Commit-ID:  241a1f22380646bc4d1dd18e5bc246877513da68
Gitweb:     https://git.kernel.org/tip/241a1f22380646bc4d1dd18e5bc246877513da68
Author:     Rick Edgecombe <rick.p.edgeco...@intel.com>
AuthorDate: Thu, 25 Apr 2019 17:11:40 -0700
Committer:  Ingo Molnar <mi...@kernel.org>
CommitDate: Tue, 30 Apr 2019 12:38:01 +0200

x86/kprobes: Use vmalloc special flag

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.

Signed-off-by: Rick Edgecombe <rick.p.edgeco...@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org>
Cc: <a...@linux-foundation.org>
Cc: <ard.biesheu...@linaro.org>
Cc: <deneen.t.d...@intel.com>
Cc: <kernel-harden...@lists.openwall.com>
Cc: <kris...@linux.intel.com>
Cc: <linux_...@icloud.com>
Cc: <will.dea...@arm.com>
Cc: Andy Lutomirski <l...@kernel.org>
Cc: Borislav Petkov <b...@alien8.de>
Cc: Dave Hansen <dave.han...@linux.intel.com>
Cc: H. Peter Anvin <h...@zytor.com>
Cc: Linus Torvalds <torva...@linux-foundation.org>
Cc: Masami Hiramatsu <mhira...@kernel.org>
Cc: Nadav Amit <nadav.a...@gmail.com>
Cc: Rik van Riel <r...@surriel.com>
Cc: Thomas Gleixner <t...@linutronix.de>
Link: https://lkml.kernel.org/r/20190426001143.4983-21-na...@vmware.com
Signed-off-by: Ingo Molnar <mi...@kernel.org>
---
 arch/x86/kernel/kprobes/core.c | 7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)

diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c
index 06058c44ab57..800593f4ddf7 100644
--- a/arch/x86/kernel/kprobes/core.c
+++ b/arch/x86/kernel/kprobes/core.c
@@ -434,6 +434,7 @@ void *alloc_insn_page(void)
        if (!page)
                return NULL;
 
+       set_vm_flush_reset_perms(page);
        /*
         * First make the page read-only, and only then make it executable to
         * prevent it from being W+X in between.
@@ -452,12 +453,6 @@ void *alloc_insn_page(void)
 /* Recover page to RW mode before releasing it */
 void free_insn_page(void *page)
 {
-       /*
-        * First make the page non-executable, and only then make it writable to
-        * prevent it from being W+X in between.
-        */
-       set_memory_nx((unsigned long)page, 1);
-       set_memory_rw((unsigned long)page, 1);
        module_memfree(page);
 }
 

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