From: Shuah Khan <skhan@linuxfoundation.org>
To: rafael@kernel.org, lenb@kernel.org, gregkh@linuxfoundation.org,
keescook@chromium.org
Cc: Shuah Khan <skhan@linuxfoundation.org>,
linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH v3 05/11] drivers/acpi: convert seqno counter_atomic32
Date: Fri, 9 Oct 2020 09:56:00 -0600 [thread overview]
Message-ID: <53a101719b89cd0db55885f726a186bc987aba1e.1602209970.git.skhan@linuxfoundation.org> (raw)
In-Reply-To: <cover.1602209970.git.skhan@linuxfoundation.org>
counter_atomic* is introduced to be used when a variable is used as
a simple counter and doesn't guard object lifetimes. This clearly
differentiates atomic_t usages that guard object lifetimes.
counter_atomic* variables wrap around to INT_MIN when it overflows and
should not be used to guard resource lifetimes, device usage and
open counts that control state changes, and pm states.
seqno is a sequence number counter for logging. This counter gets
incremented. Unsure if there is a chance of this overflowing. It
doesn't look like overflowing causes any problems since it is used
to tag the log messages and nothing more.
Convert it to use counter_atomic32.
This conversion doesn't change the overflow wrap around behavior.
Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
---
drivers/acpi/acpi_extlog.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/acpi/acpi_extlog.c b/drivers/acpi/acpi_extlog.c
index f138e12b7b82..d1e733f15cf5 100644
--- a/drivers/acpi/acpi_extlog.c
+++ b/drivers/acpi/acpi_extlog.c
@@ -12,6 +12,7 @@
#include <linux/ratelimit.h>
#include <linux/edac.h>
#include <linux/ras.h>
+#include <linux/counters.h>
#include <asm/cpu.h>
#include <asm/mce.h>
@@ -93,7 +94,7 @@ static struct acpi_hest_generic_status *extlog_elog_entry_check(int cpu, int ban
static void __print_extlog_rcd(const char *pfx,
struct acpi_hest_generic_status *estatus, int cpu)
{
- static atomic_t seqno;
+ static struct counter_atomic32 seqno;
unsigned int curr_seqno;
char pfx_seq[64];
@@ -103,7 +104,7 @@ static void __print_extlog_rcd(const char *pfx,
else
pfx = KERN_ERR;
}
- curr_seqno = atomic_inc_return(&seqno);
+ curr_seqno = counter_atomic32_inc_return(&seqno);
snprintf(pfx_seq, sizeof(pfx_seq), "%s{%u}", pfx, curr_seqno);
printk("%s""Hardware error detected on CPU%d\n", pfx_seq, cpu);
cper_estatus_print(pfx_seq, estatus);
--
2.25.1
next prev parent reply other threads:[~2020-10-09 15:56 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-09 15:55 [PATCH v3 00/11] Introduce Simple atomic counters Shuah Khan
2020-10-09 15:56 ` Shuah Khan [this message]
2020-10-09 15:56 ` [PATCH v3 06/11] drivers/acpi/apei: convert seqno counter_atomic32 Shuah Khan
2020-10-09 18:03 ` [PATCH v3 00/11] Introduce Simple atomic counters Kees Cook
2020-10-09 19:02 ` Shuah Khan
2020-10-09 19:37 ` Peter Zijlstra
2020-10-09 20:45 ` Kees Cook
2020-10-10 11:09 ` Peter Zijlstra
2020-10-14 2:12 ` Shuah Khan
2020-10-14 9:17 ` Peter Zijlstra
2020-10-14 23:31 ` Kees Cook
2020-10-16 10:53 ` Peter Zijlstra
2020-10-16 22:51 ` Kees Cook
2020-11-10 18:49 ` Dan Carpenter
2020-10-16 21:56 ` Shuah Khan
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