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    SubjectRe: [PATCH v3 18/20] x86/ftrace: Use vmalloc special flag
    On Thu, 21 Feb 2019 15:44:49 -0800
    Rick Edgecombe <rick.p.edgecombe@intel.com> wrote:

    > Use new flag VM_FLUSH_RESET_PERMS for handling freeing of special
    > permissioned memory in vmalloc and remove places where memory was set NX
    > and RW before freeing which is no longer needed.
    >
    > Cc: Steven Rostedt <rostedt@goodmis.org>
    > Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
    > Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
    > ---
    > arch/x86/kernel/ftrace.c | 6 ++----
    > 1 file changed, 2 insertions(+), 4 deletions(-)
    >
    > diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c
    > index 13c8249b197f..93efe3955333 100644
    > --- a/arch/x86/kernel/ftrace.c
    > +++ b/arch/x86/kernel/ftrace.c
    > @@ -692,10 +692,6 @@ static inline void *alloc_tramp(unsigned long size)
    > }
    > static inline void tramp_free(void *tramp, int size)

    As size is no longer used within the function, can you remove that too.

    Thanks,

    -- Steve

    > {
    > - int npages = PAGE_ALIGN(size) >> PAGE_SHIFT;
    > -
    > - set_memory_nx((unsigned long)tramp, npages);
    > - set_memory_rw((unsigned long)tramp, npages);
    > module_memfree(tramp);
    > }
    > #else
    > @@ -820,6 +816,8 @@ create_trampoline(struct ftrace_ops *ops, unsigned int *tramp_size)
    > /* ALLOC_TRAMP flags lets us know we created it */
    > ops->flags |= FTRACE_OPS_FL_ALLOC_TRAMP;
    >
    > + set_vm_flush_reset_perms(trampoline);
    > +
    > /*
    > * Module allocation needs to be completed by making the page
    > * executable. The page is still writable, which is a security hazard,

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