[PATCH v2 18/20] x86/ftrace: Use vmalloc special flag
From: Rick Edgecombe <rick.p.edgecombe@intel.com>
Date: 2019-01-29 00:39:43
Also in:
linux-integrity, linux-mm, lkml
Subsystem:
function hooks (ftrace), the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Steven Rostedt, Masami Hiramatsu, Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
Use new flag VM_HAS_SPECIAL_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> 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..cf30594a2032 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) { - 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_special(trampoline); + /* * Module allocation needs to be completed by making the page * executable. The page is still writable, which is a security hazard,
--
2.17.1