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authorDavid S. Miller <davem@davemloft.net>2018-02-26 10:37:24 -0500
committerDavid S. Miller <davem@davemloft.net>2018-02-26 10:37:24 -0500
commitba6056a41cb09575a5ffe2fcfa9a0afb1b60eb92 (patch)
treee1858eb29573b86b6a42cbd3d6fbd18aa7b565bf /arch/x86/net
parentf74290fdb363665538743d14c4f00aeacdb68d87 (diff)
parentc53507778998d45543b27266742d04cd384de356 (diff)
downloadlinux-stericsson-ba6056a41cb09575a5ffe2fcfa9a0afb1b60eb92.tar.gz
Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Daniel Borkmann says: ==================== pull-request: bpf-next 2018-02-26 The following pull-request contains BPF updates for your *net-next* tree. The main changes are: 1) Various improvements for BPF kselftests: i) skip unprivileged tests when kernel.unprivileged_bpf_disabled sysctl knob is set, ii) count the number of skipped tests from unprivileged, iii) when a test case had an unexpected error then print the actual but also the unexpected one for better comparison, from Joe. 2) Add a sample program for collecting CPU state statistics with regards to how long the CPU resides in cstate and pstate levels. Based on cpu_idle and cpu_frequency trace points, from Leo. 3) Various x64 BPF JIT optimizations to further shrink the generated image size in order to make it more icache friendly. When tested on the Cilium generated programs, image size reduced by approx 4-5% in best case mainly due to how LLVM emits unsigned 32 bit constants, from Daniel. 4) Improvements and fixes on the BPF sockmap sample programs: i) fix the sockmap's Makefile to include nlattr.o for libbpf, ii) detach the sock ops programs from the cgroup before exit, from Prashant. 5) Avoid including xdp.h in filter.h by just forward declaring the struct xdp_rxq_info in filter.h, from Jesper. 6) Fix the BPF kselftests Makefile for cgroup_helpers.c by only declaring it a dependency for test_dev_cgroup.c but not every other test case where it is not needed, from Jesper. 7) Adjust rlimit RLIMIT_MEMLOCK for test_tcpbpf_user selftest since the default is insufficient for creating the 'global_map' used in the corresponding BPF program, from Yonghong. 8) Likewise, for the xdp_redirect sample, Tushar ran into the same when invoking xdp_redirect and xdp_monitor at the same time, therefore in order to have the sample generically work bump the limit here, too. Fix from Tushar. 9) Avoid an unnecessary NULL check in BPF_CGROUP_RUN_PROG_INET_SOCK() since sk is always guaranteed to be non-NULL, from Yafang. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'arch/x86/net')
-rw-r--r--arch/x86/net/bpf_jit_comp.c219
1 files changed, 132 insertions, 87 deletions
diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c
index 45e4eb5bcbb2..cbf94d44f3d5 100644
--- a/arch/x86/net/bpf_jit_comp.c
+++ b/arch/x86/net/bpf_jit_comp.c
@@ -61,7 +61,12 @@ static bool is_imm8(int value)
static bool is_simm32(s64 value)
{
- return value == (s64) (s32) value;
+ return value == (s64)(s32)value;
+}
+
+static bool is_uimm32(u64 value)
+{
+ return value == (u64)(u32)value;
}
/* mov dst, src */
@@ -212,7 +217,7 @@ struct jit_context {
/* emit x64 prologue code for BPF program and check it's size.
* bpf_tail_call helper will skip it while jumping into another program
*/
-static void emit_prologue(u8 **pprog, u32 stack_depth)
+static void emit_prologue(u8 **pprog, u32 stack_depth, bool ebpf_from_cbpf)
{
u8 *prog = *pprog;
int cnt = 0;
@@ -247,18 +252,21 @@ static void emit_prologue(u8 **pprog, u32 stack_depth)
/* mov qword ptr [rbp+24],r15 */
EMIT4(0x4C, 0x89, 0x7D, 24);
- /* Clear the tail call counter (tail_call_cnt): for eBPF tail calls
- * we need to reset the counter to 0. It's done in two instructions,
- * resetting rax register to 0 (xor on eax gets 0 extended), and
- * moving it to the counter location.
- */
+ if (!ebpf_from_cbpf) {
+ /* Clear the tail call counter (tail_call_cnt): for eBPF tail
+ * calls we need to reset the counter to 0. It's done in two
+ * instructions, resetting rax register to 0, and moving it
+ * to the counter location.
+ */
+
+ /* xor eax, eax */
+ EMIT2(0x31, 0xc0);
+ /* mov qword ptr [rbp+32], rax */
+ EMIT4(0x48, 0x89, 0x45, 32);
- /* xor eax, eax */
- EMIT2(0x31, 0xc0);
- /* mov qword ptr [rbp+32], rax */
- EMIT4(0x48, 0x89, 0x45, 32);
+ BUILD_BUG_ON(cnt != PROLOGUE_SIZE);
+ }
- BUILD_BUG_ON(cnt != PROLOGUE_SIZE);
*pprog = prog;
}
@@ -356,6 +364,86 @@ static void emit_load_skb_data_hlen(u8 **pprog)
*pprog = prog;
}
+static void emit_mov_imm32(u8 **pprog, bool sign_propagate,
+ u32 dst_reg, const u32 imm32)
+{
+ u8 *prog = *pprog;
+ u8 b1, b2, b3;
+ int cnt = 0;
+
+ /* optimization: if imm32 is positive, use 'mov %eax, imm32'
+ * (which zero-extends imm32) to save 2 bytes.
+ */
+ if (sign_propagate && (s32)imm32 < 0) {
+ /* 'mov %rax, imm32' sign extends imm32 */
+ b1 = add_1mod(0x48, dst_reg);
+ b2 = 0xC7;
+ b3 = 0xC0;
+ EMIT3_off32(b1, b2, add_1reg(b3, dst_reg), imm32);
+ goto done;
+ }
+
+ /* optimization: if imm32 is zero, use 'xor %eax, %eax'
+ * to save 3 bytes.
+ */
+ if (imm32 == 0) {
+ if (is_ereg(dst_reg))
+ EMIT1(add_2mod(0x40, dst_reg, dst_reg));
+ b2 = 0x31; /* xor */
+ b3 = 0xC0;
+ EMIT2(b2, add_2reg(b3, dst_reg, dst_reg));
+ goto done;
+ }
+
+ /* mov %eax, imm32 */
+ if (is_ereg(dst_reg))
+ EMIT1(add_1mod(0x40, dst_reg));
+ EMIT1_off32(add_1reg(0xB8, dst_reg), imm32);
+done:
+ *pprog = prog;
+}
+
+static void emit_mov_imm64(u8 **pprog, u32 dst_reg,
+ const u32 imm32_hi, const u32 imm32_lo)
+{
+ u8 *prog = *pprog;
+ int cnt = 0;
+
+ if (is_uimm32(((u64)imm32_hi << 32) | (u32)imm32_lo)) {
+ /* For emitting plain u32, where sign bit must not be
+ * propagated LLVM tends to load imm64 over mov32
+ * directly, so save couple of bytes by just doing
+ * 'mov %eax, imm32' instead.
+ */
+ emit_mov_imm32(&prog, false, dst_reg, imm32_lo);
+ } else {
+ /* movabsq %rax, imm64 */
+ EMIT2(add_1mod(0x48, dst_reg), add_1reg(0xB8, dst_reg));
+ EMIT(imm32_lo, 4);
+ EMIT(imm32_hi, 4);
+ }
+
+ *pprog = prog;
+}
+
+static void emit_mov_reg(u8 **pprog, bool is64, u32 dst_reg, u32 src_reg)
+{
+ u8 *prog = *pprog;
+ int cnt = 0;
+
+ if (is64) {
+ /* mov dst, src */
+ EMIT_mov(dst_reg, src_reg);
+ } else {
+ /* mov32 dst, src */
+ if (is_ereg(dst_reg) || is_ereg(src_reg))
+ EMIT1(add_2mod(0x40, dst_reg, src_reg));
+ EMIT2(0x89, add_2reg(0xC0, dst_reg, src_reg));
+ }
+
+ *pprog = prog;
+}
+
static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image,
int oldproglen, struct jit_context *ctx)
{
@@ -369,7 +457,8 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image,
int proglen = 0;
u8 *prog = temp;
- emit_prologue(&prog, bpf_prog->aux->stack_depth);
+ emit_prologue(&prog, bpf_prog->aux->stack_depth,
+ bpf_prog_was_classic(bpf_prog));
if (seen_ld_abs)
emit_load_skb_data_hlen(&prog);
@@ -378,7 +467,7 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image,
const s32 imm32 = insn->imm;
u32 dst_reg = insn->dst_reg;
u32 src_reg = insn->src_reg;
- u8 b1 = 0, b2 = 0, b3 = 0;
+ u8 b2 = 0, b3 = 0;
s64 jmp_offset;
u8 jmp_cond;
bool reload_skb_data;
@@ -414,16 +503,11 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image,
EMIT2(b2, add_2reg(0xC0, dst_reg, src_reg));
break;
- /* mov dst, src */
case BPF_ALU64 | BPF_MOV | BPF_X:
- EMIT_mov(dst_reg, src_reg);
- break;
-
- /* mov32 dst, src */
case BPF_ALU | BPF_MOV | BPF_X:
- if (is_ereg(dst_reg) || is_ereg(src_reg))
- EMIT1(add_2mod(0x40, dst_reg, src_reg));
- EMIT2(0x89, add_2reg(0xC0, dst_reg, src_reg));
+ emit_mov_reg(&prog,
+ BPF_CLASS(insn->code) == BPF_ALU64,
+ dst_reg, src_reg);
break;
/* neg dst */
@@ -486,58 +570,13 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image,
break;
case BPF_ALU64 | BPF_MOV | BPF_K:
- /* optimization: if imm32 is positive,
- * use 'mov eax, imm32' (which zero-extends imm32)
- * to save 2 bytes
- */
- if (imm32 < 0) {
- /* 'mov rax, imm32' sign extends imm32 */
- b1 = add_1mod(0x48, dst_reg);
- b2 = 0xC7;
- b3 = 0xC0;
- EMIT3_off32(b1, b2, add_1reg(b3, dst_reg), imm32);
- break;
- }
-
case BPF_ALU | BPF_MOV | BPF_K:
- /* optimization: if imm32 is zero, use 'xor <dst>,<dst>'
- * to save 3 bytes.
- */
- if (imm32 == 0) {
- if (is_ereg(dst_reg))
- EMIT1(add_2mod(0x40, dst_reg, dst_reg));
- b2 = 0x31; /* xor */
- b3 = 0xC0;
- EMIT2(b2, add_2reg(b3, dst_reg, dst_reg));
- break;
- }
-
- /* mov %eax, imm32 */
- if (is_ereg(dst_reg))
- EMIT1(add_1mod(0x40, dst_reg));
- EMIT1_off32(add_1reg(0xB8, dst_reg), imm32);
+ emit_mov_imm32(&prog, BPF_CLASS(insn->code) == BPF_ALU64,
+ dst_reg, imm32);
break;
case BPF_LD | BPF_IMM | BPF_DW:
- /* optimization: if imm64 is zero, use 'xor <dst>,<dst>'
- * to save 7 bytes.
- */
- if (insn[0].imm == 0 && insn[1].imm == 0) {
- b1 = add_2mod(0x48, dst_reg, dst_reg);
- b2 = 0x31; /* xor */
- b3 = 0xC0;
- EMIT3(b1, b2, add_2reg(b3, dst_reg, dst_reg));
-
- insn++;
- i++;
- break;
- }
-
- /* movabsq %rax, imm64 */
- EMIT2(add_1mod(0x48, dst_reg), add_1reg(0xB8, dst_reg));
- EMIT(insn[0].imm, 4);
- EMIT(insn[1].imm, 4);
-
+ emit_mov_imm64(&prog, dst_reg, insn[1].imm, insn[0].imm);
insn++;
i++;
break;
@@ -594,36 +633,38 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image,
case BPF_ALU | BPF_MUL | BPF_X:
case BPF_ALU64 | BPF_MUL | BPF_K:
case BPF_ALU64 | BPF_MUL | BPF_X:
- EMIT1(0x50); /* push rax */
- EMIT1(0x52); /* push rdx */
+ {
+ bool is64 = BPF_CLASS(insn->code) == BPF_ALU64;
+
+ if (dst_reg != BPF_REG_0)
+ EMIT1(0x50); /* push rax */
+ if (dst_reg != BPF_REG_3)
+ EMIT1(0x52); /* push rdx */
/* mov r11, dst_reg */
EMIT_mov(AUX_REG, dst_reg);
if (BPF_SRC(insn->code) == BPF_X)
- /* mov rax, src_reg */
- EMIT_mov(BPF_REG_0, src_reg);
+ emit_mov_reg(&prog, is64, BPF_REG_0, src_reg);
else
- /* mov rax, imm32 */
- EMIT3_off32(0x48, 0xC7, 0xC0, imm32);
+ emit_mov_imm32(&prog, is64, BPF_REG_0, imm32);
- if (BPF_CLASS(insn->code) == BPF_ALU64)
+ if (is64)
EMIT1(add_1mod(0x48, AUX_REG));
else if (is_ereg(AUX_REG))
EMIT1(add_1mod(0x40, AUX_REG));
/* mul(q) r11 */
EMIT2(0xF7, add_1reg(0xE0, AUX_REG));
- /* mov r11, rax */
- EMIT_mov(AUX_REG, BPF_REG_0);
-
- EMIT1(0x5A); /* pop rdx */
- EMIT1(0x58); /* pop rax */
-
- /* mov dst_reg, r11 */
- EMIT_mov(dst_reg, AUX_REG);
+ if (dst_reg != BPF_REG_3)
+ EMIT1(0x5A); /* pop rdx */
+ if (dst_reg != BPF_REG_0) {
+ /* mov dst_reg, rax */
+ EMIT_mov(dst_reg, BPF_REG_0);
+ EMIT1(0x58); /* pop rax */
+ }
break;
-
+ }
/* shifts */
case BPF_ALU | BPF_LSH | BPF_K:
case BPF_ALU | BPF_RSH | BPF_K:
@@ -641,7 +682,11 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image,
case BPF_RSH: b3 = 0xE8; break;
case BPF_ARSH: b3 = 0xF8; break;
}
- EMIT3(0xC1, add_1reg(b3, dst_reg), imm32);
+
+ if (imm32 == 1)
+ EMIT2(0xD1, add_1reg(b3, dst_reg));
+ else
+ EMIT3(0xC1, add_1reg(b3, dst_reg), imm32);
break;
case BPF_ALU | BPF_LSH | BPF_X: