[PATCH v3 11/11] drivers/edac: convert pci counters to counter_atomic32

Shuah Khan
2020-10-09T15:56:48Z

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.

atomic_t variables used for pci counters keep track of pci parity and
non-parity errors. Convert them to use counter_atomic32.

Overflow will wrap around and reset the counts as was the case prior to
the conversion.

Acked-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
---
drivers/edac/edac_pci.h | 5 +++--
drivers/edac/edac_pci_sysfs.c | 28 ++++++++++++++--------------
2 files changed, 17 insertions(+), 16 deletions(-)

diff --git a/drivers/edac/edac_pci.h b/drivers/edac/edac_pci.h
index 5175f5724cfa..797b25a6afc0 100644
--- a/drivers/edac/edac_pci.h
+++ b/drivers/edac/edac_pci.h
@@ -30,12 +30,13 @@
#include <linux/pci.h>
#include <linux/types.h>
#include <linux/workqueue.h>
+#include <linux/counters.h>

#ifdef CONFIG_PCI

struct edac_pci_counter {
- atomic_t pe_count;
- atomic_t npe_count;
+ struct counter_atomic32 pe_count;
+ struct counter_atomic32 npe_count;
};

/*
diff --git a/drivers/edac/edac_pci_sysfs.c b/drivers/edac/edac_pci_sysfs.c
index 53042af7262e..d33a726234c0 100644
--- a/drivers/edac/edac_pci_sysfs.c
+++ b/drivers/edac/edac_pci_sysfs.c
@@ -23,8 +23,8 @@ static int edac_pci_log_pe = 1; /* log PCI parity errors */
static int edac_pci_log_npe = 1; /* log PCI non-parity error errors */
static int edac_pci_poll_msec = 1000; /* one second workq period */

-static atomic_t pci_parity_count = ATOMIC_INIT(0);
-static atomic_t pci_nonparity_count = ATOMIC_INIT(0);
+static struct counter_atomic32 pci_parity_count = COUNTER_ATOMIC_INIT(0);
+static struct counter_atomic32 pci_nonparity_count = COUNTER_ATOMIC_INIT(0);

static struct kobject *edac_pci_top_main_kobj;
static atomic_t edac_pci_sysfs_refcount = ATOMIC_INIT(0);
@@ -58,13 +58,13 @@ int edac_pci_get_poll_msec(void)
/**************************** EDAC PCI sysfs instance *******************/
static ssize_t instance_pe_count_show(struct edac_pci_ctl_info *pci, char *data)
{
- return sprintf(data, "%u\n", atomic_read(&pci->counters.pe_count));
+ return sprintf(data, "%u\n", counter_atomic32_read(&pci->counters.pe_count));
}

static ssize_t instance_npe_count_show(struct edac_pci_ctl_info *pci,
char *data)
{
- return sprintf(data, "%u\n", atomic_read(&pci->counters.npe_count));
+ return sprintf(data, "%u\n", counter_atomic32_read(&pci->counters.npe_count));
}

#define to_instance(k) container_of(k, struct edac_pci_ctl_info, kobj)
@@ -553,7 +553,7 @@ static void edac_pci_dev_parity_test(struct pci_dev *dev)
edac_printk(KERN_CRIT, EDAC_PCI,
"Signaled System Error on %s\n",
pci_name(dev));
- atomic_inc(&pci_nonparity_count);
+ counter_atomic32_inc(&pci_nonparity_count);
}

if (status & (PCI_STATUS_PARITY)) {
@@ -561,7 +561,7 @@ static void edac_pci_dev_parity_test(struct pci_dev *dev)
"Master Data Parity Error on %s\n",
pci_name(dev));

- atomic_inc(&pci_parity_count);
+ counter_atomic32_inc(&pci_parity_count);
}

if (status & (PCI_STATUS_DETECTED_PARITY)) {
@@ -569,7 +569,7 @@ static void edac_pci_dev_parity_test(struct pci_dev *dev)
"Detected Parity Error on %s\n",
pci_name(dev));

- atomic_inc(&pci_parity_count);
+ counter_atomic32_inc(&pci_parity_count);
}
}

@@ -592,7 +592,7 @@ static void edac_pci_dev_parity_test(struct pci_dev *dev)
edac_printk(KERN_CRIT, EDAC_PCI, "Bridge "
"Signaled System Error on %s\n",
pci_name(dev));
- atomic_inc(&pci_nonparity_count);
+ counter_atomic32_inc(&pci_nonparity_count);
}

if (status & (PCI_STATUS_PARITY)) {
@@ -600,7 +600,7 @@ static void edac_pci_dev_parity_test(struct pci_dev *dev)
"Master Data Parity Error on "
"%s\n", pci_name(dev));

- atomic_inc(&pci_parity_count);
+ counter_atomic32_inc(&pci_parity_count);
}

if (status & (PCI_STATUS_DETECTED_PARITY)) {
@@ -608,7 +608,7 @@ static void edac_pci_dev_parity_test(struct pci_dev *dev)
"Detected Parity Error on %s\n",
pci_name(dev));

- atomic_inc(&pci_parity_count);
+ counter_atomic32_inc(&pci_parity_count);
}
}
}
@@ -646,7 +646,7 @@ void edac_pci_do_parity_check(void)
if (!check_pci_errors)
return;

- before_count = atomic_read(&pci_parity_count);
+ before_count = counter_atomic32_read(&pci_parity_count);

/* scan all PCI devices looking for a Parity Error on devices and
* bridges.
@@ -658,7 +658,7 @@ void edac_pci_do_parity_check(void)
/* Only if operator has selected panic on PCI Error */
if (edac_pci_get_panic_on_pe()) {
/* If the count is different 'after' from 'before' */
- if (before_count != atomic_read(&pci_parity_count))
+ if (before_count != counter_atomic32_read(&pci_parity_count))
panic("EDAC: PCI Parity Error");
}
}
@@ -686,7 +686,7 @@ void edac_pci_handle_pe(struct edac_pci_ctl_info *pci, const char *msg)
{

/* global PE counter incremented by edac_pci_do_parity_check() */
- atomic_inc(&pci->counters.pe_count);
+ counter_atomic32_inc(&pci->counters.pe_count);

if (edac_pci_get_log_pe())
edac_pci_printk(pci, KERN_WARNING,
@@ -711,7 +711,7 @@ void edac_pci_handle_npe(struct edac_pci_ctl_info *pci, const char *msg)
{

/* global NPE counter incremented by edac_pci_do_parity_check() */
- atomic_inc(&pci->counters.npe_count);
+ counter_atomic32_inc(&pci->counters.npe_count);

if (edac_pci_get_log_npe())
edac_pci_printk(pci, KERN_WARNING,
--
2.25.1