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Message-Id: <20190422185805.1169-20-rick.p.edgecombe@intel.com> Date: Mon, 22 Apr 2019 11:58:01 -0700 From: Rick Edgecombe <rick.p.edgecombe@...el.com> To: Borislav Petkov <bp@...en8.de>, Andy Lutomirski <luto@...nel.org>, Ingo Molnar <mingo@...hat.com> Cc: linux-kernel@...r.kernel.org, x86@...nel.org, hpa@...or.com, Thomas Gleixner <tglx@...utronix.de>, Nadav Amit <nadav.amit@...il.com>, Dave Hansen <dave.hansen@...ux.intel.com>, Peter Zijlstra <peterz@...radead.org>, linux_dti@...oud.com, linux-integrity@...r.kernel.org, linux-security-module@...r.kernel.org, akpm@...ux-foundation.org, kernel-hardening@...ts.openwall.com, linux-mm@...ck.org, will.deacon@....com, ard.biesheuvel@...aro.org, kristen@...ux.intel.com, deneen.t.dock@...el.com, Rick Edgecombe <rick.p.edgecombe@...el.com>, Steven Rostedt <rostedt@...dmis.org> Subject: [PATCH v4 19/23] x86/ftrace: 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. Cc: Steven Rostedt <rostedt@...dmis.org> Acked-by: Steven Rostedt (VMware) <rostedt@...dmis.org> Signed-off-by: Rick Edgecombe <rick.p.edgecombe@...el.com> --- arch/x86/kernel/ftrace.c | 14 ++++++-------- 1 file changed, 6 insertions(+), 8 deletions(-) diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c index 53ba1aa3a01f..0caf8122d680 100644 --- a/arch/x86/kernel/ftrace.c +++ b/arch/x86/kernel/ftrace.c @@ -678,12 +678,8 @@ static inline void *alloc_tramp(unsigned long size) { return module_alloc(size); } -static inline void tramp_free(void *tramp, int size) +static inline void tramp_free(void *tramp) { - 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 @@ -692,7 +688,7 @@ static inline void *alloc_tramp(unsigned long size) { return NULL; } -static inline void tramp_free(void *tramp, int size) { } +static inline void tramp_free(void *tramp) { } #endif /* Defined as markers to the end of the ftrace default trampolines */ @@ -808,6 +804,8 @@ 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, @@ -816,7 +814,7 @@ create_trampoline(struct ftrace_ops *ops, unsigned int *tramp_size) set_memory_x((unsigned long)trampoline, npages); return (unsigned long)trampoline; fail: - tramp_free(trampoline, *tramp_size); + tramp_free(trampoline); return 0; } @@ -947,7 +945,7 @@ void arch_ftrace_trampoline_free(struct ftrace_ops *ops) if (!ops || !(ops->flags & FTRACE_OPS_FL_ALLOC_TRAMP)) return; - tramp_free((void *)ops->trampoline, ops->trampoline_size); + tramp_free((void *)ops->trampoline); ops->trampoline = 0; } -- 2.17.1
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