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
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next 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
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