lkml.org 
[lkml]   [2019]   [Apr]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v4 18/23] bpf: Use vmalloc special flag
Date
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.

Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
---
include/linux/filter.h | 17 +++--------------
kernel/bpf/core.c | 1 -
2 files changed, 3 insertions(+), 15 deletions(-)

diff --git a/include/linux/filter.h b/include/linux/filter.h
index 14ec3bdad9a9..7d3abde3f183 100644
--- a/include/linux/filter.h
+++ b/include/linux/filter.h
@@ -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);
}

diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index ff09d32a8a1b..c605397c79f0 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -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));
--
2.17.1
\
 
 \ /
  Last update: 2019-04-22 21:00    [W:0.163 / U:27.240 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site