Commit-ID: 0e664eee65337082be49fbbd2ee24aa0d111d0f2
Gitweb: https://git.kernel.org/tip/0e664eee65337082be49fbbd2ee24aa0d111d0f2
Author: Joerg Roedel <jroedel@xxxxxxx>
AuthorDate: Wed, 25 Jul 2018 17:48:02 +0200
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Mon, 30 Jul 2018 13:53:48 +0200
Revert "perf/core: Make sure the ring-buffer is mapped in all page-tables"
This reverts commit 77754cfa09a6c528c38cbca9ee4cc4f7cf6ad6f2.
The patch was necessary to silence a WARN_ON_ONCE(in_nmi())
that triggered in the vmalloc_fault() function when PTI was
enabled on x86-32.
Faulting in an NMI handler turned out to be safe and the
warning in vmalloc_fault() is gone now. So the above patch
can be reverted.
Signed-off-by: Joerg Roedel <jroedel@xxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Tested-by: David H. Gutteridge <dhgutteridge@xxxxxxxxxxxx>
Cc: "H . Peter Anvin" <hpa@xxxxxxxxx>
Cc: linux-mm@xxxxxxxxx
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxx>
Cc: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Cc: Juergen Gross <jgross@xxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Jiri Kosina <jkosina@xxxxxxx>
Cc: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>
Cc: Brian Gerst <brgerst@xxxxxxxxx>
Cc: David Laight <David.Laight@xxxxxxxxxx>
Cc: Denys Vlasenko <dvlasenk@xxxxxxxxxx>
Cc: Eduardo Valentin <eduval@xxxxxxxxxx>
Cc: Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Will Deacon <will.deacon@xxxxxxx>
Cc: aliguori@xxxxxxxxxx
Cc: daniel.gruss@xxxxxxxxxxxxxx
Cc: hughd@xxxxxxxxxx
Cc: keescook@xxxxxxxxxx
Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Cc: Waiman Long <llong@xxxxxxxxxx>
Cc: Pavel Machek <pavel@xxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: joro@xxxxxxxxxx
Link: https://lkml.kernel.org/r/1532533683-5988-3-git-send-email-joro@xxxxxxxxxx
---
kernel/events/ring_buffer.c | 16 ----------------
1 file changed, 16 deletions(-)
diff --git a/kernel/events/ring_buffer.c b/kernel/events/ring_buffer.c
index df2d8cf0072c..5d3cf407e374 100644
--- a/kernel/events/ring_buffer.c
+++ b/kernel/events/ring_buffer.c
@@ -814,13 +814,6 @@ static void rb_free_work(struct work_struct *work)
vfree(base);
kfree(rb);
-
- /*
- * FIXME: PAE workaround for vmalloc_fault(): Make sure buffer is
- * unmapped in all page-tables.
- */
- if (IS_ENABLED(CONFIG_X86_PAE))
- vmalloc_sync_all();
}
void rb_free(struct ring_buffer *rb)
@@ -847,15 +840,6 @@ struct ring_buffer *rb_alloc(int nr_pages, long watermark, int cpu, int flags)
if (!all_buf)
goto fail_all_buf;
- /*
- * FIXME: PAE workaround for vmalloc_fault(): The buffer is
- * accessed in NMI handlers, make sure it is mapped in all
- * page-tables in the system so that we don't fault on the range in
- * an NMI handler.
- */
- if (IS_ENABLED(CONFIG_X86_PAE))
- vmalloc_sync_all();
-
rb->user_page = all_buf;
rb->data_pages[0] = all_buf + PAGE_SIZE;
if (nr_pages) {
--
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