* Re: [PATCH v3] Fix hardware watchpoints in replay mode
2023-11-21 16:42 ` [PATCH v3] Fix hardware watchpoints in replay mode Hannes Domani
@ 2023-12-05 17:57 ` Hannes Domani
2023-12-06 12:00 ` Guinevere Larsen
1 sibling, 0 replies; 4+ messages in thread
From: Hannes Domani @ 2023-12-05 17:57 UTC (permalink / raw)
To: gdb-patches
Ping.
Am Dienstag, 21. November 2023, 17:43:23 MEZ hat Hannes Domani <ssbssa@yahoo.de> Folgendes geschrieben:
> Changes introduced by commit 9e8915c6cee5c37637521b424d723e990e06d597
> caused a regression that meant hardware watchpoint stops would not
> trigger in reverse execution or replay mode. This was documented in
> PR breakpoints/21969.
> The problem is that record_check_stopped_by_breakpoint always overwrites
> record_full_stop_reason, thus loosing the TARGET_STOPPED_BY_WATCHPOINT
> value which would be checked afterwards.
>
> This commit fixes that by not overwriting the stop-reason in
> record_full_stop_reason if we're not stopped at a breakpoint.
>
> And the test for hw watchpoints in gdb.reverse/watch-reverse.exp actually
> tested sw watchpoints again, since "set can-use-hw-watchpoints 1"
> doesn't convert enabled watchpoints to use hardware.
> This is fixed by disabling said watchpoint while enabling hw watchpoints.
> The same is not done for gdb.reverse/watch-precsave.exp, since it's not
> possible to use hw watchpoints in restored recordings anyways.
>
> Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=21969
> ---
> gdb/record.c | 1 -
> gdb/testsuite/gdb.reverse/watch-reverse.exp | 4 ++++
> 2 files changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/gdb/record.c b/gdb/record.c
> index f7c82665b05..88235e36da7 100644
> --- a/gdb/record.c
> +++ b/gdb/record.c
> @@ -248,7 +248,6 @@ record_check_stopped_by_breakpoint (const address_space *aspace,
> return 1;
> }
>
> - *reason = TARGET_STOPPED_BY_NO_REASON;
> return 0;
> }
>
> diff --git a/gdb/testsuite/gdb.reverse/watch-reverse.exp b/gdb/testsuite/gdb.reverse/watch-reverse.exp
> index 6b81a6fdf88..a7126ac9b1d 100644
> --- a/gdb/testsuite/gdb.reverse/watch-reverse.exp
> +++ b/gdb/testsuite/gdb.reverse/watch-reverse.exp
> @@ -118,8 +118,12 @@ gdb_test "continue" \
> ".*\[Ww\]atchpoint.*ival3.*Old value = 0.*New value = -1.*ival3 = count; ival4 = count;.*" \
> "watchpoint hit in reverse, fifth time"
>
> +gdb_test_no_output "disable \$bpnum" "disable non-hw watchpoint"
> +
> gdb_test_no_output "set can-use-hw-watchpoints 1" "enable hw watchpoints"
>
> +gdb_test_no_output "enable \$bpnum" "enable hw watchpoint"
> +
> ###
> ###
> ###
> --
> 2.35.1
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v3] Fix hardware watchpoints in replay mode
2023-11-21 16:42 ` [PATCH v3] Fix hardware watchpoints in replay mode Hannes Domani
2023-12-05 17:57 ` Hannes Domani
@ 2023-12-06 12:00 ` Guinevere Larsen
2023-12-06 12:49 ` Hannes Domani
1 sibling, 1 reply; 4+ messages in thread
From: Guinevere Larsen @ 2023-12-06 12:00 UTC (permalink / raw)
To: Hannes Domani, gdb-patches; +Cc: pedro
On 21/11/2023 17:42, Hannes Domani wrote:
> Changes introduced by commit 9e8915c6cee5c37637521b424d723e990e06d597
> caused a regression that meant hardware watchpoint stops would not
> trigger in reverse execution or replay mode. This was documented in
> PR breakpoints/21969.
> The problem is that record_check_stopped_by_breakpoint always overwrites
> record_full_stop_reason, thus loosing the TARGET_STOPPED_BY_WATCHPOINT
> value which would be checked afterwards.
>
> This commit fixes that by not overwriting the stop-reason in
> record_full_stop_reason if we're not stopped at a breakpoint.
>
> And the test for hw watchpoints in gdb.reverse/watch-reverse.exp actually
> tested sw watchpoints again, since "set can-use-hw-watchpoints 1"
> doesn't convert enabled watchpoints to use hardware.
> This is fixed by disabling said watchpoint while enabling hw watchpoints.
> The same is not done for gdb.reverse/watch-precsave.exp, since it's not
> possible to use hw watchpoints in restored recordings anyways.
>
> Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=21969
> ---
I checked again; this patch adds no regression, and fixes the issue that
you described. Since this patch only relates to reverse execution, I say
its ready for upstreaming.
Approved-by: Guinevere Larsen <blarsen@redhat.com>
--
Cheers,
Guinevere Larsen
She/Her/Hers
> gdb/record.c | 1 -
> gdb/testsuite/gdb.reverse/watch-reverse.exp | 4 ++++
> 2 files changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/gdb/record.c b/gdb/record.c
> index f7c82665b05..88235e36da7 100644
> --- a/gdb/record.c
> +++ b/gdb/record.c
> @@ -248,7 +248,6 @@ record_check_stopped_by_breakpoint (const address_space *aspace,
> return 1;
> }
>
> - *reason = TARGET_STOPPED_BY_NO_REASON;
> return 0;
> }
>
> diff --git a/gdb/testsuite/gdb.reverse/watch-reverse.exp b/gdb/testsuite/gdb.reverse/watch-reverse.exp
> index 6b81a6fdf88..a7126ac9b1d 100644
> --- a/gdb/testsuite/gdb.reverse/watch-reverse.exp
> +++ b/gdb/testsuite/gdb.reverse/watch-reverse.exp
> @@ -118,8 +118,12 @@ gdb_test "continue" \
> ".*\[Ww\]atchpoint.*ival3.*Old value = 0.*New value = -1.*ival3 = count; ival4 = count;.*" \
> "watchpoint hit in reverse, fifth time"
>
> +gdb_test_no_output "disable \$bpnum" "disable non-hw watchpoint"
> +
> gdb_test_no_output "set can-use-hw-watchpoints 1" "enable hw watchpoints"
>
> +gdb_test_no_output "enable \$bpnum" "enable hw watchpoint"
> +
> ###
> ###
> ###
^ permalink raw reply [flat|nested] 4+ messages in thread