Messages in this thread Patch in this message | | | From | Shuah Khan <> | Subject | [PATCH v3 05/11] drivers/acpi: convert seqno counter_atomic32 | Date | Fri, 9 Oct 2020 09:56:00 -0600 |
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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
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