Koudai Iwahori
2022-10-04 9:27 ` Luis Machado [this message]
2022-10-05 2:07 ` Koudai Iwahori
2022-10-05 2:07 ` Koudai Iwahori
2022-10-05 8:52 ` Luis Machado
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