From: Samuel Holland <samuel.holland@sifive.com> To: Palmer Dabbelt <palmer@dabbelt.com> Cc: "Björn Töpel" <bjorn@rivosinc.com>, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, "Samuel Holland" <samuel.holland@sifive.com> Subject: [PATCH v2 4/7] riscv: Simplify text patching loops Date: Wed, 27 Mar 2024 09:04:43 -0700 [thread overview] Message-ID: <20240327160520.791322-5-samuel.holland@sifive.com> (raw) In-Reply-To: <20240327160520.791322-1-samuel.holland@sifive.com> This reduces the number of variables and makes the code easier to parse. Signed-off-by: Samuel Holland <samuel.holland@sifive.com> --- Changes in v2: - Further simplify patch_insn_set()/patch_insn_write() loop conditions - Use min() instead of min_t() since both sides are unsigned long arch/riscv/kernel/patch.c | 37 +++++++++++++++++++++---------------- 1 file changed, 21 insertions(+), 16 deletions(-) diff --git a/arch/riscv/kernel/patch.c b/arch/riscv/kernel/patch.c index 9a1bce1adf5a..0d1700d1934c 100644 --- a/arch/riscv/kernel/patch.c +++ b/arch/riscv/kernel/patch.c @@ -155,22 +155,24 @@ NOKPROBE_SYMBOL(__patch_insn_write); static int patch_insn_set(void *addr, u8 c, size_t len) { - size_t patched = 0; size_t size; - int ret = 0; + int ret; /* * __patch_insn_set() can only work on 2 pages at a time so call it in a * loop with len <= 2 * PAGE_SIZE. */ - while (patched < len && !ret) { - size = min_t(size_t, PAGE_SIZE * 2 - offset_in_page(addr + patched), len - patched); - ret = __patch_insn_set(addr + patched, c, size); - - patched += size; + while (len) { + size = min(len, PAGE_SIZE * 2 - offset_in_page(addr)); + ret = __patch_insn_set(addr, c, size); + if (ret) + return ret; + + addr += size; + len -= size; } - return ret; + return 0; } NOKPROBE_SYMBOL(patch_insn_set); @@ -190,22 +192,25 @@ NOKPROBE_SYMBOL(patch_text_set_nosync); int patch_insn_write(void *addr, const void *insn, size_t len) { - size_t patched = 0; size_t size; - int ret = 0; + int ret; /* * Copy the instructions to the destination address, two pages at a time * because __patch_insn_write() can only handle len <= 2 * PAGE_SIZE. */ - while (patched < len && !ret) { - size = min_t(size_t, PAGE_SIZE * 2 - offset_in_page(addr + patched), len - patched); - ret = __patch_insn_write(addr + patched, insn + patched, size); - - patched += size; + while (len) { + size = min(len, PAGE_SIZE * 2 - offset_in_page(addr)); + ret = __patch_insn_write(addr, insn, size); + if (ret) + return ret; + + addr += size; + insn += size; + len -= size; } - return ret; + return 0; } NOKPROBE_SYMBOL(patch_insn_write); -- 2.43.1
WARNING: multiple messages have this Message-ID (diff)
From: Samuel Holland <samuel.holland@sifive.com> To: Palmer Dabbelt <palmer@dabbelt.com> Cc: "Björn Töpel" <bjorn@rivosinc.com>, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, "Samuel Holland" <samuel.holland@sifive.com> Subject: [PATCH v2 4/7] riscv: Simplify text patching loops Date: Wed, 27 Mar 2024 09:04:43 -0700 [thread overview] Message-ID: <20240327160520.791322-5-samuel.holland@sifive.com> (raw) In-Reply-To: <20240327160520.791322-1-samuel.holland@sifive.com> This reduces the number of variables and makes the code easier to parse. Signed-off-by: Samuel Holland <samuel.holland@sifive.com> --- Changes in v2: - Further simplify patch_insn_set()/patch_insn_write() loop conditions - Use min() instead of min_t() since both sides are unsigned long arch/riscv/kernel/patch.c | 37 +++++++++++++++++++++---------------- 1 file changed, 21 insertions(+), 16 deletions(-) diff --git a/arch/riscv/kernel/patch.c b/arch/riscv/kernel/patch.c index 9a1bce1adf5a..0d1700d1934c 100644 --- a/arch/riscv/kernel/patch.c +++ b/arch/riscv/kernel/patch.c @@ -155,22 +155,24 @@ NOKPROBE_SYMBOL(__patch_insn_write); static int patch_insn_set(void *addr, u8 c, size_t len) { - size_t patched = 0; size_t size; - int ret = 0; + int ret; /* * __patch_insn_set() can only work on 2 pages at a time so call it in a * loop with len <= 2 * PAGE_SIZE. */ - while (patched < len && !ret) { - size = min_t(size_t, PAGE_SIZE * 2 - offset_in_page(addr + patched), len - patched); - ret = __patch_insn_set(addr + patched, c, size); - - patched += size; + while (len) { + size = min(len, PAGE_SIZE * 2 - offset_in_page(addr)); + ret = __patch_insn_set(addr, c, size); + if (ret) + return ret; + + addr += size; + len -= size; } - return ret; + return 0; } NOKPROBE_SYMBOL(patch_insn_set); @@ -190,22 +192,25 @@ NOKPROBE_SYMBOL(patch_text_set_nosync); int patch_insn_write(void *addr, const void *insn, size_t len) { - size_t patched = 0; size_t size; - int ret = 0; + int ret; /* * Copy the instructions to the destination address, two pages at a time * because __patch_insn_write() can only handle len <= 2 * PAGE_SIZE. */ - while (patched < len && !ret) { - size = min_t(size_t, PAGE_SIZE * 2 - offset_in_page(addr + patched), len - patched); - ret = __patch_insn_write(addr + patched, insn + patched, size); - - patched += size; + while (len) { + size = min(len, PAGE_SIZE * 2 - offset_in_page(addr)); + ret = __patch_insn_write(addr, insn, size); + if (ret) + return ret; + + addr += size; + insn += size; + len -= size; } - return ret; + return 0; } NOKPROBE_SYMBOL(patch_insn_write); -- 2.43.1 _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv
next prev parent reply other threads:[~2024-03-27 16:05 UTC|newest] Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top 2024-03-27 16:04 [PATCH v2 0/7] riscv: Various text patching improvements Samuel Holland 2024-03-27 16:04 ` Samuel Holland 2024-03-27 16:04 ` [PATCH v2 1/7] riscv: jump_label: Batch icache maintenance Samuel Holland 2024-03-27 16:04 ` Samuel Holland 2024-03-27 16:04 ` [PATCH v2 2/7] riscv: jump_label: Simplify assembly syntax Samuel Holland 2024-03-27 16:04 ` Samuel Holland 2024-03-27 16:04 ` [PATCH v2 3/7] riscv: kprobes: Use patch_text_nosync() for insn slots Samuel Holland 2024-03-27 16:04 ` Samuel Holland 2024-03-27 16:04 ` Samuel Holland [this message] 2024-03-27 16:04 ` [PATCH v2 4/7] riscv: Simplify text patching loops Samuel Holland 2024-04-02 11:13 ` Björn Töpel 2024-04-02 11:13 ` Björn Töpel 2024-04-24 10:44 ` Conor Dooley 2024-04-24 10:44 ` Conor Dooley 2024-04-24 10:47 ` Conor Dooley 2024-04-24 10:47 ` Conor Dooley 2024-03-27 16:04 ` [PATCH v2 5/7] riscv: Pass patch_text() the length in bytes Samuel Holland 2024-03-27 16:04 ` Samuel Holland 2024-04-24 10:49 ` Conor Dooley 2024-04-24 10:49 ` Conor Dooley 2024-03-27 16:04 ` [PATCH v2 6/7] riscv: Use offset_in_page() in text patching functions Samuel Holland 2024-03-27 16:04 ` Samuel Holland 2024-04-24 10:51 ` Conor Dooley 2024-04-24 10:51 ` Conor Dooley 2024-03-27 16:04 ` [PATCH v2 7/7] riscv: Remove extra variable in patch_text_nosync() Samuel Holland 2024-03-27 16:04 ` Samuel Holland 2024-04-24 10:54 ` Conor Dooley 2024-04-24 10:54 ` Conor Dooley
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