Re: [PATCH v3 10/16] [gdb/aarch64] sme: Fixup sigframe gdbarch when vg/svg changes

Luis Machado via Gdb-patches
2023-07-31T12:28:17Z

On 7/28/23 02:01, Thiago Jung Bauermann wrote:
>
> Luis Machado via Gdb-patches <gdb-patches@sourceware.org> writes:
>
>> case AARCH64_SVE_MAGIC:
>> {
>> /* Check if the section is followed by a full SVE dump, and set
>> sve_regs if it is. */
>> gdb_byte buf[4];
>> - uint16_t flags;
>> -
>> - if (!tdep->has_sve ())
>> - break;
>>
>> + /* Extract the vector length. */
>> if (target_read_memory (section + AARCH64_SVE_CONTEXT_VL_OFFSET,
>> buf, 2) != 0)
>> {
>> + warning (_("Failed to read the vector length from the SVE "
>> + " signal frame context."));
>
> Extraneous space between "SVE" and "signal".
>

Fixed.

>> section += size;
>> break;
>> }
>
>> case AARCH64_ZA_MAGIC:
>> {
>> - if (!tdep->has_sme ())
>> - {
>> - section += size;
>> - break;
>> - }
>> -
>> /* Check if the section is followed by a full ZA dump, and set
>> za_state if it is. */
>> gdb_byte buf[2];
>>
>> + /* Extract the streaming vector length. */
>> if (target_read_memory (section + AARCH64_SVE_CONTEXT_VL_OFFSET,
>
> Same comment from the previous patch about using the SME macro instead
> of the SVE one.
>
>> buf, 2) != 0)
>> {
>> + warning (_("Failed to read the streaming vector length from "
>> + " ZA signal frame context."));
>
> Extraneous space between "SVE" and "signal".
>

Fixed.

>> section += size;
>> break;
>> }
>
>> @@ -477,11 +499,49 @@ aarch64_linux_sigframe_init (const struct tramp_frame *self,
>> if (!extra_found && section > section_end)
>> break;
>> }
>> +}
>> +
>> +/* Implement the "init" method of struct tramp_frame. */
>> +
>> +static void
>> +aarch64_linux_sigframe_init (const struct tramp_frame *self,
>> + frame_info_ptr this_frame,
>> + struct trad_frame_cache *this_cache,
>> + CORE_ADDR func)
>> +{
>> + /* Read the signal context information. */
>> + struct aarch64_linux_sigframe signal_frame;
>> + aarch64_linux_read_signal_frame_info (this_frame, signal_frame);
>> +
>> + /* Now we have all the data required to restore the registers from the
>> + signal frame. */
>> +
>> + /* Restore the general purpose registers. */
>> + CORE_ADDR offset
>> + = signal_frame.sigcontext_address + AARCH64_SIGCONTEXT_XO_OFFSET;
>
> You can simplify the above to
>
> CORE_ADDR offset = signal_frame.gpr_section;
>

Yep. Agreed. Changed it now.

>> + for (int i = 0; i < 31; i++)
>> + {
>> + trad_frame_set_reg_addr (this_cache, AARCH64_X0_REGNUM + i, offset);
>> + offset += AARCH64_SIGCONTEXT_REG_SIZE;
>> + }
>> + trad_frame_set_reg_addr (this_cache, AARCH64_SP_REGNUM, offset);
>> + offset += AARCH64_SIGCONTEXT_REG_SIZE;
>> + trad_frame_set_reg_addr (this_cache, AARCH64_PC_REGNUM, offset);
>
>> diff --git a/gdb/tramp-frame.h b/gdb/tramp-frame.h
>> index fa0241acb2d..563c34ae595 100644
>> --- a/gdb/tramp-frame.h
>> +++ b/gdb/tramp-frame.h
>> @@ -42,6 +42,13 @@ struct trad_frame_cache;
>> instruction sequence. */
>> #define TRAMP_SENTINEL_INSN ULONGEST_MAX
>>
>> +/* Assuming the frame chain: (outer) prev <-> this <-> next (inner);
>> + use THIS frame, and implicitly the NEXT frame's register unwind
>> + method, return PREV frame's architecture. */
>
> Maybe s/return/to return/ ?
>

Yes, "to return" is what I had in mind.

>> +
>> +typedef struct gdbarch *(frame_prev_arch_ftype) (frame_info_ptr this_frame,
>> + void **this_prologue_cache);
>> +
>> struct tramp_frame
>> {
>> /* The trampoline's type, some a signal trampolines, some are normal
>> @@ -75,6 +82,11 @@ struct tramp_frame
>> int (*validate) (const struct tramp_frame *self,
>> frame_info_ptr this_frame,
>> CORE_ADDR *pc);
>> +
>> + /* Given the current frame in THIS_FRAME and a frame cache in FRAME_CACHE,
>> + return the architecture of the previous frame. */
>> + struct gdbarch *(*prev_arch) (frame_info_ptr this_frame,
>> + void **frame_cache);
>
> Shouldn't the typedef defined above be used here?
>

Yep. Change it to use the typedef now.

>> };
>

Thanks!