systeminfo_gpci_request() and
affinity_domain_via_partition_result_parse() hex-encode hypervisor data
into the single-page sysfs read buffer with sprintf(buf + *n, ...).
Both helpers only check PAGE_SIZE after the formatting loops have
already advanced past the end of the buffer.
Add small helpers around sysfs_emit_at() for hex-byte and newline
appends, and stop once the sysfs buffer is full. This keeps the repeated
bounds handling local instead of open-coding it at each append site.
Fixes: 71f1c39647d8 ("powerpc/hv_gpci: Add sysfs file inside hv_gpci device to
show processor bus topology information")
Fixes: a15e0d6a6929 ("powerpc/hv_gpci: Add sysfs file inside hv_gpci device to
show affinity domain via partition information")
Signed-off-by: Pengpeng Hou <[email protected]>
---
Changes since v1:
- refactor the repeated sysfs_emit_at() handling into helpers as suggested
by Christophe Leroy
diff --git a/arch/powerpc/perf/hv-gpci.c b/arch/powerpc/perf/hv-gpci.c
index 5cac2cf3bd1e..2f543f0671ba 100644
--- a/arch/powerpc/perf/hv-gpci.c
+++ b/arch/powerpc/perf/hv-gpci.c
@@ -11,6 +11,7 @@
#include <linux/init.h>
#include <linux/perf_event.h>
+#include <linux/sysfs.h>
#include <asm/firmware.h>
#include <asm/hvcall.h>
#include <asm/io.h>
@@ -129,11 +130,36 @@ static int sysinfo_counter_request[] = {
static DEFINE_PER_CPU(char, hv_gpci_reqb[HGPCI_REQ_BUFFER_SIZE])
__aligned(sizeof(uint64_t));
+static int hv_gpci_emit_hex_byte(char *buf, size_t *n, u8 byte)
+{
+ int len;
+
+ len = sysfs_emit_at(buf, *n, "%02x", byte);
+ if (len <= 0)
+ return -EFBIG;
+
+ *n += len;
+ return 0;
+}
+
+static int hv_gpci_emit_newline(char *buf, size_t *n)
+{
+ int len;
+
+ len = sysfs_emit_at(buf, *n, "\n");
+ if (len <= 0)
+ return -EFBIG;
+
+ *n += len;
+ return 0;
+}
+
static unsigned long systeminfo_gpci_request(u32 req, u32 starting_index,
u16 secondary_index, char *buf,
size_t *n, struct hv_gpci_request_buffer *arg)
{
unsigned long ret;
+ int rc;
size_t i, j;
arg->params.counter_request = cpu_to_be32(req);
@@ -176,9 +202,14 @@ static unsigned long systeminfo_gpci_request(u32 req, u32
starting_index,
for (i = 0; i < be16_to_cpu(arg->params.returned_values); i++) {
j = i * be16_to_cpu(arg->params.cv_element_size);
- for (; j < (i + 1) * be16_to_cpu(arg->params.cv_element_size);
j++)
- *n += sprintf(buf + *n, "%02x", (u8)arg->bytes[j]);
- *n += sprintf(buf + *n, "\n");
+ for (; j < (i + 1) * be16_to_cpu(arg->params.cv_element_size);
j++) {
+ rc = hv_gpci_emit_hex_byte(buf, n, (u8)arg->bytes[j]);
+ if (rc)
+ return rc;
+ }
+ rc = hv_gpci_emit_newline(buf, n);
+ if (rc)
+ return rc;
}
if (*n >= PAGE_SIZE) {
@@ -461,10 +492,14 @@ static ssize_t affinity_domain_via_domain_show(struct
device *dev, struct device
return ret;
}
-static void affinity_domain_via_partition_result_parse(int returned_values,
- int element_size, char *buf, size_t *last_element,
- size_t *n, struct hv_gpci_request_buffer *arg)
+static int affinity_domain_via_partition_result_parse(int returned_values,
+ int element_size,
+ char *buf,
+ size_t *last_element,
+ size_t *n,
+ struct
hv_gpci_request_buffer *arg)
{
+ int rc;
size_t i = 0, j = 0;
size_t k, l, m;
uint16_t total_affinity_domain_ele, size_of_each_affinity_domain_ele;
@@ -483,27 +518,40 @@ static void
affinity_domain_via_partition_result_parse(int returned_values,
*/
while (i < returned_values) {
k = j;
- for (; k < j + element_size; k++)
- *n += sprintf(buf + *n, "%02x", (u8)arg->bytes[k]);
- *n += sprintf(buf + *n, "\n");
+ for (; k < j + element_size; k++) {
+ rc = hv_gpci_emit_hex_byte(buf, n, (u8)arg->bytes[k]);
+ if (rc)
+ return rc;
+ }
+ rc = hv_gpci_emit_newline(buf, n);
+ if (rc)
+ return rc;
total_affinity_domain_ele = (u8)arg->bytes[k - 2] << 8 |
(u8)arg->bytes[k - 3];
size_of_each_affinity_domain_ele = (u8)arg->bytes[k] << 8 |
(u8)arg->bytes[k - 1];
for (l = 0; l < total_affinity_domain_ele; l++) {
for (m = 0; m < size_of_each_affinity_domain_ele; m++) {
- *n += sprintf(buf + *n, "%02x",
(u8)arg->bytes[k]);
+ rc = hv_gpci_emit_hex_byte(buf, n,
(u8)arg->bytes[k]);
+ if (rc)
+ return rc;
k++;
}
- *n += sprintf(buf + *n, "\n");
+ rc = hv_gpci_emit_newline(buf, n);
+ if (rc)
+ return rc;
}
- *n += sprintf(buf + *n, "\n");
+ rc = hv_gpci_emit_newline(buf, n);
+ if (rc)
+ return rc;
i++;
j = k;
}
*last_element = k;
+
+ return 0;
}
static ssize_t affinity_domain_via_partition_show(struct device *dev, struct
device_attribute *attr,
@@ -514,6 +562,7 @@ static ssize_t affinity_domain_via_partition_show(struct
device *dev, struct dev
size_t n = 0;
size_t last_element = 0;
u32 starting_index;
+ int element_size, rc, returned_values;
arg = (void *)get_cpu_var(hv_gpci_reqb);
memset(arg, 0, HGPCI_REQ_BUFFER_SIZE);
@@ -546,10 +595,16 @@ static ssize_t affinity_domain_via_partition_show(struct
device *dev, struct dev
* to buffer util we get all the information.
*/
while (ret == H_PARAMETER) {
- affinity_domain_via_partition_result_parse(
- be16_to_cpu(arg->params.returned_values) - 1,
- be16_to_cpu(arg->params.cv_element_size), buf,
- &last_element, &n, arg);
+ returned_values = be16_to_cpu(arg->params.returned_values);
+ element_size = be16_to_cpu(arg->params.cv_element_size);
+ rc = affinity_domain_via_partition_result_parse(returned_values
- 1,
+ element_size,
buf,
+ &last_element,
&n,
+ arg);
+ if (rc) {
+ put_cpu_var(hv_gpci_reqb);
+ return rc;
+ }
if (n >= PAGE_SIZE) {
put_cpu_var(hv_gpci_reqb);
@@ -578,10 +633,15 @@ static ssize_t affinity_domain_via_partition_show(struct
device *dev, struct dev
}
parse_result:
- affinity_domain_via_partition_result_parse(
- be16_to_cpu(arg->params.returned_values),
- be16_to_cpu(arg->params.cv_element_size),
- buf, &last_element, &n, arg);
+ returned_values = be16_to_cpu(arg->params.returned_values);
+ element_size = be16_to_cpu(arg->params.cv_element_size);
+ rc = affinity_domain_via_partition_result_parse(returned_values,
+ element_size, buf,
+ &last_element, &n, arg);
+ if (rc) {
+ put_cpu_var(hv_gpci_reqb);
+ return rc;
+ }
put_cpu_var(hv_gpci_reqb);
return n;
--
2.50.1 (Apple Git-155)
