All of lore.kernel.org
 help / color / mirror / Atom feed
From: "Clément Léger" <clement.leger@linux.dev>
To: Paul Walmsley <pjw@kernel.org>,
	Palmer Dabbelt <palmer@dabbelt.com>,
	Albert Ou <aou@eecs.berkeley.edu>
Cc: "Clément Léger" <clement.leger@linux.dev>,
	"Alexandre Ghiti" <alex@ghiti.fr>,
	WangYuli <wangyuli@uniontech.com>,
	linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: [PATCH 0/3] riscv: kgdb: Fix break size, insn patch and masking
Date: Fri, 13 Nov 2026 08:16:11 +0100	[thread overview]
Message-ID: <20261113071616.219623-1-clement.leger@linux.dev> (raw)

This small series fixes a few problems that were spotted with kgdb.

First patch is the use of patch_insn_write() to set breakpoints instead
of copy_to_kernel_nofault(). This fixes the use of kgdb with
CONFIG_STRICT_KERNEL_RWX which maps text as RX.

Second patch removes the hardcoded epc += 4 with BREAK_INSTR_SIZE so
that it works with CONFIG_RISCV_ISA_C.

Last one is more of a correctness fix with respect to jalr instructions.
ISA specifies that the target address is computed by masking the LSB to
0.

Clément Léger (3):
  riscv: kgdb: use patch_insn_write() to set breakpoints
  riscv: kgdb: use BREAK_INSTR_SIZE instead of hardcoded value
  riscv: kgdb: clear bit 0 of single-step jump targets

 arch/riscv/kernel/kgdb.c | 39 ++++++++++++++++++++++++++++++++-------
 1 file changed, 32 insertions(+), 7 deletions(-)

-- 
Clément Léger

WARNING: multiple messages have this Message-ID (diff)
From: "Clément Léger" <clement.leger@linux.dev>
To: Paul Walmsley <pjw@kernel.org>,
	Palmer Dabbelt <palmer@dabbelt.com>,
	Albert Ou <aou@eecs.berkeley.edu>
Cc: "Clément Léger" <clement.leger@linux.dev>,
	"Alexandre Ghiti" <alex@ghiti.fr>,
	WangYuli <wangyuli@uniontech.com>,
	linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: [PATCH 0/3] riscv: kgdb: Fix break size, insn patch and masking
Date: Fri, 13 Nov 2026 08:16:11 +0100	[thread overview]
Message-ID: <20261113071616.219623-1-clement.leger@linux.dev> (raw)

This small series fixes a few problems that were spotted with kgdb.

First patch is the use of patch_insn_write() to set breakpoints instead
of copy_to_kernel_nofault(). This fixes the use of kgdb with
CONFIG_STRICT_KERNEL_RWX which maps text as RX.

Second patch removes the hardcoded epc += 4 with BREAK_INSTR_SIZE so
that it works with CONFIG_RISCV_ISA_C.

Last one is more of a correctness fix with respect to jalr instructions.
ISA specifies that the target address is computed by masking the LSB to
0.

Clément Léger (3):
  riscv: kgdb: use patch_insn_write() to set breakpoints
  riscv: kgdb: use BREAK_INSTR_SIZE instead of hardcoded value
  riscv: kgdb: clear bit 0 of single-step jump targets

 arch/riscv/kernel/kgdb.c | 39 ++++++++++++++++++++++++++++++++-------
 1 file changed, 32 insertions(+), 7 deletions(-)

-- 
Clément Léger

_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv

             reply	other threads:[~2026-11-13  7:16 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-11-13  7:16 Clément Léger [this message]
2026-11-13  7:16 ` [PATCH 0/3] riscv: kgdb: Fix break size, insn patch and masking Clément Léger
2026-11-13  7:16 ` [PATCH 1/3] riscv: kgdb: use patch_insn_write() to set breakpoints Clément Léger
2026-11-13  7:16   ` Clément Léger
2026-11-13  7:16 ` [PATCH 2/3] riscv: kgdb: use BREAK_INSTR_SIZE instead of hardcoded value Clément Léger
2026-11-13  7:16   ` Clément Léger
2026-11-13  7:16 ` [PATCH 3/3] riscv: kgdb: clear bit 0 of single-step jump targets Clément Léger
2026-11-13  7:16   ` Clément Léger

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20261113071616.219623-1-clement.leger@linux.dev \
    --to=clement.leger@linux.dev \
    --cc=alex@ghiti.fr \
    --cc=aou@eecs.berkeley.edu \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-riscv@lists.infradead.org \
    --cc=palmer@dabbelt.com \
    --cc=pjw@kernel.org \
    --cc=wangyuli@uniontech.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.