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From: Mark Rutland <mark.rutland@arm.com>
To: linux-arm-kernel@lists.infradead.org
Cc: ardb@kernel.org, catalin.marinas@arm.com, james.morse@arm.com,
	joey.gouly@arm.com, mark.rutland@arm.com, maz@kernel.org,
	will@kernel.org
Subject: [PATCH 4/9] arm64: alternatives: hoist print out of __apply_alternatives()
Date: Thu,  1 Sep 2022 16:13:58 +0100	[thread overview]
Message-ID: <20220901151403.1735836-5-mark.rutland@arm.com> (raw)
In-Reply-To: <20220901151403.1735836-1-mark.rutland@arm.com>

Printing in the middle of __apply_alternatives() is potentially unsafe
and not all that helpful given these days we practically always patch
*something*.

Hoist the print out of __apply_alternatives(), and add separate prints
to __apply_alternatives() and apply_alternatives_all(), which will make
it easier to spot if either patching call goes wrong.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Joey Gouly <joey.gouly@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Will Deacon <will@kernel.org>
---
 arch/arm64/kernel/alternative.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/kernel/alternative.c b/arch/arm64/kernel/alternative.c
index 9bcaa5eacf16c..d94d97cb4a0bf 100644
--- a/arch/arm64/kernel/alternative.c
+++ b/arch/arm64/kernel/alternative.c
@@ -156,8 +156,6 @@ static void __nocfi __apply_alternatives(struct alt_region *region, bool is_modu
 		else
 			BUG_ON(alt->alt_len != alt->orig_len);
 
-		pr_info_once("patching kernel code\n");
-
 		origptr = ALT_ORIG_PTR(alt);
 		updptr = is_module ? origptr : lm_alias(origptr);
 		nr_inst = alt->orig_len / AARCH64_INSN_SIZE;
@@ -225,6 +223,8 @@ static int __apply_alternatives_multi_stop(void *unused)
 
 void __init apply_alternatives_all(void)
 {
+	pr_info("applying system-wide alternatives\n");
+
 	/* better not try code patching on a live SMP system */
 	stop_machine(__apply_alternatives_multi_stop, NULL, cpu_online_mask);
 }
@@ -244,6 +244,8 @@ void __init apply_boot_alternatives(void)
 	/* If called on non-boot cpu things could go wrong */
 	WARN_ON(smp_processor_id() != 0);
 
+	pr_info("applying boot alternatives\n");
+
 	__apply_alternatives(&region, false, &boot_capabilities[0]);
 }
 
-- 
2.30.2


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  parent reply	other threads:[~2022-09-01 15:15 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-09-01 15:13 [PATCH 0/9] arm64: alternatives: improvements Mark Rutland
2022-09-01 15:13 ` [PATCH 1/9] arm64: cpufeature: make cpus_have_cap() noinstr-safe Mark Rutland
2022-09-01 15:13 ` [PATCH 2/9] arm64: alternatives: kvm: prepare for cap changes Mark Rutland
2022-09-01 15:13 ` [PATCH 3/9] arm64: alternatives: proton-pack: " Mark Rutland
2022-09-02 16:19   ` Joey Gouly
2022-09-05  8:46     ` Mark Rutland
2022-09-01 15:13 ` Mark Rutland [this message]
2022-09-01 15:13 ` [PATCH 5/9] arm64: alternatives: make alt_region const Mark Rutland
2022-09-06 15:18   ` Ard Biesheuvel
2022-09-12  9:31     ` Mark Rutland
2022-09-12 10:13       ` Ard Biesheuvel
2022-09-12 12:13         ` Mark Rutland
2022-09-01 15:14 ` [PATCH 6/9] arm64: alternatives: have callbacks take a cap Mark Rutland
2022-09-02 15:54   ` Joey Gouly
2022-09-05  8:48     ` Mark Rutland
2022-09-01 15:14 ` [PATCH 7/9] arm64: alternatives: add alternative_has_feature_*() Mark Rutland
2022-09-01 15:14 ` [PATCH 8/9] arm64: alternatives: add shared NOP callback Mark Rutland
2022-09-01 15:14 ` [PATCH 9/9] HACK: arm64: alternatives: dump summary of alternatives Mark Rutland
2022-09-12 12:36   ` Mark Brown
2022-09-12 16:14     ` Mark Rutland

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