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authorIdo Schimmel <idosch@nvidia.com>2024-04-22 17:25:54 +0200
committerJakub Kicinski <kuba@kernel.org>2024-04-24 19:32:59 -0700
commit627f9c1bb882765a84aa78015abbacd783d429be (patch)
tree7a9997f9954fe8cc03fc1def33ad7339699db305 /drivers/net/ethernet/mellanox
parent5ea7b72d4fac2fdbc0425cd8f2ea33abe95235b2 (diff)
mlxsw: spectrum_acl_tcam: Fix race in region ID allocation
Region identifiers can be allocated both when user space tries to insert a new tc filter and when filters are migrated from one region to another as part of the rehash delayed work. There is no lock protecting the bitmap from which these identifiers are allocated from, which is racy and leads to bad parameter errors from the device's firmware. Fix by converting the bitmap to IDA which handles its own locking. For consistency, do the same for the group identifiers that are part of the same structure. Fixes: 2bffc5322fd8 ("mlxsw: spectrum_acl: Don't take mutex in mlxsw_sp_acl_tcam_vregion_rehash_work()") Reported-by: Amit Cohen <amcohen@nvidia.com> Signed-off-by: Ido Schimmel <idosch@nvidia.com> Tested-by: Alexander Zubkov <green@qrator.net> Reviewed-by: Petr Machata <petrm@nvidia.com> Signed-off-by: Petr Machata <petrm@nvidia.com> Reviewed-by: Simon Horman <horms@kernel.org> Link: https://lore.kernel.org/r/ce494b7940cadfe84f3e18da7785b51ef5f776e3.1713797103.git.petrm@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'drivers/net/ethernet/mellanox')
-rw-r--r--drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_tcam.c61
-rw-r--r--drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_tcam.h5
2 files changed, 30 insertions, 36 deletions
diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_tcam.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_tcam.c
index f20052776b3f..b6a4652a6475 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_tcam.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_tcam.c
@@ -10,6 +10,7 @@
#include <linux/netdevice.h>
#include <linux/mutex.h>
#include <linux/refcount.h>
+#include <linux/idr.h>
#include <net/devlink.h>
#include <trace/events/mlxsw.h>
@@ -58,41 +59,43 @@ int mlxsw_sp_acl_tcam_priority_get(struct mlxsw_sp *mlxsw_sp,
static int mlxsw_sp_acl_tcam_region_id_get(struct mlxsw_sp_acl_tcam *tcam,
u16 *p_id)
{
- u16 id;
+ int id;
- id = find_first_zero_bit(tcam->used_regions, tcam->max_regions);
- if (id < tcam->max_regions) {
- __set_bit(id, tcam->used_regions);
- *p_id = id;
- return 0;
- }
- return -ENOBUFS;
+ id = ida_alloc_max(&tcam->used_regions, tcam->max_regions - 1,
+ GFP_KERNEL);
+ if (id < 0)
+ return id;
+
+ *p_id = id;
+
+ return 0;
}
static void mlxsw_sp_acl_tcam_region_id_put(struct mlxsw_sp_acl_tcam *tcam,
u16 id)
{
- __clear_bit(id, tcam->used_regions);
+ ida_free(&tcam->used_regions, id);
}
static int mlxsw_sp_acl_tcam_group_id_get(struct mlxsw_sp_acl_tcam *tcam,
u16 *p_id)
{
- u16 id;
+ int id;
- id = find_first_zero_bit(tcam->used_groups, tcam->max_groups);
- if (id < tcam->max_groups) {
- __set_bit(id, tcam->used_groups);
- *p_id = id;
- return 0;
- }
- return -ENOBUFS;
+ id = ida_alloc_max(&tcam->used_groups, tcam->max_groups - 1,
+ GFP_KERNEL);
+ if (id < 0)
+ return id;
+
+ *p_id = id;
+
+ return 0;
}
static void mlxsw_sp_acl_tcam_group_id_put(struct mlxsw_sp_acl_tcam *tcam,
u16 id)
{
- __clear_bit(id, tcam->used_groups);
+ ida_free(&tcam->used_groups, id);
}
struct mlxsw_sp_acl_tcam_pattern {
@@ -1549,19 +1552,11 @@ int mlxsw_sp_acl_tcam_init(struct mlxsw_sp *mlxsw_sp,
if (max_tcam_regions < max_regions)
max_regions = max_tcam_regions;
- tcam->used_regions = bitmap_zalloc(max_regions, GFP_KERNEL);
- if (!tcam->used_regions) {
- err = -ENOMEM;
- goto err_alloc_used_regions;
- }
+ ida_init(&tcam->used_regions);
tcam->max_regions = max_regions;
max_groups = MLXSW_CORE_RES_GET(mlxsw_sp->core, ACL_MAX_GROUPS);
- tcam->used_groups = bitmap_zalloc(max_groups, GFP_KERNEL);
- if (!tcam->used_groups) {
- err = -ENOMEM;
- goto err_alloc_used_groups;
- }
+ ida_init(&tcam->used_groups);
tcam->max_groups = max_groups;
tcam->max_group_size = MLXSW_CORE_RES_GET(mlxsw_sp->core,
ACL_MAX_GROUP_SIZE);
@@ -1575,10 +1570,8 @@ int mlxsw_sp_acl_tcam_init(struct mlxsw_sp *mlxsw_sp,
return 0;
err_tcam_init:
- bitmap_free(tcam->used_groups);
-err_alloc_used_groups:
- bitmap_free(tcam->used_regions);
-err_alloc_used_regions:
+ ida_destroy(&tcam->used_groups);
+ ida_destroy(&tcam->used_regions);
mlxsw_sp_acl_tcam_rehash_params_unregister(mlxsw_sp);
err_rehash_params_register:
mutex_destroy(&tcam->lock);
@@ -1591,8 +1584,8 @@ void mlxsw_sp_acl_tcam_fini(struct mlxsw_sp *mlxsw_sp,
const struct mlxsw_sp_acl_tcam_ops *ops = mlxsw_sp->acl_tcam_ops;
ops->fini(mlxsw_sp, tcam->priv);
- bitmap_free(tcam->used_groups);
- bitmap_free(tcam->used_regions);
+ ida_destroy(&tcam->used_groups);
+ ida_destroy(&tcam->used_regions);
mlxsw_sp_acl_tcam_rehash_params_unregister(mlxsw_sp);
mutex_destroy(&tcam->lock);
}
diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_tcam.h b/drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_tcam.h
index 462bf448497d..79a1d8606512 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_tcam.h
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_tcam.h
@@ -6,15 +6,16 @@
#include <linux/list.h>
#include <linux/parman.h>
+#include <linux/idr.h>
#include "reg.h"
#include "spectrum.h"
#include "core_acl_flex_keys.h"
struct mlxsw_sp_acl_tcam {
- unsigned long *used_regions; /* bit array */
+ struct ida used_regions;
unsigned int max_regions;
- unsigned long *used_groups; /* bit array */
+ struct ida used_groups;
unsigned int max_groups;
unsigned int max_group_size;
struct mutex lock; /* guards vregion list */