b0e2b32712
[ Upstream commit de920fc64cbaa031f947e9be964bda05fd090380 ]
x86 bpf_jit_comp.c used kmalloc_array to store jited addresses
for each bpf insn. With a large bpf program, we have see the
following allocation failures in our production server:
page allocation failure: order:5, mode:0x40cc0(GFP_KERNEL|__GFP_COMP),
nodemask=(null),cpuset=/,mems_allowed=0"
Call Trace:
dump_stack+0x50/0x70
warn_alloc.cold.120+0x72/0xd2
? __alloc_pages_direct_compact+0x157/0x160
__alloc_pages_slowpath+0xcdb/0xd00
? get_page_from_freelist+0xe44/0x1600
? vunmap_page_range+0x1ba/0x340
__alloc_pages_nodemask+0x2c9/0x320
kmalloc_order+0x18/0x80
kmalloc_order_trace+0x1d/0xa0
bpf_int_jit_compile+0x1e2/0x484
? kmalloc_order_trace+0x1d/0xa0
bpf_prog_select_runtime+0xc3/0x150
bpf_prog_load+0x480/0x720
? __mod_memcg_lruvec_state+0x21/0x100
__do_sys_bpf+0xc31/0x2040
? close_pdeo+0x86/0xe0
do_syscall_64+0x42/0x110
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7f2f300f7fa9
Code: Bad RIP value.
Dumped assembly:
ffffffff810b6d70 <bpf_int_jit_compile>:
; {
ffffffff810b6d70: e8 eb a5 b4 00 callq 0xffffffff81c01360 <__fentry__>
ffffffff810b6d75: 41 57 pushq %r15
...
ffffffff810b6f39: e9 72 fe ff ff jmp 0xffffffff810b6db0 <bpf_int_jit_compile+0x40>
; addrs = kmalloc_array(prog->len + 1, sizeof(*addrs), GFP_KERNEL);
ffffffff810b6f3e: 8b 45 0c movl 12(%rbp), %eax
; return __kmalloc(bytes, flags);
ffffffff810b6f41: be c0 0c 00 00 movl $3264, %esi
; addrs = kmalloc_array(prog->len + 1, sizeof(*addrs), GFP_KERNEL);
ffffffff810b6f46: 8d 78 01 leal 1(%rax), %edi
; if (unlikely(check_mul_overflow(n, size, &bytes)))
ffffffff810b6f49: 48 c1 e7 02 shlq $2, %rdi
; return __kmalloc(bytes, flags);
ffffffff810b6f4d: e8 8e 0c 1d 00 callq 0xffffffff81287be0 <__kmalloc>
; if (!addrs) {
ffffffff810b6f52: 48 85 c0 testq %rax, %rax
Change kmalloc_array() to kvmalloc_array() to avoid potential
allocation error for big bpf programs.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210309015647.3657852-1-yhs@fb.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.