From: Bruno Larsen <blarsen@redhat.com>
To: Tankut Baris Aktemur <tankut.baris.aktemur@intel.com>,
gdb-patches@sourceware.org
Subject: Re: [PATCH v2 1/2] gdb/regcache: return REG_UNAVAILABLE if raw_update raises NOT_AVAILABLE_ERROR
Date: Wed, 16 Mar 2022 12:18:42 -0300 [thread overview]
Message-ID: <4a9fc5ba-2053-f0ee-5ef7-450dfaf69d83@redhat.com> (raw)
In-Reply-To: <cee11ea5c077124ed26bde1a58b7b22e0d56c703.1644311043.git.tankut.baris.aktemur@intel.com>
Hello Tankut,
On 2/8/22 06:15, Tankut Baris Aktemur via Gdb-patches wrote:
> In regcache's raw_read, it is possible that 'raw_update' fails with an
> exception. Catch this exception and return REG_UNAVAILABLE if the
> error is of kind NOT_AVAILABLE_ERROR. This makes clients' lives easier.
This looks like a good idea for a change. I just have a few small comments.
Firstly, I'm not sure this change is complex enough to warrant its own commit, since - from what I can see - there is no noticeable change in GDB, and the patch itself is quite small, it could maybe just be part of patch 2. However, I am not a global maintainer or very experienced in patch review, so take this comment with a grain of salt. If the commits do stay separate, I would add a mention of raw_read in the commit title, otherwise which function is returning REG_UNAVAILABLE is not mentioned at all.
Also, the commit message is not very descriptive of what could cause the exception in the first place, and I feel like that could be good for future reference, but this may just be my GDB inexperience speaking.
>
> Regression-tested on X86_64-Linux.
> ---
> gdb/regcache.c | 11 ++++++++++-
> 1 file changed, 10 insertions(+), 1 deletion(-)
>
> diff --git a/gdb/regcache.c b/gdb/regcache.c
> index 00d7a10e289..0379e6a8d0f 100644
> --- a/gdb/regcache.c
> +++ b/gdb/regcache.c
> @@ -598,7 +598,16 @@ enum register_status
> readable_regcache::raw_read (int regnum, gdb_byte *buf)
> {
> gdb_assert (buf != NULL);
> - raw_update (regnum);
> + try
> + {
> + raw_update (regnum);
> + }
> + catch (const gdb_exception_error &ex)
> + {
> + if (ex.error == NOT_AVAILABLE_ERROR)
> + return REG_UNAVAILABLE;
Lastly, Since this function is returning as if nothing unexpected happened, it should probably also set buf to 0 and possibly set m_register_status to REG_UNAVAILABLE - if it isn't set by whatever throws the exception.
> + throw;> + }
>
> if (m_register_status[regnum] != REG_VALID)
> memset (buf, 0, m_descr->sizeof_register[regnum]);
--
Cheers!
Bruno Larsen
next prev parent reply other threads:[~2022-03-16 15:18 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-08 9:15 [PATCH v2 0/2] Querying registers of already-exited processes Tankut Baris Aktemur
2022-02-08 9:15 ` [PATCH v2 1/2] gdb/regcache: return REG_UNAVAILABLE if raw_update raises NOT_AVAILABLE_ERROR Tankut Baris Aktemur
2022-03-16 15:18 ` Bruno Larsen [this message]
2022-03-23 12:55 ` Aktemur, Tankut Baris
2022-02-08 9:15 ` [PATCH v2 2/2] gdb: raise and handle NOT_AVAILABLE_ERROR when accessing frame PC Tankut Baris Aktemur
2022-03-16 17:26 ` Bruno Larsen
2022-03-23 12:55 ` Aktemur, Tankut Baris
2022-03-23 13:34 ` Bruno Larsen
2022-03-24 8:46 ` Aktemur, Tankut Baris
2022-02-22 7:31 ` [PATCH v2 0/2] Querying registers of already-exited processes Aktemur, Tankut Baris
2022-03-07 8:00 ` Aktemur, Tankut Baris
2022-03-23 13:05 ` [PATCH v3 " Tankut Baris Aktemur
2022-03-23 13:05 ` [PATCH v3 1/2] gdb/regcache: return REG_UNAVAILABLE in raw_read if NOT_AVAILABLE_ERROR is seen Tankut Baris Aktemur
2022-03-23 13:05 ` [PATCH v3 2/2] gdb: raise and handle NOT_AVAILABLE_ERROR when accessing frame PC Tankut Baris Aktemur
2022-05-04 7:19 ` [PATCH v3 0/2] Querying registers of already-exited processes Aktemur, Tankut Baris
2022-12-23 17:10 ` Aktemur, Tankut Baris
2023-01-17 20:40 ` Aktemur, Tankut Baris
2023-01-24 10:35 ` Aktemur, Tankut Baris
2023-01-31 20:14 ` Aktemur, Tankut Baris
2023-02-20 13:07 ` Aktemur, Tankut Baris
2023-03-03 7:46 ` Aktemur, Tankut Baris
2023-03-28 13:40 ` Aktemur, Tankut Baris
2023-12-18 14:40 ` [PATCH v4 " Tankut Baris Aktemur
2023-12-18 14:40 ` [PATCH v4 1/2] gdb/regcache: return REG_UNAVAILABLE in raw_read if NOT_AVAILABLE_ERROR is seen Tankut Baris Aktemur
2023-12-18 14:40 ` [PATCH v4 2/2] gdb: raise and handle NOT_AVAILABLE_ERROR when accessing frame PC Tankut Baris Aktemur
2023-12-20 22:00 ` John Baldwin
2023-12-21 6:41 ` Eli Zaretskii
2023-12-27 18:41 ` Aktemur, Tankut Baris
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