Commit d53d2f78 authored by Rick Edgecombe's avatar Rick Edgecombe Committed by Ingo Molnar
Browse files

bpf: 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 RW
before freeing which is no longer needed. Don't track if the memory is RO
anymore because it is now tracked in vmalloc.

Signed-off-by: default avatarRick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: <akpm@linux-foundation.org>
Cc: <ard.biesheuvel@linaro.org>
Cc: <deneen.t.dock@intel.com>
Cc: <kernel-hardening@lists.openwall.com>
Cc: <kristen@linux.intel.com>
Cc: <linux_dti@icloud.com>
Cc: <will.deacon@arm.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190426001143.4983-19-namit@vmware.com


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 1a7b7d92

include/linux/filter.h

+3 −14
Original line number Diff line number Diff line
@@ -20,6 +20,7 @@ 
#include <linux/set_memory.h>

#include <linux/kallsyms.h>

#include <linux/if_vlan.h>

#include <linux/vmalloc.h>



#include <net/sch_generic.h>
@@ -503,7 +504,6 @@ struct bpf_prog { 
	u16			pages;		/* Number of allocated pages */

	u16			jited:1,	/* Is our filter JIT'ed? */

				jit_requested:1,/* archs need to JIT the prog */

				undo_set_mem:1,	/* Passed set_memory_ro() checkpoint */

				gpl_compatible:1, /* Is filter GPL compatible? */

				cb_access:1,	/* Is control block accessed? */

				dst_needed:1,	/* Do we need dst entry? */
@@ -733,27 +733,17 @@ bpf_ctx_narrow_access_ok(u32 off, u32 size, u32 size_default) 


static inline void bpf_prog_lock_ro(struct bpf_prog *fp)

{

	fp->undo_set_mem = 1;

	set_vm_flush_reset_perms(fp);

	set_memory_ro((unsigned long)fp, fp->pages);

}



static inline void bpf_prog_unlock_ro(struct bpf_prog *fp)

{

	if (fp->undo_set_mem)

		set_memory_rw((unsigned long)fp, fp->pages);

}



static inline void bpf_jit_binary_lock_ro(struct bpf_binary_header *hdr)

{

	set_vm_flush_reset_perms(hdr);

	set_memory_ro((unsigned long)hdr, hdr->pages);

	set_memory_x((unsigned long)hdr, hdr->pages);

}



static inline void bpf_jit_binary_unlock_ro(struct bpf_binary_header *hdr)

{

	set_memory_rw((unsigned long)hdr, hdr->pages);

}



static inline struct bpf_binary_header *

bpf_jit_binary_hdr(const struct bpf_prog *fp)

{
@@ -789,7 +779,6 @@ void __bpf_prog_free(struct bpf_prog *fp); 


static inline void bpf_prog_unlock_free(struct bpf_prog *fp)

{

	bpf_prog_unlock_ro(fp);

	__bpf_prog_free(fp);

}

kernel/bpf/core.c

+0 −1
Original line number Diff line number Diff line
@@ -848,7 +848,6 @@ void __weak bpf_jit_free(struct bpf_prog *fp) 
	if (fp->jited) {

		struct bpf_binary_header *hdr = bpf_jit_binary_hdr(fp);



		bpf_jit_binary_unlock_ro(hdr);

		bpf_jit_binary_free(hdr);



		WARN_ON_ONCE(!bpf_prog_kallsyms_verify_off(fp));

CRA Git | Maintained and supported by SUSTech CRA and CCSE