* [PATCH v2] eal: handle sysconf(_SC_PAGESIZE) negative return value
2025-06-10 13:13 [PATCH] eal: handle sysconf() negative return value Morten Brørup
@ 2025-06-12 14:06 ` Morten Brørup
0 siblings, 0 replies; 2+ messages in thread
From: Morten Brørup @ 2025-06-12 14:06 UTC (permalink / raw)
To: Tyler Retzlaff, Anatoly Burakov, Bruce Richardson,
Maxime Coquelin, Chenbo Xia, Tomasz Duszynski, Stephen Hemminger,
dev
Cc: Morten Brørup
eal: handle sysconf(_SC_PAGESIZE) negative return value
Coverity reports some defects, where the root cause seems to be negative
return value from sysconf(_SC_PAGESIZE) not being handled.
rte_mem_page_size() was updated to handle negative return value from
sysconf(_SC_PAGESIZE).
All other functions calling sysconf(_SC_PAGESIZE) directly were updated to
call rte_mem_page_size() instead.
At this time, no other calls to sysconf(_SC_PAGESIZE) have been found in
the DPDK libraries.
PS: "_SC_PAGESIZE" has the alias "_SC_PAGE_SIZE". Both are covered here.
Moved the PMU library to the correct location in the meson.build file; it
depends on the EAL, not vice versa.
And an unrelated drive-by minor fix in eal_mem_set_dump():
When madvise() failed, an incorrect reason was logged.
Signed-off-by: Morten Brørup <mb@smartsharesystems.com>
---
v2:
* Clarify in title and description that only sysconf(_SC_PAGESIZE) is
covered, and in description that only DPDK libs have been patched.
* Include new PMU library in patch after rebasing.
v1:
* Improve comment about errno for indeterminate sysconf() values.
(Stephen)
---
lib/eal/freebsd/eal.c | 3 ++-
lib/eal/freebsd/eal_memory.c | 7 +++----
lib/eal/linux/eal.c | 3 ++-
lib/eal/unix/eal_unix_memory.c | 16 ++++++++++++++--
lib/meson.build | 2 +-
lib/pmu/pmu.c | 8 ++++----
lib/vhost/vduse.c | 3 ++-
7 files changed, 28 insertions(+), 14 deletions(-)
diff --git a/lib/eal/freebsd/eal.c b/lib/eal/freebsd/eal.c
index 82382d6e8f..c1ab8d86d2 100644
--- a/lib/eal/freebsd/eal.c
+++ b/lib/eal/freebsd/eal.c
@@ -26,6 +26,7 @@
#include <rte_launch.h>
#include <rte_eal.h>
#include <rte_eal_memconfig.h>
+#include <rte_eal_paging.h>
#include <rte_errno.h>
#include <rte_per_lcore.h>
#include <rte_lcore.h>
@@ -98,7 +99,7 @@ rte_eal_config_create(void)
struct rte_config *config = rte_eal_get_configuration();
const struct internal_config *internal_conf =
eal_get_internal_configuration();
- size_t page_sz = sysconf(_SC_PAGE_SIZE);
+ size_t page_sz = rte_mem_page_size();
size_t cfg_len = sizeof(struct rte_mem_config);
size_t cfg_len_aligned = RTE_ALIGN(cfg_len, page_sz);
void *rte_mem_cfg_addr, *mapped_mem_cfg_addr;
diff --git a/lib/eal/freebsd/eal_memory.c b/lib/eal/freebsd/eal_memory.c
index 3b72e13506..6d3d46a390 100644
--- a/lib/eal/freebsd/eal_memory.c
+++ b/lib/eal/freebsd/eal_memory.c
@@ -11,6 +11,7 @@
#include <fcntl.h>
#include <rte_eal.h>
+#include <rte_eal_paging.h>
#include <rte_errno.h>
#include <rte_log.h>
#include <rte_string_fns.h>
@@ -22,8 +23,6 @@
#include "eal_memcfg.h"
#include "eal_options.h"
-#define EAL_PAGE_SIZE (sysconf(_SC_PAGESIZE))
-
uint64_t eal_get_baseaddr(void)
{
/*
@@ -191,7 +190,7 @@ rte_eal_hugepage_init(void)
addr = mmap(addr, page_sz, PROT_READ|PROT_WRITE,
MAP_SHARED | MAP_FIXED,
hpi->lock_descriptor,
- j * EAL_PAGE_SIZE);
+ j * rte_mem_page_size());
if (addr == MAP_FAILED) {
EAL_LOG(ERR, "Failed to mmap buffer %u from %s",
j, hpi->hugedir);
@@ -243,7 +242,7 @@ attach_segment(const struct rte_memseg_list *msl, const struct rte_memseg *ms,
addr = mmap(ms->addr, ms->len, PROT_READ | PROT_WRITE,
MAP_SHARED | MAP_FIXED, wa->fd_hugepage,
- wa->seg_idx * EAL_PAGE_SIZE);
+ wa->seg_idx * rte_mem_page_size());
if (addr == MAP_FAILED || addr != ms->addr)
return -1;
wa->seg_idx++;
diff --git a/lib/eal/linux/eal.c b/lib/eal/linux/eal.c
index 54bee4a2cf..52efb8626b 100644
--- a/lib/eal/linux/eal.c
+++ b/lib/eal/linux/eal.c
@@ -31,6 +31,7 @@
#include <rte_launch.h>
#include <rte_eal.h>
#include <rte_eal_memconfig.h>
+#include <rte_eal_paging.h>
#include <rte_errno.h>
#include <rte_lcore.h>
#include <rte_service_component.h>
@@ -179,7 +180,7 @@ static int
rte_eal_config_create(void)
{
struct rte_config *config = rte_eal_get_configuration();
- size_t page_sz = sysconf(_SC_PAGE_SIZE);
+ size_t page_sz = rte_mem_page_size();
size_t cfg_len = sizeof(*config->mem_config);
size_t cfg_len_aligned = RTE_ALIGN(cfg_len, page_sz);
void *rte_mem_cfg_addr, *mapped_mem_cfg_addr;
diff --git a/lib/eal/unix/eal_unix_memory.c b/lib/eal/unix/eal_unix_memory.c
index 61e914b8db..562b2b6d92 100644
--- a/lib/eal/unix/eal_unix_memory.c
+++ b/lib/eal/unix/eal_unix_memory.c
@@ -89,7 +89,7 @@ eal_mem_set_dump(void *virt, size_t size, bool dump)
int ret = madvise(virt, size, flags);
if (ret) {
EAL_LOG(DEBUG, "madvise(%p, %#zx, %d) failed: %s",
- virt, size, flags, strerror(rte_errno));
+ virt, size, flags, strerror(errno));
rte_errno = errno;
}
return ret;
@@ -147,8 +147,20 @@ rte_mem_page_size(void)
{
static size_t page_size;
- if (!page_size)
+ if (page_size == 0) {
+ /*
+ * When the sysconf value cannot be determined, sysconf()
+ * returns -1 without setting errno.
+ * To distinguish an indeterminate value from an error,
+ * clear errno before calling sysconf(), and check whether
+ * errno has been set if sysconf() returns -1.
+ */
+ errno = 0;
page_size = sysconf(_SC_PAGESIZE);
+ if ((ssize_t)page_size < 0)
+ rte_panic("sysconf(_SC_PAGESIZE) failed: %s",
+ errno == 0 ? "Indeterminate" : strerror(errno));
+ }
return page_size;
}
diff --git a/lib/meson.build b/lib/meson.build
index 1934cb4a29..7c1c21e6bc 100644
--- a/lib/meson.build
+++ b/lib/meson.build
@@ -13,7 +13,6 @@ libraries = [
'kvargs', # eal depends on kvargs
'argparse',
'telemetry', # basic info querying
- 'pmu',
'eal', # everything depends on eal
'ptr_compress',
'ring',
@@ -49,6 +48,7 @@ libraries = [
'lpm',
'member',
'pcapng',
+ 'pmu',
'power',
'rawdev',
'regexdev',
diff --git a/lib/pmu/pmu.c b/lib/pmu/pmu.c
index 46b0b450ac..267d48c3d6 100644
--- a/lib/pmu/pmu.c
+++ b/lib/pmu/pmu.c
@@ -14,6 +14,7 @@
#include <eal_export.h>
#include <rte_bitops.h>
+#include <rte_eal_paging.h>
#include <rte_tailq.h>
#include <rte_log.h>
@@ -215,13 +216,12 @@ open_events(struct rte_pmu_event_group *group)
static int
mmap_events(struct rte_pmu_event_group *group)
{
- long page_size = sysconf(_SC_PAGE_SIZE);
unsigned int i;
void *addr;
int ret;
for (i = 0; i < rte_pmu.num_group_events; i++) {
- addr = mmap(0, page_size, PROT_READ, MAP_SHARED, group->fds[i], 0);
+ addr = mmap(0, rte_mem_page_size(), PROT_READ, MAP_SHARED, group->fds[i], 0);
if (addr == MAP_FAILED) {
ret = -errno;
goto out;
@@ -233,7 +233,7 @@ mmap_events(struct rte_pmu_event_group *group)
return 0;
out:
for (; i; i--) {
- munmap(group->mmap_pages[i - 1], page_size);
+ munmap(group->mmap_pages[i - 1], rte_mem_page_size());
group->mmap_pages[i - 1] = NULL;
}
@@ -250,7 +250,7 @@ cleanup_events(struct rte_pmu_event_group *group)
for (i = 0; i < rte_pmu.num_group_events; i++) {
if (group->mmap_pages[i]) {
- munmap(group->mmap_pages[i], sysconf(_SC_PAGE_SIZE));
+ munmap(group->mmap_pages[i], rte_mem_page_size());
group->mmap_pages[i] = NULL;
}
diff --git a/lib/vhost/vduse.c b/lib/vhost/vduse.c
index a2a7d73388..9de7f04a4f 100644
--- a/lib/vhost/vduse.c
+++ b/lib/vhost/vduse.c
@@ -16,6 +16,7 @@
#include <sys/stat.h>
#include <rte_common.h>
+#include <rte_eal_paging.h>
#include <rte_thread.h>
#include "fd_man.h"
@@ -690,7 +691,7 @@ vduse_device_create(const char *path, bool compliant_ol_flags)
dev_config->vendor_id = 0;
dev_config->features = features;
dev_config->vq_num = total_queues;
- dev_config->vq_align = sysconf(_SC_PAGE_SIZE);
+ dev_config->vq_align = rte_mem_page_size();
dev_config->config_size = sizeof(struct virtio_net_config);
memcpy(dev_config->config, &vnet_config, sizeof(vnet_config));
--
2.43.0
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