Messages in this thread Patch in this message | | | Date | Mon, 30 Jul 2018 04:58:25 -0700 | From | tip-bot for Joerg Roedel <> | Subject | [tip:x86/pti] Revert "perf/core: Make sure the ring-buffer is mapped in all page-tables" |
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Commit-ID: 0e664eee65337082be49fbbd2ee24aa0d111d0f2 Gitweb: https://git.kernel.org/tip/0e664eee65337082be49fbbd2ee24aa0d111d0f2 Author: Joerg Roedel <jroedel@suse.de> AuthorDate: Wed, 25 Jul 2018 17:48:02 +0200 Committer: Thomas Gleixner <tglx@linutronix.de> 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@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: David H. Gutteridge <dhgutteridge@sympatico.ca> Cc: "H . Peter Anvin" <hpa@zytor.com> Cc: linux-mm@kvack.org Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Brian Gerst <brgerst@gmail.com> Cc: David Laight <David.Laight@aculab.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Eduardo Valentin <eduval@amazon.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Will Deacon <will.deacon@arm.com> Cc: aliguori@amazon.com Cc: daniel.gruss@iaik.tugraz.at Cc: hughd@google.com Cc: keescook@google.com Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Waiman Long <llong@redhat.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: joro@8bytes.org Link: https://lkml.kernel.org/r/1532533683-5988-3-git-send-email-joro@8bytes.org
--- 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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