[PATCH v2 0/3] EAL memory fixes

[PATCH v2 0/3] EAL memory fixes

[Jake Freeland]

Hi there,

This patchset contains a number of EAL-specific memory fixes that I've
made over the last year. Two pertain to FreeBSD, one pertains to Linux.

v2:
* Log messages are no longer split across multiple lines.
* The patch titled "Do not index out of bounds in memseg list" has been
  removed since there was no indexing out of bounds happening.
* A new patch has been added per Anatoly's recommendation that starts
  searching for memseg entries after the last used entry.

Jake Freeland (3):
  eal/freebsd: Do not use prev_ms_idx for hole detection
  eal/freebsd: Avoid claiming memseg holes
  eal/linux: Check hugepage access permissions

 lib/eal/freebsd/eal_memory.c      | 24 +++++++++++++++++++-----
 lib/eal/linux/eal_hugepage_info.c |  7 +++++++
 2 files changed, 26 insertions(+), 5 deletions(-)

--
2.47.2

[PATCH v2 1/3] eal/freebsd: Do not use prev_ms_idx for hole detection

[Jake Freeland]

Use rte_fbarray_is_used() to check if the previous fbarray entry is
already empty.

Using prev_ms_idx to do this is flawed in cases where we loop through
multiple memseg lists. Each memseg list has its own count and length,
so using a prev_ms_idx from one memseg list to check for used entries
in another non-empty memseg list can lead to incorrect hole placement.

Signed-off-by: Jake Freeland <jfree@FreeBSD.org>
---
 lib/eal/freebsd/eal_memory.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/lib/eal/freebsd/eal_memory.c b/lib/eal/freebsd/eal_memory.c
index 6d3d46a390..be3bde2cb9 100644
--- a/lib/eal/freebsd/eal_memory.c
+++ b/lib/eal/freebsd/eal_memory.c
@@ -103,7 +103,6 @@ rte_eal_hugepage_init(void)
 	for (i = 0; i < internal_conf->num_hugepage_sizes; i++) {
 		struct hugepage_info *hpi;
 		rte_iova_t prev_end = 0;
-		int prev_ms_idx = -1;
 		uint64_t page_sz, mem_needed;
 		unsigned int n_pages, max_pages;
 
@@ -167,9 +166,9 @@ rte_eal_hugepage_init(void)
 				if (ms_idx < 0)
 					continue;
 
-				if (need_hole && prev_ms_idx == ms_idx - 1)
+				if (need_hole &&
+				    rte_fbarray_is_used(arr, ms_idx - 1))
 					ms_idx++;
-				prev_ms_idx = ms_idx;
 
 				break;
 			}
-- 
2.47.2

[PATCH v2 2/3] eal/freebsd: Avoid claiming memseg holes

[Jake Freeland]

When need_hole is false, memseg searches will only be done for a single
element. If the search starts at beginning of the list, an element that
was previously reserved as a hole may be wrongly claimed.

To avoid this, begin the search following the last used entry. This way,
we ignore all pre-existing holes.

Signed-off-by: Jake Freeland <jfree@FreeBSD.org>
---
 lib/eal/freebsd/eal_memory.c | 19 +++++++++++++++++--
 1 file changed, 17 insertions(+), 2 deletions(-)

diff --git a/lib/eal/freebsd/eal_memory.c b/lib/eal/freebsd/eal_memory.c
index be3bde2cb9..b159e9ef4e 100644
--- a/lib/eal/freebsd/eal_memory.c
+++ b/lib/eal/freebsd/eal_memory.c
@@ -143,6 +143,7 @@ rte_eal_hugepage_init(void)
 
 			for (msl_idx = 0; msl_idx < RTE_MAX_MEMSEG_LISTS;
 					msl_idx++) {
+				int start_idx, num_elems;
 				bool empty, need_hole;
 				msl = &mcfg->memsegs[msl_idx];
 				arr = &msl->memseg_arr;
@@ -157,10 +158,24 @@ rte_eal_hugepage_init(void)
 				 * adjacent to current one.
 				 */
 				need_hole = !empty && !is_adjacent;
+				if (need_hole) {
+					start_idx = 0;
+					/* we need 1, plus hole */
+					num_elems = 2;
+				} else {
+					/* begin our search after the last used
+					 * element in the list, skipping over
+					 * any previously placed holes
+					 */
+					start_idx = rte_fbarray_find_prev_n_used(
+							arr, arr->len - 1, 1) + 1;
+					if (start_idx < 0)
+						start_idx = 0;
+					num_elems = 1;
+				}
 
-				/* we need 1, plus hole if not adjacent */
 				ms_idx = rte_fbarray_find_next_n_free(arr,
-						0, 1 + (need_hole ? 1 : 0));
+						start_idx, num_elems);
 
 				/* memseg list is full? */
 				if (ms_idx < 0)
-- 
2.47.2

[PATCH v2 3/3] eal/linux: Check hugepage access permissions

[Jake Freeland]

Currently, hugepage mountpoints will be used irrespective of permissions,
leading to potential EACCES errors during memory allocation. Fix this by
not using a mountpoint if we do not have read/write permissions on it.

Signed-off-by: Jake Freeland <jfree@FreeBSD.org>
---
 lib/eal/linux/eal_hugepage_info.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/lib/eal/linux/eal_hugepage_info.c b/lib/eal/linux/eal_hugepage_info.c
index d47a19c56a..e2ddd6218b 100644
--- a/lib/eal/linux/eal_hugepage_info.c
+++ b/lib/eal/linux/eal_hugepage_info.c
@@ -260,6 +260,13 @@ get_hugepage_dir(uint64_t hugepage_sz, char *hugedir, int len)
 				continue;
 		}
 
+		if (access(splitstr[MOUNTPT], R_OK | W_OK) < 0) {
+			EAL_LOG(NOTICE,
+				"Skipping hugepage dir '%s': missing r/w perms",
+				splitstr[MOUNTPT]);
+			continue;
+		}
+
 		/*
 		 * If no --huge-dir option has been given, we're done.
 		 */
-- 
2.47.2