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bpf: Use vmalloc special flag

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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: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Peter 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: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Rick Edgecombe 2019-04-25 17:11:38 -07:00 committed by Ingo Molnar
parent 1a7b7d9220
commit d53d2f78ce
2 changed files with 3 additions and 15 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

17
include/linux/filter.h
View File

@ -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);
}

1
kernel/bpf/core.c
View File

@ -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));