From: Andrew Jones <ajones@ventanamicro•com>
To: x86@kernel•org, linux-riscv@lists•infradead.org,
linux-kernel@vger•kernel.org
Cc: Jonas Bonn <jonas@southpole•se>,
linux-s390@vger•kernel.org,
Alexander Gordeev <agordeev@linux•ibm.com>,
Albert Ou <aou@eecs•berkeley.edu>,
Vasily Gorbik <gor@linux•ibm.com>,
Yury Norov <yury.norov@gmail•com>,
Heiko Carstens <hca@linux•ibm.com>,
Dave Hansen <dave.hansen@linux•intel.com>,
Stefan Kristiansson <stefan.kristiansson@saunalahti•fi>,
Ingo Molnar <mingo@redhat•com>, Borislav Petkov <bp@alien8•de>,
Paul Walmsley <paul.walmsley@sifive•com>,
Palmer Dabbelt <palmer@dabbelt•com>,
Thomas Gleixner <tglx@linutronix•de>,
linuxppc-dev@lists•ozlabs.org, Stafford Horne <shorne@gmail•com>,
openrisc@lists•librecores.org
Subject: [PATCH v3 2/2] x86: Fix /proc/cpuinfo cpumask warning
Date: Fri, 14 Oct 2022 17:58:45 +0200 [thread overview]
Message-ID: <20221014155845.1986223-3-ajones@ventanamicro.com> (raw)
In-Reply-To: <20221014155845.1986223-1-ajones@ventanamicro.com>
Commit 78e5a3399421 ("cpumask: fix checking valid cpu range") has
started issuing warnings[*] when cpu indices equal to nr_cpu_ids - 1
are passed to cpumask_next* functions. seq_read_iter() and cpuinfo's
start and next seq operations implement a pattern like
n = cpumask_next(n - 1, mask);
show(n);
while (1) {
++n;
n = cpumask_next(n - 1, mask);
if (n >= nr_cpu_ids)
break;
show(n);
}
which will issue the warning when reading /proc/cpuinfo. Ensure no
warning is generated by validating the cpu index before calling
cpumask_next().
[*] Warnings will only appear with DEBUG_PER_CPU_MAPS enabled.
Signed-off-by: Andrew Jones <ajones@ventanamicro•com>
Cc: Yury Norov <yury.norov@gmail•com>
---
arch/x86/kernel/cpu/proc.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/arch/x86/kernel/cpu/proc.c b/arch/x86/kernel/cpu/proc.c
index 099b6f0d96bd..de3f93ac6e49 100644
--- a/arch/x86/kernel/cpu/proc.c
+++ b/arch/x86/kernel/cpu/proc.c
@@ -153,6 +153,9 @@ static int show_cpuinfo(struct seq_file *m, void *v)
static void *c_start(struct seq_file *m, loff_t *pos)
{
+ if (*pos == nr_cpu_ids)
+ return NULL;
+
*pos = cpumask_next(*pos - 1, cpu_online_mask);
if ((*pos) < nr_cpu_ids)
return &cpu_data(*pos);
--
2.37.3
next prev parent reply other threads:[~2022-10-14 16:00 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-14 15:58 [PATCH v3 0/2] Fix /proc/cpuinfo cpumask warning Andrew Jones
2022-10-14 15:58 ` [PATCH v3 1/2] RISC-V: " Andrew Jones
2022-10-14 15:58 ` Andrew Jones [this message]
2022-10-28 7:48 ` [PATCH v3 2/2] x86: " Andrew Jones
2022-10-28 14:46 ` Yury Norov
2022-10-28 15:03 ` Borislav Petkov
2022-10-28 15:13 ` Yury Norov
2022-10-28 16:06 ` Borislav Petkov
2022-10-31 8:06 ` Andrew Jones
2022-10-31 8:58 ` Borislav Petkov
2022-10-31 10:03 ` Andrew Jones
2022-11-02 18:44 ` Borislav Petkov
2022-11-03 12:59 ` Andrew Jones
2022-11-03 15:02 ` Borislav Petkov
2022-11-03 15:34 ` Andrew Jones
2022-11-03 15:54 ` Borislav Petkov
2022-11-03 16:30 ` yury.norov
2022-11-03 16:49 ` Borislav Petkov
2022-11-03 17:31 ` Yury Norov
2022-11-03 23:22 ` Borislav Petkov
2022-10-15 18:08 ` [PATCH v3 0/2] " Yury Norov
2022-10-27 23:07 ` Palmer Dabbelt
2022-10-28 7:40 ` Andrew Jones
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