github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-09-23 05:04:02 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

s390/mm: Add __context_unsafe() attribute to gmap helper functions

Browse Source 
Disable context analysis for various gmap helper functions to get rid
of a few warnings:

arch/s390/mm/gmap_helpers.c:80:1: warning: spinlock 'ptl' is not held on every path through here
arch/s390/mm/gmap_helpers.c:116:2: warning: releasing spinlock 'ptl' that was not held
arch/s390/mm/gmap_helpers.c:186:2: warning: releasing spinlock 'ptl' that was not held

Use __context_unsafe() to give a short comment why for function context
analysis is disabled.

try_get_locked_pte() is disabled since it may return a nonull value
regardless if it returns with a lock held or not.

This cannot be reflected with the context analysis attributes. It is
however possible to workaround this e.g. by adding a another `contended`
function parameter, however this would lead to the next problem:
pte_unmap_unlock() is a macro and therefore doesn't come with the
required context analysis attribute to address this.

For that reason also disable context analysis for
gmap_helper_zap_one_page() and gmap_helper_try_set_pte_unused()
until this has been addressed.

Acked-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
This commit is contained in:
Heiko Carstens 2026-08-03 19:21:43 +02:00 committed by Vasily Gorbik
parent 46a8c8d142
commit fa25991cbf
1 changed files with 3 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
arch/s390/mm/gmap_helpers.c
View File

@ -40,6 +40,7 @@
* and locked.
*/
pte_t *try_get_locked_pte(struct mm_struct *mm, unsigned long vmaddr, spinlock_t **ptl)
__context_unsafe(/* Returns nonnull if lock taken or not taken */)
{
pmd_t *pmdp, pmd, pmdval;
pud_t *pudp, pud;
@ -90,6 +91,7 @@ EXPORT_SYMBOL_GPL(try_get_locked_pte);
* Context: needs to be called while holding the mmap lock.
*/
void gmap_helper_zap_one_page(struct mm_struct *mm, unsigned long vmaddr)
__context_unsafe(/* pte_unmap_unlock() not instrumented */)
{
struct vm_area_struct *vma;
spinlock_t *ptl; /* Lock for the host (userspace) page table */
@ -161,6 +163,7 @@ EXPORT_SYMBOL_GPL(gmap_helper_discard);
* disabled.
*/
void gmap_helper_try_set_pte_unused(struct mm_struct *mm, unsigned long vmaddr)
__context_unsafe(/* pte_unmap_unlock() not instrumented */)
{
spinlock_t *ptl; /* Lock for the host (userspace) page table */
pte_t *ptep;