diff options
| author | David Hildenbrand <david@redhat.com> | 2024-08-02 17:55:22 +0200 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2024-09-01 20:26:01 -0700 |
| commit | 0b31a3cef4462ef99ef4667291091ecbcfcc8749 (patch) | |
| tree | ecaa3cfda39538790d650a5312d3dd1e4f59a69b | |
| parent | 85a7e5432dba4c750129797feb399a7bff8b241f (diff) | |
s390/mm/fault: convert do_secure_storage_access() from follow_page() to folio_walk
Let's get rid of another follow_page() user and perform the conversion
under PTL: Note that this is also what follow_page_pte() ends up doing.
Unfortunately we cannot currently optimize out the additional reference,
because arch_make_folio_accessible() must be called with a raised refcount
to protect against concurrent conversion to secure. We can just move the
arch_make_folio_accessible() under the PTL, like follow_page_pte() would.
We'll effectively drop the "writable" check implied by FOLL_WRITE:
follow_page_pte() would also not check that when calling
arch_make_folio_accessible(), so there is no good reason for doing that
here.
We'll lose the secretmem check from follow_page() as well, about which we
shouldn't really care.
Link: https://lkml.kernel.org/r/20240802155524.517137-10-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Janosch Frank <frankja@linux.ibm.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| -rw-r--r-- | arch/s390/mm/fault.c | 16 |
1 files changed, 10 insertions, 6 deletions
diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c index 8e149ef5e89b..ad8b0d6b77ea 100644 --- a/arch/s390/mm/fault.c +++ b/arch/s390/mm/fault.c @@ -34,6 +34,7 @@ #include <linux/uaccess.h> #include <linux/hugetlb.h> #include <linux/kfence.h> +#include <linux/pagewalk.h> #include <asm/asm-extable.h> #include <asm/asm-offsets.h> #include <asm/ptrace.h> @@ -492,9 +493,9 @@ void do_secure_storage_access(struct pt_regs *regs) union teid teid = { .val = regs->int_parm_long }; unsigned long addr = get_fault_address(regs); struct vm_area_struct *vma; + struct folio_walk fw; struct mm_struct *mm; struct folio *folio; - struct page *page; struct gmap *gmap; int rc; @@ -536,15 +537,18 @@ void do_secure_storage_access(struct pt_regs *regs) vma = find_vma(mm, addr); if (!vma) return handle_fault_error(regs, SEGV_MAPERR); - page = follow_page(vma, addr, FOLL_WRITE | FOLL_GET); - if (IS_ERR_OR_NULL(page)) { + folio = folio_walk_start(&fw, vma, addr, 0); + if (!folio) { mmap_read_unlock(mm); break; } - folio = page_folio(page); - if (arch_make_folio_accessible(folio)) - send_sig(SIGSEGV, current, 0); + /* arch_make_folio_accessible() needs a raised refcount. */ + folio_get(folio); + rc = arch_make_folio_accessible(folio); folio_put(folio); + folio_walk_end(&fw, vma); + if (rc) + send_sig(SIGSEGV, current, 0); mmap_read_unlock(mm); break; case KERNEL_FAULT: |