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From: Shuah Khan <skhan@linuxfoundation.org>
To: rafael@kernel.org, james.morse@arm.com, tony.luck@intel.com,
	bp@alien8.de, gregkh@linuxfoundation.org, keescook@chromium.org
Cc: Shuah Khan <skhan@linuxfoundation.org>,
	linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org,
	Borislav Petkov <bp@suse.de>
Subject: [PATCH v2 06/11] drivers/acpi/apei: convert seqno counter_atomic32
Date: Tue,  6 Oct 2020 14:44:37 -0600	[thread overview]
Message-ID: <884f1fddfbc1a991f5f5bbada3ea63c1e3afab20.1602011710.git.skhan@linuxfoundation.org> (raw)
In-Reply-To: <cover.1602011710.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 will wrap around to 0 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>
Acked-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
---
 drivers/acpi/apei/ghes.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c
index 81bf71b10d44..92169436be18 100644
--- a/drivers/acpi/apei/ghes.c
+++ b/drivers/acpi/apei/ghes.c
@@ -41,6 +41,7 @@
 #include <linux/uuid.h>
 #include <linux/ras.h>
 #include <linux/task_work.h>
+#include <linux/counters.h>
 
 #include <acpi/actbl1.h>
 #include <acpi/ghes.h>
@@ -562,7 +563,7 @@ static void __ghes_print_estatus(const char *pfx,
 				 const struct acpi_hest_generic *generic,
 				 const struct acpi_hest_generic_status *estatus)
 {
-	static atomic_t seqno;
+	static struct counter_atomic32 seqno = COUNTER_ATOMIC_INIT(0);
 	unsigned int curr_seqno;
 	char pfx_seq[64];
 
@@ -573,7 +574,7 @@ static void __ghes_print_estatus(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}" HW_ERR, pfx, curr_seqno);
 	printk("%s""Hardware error from APEI Generic Hardware Error Source: %d\n",
 	       pfx_seq, generic->header.source_id);
-- 
2.25.1


  parent reply	other threads:[~2020-10-06 20:46 UTC|newest]

Thread overview: 36+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-10-06 20:44 [PATCH v2 00/11] Introduce Simple atomic counters Shuah Khan
2020-10-06 20:44 ` [PATCH v2 01/11] counters: Introduce counter_atomic* counters Shuah Khan
2020-10-07  9:04   ` Greg KH
2020-10-08 17:18     ` Shuah Khan
2020-10-07 18:11   ` Kees Cook
2020-10-07 19:26     ` Shuah Khan
2020-10-07 20:30       ` Kees Cook
2020-10-06 20:44 ` [PATCH v2 02/11] selftests:lib:test_counters: add new test for counters Shuah Khan
2020-10-07 18:12   ` Kees Cook
2020-10-06 20:44 ` [PATCH v2 03/11] drivers/base: convert deferred_trigger_count and probe_count to counter_atomic32 Shuah Khan
2020-10-07 18:13   ` Kees Cook
2020-10-06 20:44 ` [PATCH v2 04/11] drivers/base/devcoredump: convert devcd_count " Shuah Khan
2020-10-07 18:15   ` Kees Cook
2020-10-07 19:33     ` Shuah Khan
2020-10-07 19:38       ` Johannes Berg
2020-10-07 19:59         ` Shuah Khan
2020-10-07 20:43         ` Kees Cook
2020-10-08  6:42           ` Johannes Berg
2020-10-08  7:37             ` Kees Cook
2020-10-06 20:44 ` [PATCH v2 05/11] drivers/acpi: convert seqno counter_atomic32 Shuah Khan
2020-10-07 18:16   ` Kees Cook
2020-10-06 20:44 ` Shuah Khan [this message]
2020-10-07 18:17   ` [PATCH v2 06/11] drivers/acpi/apei: " Kees Cook
2020-10-06 20:44 ` [PATCH v2 07/11] drivers/android/binder: convert stats, transaction_log to counter_atomic32 Shuah Khan
2020-10-07 18:18   ` Kees Cook
2020-10-09 12:39   ` Christian Brauner
2020-10-06 20:44 ` [PATCH v2 08/11] drivers/base/test/test_async_driver_probe: convert to use counter_atomic32 Shuah Khan
2020-10-07 18:20   ` Kees Cook
2020-10-06 20:44 ` [PATCH v2 09/11] drivers/char/ipmi: convert stats " Shuah Khan
2020-10-07 18:21   ` Kees Cook
2020-10-06 20:44 ` [PATCH v2 10/11] drivers/misc/vmw_vmci: convert num guest devices counter to counter_atomic32 Shuah Khan
2020-10-07 18:27   ` Kees Cook
2020-10-08 17:12     ` Shuah Khan
2020-10-06 20:44 ` [PATCH v2 11/11] drivers/edac: convert pci counters " Shuah Khan
2020-10-07 18:28   ` Kees Cook
2020-10-07 18:30 ` [PATCH v2 00/11] Introduce Simple atomic counters Kees Cook

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