* [PATCH][v2] x86/sgx: Use list_for_each_entry_srcu() for mm_list traversal
@ 2026-02-26 1:40 lirongqing
2026-03-05 8:43 ` 答复: " Li,Rongqing(ACG CCN)
2026-04-14 7:47 ` Li,Rongqing(ACG CCN)
0 siblings, 2 replies; 3+ messages in thread
From: lirongqing @ 2026-02-26 1:40 UTC (permalink / raw)
To: Jarkko Sakkinen, Dave Hansen, Thomas Gleixner, Ingo Molnar,
Borislav Petkov, x86, H . Peter Anvin, Kai Huang, linux-sgx,
linux-kernel
Cc: Li RongQing
From: Li RongQing <lirongqing@baidu.com>
In commit 1728ab54b4be ("x86/sgx: Add a page reclaimer") (v5.11),
list_for_each_entry_rcu() was used to traverse the enclave's mm_list.
However, this is incorrect because the list is protected by a Sleepable
RCU (SRCU) lock (encl->srcu).
Since commit 28875945ba98 ("rcu: Add support for consolidated-RCU reader
checking") (v5.4), RCU lockdep checking has become stricter. When
CONFIG_PROVE_RCU is enabled, using the standard list_for_each_entry_rcu()
while only holding an SRCU lock triggers "suspicious RCU usage" false
positive warnings, as it does not recognize SRCU read-side critical
sections.
Fix this by switching to list_for_each_entry_srcu(), which was
introduced specifically for this purpose in commit ae2212a7216b
("rculist: Introduce list/hlist_for_each_entry_srcu() macros") (v5.10).
This correctly associates the traversal with the SRCU lock and
eliminates the lockdep warnings.
Fixes: 1728ab54b4be ("x86/sgx: Add a page reclaimer")
Signed-off-by: Li RongQing <lirongqing@baidu.com>
Acked-by: Kai Huang <kai.huang@intel.com>
---
Diff with v1: rewrite changelog
arch/x86/kernel/cpu/sgx/encl.c | 12 ++++++++----
arch/x86/kernel/cpu/sgx/main.c | 3 ++-
2 files changed, 10 insertions(+), 5 deletions(-)
diff --git a/arch/x86/kernel/cpu/sgx/encl.c b/arch/x86/kernel/cpu/sgx/encl.c
index ac60ebd..91362d7 100644
--- a/arch/x86/kernel/cpu/sgx/encl.c
+++ b/arch/x86/kernel/cpu/sgx/encl.c
@@ -822,7 +822,8 @@ static struct sgx_encl_mm *sgx_encl_find_mm(struct sgx_encl *encl,
idx = srcu_read_lock(&encl->srcu);
- list_for_each_entry_rcu(tmp, &encl->mm_list, list) {
+ list_for_each_entry_srcu(tmp, &encl->mm_list, list,
+ srcu_read_lock_held(&encl->srcu)) {
if (tmp->mm == mm) {
encl_mm = tmp;
break;
@@ -933,7 +934,8 @@ const cpumask_t *sgx_encl_cpumask(struct sgx_encl *encl)
idx = srcu_read_lock(&encl->srcu);
- list_for_each_entry_rcu(encl_mm, &encl->mm_list, list) {
+ list_for_each_entry_srcu(encl_mm, &encl->mm_list, list,
+ srcu_read_lock_held(&encl->srcu)) {
if (!mmget_not_zero(encl_mm->mm))
continue;
@@ -1018,7 +1020,8 @@ static struct mem_cgroup *sgx_encl_get_mem_cgroup(struct sgx_encl *encl)
*/
idx = srcu_read_lock(&encl->srcu);
- list_for_each_entry_rcu(encl_mm, &encl->mm_list, list) {
+ list_for_each_entry_srcu(encl_mm, &encl->mm_list, list,
+ srcu_read_lock_held(&encl->srcu)) {
if (!mmget_not_zero(encl_mm->mm))
continue;
@@ -1212,7 +1215,8 @@ void sgx_zap_enclave_ptes(struct sgx_encl *encl, unsigned long addr)
idx = srcu_read_lock(&encl->srcu);
- list_for_each_entry_rcu(encl_mm, &encl->mm_list, list) {
+ list_for_each_entry_srcu(encl_mm, &encl->mm_list, list,
+ srcu_read_lock_held(&encl->srcu)) {
if (!mmget_not_zero(encl_mm->mm))
continue;
diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c
index 38b7fd2..581e0c4 100644
--- a/arch/x86/kernel/cpu/sgx/main.c
+++ b/arch/x86/kernel/cpu/sgx/main.c
@@ -120,7 +120,8 @@ static bool sgx_reclaimer_age(struct sgx_epc_page *epc_page)
idx = srcu_read_lock(&encl->srcu);
- list_for_each_entry_rcu(encl_mm, &encl->mm_list, list) {
+ list_for_each_entry_srcu(encl_mm, &encl->mm_list, list,
+ srcu_read_lock_held(&encl->srcu)) {
if (!mmget_not_zero(encl_mm->mm))
continue;
--
2.9.4
^ permalink raw reply related [flat|nested] 3+ messages in thread* 答复: [PATCH][v2] x86/sgx: Use list_for_each_entry_srcu() for mm_list traversal
2026-02-26 1:40 [PATCH][v2] x86/sgx: Use list_for_each_entry_srcu() for mm_list traversal lirongqing
@ 2026-03-05 8:43 ` Li,Rongqing(ACG CCN)
2026-04-14 7:47 ` Li,Rongqing(ACG CCN)
1 sibling, 0 replies; 3+ messages in thread
From: Li,Rongqing(ACG CCN) @ 2026-03-05 8:43 UTC (permalink / raw)
To: Jarkko Sakkinen, Dave Hansen, Thomas Gleixner, Ingo Molnar,
Borislav Petkov, x86@kernel.org, H . Peter Anvin, Kai Huang,
linux-sgx@vger.kernel.org, linux-kernel@vger.kernel.org
> From: Li RongQing <lirongqing@baidu.com>
>
> In commit 1728ab54b4be ("x86/sgx: Add a page reclaimer") (v5.11),
> list_for_each_entry_rcu() was used to traverse the enclave's mm_list.
> However, this is incorrect because the list is protected by a Sleepable RCU (SRCU)
> lock (encl->srcu).
>
> Since commit 28875945ba98 ("rcu: Add support for consolidated-RCU reader
> checking") (v5.4), RCU lockdep checking has become stricter. When
> CONFIG_PROVE_RCU is enabled, using the standard list_for_each_entry_rcu()
> while only holding an SRCU lock triggers "suspicious RCU usage" false positive
> warnings, as it does not recognize SRCU read-side critical sections.
>
> Fix this by switching to list_for_each_entry_srcu(), which was introduced
> specifically for this purpose in commit ae2212a7216b
> ("rculist: Introduce list/hlist_for_each_entry_srcu() macros") (v5.10).
> This correctly associates the traversal with the SRCU lock and eliminates the
> lockdep warnings.
>
Ping
[Li,Rongqing]
> Fixes: 1728ab54b4be ("x86/sgx: Add a page reclaimer")
> Signed-off-by: Li RongQing <lirongqing@baidu.com>
> Acked-by: Kai Huang <kai.huang@intel.com>
> ---
> Diff with v1: rewrite changelog
>
> arch/x86/kernel/cpu/sgx/encl.c | 12 ++++++++----
> arch/x86/kernel/cpu/sgx/main.c | 3 ++-
> 2 files changed, 10 insertions(+), 5 deletions(-)
>
> diff --git a/arch/x86/kernel/cpu/sgx/encl.c b/arch/x86/kernel/cpu/sgx/encl.c
> index ac60ebd..91362d7 100644
> --- a/arch/x86/kernel/cpu/sgx/encl.c
> +++ b/arch/x86/kernel/cpu/sgx/encl.c
> @@ -822,7 +822,8 @@ static struct sgx_encl_mm *sgx_encl_find_mm(struct
> sgx_encl *encl,
>
> idx = srcu_read_lock(&encl->srcu);
>
> - list_for_each_entry_rcu(tmp, &encl->mm_list, list) {
> + list_for_each_entry_srcu(tmp, &encl->mm_list, list,
> + srcu_read_lock_held(&encl->srcu)) {
> if (tmp->mm == mm) {
> encl_mm = tmp;
> break;
> @@ -933,7 +934,8 @@ const cpumask_t *sgx_encl_cpumask(struct sgx_encl
> *encl)
>
> idx = srcu_read_lock(&encl->srcu);
>
> - list_for_each_entry_rcu(encl_mm, &encl->mm_list, list) {
> + list_for_each_entry_srcu(encl_mm, &encl->mm_list, list,
> + srcu_read_lock_held(&encl->srcu)) {
> if (!mmget_not_zero(encl_mm->mm))
> continue;
>
> @@ -1018,7 +1020,8 @@ static struct mem_cgroup
> *sgx_encl_get_mem_cgroup(struct sgx_encl *encl)
> */
> idx = srcu_read_lock(&encl->srcu);
>
> - list_for_each_entry_rcu(encl_mm, &encl->mm_list, list) {
> + list_for_each_entry_srcu(encl_mm, &encl->mm_list, list,
> + srcu_read_lock_held(&encl->srcu)) {
> if (!mmget_not_zero(encl_mm->mm))
> continue;
>
> @@ -1212,7 +1215,8 @@ void sgx_zap_enclave_ptes(struct sgx_encl *encl,
> unsigned long addr)
>
> idx = srcu_read_lock(&encl->srcu);
>
> - list_for_each_entry_rcu(encl_mm, &encl->mm_list, list) {
> + list_for_each_entry_srcu(encl_mm, &encl->mm_list, list,
> + srcu_read_lock_held(&encl->srcu)) {
> if (!mmget_not_zero(encl_mm->mm))
> continue;
>
> diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c
> index 38b7fd2..581e0c4 100644
> --- a/arch/x86/kernel/cpu/sgx/main.c
> +++ b/arch/x86/kernel/cpu/sgx/main.c
> @@ -120,7 +120,8 @@ static bool sgx_reclaimer_age(struct sgx_epc_page
> *epc_page)
>
> idx = srcu_read_lock(&encl->srcu);
>
> - list_for_each_entry_rcu(encl_mm, &encl->mm_list, list) {
> + list_for_each_entry_srcu(encl_mm, &encl->mm_list, list,
> + srcu_read_lock_held(&encl->srcu)) {
> if (!mmget_not_zero(encl_mm->mm))
> continue;
>
> --
> 2.9.4
^ permalink raw reply [flat|nested] 3+ messages in thread* 答复: [PATCH][v2] x86/sgx: Use list_for_each_entry_srcu() for mm_list traversal
2026-02-26 1:40 [PATCH][v2] x86/sgx: Use list_for_each_entry_srcu() for mm_list traversal lirongqing
2026-03-05 8:43 ` 答复: " Li,Rongqing(ACG CCN)
@ 2026-04-14 7:47 ` Li,Rongqing(ACG CCN)
1 sibling, 0 replies; 3+ messages in thread
From: Li,Rongqing(ACG CCN) @ 2026-04-14 7:47 UTC (permalink / raw)
To: Jarkko Sakkinen, Dave Hansen, Thomas Gleixner, Ingo Molnar,
Borislav Petkov, x86@kernel.org, H . Peter Anvin, Kai Huang,
linux-sgx@vger.kernel.org, linux-kernel@vger.kernel.org
> From: Li RongQing <lirongqing@baidu.com>
>
> In commit 1728ab54b4be ("x86/sgx: Add a page reclaimer") (v5.11),
> list_for_each_entry_rcu() was used to traverse the enclave's mm_list.
> However, this is incorrect because the list is protected by a Sleepable RCU (SRCU)
> lock (encl->srcu).
>
> Since commit 28875945ba98 ("rcu: Add support for consolidated-RCU reader
> checking") (v5.4), RCU lockdep checking has become stricter. When
> CONFIG_PROVE_RCU is enabled, using the standard list_for_each_entry_rcu()
> while only holding an SRCU lock triggers "suspicious RCU usage" false positive
> warnings, as it does not recognize SRCU read-side critical sections.
>
> Fix this by switching to list_for_each_entry_srcu(), which was introduced
> specifically for this purpose in commit ae2212a7216b
> ("rculist: Introduce list/hlist_for_each_entry_srcu() macros") (v5.10).
> This correctly associates the traversal with the SRCU lock and eliminates the
> lockdep warnings.
>
> Fixes: 1728ab54b4be ("x86/sgx: Add a page reclaimer")
> Signed-off-by: Li RongQing <lirongqing@baidu.com>
> Acked-by: Kai Huang <kai.huang@intel.com>
> ---
Ping
thanks
[Li,Rongqing]
> Diff with v1: rewrite changelog
>
> arch/x86/kernel/cpu/sgx/encl.c | 12 ++++++++----
> arch/x86/kernel/cpu/sgx/main.c | 3 ++-
> 2 files changed, 10 insertions(+), 5 deletions(-)
>
> diff --git a/arch/x86/kernel/cpu/sgx/encl.c b/arch/x86/kernel/cpu/sgx/encl.c
> index ac60ebd..91362d7 100644
> --- a/arch/x86/kernel/cpu/sgx/encl.c
> +++ b/arch/x86/kernel/cpu/sgx/encl.c
> @@ -822,7 +822,8 @@ static struct sgx_encl_mm *sgx_encl_find_mm(struct
> sgx_encl *encl,
>
> idx = srcu_read_lock(&encl->srcu);
>
> - list_for_each_entry_rcu(tmp, &encl->mm_list, list) {
> + list_for_each_entry_srcu(tmp, &encl->mm_list, list,
> + srcu_read_lock_held(&encl->srcu)) {
> if (tmp->mm == mm) {
> encl_mm = tmp;
> break;
> @@ -933,7 +934,8 @@ const cpumask_t *sgx_encl_cpumask(struct sgx_encl
> *encl)
>
> idx = srcu_read_lock(&encl->srcu);
>
> - list_for_each_entry_rcu(encl_mm, &encl->mm_list, list) {
> + list_for_each_entry_srcu(encl_mm, &encl->mm_list, list,
> + srcu_read_lock_held(&encl->srcu)) {
> if (!mmget_not_zero(encl_mm->mm))
> continue;
>
> @@ -1018,7 +1020,8 @@ static struct mem_cgroup
> *sgx_encl_get_mem_cgroup(struct sgx_encl *encl)
> */
> idx = srcu_read_lock(&encl->srcu);
>
> - list_for_each_entry_rcu(encl_mm, &encl->mm_list, list) {
> + list_for_each_entry_srcu(encl_mm, &encl->mm_list, list,
> + srcu_read_lock_held(&encl->srcu)) {
> if (!mmget_not_zero(encl_mm->mm))
> continue;
>
> @@ -1212,7 +1215,8 @@ void sgx_zap_enclave_ptes(struct sgx_encl *encl,
> unsigned long addr)
>
> idx = srcu_read_lock(&encl->srcu);
>
> - list_for_each_entry_rcu(encl_mm, &encl->mm_list, list) {
> + list_for_each_entry_srcu(encl_mm, &encl->mm_list, list,
> + srcu_read_lock_held(&encl->srcu)) {
> if (!mmget_not_zero(encl_mm->mm))
> continue;
>
> diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c
> index 38b7fd2..581e0c4 100644
> --- a/arch/x86/kernel/cpu/sgx/main.c
> +++ b/arch/x86/kernel/cpu/sgx/main.c
> @@ -120,7 +120,8 @@ static bool sgx_reclaimer_age(struct sgx_epc_page
> *epc_page)
>
> idx = srcu_read_lock(&encl->srcu);
>
> - list_for_each_entry_rcu(encl_mm, &encl->mm_list, list) {
> + list_for_each_entry_srcu(encl_mm, &encl->mm_list, list,
> + srcu_read_lock_held(&encl->srcu)) {
> if (!mmget_not_zero(encl_mm->mm))
> continue;
>
> --
> 2.9.4
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2026-04-14 7:48 UTC | newest]
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2026-02-26 1:40 [PATCH][v2] x86/sgx: Use list_for_each_entry_srcu() for mm_list traversal lirongqing
2026-03-05 8:43 ` 答复: " Li,Rongqing(ACG CCN)
2026-04-14 7:47 ` Li,Rongqing(ACG CCN)
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