Commit-ID: 0e664eee65337082be49fbbd2ee24aa0d111d0f2 Gitweb: https://git.kernel.org/tip/0e664eee65337082be49fbbd2ee24aa0d111d0f2 Author: Joerg Roedel <[email protected]> AuthorDate: Wed, 25 Jul 2018 17:48:02 +0200 Committer: Thomas Gleixner <[email protected]> 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 <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Tested-by: David H. Gutteridge <[email protected]> Cc: "H . Peter Anvin" <[email protected]> Cc: [email protected] Cc: Linus Torvalds <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Dave Hansen <[email protected]> Cc: Josh Poimboeuf <[email protected]> Cc: Juergen Gross <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Jiri Kosina <[email protected]> Cc: Boris Ostrovsky <[email protected]> Cc: Brian Gerst <[email protected]> Cc: David Laight <[email protected]> Cc: Denys Vlasenko <[email protected]> Cc: Eduardo Valentin <[email protected]> Cc: Greg KH <[email protected]> Cc: Will Deacon <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: Andrea Arcangeli <[email protected]> Cc: Waiman Long <[email protected]> Cc: Pavel Machek <[email protected]> Cc: Arnaldo Carvalho de Melo <[email protected]> Cc: Alexander Shishkin <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: [email protected] Link: https://lkml.kernel.org/r/[email protected] --- 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) {
