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Diffstat (limited to 'arch/x86/net/bpf_jit_comp32.c')
-rw-r--r--arch/x86/net/bpf_jit_comp32.c986
1 files changed, 595 insertions, 391 deletions
diff --git a/arch/x86/net/bpf_jit_comp32.c b/arch/x86/net/bpf_jit_comp32.c
index 8f6cc71e0848..de0f9e5f9f73 100644
--- a/arch/x86/net/bpf_jit_comp32.c
+++ b/arch/x86/net/bpf_jit_comp32.c
@@ -15,6 +15,7 @@
#include <asm/cacheflush.h>
#include <asm/set_memory.h>
#include <asm/nospec-branch.h>
+#include <asm/asm-prototypes.h>
#include <linux/bpf.h>
/*
@@ -117,6 +118,8 @@ static bool is_simm32(s64 value)
#define IA32_JLE 0x7E
#define IA32_JG 0x7F
+#define COND_JMP_OPCODE_INVALID (0xFF)
+
/*
* Map eBPF registers to IA32 32bit registers or stack scratch space.
*
@@ -251,13 +254,14 @@ static inline void emit_ia32_mov_r(const u8 dst, const u8 src, bool dstk,
/* dst = src */
static inline void emit_ia32_mov_r64(const bool is64, const u8 dst[],
const u8 src[], bool dstk,
- bool sstk, u8 **pprog)
+ bool sstk, u8 **pprog,
+ const struct bpf_prog_aux *aux)
{
emit_ia32_mov_r(dst_lo, src_lo, dstk, sstk, pprog);
if (is64)
/* complete 8 byte move */
emit_ia32_mov_r(dst_hi, src_hi, dstk, sstk, pprog);
- else
+ else if (!aux->verifier_zext)
/* zero out high 4 bytes */
emit_ia32_mov_i(dst_hi, 0, dstk, pprog);
}
@@ -311,7 +315,8 @@ static inline void emit_ia32_mul_r(const u8 dst, const u8 src, bool dstk,
}
static inline void emit_ia32_to_le_r64(const u8 dst[], s32 val,
- bool dstk, u8 **pprog)
+ bool dstk, u8 **pprog,
+ const struct bpf_prog_aux *aux)
{
u8 *prog = *pprog;
int cnt = 0;
@@ -332,12 +337,14 @@ static inline void emit_ia32_to_le_r64(const u8 dst[], s32 val,
*/
EMIT2(0x0F, 0xB7);
EMIT1(add_2reg(0xC0, dreg_lo, dreg_lo));
- /* xor dreg_hi,dreg_hi */
- EMIT2(0x33, add_2reg(0xC0, dreg_hi, dreg_hi));
+ if (!aux->verifier_zext)
+ /* xor dreg_hi,dreg_hi */
+ EMIT2(0x33, add_2reg(0xC0, dreg_hi, dreg_hi));
break;
case 32:
- /* xor dreg_hi,dreg_hi */
- EMIT2(0x33, add_2reg(0xC0, dreg_hi, dreg_hi));
+ if (!aux->verifier_zext)
+ /* xor dreg_hi,dreg_hi */
+ EMIT2(0x33, add_2reg(0xC0, dreg_hi, dreg_hi));
break;
case 64:
/* nop */
@@ -356,7 +363,8 @@ static inline void emit_ia32_to_le_r64(const u8 dst[], s32 val,
}
static inline void emit_ia32_to_be_r64(const u8 dst[], s32 val,
- bool dstk, u8 **pprog)
+ bool dstk, u8 **pprog,
+ const struct bpf_prog_aux *aux)
{
u8 *prog = *pprog;
int cnt = 0;
@@ -378,16 +386,18 @@ static inline void emit_ia32_to_be_r64(const u8 dst[], s32 val,
EMIT2(0x0F, 0xB7);
EMIT1(add_2reg(0xC0, dreg_lo, dreg_lo));
- /* xor dreg_hi,dreg_hi */
- EMIT2(0x33, add_2reg(0xC0, dreg_hi, dreg_hi));
+ if (!aux->verifier_zext)
+ /* xor dreg_hi,dreg_hi */
+ EMIT2(0x33, add_2reg(0xC0, dreg_hi, dreg_hi));
break;
case 32:
/* Emit 'bswap eax' to swap lower 4 bytes */
EMIT1(0x0F);
EMIT1(add_1reg(0xC8, dreg_lo));
- /* xor dreg_hi,dreg_hi */
- EMIT2(0x33, add_2reg(0xC0, dreg_hi, dreg_hi));
+ if (!aux->verifier_zext)
+ /* xor dreg_hi,dreg_hi */
+ EMIT2(0x33, add_2reg(0xC0, dreg_hi, dreg_hi));
break;
case 64:
/* Emit 'bswap eax' to swap lower 4 bytes */
@@ -567,7 +577,7 @@ static inline void emit_ia32_alu_r(const bool is64, const bool hi, const u8 op,
static inline void emit_ia32_alu_r64(const bool is64, const u8 op,
const u8 dst[], const u8 src[],
bool dstk, bool sstk,
- u8 **pprog)
+ u8 **pprog, const struct bpf_prog_aux *aux)
{
u8 *prog = *pprog;
@@ -575,7 +585,7 @@ static inline void emit_ia32_alu_r64(const bool is64, const u8 op,
if (is64)
emit_ia32_alu_r(is64, true, op, dst_hi, src_hi, dstk, sstk,
&prog);
- else
+ else if (!aux->verifier_zext)
emit_ia32_mov_i(dst_hi, 0, dstk, &prog);
*pprog = prog;
}
@@ -666,7 +676,8 @@ static inline void emit_ia32_alu_i(const bool is64, const bool hi, const u8 op,
/* ALU operation (64 bit) */
static inline void emit_ia32_alu_i64(const bool is64, const u8 op,
const u8 dst[], const u32 val,
- bool dstk, u8 **pprog)
+ bool dstk, u8 **pprog,
+ const struct bpf_prog_aux *aux)
{
u8 *prog = *pprog;
u32 hi = 0;
@@ -677,7 +688,7 @@ static inline void emit_ia32_alu_i64(const bool is64, const u8 op,
emit_ia32_alu_i(is64, false, op, dst_lo, val, dstk, &prog);
if (is64)
emit_ia32_alu_i(is64, true, op, dst_hi, hi, dstk, &prog);
- else
+ else if (!aux->verifier_zext)
emit_ia32_mov_i(dst_hi, 0, dstk, &prog);
*pprog = prog;
@@ -698,19 +709,12 @@ static inline void emit_ia32_neg64(const u8 dst[], bool dstk, u8 **pprog)
STACK_VAR(dst_hi));
}
- /* xor ecx,ecx */
- EMIT2(0x31, add_2reg(0xC0, IA32_ECX, IA32_ECX));
- /* sub dreg_lo,ecx */
- EMIT2(0x2B, add_2reg(0xC0, dreg_lo, IA32_ECX));
- /* mov dreg_lo,ecx */
- EMIT2(0x89, add_2reg(0xC0, dreg_lo, IA32_ECX));
-
- /* xor ecx,ecx */
- EMIT2(0x31, add_2reg(0xC0, IA32_ECX, IA32_ECX));
- /* sbb dreg_hi,ecx */
- EMIT2(0x19, add_2reg(0xC0, dreg_hi, IA32_ECX));
- /* mov dreg_hi,ecx */
- EMIT2(0x89, add_2reg(0xC0, dreg_hi, IA32_ECX));
+ /* neg dreg_lo */
+ EMIT2(0xF7, add_1reg(0xD8, dreg_lo));
+ /* adc dreg_hi,0x0 */
+ EMIT3(0x83, add_1reg(0xD0, dreg_hi), 0x00);
+ /* neg dreg_hi */
+ EMIT2(0xF7, add_1reg(0xD8, dreg_hi));
if (dstk) {
/* mov dword ptr [ebp+off],dreg_lo */
@@ -729,9 +733,6 @@ static inline void emit_ia32_lsh_r64(const u8 dst[], const u8 src[],
{
u8 *prog = *pprog;
int cnt = 0;
- static int jmp_label1 = -1;
- static int jmp_label2 = -1;
- static int jmp_label3 = -1;
u8 dreg_lo = dstk ? IA32_EAX : dst_lo;
u8 dreg_hi = dstk ? IA32_EDX : dst_hi;
@@ -750,79 +751,23 @@ static inline void emit_ia32_lsh_r64(const u8 dst[], const u8 src[],
/* mov ecx,src_lo */
EMIT2(0x8B, add_2reg(0xC0, src_lo, IA32_ECX));
- /* cmp ecx,32 */
- EMIT3(0x83, add_1reg(0xF8, IA32_ECX), 32);
- /* Jumps when >= 32 */
- if (is_imm8(jmp_label(jmp_label1, 2)))
- EMIT2(IA32_JAE, jmp_label(jmp_label1, 2));
- else
- EMIT2_off32(0x0F, IA32_JAE + 0x10, jmp_label(jmp_label1, 6));
-
- /* < 32 */
- /* shl dreg_hi,cl */
- EMIT2(0xD3, add_1reg(0xE0, dreg_hi));
- /* mov ebx,dreg_lo */
- EMIT2(0x8B, add_2reg(0xC0, dreg_lo, IA32_EBX));
+ /* shld dreg_hi,dreg_lo,cl */
+ EMIT3(0x0F, 0xA5, add_2reg(0xC0, dreg_hi, dreg_lo));
/* shl dreg_lo,cl */
EMIT2(0xD3, add_1reg(0xE0, dreg_lo));
- /* IA32_ECX = -IA32_ECX + 32 */
- /* neg ecx */
- EMIT2(0xF7, add_1reg(0xD8, IA32_ECX));
- /* add ecx,32 */
- EMIT3(0x83, add_1reg(0xC0, IA32_ECX), 32);
+ /* if ecx >= 32, mov dreg_lo into dreg_hi and clear dreg_lo */
- /* shr ebx,cl */
- EMIT2(0xD3, add_1reg(0xE8, IA32_EBX));
- /* or dreg_hi,ebx */
- EMIT2(0x09, add_2reg(0xC0, dreg_hi, IA32_EBX));
-
- /* goto out; */
- if (is_imm8(jmp_label(jmp_label3, 2)))
- EMIT2(0xEB, jmp_label(jmp_label3, 2));
- else
- EMIT1_off32(0xE9, jmp_label(jmp_label3, 5));
-
- /* >= 32 */
- if (jmp_label1 == -1)
- jmp_label1 = cnt;
-
- /* cmp ecx,64 */
- EMIT3(0x83, add_1reg(0xF8, IA32_ECX), 64);
- /* Jumps when >= 64 */
- if (is_imm8(jmp_label(jmp_label2, 2)))
- EMIT2(IA32_JAE, jmp_label(jmp_label2, 2));
- else
- EMIT2_off32(0x0F, IA32_JAE + 0x10, jmp_label(jmp_label2, 6));
+ /* cmp ecx,32 */
+ EMIT3(0x83, add_1reg(0xF8, IA32_ECX), 32);
+ /* skip the next two instructions (4 bytes) when < 32 */
+ EMIT2(IA32_JB, 4);
- /* >= 32 && < 64 */
- /* sub ecx,32 */
- EMIT3(0x83, add_1reg(0xE8, IA32_ECX), 32);
- /* shl dreg_lo,cl */
- EMIT2(0xD3, add_1reg(0xE0, dreg_lo));
/* mov dreg_hi,dreg_lo */
EMIT2(0x89, add_2reg(0xC0, dreg_hi, dreg_lo));
-
/* xor dreg_lo,dreg_lo */
EMIT2(0x33, add_2reg(0xC0, dreg_lo, dreg_lo));
- /* goto out; */
- if (is_imm8(jmp_label(jmp_label3, 2)))
- EMIT2(0xEB, jmp_label(jmp_label3, 2));
- else
- EMIT1_off32(0xE9, jmp_label(jmp_label3, 5));
-
- /* >= 64 */
- if (jmp_label2 == -1)
- jmp_label2 = cnt;
- /* xor dreg_lo,dreg_lo */
- EMIT2(0x33, add_2reg(0xC0, dreg_lo, dreg_lo));
- /* xor dreg_hi,dreg_hi */
- EMIT2(0x33, add_2reg(0xC0, dreg_hi, dreg_hi));
-
- if (jmp_label3 == -1)
- jmp_label3 = cnt;
-
if (dstk) {
/* mov dword ptr [ebp+off],dreg_lo */
EMIT3(0x89, add_2reg(0x40, IA32_EBP, dreg_lo),
@@ -841,9 +786,6 @@ static inline void emit_ia32_arsh_r64(const u8 dst[], const u8 src[],
{
u8 *prog = *pprog;
int cnt = 0;
- static int jmp_label1 = -1;
- static int jmp_label2 = -1;
- static int jmp_label3 = -1;
u8 dreg_lo = dstk ? IA32_EAX : dst_lo;
u8 dreg_hi = dstk ? IA32_EDX : dst_hi;
@@ -862,78 +804,22 @@ static inline void emit_ia32_arsh_r64(const u8 dst[], const u8 src[],
/* mov ecx,src_lo */
EMIT2(0x8B, add_2reg(0xC0, src_lo, IA32_ECX));
- /* cmp ecx,32 */
- EMIT3(0x83, add_1reg(0xF8, IA32_ECX), 32);
- /* Jumps when >= 32 */
- if (is_imm8(jmp_label(jmp_label1, 2)))
- EMIT2(IA32_JAE, jmp_label(jmp_label1, 2));
- else
- EMIT2_off32(0x0F, IA32_JAE + 0x10, jmp_label(jmp_label1, 6));
-
- /* < 32 */
- /* lshr dreg_lo,cl */
- EMIT2(0xD3, add_1reg(0xE8, dreg_lo));
- /* mov ebx,dreg_hi */
- EMIT2(0x8B, add_2reg(0xC0, dreg_hi, IA32_EBX));
- /* ashr dreg_hi,cl */
+ /* shrd dreg_lo,dreg_hi,cl */
+ EMIT3(0x0F, 0xAD, add_2reg(0xC0, dreg_lo, dreg_hi));
+ /* sar dreg_hi,cl */
EMIT2(0xD3, add_1reg(0xF8, dreg_hi));
- /* IA32_ECX = -IA32_ECX + 32 */
- /* neg ecx */
- EMIT2(0xF7, add_1reg(0xD8, IA32_ECX));
- /* add ecx,32 */
- EMIT3(0x83, add_1reg(0xC0, IA32_ECX), 32);
+ /* if ecx >= 32, mov dreg_hi to dreg_lo and set/clear dreg_hi depending on sign */
- /* shl ebx,cl */
- EMIT2(0xD3, add_1reg(0xE0, IA32_EBX));
- /* or dreg_lo,ebx */
- EMIT2(0x09, add_2reg(0xC0, dreg_lo, IA32_EBX));
-
- /* goto out; */
- if (is_imm8(jmp_label(jmp_label3, 2)))
- EMIT2(0xEB, jmp_label(jmp_label3, 2));
- else
- EMIT1_off32(0xE9, jmp_label(jmp_label3, 5));
-
- /* >= 32 */
- if (jmp_label1 == -1)
- jmp_label1 = cnt;
-
- /* cmp ecx,64 */
- EMIT3(0x83, add_1reg(0xF8, IA32_ECX), 64);
- /* Jumps when >= 64 */
- if (is_imm8(jmp_label(jmp_label2, 2)))
- EMIT2(IA32_JAE, jmp_label(jmp_label2, 2));
- else
- EMIT2_off32(0x0F, IA32_JAE + 0x10, jmp_label(jmp_label2, 6));
+ /* cmp ecx,32 */
+ EMIT3(0x83, add_1reg(0xF8, IA32_ECX), 32);
+ /* skip the next two instructions (5 bytes) when < 32 */
+ EMIT2(IA32_JB, 5);
- /* >= 32 && < 64 */
- /* sub ecx,32 */
- EMIT3(0x83, add_1reg(0xE8, IA32_ECX), 32);
- /* ashr dreg_hi,cl */
- EMIT2(0xD3, add_1reg(0xF8, dreg_hi));
/* mov dreg_lo,dreg_hi */
EMIT2(0x89, add_2reg(0xC0, dreg_lo, dreg_hi));
-
- /* ashr dreg_hi,imm8 */
- EMIT3(0xC1, add_1reg(0xF8, dreg_hi), 31);
-
- /* goto out; */
- if (is_imm8(jmp_label(jmp_label3, 2)))
- EMIT2(0xEB, jmp_label(jmp_label3, 2));
- else
- EMIT1_off32(0xE9, jmp_label(jmp_label3, 5));
-
- /* >= 64 */
- if (jmp_label2 == -1)
- jmp_label2 = cnt;
- /* ashr dreg_hi,imm8 */
+ /* sar dreg_hi,31 */
EMIT3(0xC1, add_1reg(0xF8, dreg_hi), 31);
- /* mov dreg_lo,dreg_hi */
- EMIT2(0x89, add_2reg(0xC0, dreg_lo, dreg_hi));
-
- if (jmp_label3 == -1)
- jmp_label3 = cnt;
if (dstk) {
/* mov dword ptr [ebp+off],dreg_lo */
@@ -953,9 +839,6 @@ static inline void emit_ia32_rsh_r64(const u8 dst[], const u8 src[], bool dstk,
{
u8 *prog = *pprog;
int cnt = 0;
- static int jmp_label1 = -1;
- static int jmp_label2 = -1;
- static int jmp_label3 = -1;
u8 dreg_lo = dstk ? IA32_EAX : dst_lo;
u8 dreg_hi = dstk ? IA32_EDX : dst_hi;
@@ -974,77 +857,23 @@ static inline void emit_ia32_rsh_r64(const u8 dst[], const u8 src[], bool dstk,
/* mov ecx,src_lo */
EMIT2(0x8B, add_2reg(0xC0, src_lo, IA32_ECX));
- /* cmp ecx,32 */
- EMIT3(0x83, add_1reg(0xF8, IA32_ECX), 32);
- /* Jumps when >= 32 */
- if (is_imm8(jmp_label(jmp_label1, 2)))
- EMIT2(IA32_JAE, jmp_label(jmp_label1, 2));
- else
- EMIT2_off32(0x0F, IA32_JAE + 0x10, jmp_label(jmp_label1, 6));
-
- /* < 32 */
- /* lshr dreg_lo,cl */
- EMIT2(0xD3, add_1reg(0xE8, dreg_lo));
- /* mov ebx,dreg_hi */
- EMIT2(0x8B, add_2reg(0xC0, dreg_hi, IA32_EBX));
+ /* shrd dreg_lo,dreg_hi,cl */
+ EMIT3(0x0F, 0xAD, add_2reg(0xC0, dreg_lo, dreg_hi));
/* shr dreg_hi,cl */
EMIT2(0xD3, add_1reg(0xE8, dreg_hi));
- /* IA32_ECX = -IA32_ECX + 32 */
- /* neg ecx */
- EMIT2(0xF7, add_1reg(0xD8, IA32_ECX));
- /* add ecx,32 */
- EMIT3(0x83, add_1reg(0xC0, IA32_ECX), 32);
-
- /* shl ebx,cl */
- EMIT2(0xD3, add_1reg(0xE0, IA32_EBX));
- /* or dreg_lo,ebx */
- EMIT2(0x09, add_2reg(0xC0, dreg_lo, IA32_EBX));
+ /* if ecx >= 32, mov dreg_hi to dreg_lo and clear dreg_hi */
- /* goto out; */
- if (is_imm8(jmp_label(jmp_label3, 2)))
- EMIT2(0xEB, jmp_label(jmp_label3, 2));
- else
- EMIT1_off32(0xE9, jmp_label(jmp_label3, 5));
-
- /* >= 32 */
- if (jmp_label1 == -1)
- jmp_label1 = cnt;
- /* cmp ecx,64 */
- EMIT3(0x83, add_1reg(0xF8, IA32_ECX), 64);
- /* Jumps when >= 64 */
- if (is_imm8(jmp_label(jmp_label2, 2)))
- EMIT2(IA32_JAE, jmp_label(jmp_label2, 2));
- else
- EMIT2_off32(0x0F, IA32_JAE + 0x10, jmp_label(jmp_label2, 6));
+ /* cmp ecx,32 */
+ EMIT3(0x83, add_1reg(0xF8, IA32_ECX), 32);
+ /* skip the next two instructions (4 bytes) when < 32 */
+ EMIT2(IA32_JB, 4);
- /* >= 32 && < 64 */
- /* sub ecx,32 */
- EMIT3(0x83, add_1reg(0xE8, IA32_ECX), 32);
- /* shr dreg_hi,cl */
- EMIT2(0xD3, add_1reg(0xE8, dreg_hi));
/* mov dreg_lo,dreg_hi */
EMIT2(0x89, add_2reg(0xC0, dreg_lo, dreg_hi));
/* xor dreg_hi,dreg_hi */
EMIT2(0x33, add_2reg(0xC0, dreg_hi, dreg_hi));
- /* goto out; */
- if (is_imm8(jmp_label(jmp_label3, 2)))
- EMIT2(0xEB, jmp_label(jmp_label3, 2));
- else
- EMIT1_off32(0xE9, jmp_label(jmp_label3, 5));
-
- /* >= 64 */
- if (jmp_label2 == -1)
- jmp_label2 = cnt;
- /* xor dreg_lo,dreg_lo */
- EMIT2(0x33, add_2reg(0xC0, dreg_lo, dreg_lo));
- /* xor dreg_hi,dreg_hi */
- EMIT2(0x33, add_2reg(0xC0, dreg_hi, dreg_hi));
-
- if (jmp_label3 == -1)
- jmp_label3 = cnt;
-
if (dstk) {
/* mov dword ptr [ebp+off],dreg_lo */
EMIT3(0x89, add_2reg(0x40, IA32_EBP, dreg_lo),
@@ -1074,27 +903,10 @@ static inline void emit_ia32_lsh_i64(const u8 dst[], const u32 val,
}
/* Do LSH operation */
if (val < 32) {
- /* shl dreg_hi,imm8 */
- EMIT3(0xC1, add_1reg(0xE0, dreg_hi), val);
- /* mov ebx,dreg_lo */
- EMIT2(0x8B, add_2reg(0xC0, dreg_lo, IA32_EBX));
+ /* shld dreg_hi,dreg_lo,imm8 */
+ EMIT4(0x0F, 0xA4, add_2reg(0xC0, dreg_hi, dreg_lo), val);
/* shl dreg_lo,imm8 */
EMIT3(0xC1, add_1reg(0xE0, dreg_lo), val);
-
- /* IA32_ECX = 32 - val */
- /* mov ecx,val */
- EMIT2(0xB1, val);
- /* movzx ecx,ecx */
- EMIT3(0x0F, 0xB6, add_2reg(0xC0, IA32_ECX, IA32_ECX));
- /* neg ecx */
- EMIT2(0xF7, add_1reg(0xD8, IA32_ECX));
- /* add ecx,32 */
- EMIT3(0x83, add_1reg(0xC0, IA32_ECX), 32);
-
- /* shr ebx,cl */
- EMIT2(0xD3, add_1reg(0xE8, IA32_EBX));
- /* or dreg_hi,ebx */
- EMIT2(0x09, add_2reg(0xC0, dreg_hi, IA32_EBX));
} else if (val >= 32 && val < 64) {
u32 value = val - 32;
@@ -1140,27 +952,10 @@ static inline void emit_ia32_rsh_i64(const u8 dst[], const u32 val,
/* Do RSH operation */
if (val < 32) {
- /* shr dreg_lo,imm8 */
- EMIT3(0xC1, add_1reg(0xE8, dreg_lo), val);
- /* mov ebx,dreg_hi */
- EMIT2(0x8B, add_2reg(0xC0, dreg_hi, IA32_EBX));
+ /* shrd dreg_lo,dreg_hi,imm8 */
+ EMIT4(0x0F, 0xAC, add_2reg(0xC0, dreg_lo, dreg_hi), val);
/* shr dreg_hi,imm8 */
EMIT3(0xC1, add_1reg(0xE8, dreg_hi), val);
-
- /* IA32_ECX = 32 - val */
- /* mov ecx,val */
- EMIT2(0xB1, val);
- /* movzx ecx,ecx */
- EMIT3(0x0F, 0xB6, add_2reg(0xC0, IA32_ECX, IA32_ECX));
- /* neg ecx */
- EMIT2(0xF7, add_1reg(0xD8, IA32_ECX));
- /* add ecx,32 */
- EMIT3(0x83, add_1reg(0xC0, IA32_ECX), 32);
-
- /* shl ebx,cl */
- EMIT2(0xD3, add_1reg(0xE0, IA32_EBX));
- /* or dreg_lo,ebx */
- EMIT2(0x09, add_2reg(0xC0, dreg_lo, IA32_EBX));
} else if (val >= 32 && val < 64) {
u32 value = val - 32;
@@ -1205,27 +1000,10 @@ static inline void emit_ia32_arsh_i64(const u8 dst[], const u32 val,
}
/* Do RSH operation */
if (val < 32) {
- /* shr dreg_lo,imm8 */
- EMIT3(0xC1, add_1reg(0xE8, dreg_lo), val);
- /* mov ebx,dreg_hi */
- EMIT2(0x8B, add_2reg(0xC0, dreg_hi, IA32_EBX));
+ /* shrd dreg_lo,dreg_hi,imm8 */
+ EMIT4(0x0F, 0xAC, add_2reg(0xC0, dreg_lo, dreg_hi), val);
/* ashr dreg_hi,imm8 */
EMIT3(0xC1, add_1reg(0xF8, dreg_hi), val);
-
- /* IA32_ECX = 32 - val */
- /* mov ecx,val */
- EMIT2(0xB1, val);
- /* movzx ecx,ecx */
- EMIT3(0x0F, 0xB6, add_2reg(0xC0, IA32_ECX, IA32_ECX));
- /* neg ecx */
- EMIT2(0xF7, add_1reg(0xD8, IA32_ECX));
- /* add ecx,32 */
- EMIT3(0x83, add_1reg(0xC0, IA32_ECX), 32);
-
- /* shl ebx,cl */
- EMIT2(0xD3, add_1reg(0xE0, IA32_EBX));
- /* or dreg_lo,ebx */
- EMIT2(0x09, add_2reg(0xC0, dreg_lo, IA32_EBX));
} else if (val >= 32 && val < 64) {
u32 value = val - 32;
@@ -1416,7 +1194,7 @@ struct jit_context {
#define PROLOGUE_SIZE 35
/*
- * Emit prologue code for BPF program and check it's size.
+ * Emit prologue code for BPF program and check its size.
* bpf_tail_call helper will skip it while jumping into another program.
*/
static void emit_prologue(u8 **pprog, u32 stack_depth)
@@ -1490,6 +1268,21 @@ static void emit_epilogue(u8 **pprog, u32 stack_depth)
*pprog = prog;
}
+static int emit_jmp_edx(u8 **pprog, u8 *ip)
+{
+ u8 *prog = *pprog;
+ int cnt = 0;
+
+#ifdef CONFIG_MITIGATION_RETPOLINE
+ EMIT1_off32(0xE9, (u8 *)__x86_indirect_thunk_edx - (ip + 5));
+#else
+ EMIT2(0xFF, 0xE2);
+#endif
+ *pprog = prog;
+
+ return cnt;
+}
+
/*
* Generate the following code:
* ... bpf_tail_call(void *ctx, struct bpf_array *array, u64 index) ...
@@ -1503,7 +1296,7 @@ static void emit_epilogue(u8 **pprog, u32 stack_depth)
* goto *(prog->bpf_func + prologue_size);
* out:
*/
-static void emit_bpf_tail_call(u8 **pprog)
+static void emit_bpf_tail_call(u8 **pprog, u8 *ip)
{
u8 *prog = *pprog;
int cnt = 0;
@@ -1530,7 +1323,7 @@ static void emit_bpf_tail_call(u8 **pprog)
EMIT2(IA32_JBE, jmp_label(jmp_label1, 2));
/*
- * if (tail_call_cnt > MAX_TAIL_CALL_CNT)
+ * if (tail_call_cnt++ >= MAX_TAIL_CALL_CNT)
* goto out;
*/
lo = (u32)MAX_TAIL_CALL_CNT;
@@ -1544,7 +1337,7 @@ static void emit_bpf_tail_call(u8 **pprog)
/* cmp ecx,lo */
EMIT3(0x83, add_1reg(0xF8, IA32_ECX), lo);
- /* ja out */
+ /* jae out */
EMIT2(IA32_JAE, jmp_label(jmp_label1, 2));
/* add eax,0x1 */
@@ -1585,7 +1378,7 @@ static void emit_bpf_tail_call(u8 **pprog)
* eax == ctx (1st arg)
* edx == prog->bpf_func + prologue_size
*/
- RETPOLINE_EDX_BPF_JIT();
+ cnt += emit_jmp_edx(&prog, ip + cnt);
if (jmp_label1 == -1)
jmp_label1 = cnt;
@@ -1613,6 +1406,256 @@ static inline void emit_push_r64(const u8 src[], u8 **pprog)
*pprog = prog;
}
+static void emit_push_r32(const u8 src[], u8 **pprog)
+{
+ u8 *prog = *pprog;
+ int cnt = 0;
+
+ /* mov ecx,dword ptr [ebp+off] */
+ EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_ECX), STACK_VAR(src_lo));
+ /* push ecx */
+ EMIT1(0x51);
+
+ *pprog = prog;
+}
+
+static u8 get_cond_jmp_opcode(const u8 op, bool is_cmp_lo)
+{
+ u8 jmp_cond;
+
+ /* Convert BPF opcode to x86 */
+ switch (op) {
+ case BPF_JEQ:
+ jmp_cond = IA32_JE;
+ break;
+ case BPF_JSET:
+ case BPF_JNE:
+ jmp_cond = IA32_JNE;
+ break;
+ case BPF_JGT:
+ /* GT is unsigned '>', JA in x86 */
+ jmp_cond = IA32_JA;
+ break;
+ case BPF_JLT:
+ /* LT is unsigned '<', JB in x86 */
+ jmp_cond = IA32_JB;
+ break;
+ case BPF_JGE:
+ /* GE is unsigned '>=', JAE in x86 */
+ jmp_cond = IA32_JAE;
+ break;
+ case BPF_JLE:
+ /* LE is unsigned '<=', JBE in x86 */
+ jmp_cond = IA32_JBE;
+ break;
+ case BPF_JSGT:
+ if (!is_cmp_lo)
+ /* Signed '>', GT in x86 */
+ jmp_cond = IA32_JG;
+ else
+ /* GT is unsigned '>', JA in x86 */
+ jmp_cond = IA32_JA;
+ break;
+ case BPF_JSLT:
+ if (!is_cmp_lo)
+ /* Signed '<', LT in x86 */
+ jmp_cond = IA32_JL;
+ else
+ /* LT is unsigned '<', JB in x86 */
+ jmp_cond = IA32_JB;
+ break;
+ case BPF_JSGE:
+ if (!is_cmp_lo)
+ /* Signed '>=', GE in x86 */
+ jmp_cond = IA32_JGE;
+ else
+ /* GE is unsigned '>=', JAE in x86 */
+ jmp_cond = IA32_JAE;
+ break;
+ case BPF_JSLE:
+ if (!is_cmp_lo)
+ /* Signed '<=', LE in x86 */
+ jmp_cond = IA32_JLE;
+ else
+ /* LE is unsigned '<=', JBE in x86 */
+ jmp_cond = IA32_JBE;
+ break;
+ default: /* to silence GCC warning */
+ jmp_cond = COND_JMP_OPCODE_INVALID;
+ break;
+ }
+
+ return jmp_cond;
+}
+
+/* i386 kernel compiles with "-mregparm=3". From gcc document:
+ *
+ * ==== snippet ====
+ * regparm (number)
+ * On x86-32 targets, the regparm attribute causes the compiler
+ * to pass arguments number one to (number) if they are of integral
+ * type in registers EAX, EDX, and ECX instead of on the stack.
+ * Functions that take a variable number of arguments continue
+ * to be passed all of their arguments on the stack.
+ * ==== snippet ====
+ *
+ * The first three args of a function will be considered for
+ * putting into the 32bit register EAX, EDX, and ECX.
+ *
+ * Two 32bit registers are used to pass a 64bit arg.
+ *
+ * For example,
+ * void foo(u32 a, u32 b, u32 c, u32 d):
+ * u32 a: EAX
+ * u32 b: EDX
+ * u32 c: ECX
+ * u32 d: stack
+ *
+ * void foo(u64 a, u32 b, u32 c):
+ * u64 a: EAX (lo32) EDX (hi32)
+ * u32 b: ECX
+ * u32 c: stack
+ *
+ * void foo(u32 a, u64 b, u32 c):
+ * u32 a: EAX
+ * u64 b: EDX (lo32) ECX (hi32)
+ * u32 c: stack
+ *
+ * void foo(u32 a, u32 b, u64 c):
+ * u32 a: EAX
+ * u32 b: EDX
+ * u64 c: stack
+ *
+ * The return value will be stored in the EAX (and EDX for 64bit value).
+ *
+ * For example,
+ * u32 foo(u32 a, u32 b, u32 c):
+ * return value: EAX
+ *
+ * u64 foo(u32 a, u32 b, u32 c):
+ * return value: EAX (lo32) EDX (hi32)
+ *
+ * Notes:
+ * The verifier only accepts function having integer and pointers
+ * as its args and return value, so it does not have
+ * struct-by-value.
+ *
+ * emit_kfunc_call() finds out the btf_func_model by calling
+ * bpf_jit_find_kfunc_model(). A btf_func_model
+ * has the details about the number of args, size of each arg,
+ * and the size of the return value.
+ *
+ * It first decides how many args can be passed by EAX, EDX, and ECX.
+ * That will decide what args should be pushed to the stack:
+ * [first_stack_regno, last_stack_regno] are the bpf regnos
+ * that should be pushed to the stack.
+ *
+ * It will first push all args to the stack because the push
+ * will need to use ECX. Then, it moves
+ * [BPF_REG_1, first_stack_regno) to EAX, EDX, and ECX.
+ *
+ * When emitting a call (0xE8), it needs to figure out
+ * the jmp_offset relative to the jit-insn address immediately
+ * following the call (0xE8) instruction. At this point, it knows
+ * the end of the jit-insn address after completely translated the
+ * current (BPF_JMP | BPF_CALL) bpf-insn. It is passed as "end_addr"
+ * to the emit_kfunc_call(). Thus, it can learn the "immediate-follow-call"
+ * address by figuring out how many jit-insn is generated between
+ * the call (0xE8) and the end_addr:
+ * - 0-1 jit-insn (3 bytes each) to restore the esp pointer if there
+ * is arg pushed to the stack.
+ * - 0-2 jit-insns (3 bytes each) to handle the return value.
+ */
+static int emit_kfunc_call(const struct bpf_prog *bpf_prog, u8 *end_addr,
+ const struct bpf_insn *insn, u8 **pprog)
+{
+ const u8 arg_regs[] = { IA32_EAX, IA32_EDX, IA32_ECX };
+ int i, cnt = 0, first_stack_regno, last_stack_regno;
+ int free_arg_regs = ARRAY_SIZE(arg_regs);
+ const struct btf_func_model *fm;
+ int bytes_in_stack = 0;
+ const u8 *cur_arg_reg;
+ u8 *prog = *pprog;
+ s64 jmp_offset;
+
+ fm = bpf_jit_find_kfunc_model(bpf_prog, insn);
+ if (!fm)
+ return -EINVAL;
+
+ first_stack_regno = BPF_REG_1;
+ for (i = 0; i < fm->nr_args; i++) {
+ int regs_needed = fm->arg_size[i] > sizeof(u32) ? 2 : 1;
+
+ if (regs_needed > free_arg_regs)
+ break;
+
+ free_arg_regs -= regs_needed;
+ first_stack_regno++;
+ }
+
+ /* Push the args to the stack */
+ last_stack_regno = BPF_REG_0 + fm->nr_args;
+ for (i = last_stack_regno; i >= first_stack_regno; i--) {
+ if (fm->arg_size[i - 1] > sizeof(u32)) {
+ emit_push_r64(bpf2ia32[i], &prog);
+ bytes_in_stack += 8;
+ } else {
+ emit_push_r32(bpf2ia32[i], &prog);
+ bytes_in_stack += 4;
+ }
+ }
+
+ cur_arg_reg = &arg_regs[0];
+ for (i = BPF_REG_1; i < first_stack_regno; i++) {
+ /* mov e[adc]x,dword ptr [ebp+off] */
+ EMIT3(0x8B, add_2reg(0x40, IA32_EBP, *cur_arg_reg++),
+ STACK_VAR(bpf2ia32[i][0]));
+ if (fm->arg_size[i - 1] > sizeof(u32))
+ /* mov e[adc]x,dword ptr [ebp+off] */
+ EMIT3(0x8B, add_2reg(0x40, IA32_EBP, *cur_arg_reg++),
+ STACK_VAR(bpf2ia32[i][1]));
+ }
+
+ if (bytes_in_stack)
+ /* add esp,"bytes_in_stack" */
+ end_addr -= 3;
+
+ /* mov dword ptr [ebp+off],edx */
+ if (fm->ret_size > sizeof(u32))
+ end_addr -= 3;
+
+ /* mov dword ptr [ebp+off],eax */
+ if (fm->ret_size)
+ end_addr -= 3;
+
+ jmp_offset = (u8 *)__bpf_call_base + insn->imm - end_addr;
+ if (!is_simm32(jmp_offset)) {
+ pr_err("unsupported BPF kernel function jmp_offset:%lld\n",
+ jmp_offset);
+ return -EINVAL;
+ }
+
+ EMIT1_off32(0xE8, jmp_offset);
+
+ if (fm->ret_size)
+ /* mov dword ptr [ebp+off],eax */
+ EMIT3(0x89, add_2reg(0x40, IA32_EBP, IA32_EAX),
+ STACK_VAR(bpf2ia32[BPF_REG_0][0]));
+
+ if (fm->ret_size > sizeof(u32))
+ /* mov dword ptr [ebp+off],edx */
+ EMIT3(0x89, add_2reg(0x40, IA32_EBP, IA32_EDX),
+ STACK_VAR(bpf2ia32[BPF_REG_0][1]));
+
+ if (bytes_in_stack)
+ /* add esp,"bytes_in_stack" */
+ EMIT3(0x83, add_1reg(0xC0, IA32_ESP), bytes_in_stack);
+
+ *pprog = prog;
+
+ return 0;
+}
+
static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image,
int oldproglen, struct jit_context *ctx)
{
@@ -1629,8 +1672,8 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image,
for (i = 0; i < insn_cnt; i++, insn++) {
const s32 imm32 = insn->imm;
const bool is64 = BPF_CLASS(insn->code) == BPF_ALU64;
- const bool dstk = insn->dst_reg == BPF_REG_AX ? false : true;
- const bool sstk = insn->src_reg == BPF_REG_AX ? false : true;
+ const bool dstk = insn->dst_reg != BPF_REG_AX;
+ const bool sstk = insn->src_reg != BPF_REG_AX;
const u8 code = insn->code;
const u8 *dst = bpf2ia32[insn->dst_reg];
const u8 *src = bpf2ia32[insn->src_reg];
@@ -1649,8 +1692,13 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image,
case BPF_ALU64 | BPF_MOV | BPF_X:
switch (BPF_SRC(code)) {
case BPF_X:
- emit_ia32_mov_r64(is64, dst, src, dstk,
- sstk, &prog);
+ if (imm32 == 1) {
+ /* Special mov32 for zext. */
+ emit_ia32_mov_i(dst_hi, 0, dstk, &prog);
+ break;
+ }
+ emit_ia32_mov_r64(is64, dst, src, dstk, sstk,
+ &prog, bpf_prog->aux);
break;
case BPF_K:
/* Sign-extend immediate value to dst reg */
@@ -1690,11 +1738,13 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image,
switch (BPF_SRC(code)) {
case BPF_X:
emit_ia32_alu_r64(is64, BPF_OP(code), dst,
- src, dstk, sstk, &prog);
+ src, dstk, sstk, &prog,
+ bpf_prog->aux);
break;
case BPF_K:
emit_ia32_alu_i64(is64, BPF_OP(code), dst,
- imm32, dstk, &prog);
+ imm32, dstk, &prog,
+ bpf_prog->aux);
break;
}
break;
@@ -1713,7 +1763,8 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image,
false, &prog);
break;
}
- emit_ia32_mov_i(dst_hi, 0, dstk, &prog);
+ if (!bpf_prog->aux->verifier_zext)
+ emit_ia32_mov_i(dst_hi, 0, dstk, &prog);
break;
case BPF_ALU | BPF_LSH | BPF_X:
case BPF_ALU | BPF_RSH | BPF_X:
@@ -1733,7 +1784,8 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image,
&prog);
break;
}
- emit_ia32_mov_i(dst_hi, 0, dstk, &prog);
+ if (!bpf_prog->aux->verifier_zext)
+ emit_ia32_mov_i(dst_hi, 0, dstk, &prog);
break;
/* dst = dst / src(imm) */
/* dst = dst % src(imm) */
@@ -1755,7 +1807,8 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image,
&prog);
break;
}
- emit_ia32_mov_i(dst_hi, 0, dstk, &prog);
+ if (!bpf_prog->aux->verifier_zext)
+ emit_ia32_mov_i(dst_hi, 0, dstk, &prog);
break;
case BPF_ALU64 | BPF_DIV | BPF_K:
case BPF_ALU64 | BPF_DIV | BPF_X:
@@ -1772,7 +1825,8 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image,
EMIT2_off32(0xC7, add_1reg(0xC0, IA32_ECX), imm32);
emit_ia32_shift_r(BPF_OP(code), dst_lo, IA32_ECX, dstk,
false, &prog);
- emit_ia32_mov_i(dst_hi, 0, dstk, &prog);
+ if (!bpf_prog->aux->verifier_zext)
+ emit_ia32_mov_i(dst_hi, 0, dstk, &prog);
break;
/* dst = dst << imm */
case BPF_ALU64 | BPF_LSH | BPF_K:
@@ -1808,7 +1862,8 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image,
case BPF_ALU | BPF_NEG:
emit_ia32_alu_i(is64, false, BPF_OP(code),
dst_lo, 0, dstk, &prog);
- emit_ia32_mov_i(dst_hi, 0, dstk, &prog);
+ if (!bpf_prog->aux->verifier_zext)
+ emit_ia32_mov_i(dst_hi, 0, dstk, &prog);
break;
/* dst = ~dst (64 bit) */
case BPF_ALU64 | BPF_NEG:
@@ -1828,11 +1883,13 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image,
break;
/* dst = htole(dst) */
case BPF_ALU | BPF_END | BPF_FROM_LE:
- emit_ia32_to_le_r64(dst, imm32, dstk, &prog);
+ emit_ia32_to_le_r64(dst, imm32, dstk, &prog,
+ bpf_prog->aux);
break;
/* dst = htobe(dst) */
case BPF_ALU | BPF_END | BPF_FROM_BE:
- emit_ia32_to_be_r64(dst, imm32, dstk, &prog);
+ emit_ia32_to_be_r64(dst, imm32, dstk, &prog,
+ bpf_prog->aux);
break;
/* dst = imm64 */
case BPF_LD | BPF_IMM | BPF_DW: {
@@ -1845,6 +1902,12 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image,
i++;
break;
}
+ /* speculation barrier */
+ case BPF_ST | BPF_NOSPEC:
+ if (boot_cpu_has(X86_FEATURE_XMM2))
+ /* Emit 'lfence' */
+ EMIT3(0x0F, 0xAE, 0xE8);
+ break;
/* ST: *(u8*)(dst_reg + off) = imm */
case BPF_ST | BPF_MEM | BPF_H:
case BPF_ST | BPF_MEM | BPF_B:
@@ -1987,12 +2050,16 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image,
case BPF_B:
case BPF_H:
case BPF_W:
+ if (bpf_prog->aux->verifier_zext)
+ break;
if (dstk) {
EMIT3(0xC7, add_1reg(0x40, IA32_EBP),
STACK_VAR(dst_hi));
EMIT(0x0, 4);
} else {
- EMIT3(0xC7, add_1reg(0xC0, dst_hi), 0);
+ /* xor dst_hi,dst_hi */
+ EMIT2(0x33,
+ add_2reg(0xC0, dst_hi, dst_hi));
}
break;
case BPF_DW:
@@ -2024,6 +2091,18 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image,
if (insn->src_reg == BPF_PSEUDO_CALL)
goto notyet;
+ if (insn->src_reg == BPF_PSEUDO_KFUNC_CALL) {
+ int err;
+
+ err = emit_kfunc_call(bpf_prog,
+ image + addrs[i],
+ insn, &prog);
+
+ if (err)
+ return err;
+ break;
+ }
+
func = (u8 *) __bpf_call_base + imm32;
jmp_offset = func - (image + addrs[i]);
@@ -2059,7 +2138,7 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image,
break;
}
case BPF_JMP | BPF_TAIL_CALL:
- emit_bpf_tail_call(&prog);
+ emit_bpf_tail_call(&prog, image + addrs[i - 1]);
break;
/* cond jump */
@@ -2069,6 +2148,51 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image,
case BPF_JMP | BPF_JLT | BPF_X:
case BPF_JMP | BPF_JGE | BPF_X:
case BPF_JMP | BPF_JLE | BPF_X:
+ case BPF_JMP32 | BPF_JEQ | BPF_X:
+ case BPF_JMP32 | BPF_JNE | BPF_X:
+ case BPF_JMP32 | BPF_JGT | BPF_X:
+ case BPF_JMP32 | BPF_JLT | BPF_X:
+ case BPF_JMP32 | BPF_JGE | BPF_X:
+ case BPF_JMP32 | BPF_JLE | BPF_X:
+ case BPF_JMP32 | BPF_JSGT | BPF_X:
+ case BPF_JMP32 | BPF_JSLE | BPF_X:
+ case BPF_JMP32 | BPF_JSLT | BPF_X:
+ case BPF_JMP32 | BPF_JSGE | BPF_X: {
+ bool is_jmp64 = BPF_CLASS(insn->code) == BPF_JMP;
+ u8 dreg_lo = dstk ? IA32_EAX : dst_lo;
+ u8 dreg_hi = dstk ? IA32_EDX : dst_hi;
+ u8 sreg_lo = sstk ? IA32_ECX : src_lo;
+ u8 sreg_hi = sstk ? IA32_EBX : src_hi;
+
+ if (dstk) {
+ EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_EAX),
+ STACK_VAR(dst_lo));
+ if (is_jmp64)
+ EMIT3(0x8B,
+ add_2reg(0x40, IA32_EBP,
+ IA32_EDX),
+ STACK_VAR(dst_hi));
+ }
+
+ if (sstk) {
+ EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_ECX),
+ STACK_VAR(src_lo));
+ if (is_jmp64)
+ EMIT3(0x8B,
+ add_2reg(0x40, IA32_EBP,
+ IA32_EBX),
+ STACK_VAR(src_hi));
+ }
+
+ if (is_jmp64) {
+ /* cmp dreg_hi,sreg_hi */
+ EMIT2(0x39, add_2reg(0xC0, dreg_hi, sreg_hi));
+ EMIT2(IA32_JNE, 2);
+ }
+ /* cmp dreg_lo,sreg_lo */
+ EMIT2(0x39, add_2reg(0xC0, dreg_lo, sreg_lo));
+ goto emit_cond_jmp;
+ }
case BPF_JMP | BPF_JSGT | BPF_X:
case BPF_JMP | BPF_JSLE | BPF_X:
case BPF_JMP | BPF_JSLT | BPF_X:
@@ -2081,77 +2205,112 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image,
if (dstk) {
EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_EAX),
STACK_VAR(dst_lo));
- EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_EDX),
+ EMIT3(0x8B,
+ add_2reg(0x40, IA32_EBP,
+ IA32_EDX),
STACK_VAR(dst_hi));
}
if (sstk) {
EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_ECX),
STACK_VAR(src_lo));
- EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_EBX),
+ EMIT3(0x8B,
+ add_2reg(0x40, IA32_EBP,
+ IA32_EBX),
STACK_VAR(src_hi));
}
/* cmp dreg_hi,sreg_hi */
EMIT2(0x39, add_2reg(0xC0, dreg_hi, sreg_hi));
- EMIT2(IA32_JNE, 2);
+ EMIT2(IA32_JNE, 10);
/* cmp dreg_lo,sreg_lo */
EMIT2(0x39, add_2reg(0xC0, dreg_lo, sreg_lo));
- goto emit_cond_jmp;
+ goto emit_cond_jmp_signed;
}
- case BPF_JMP | BPF_JSET | BPF_X: {
- u8 dreg_lo = dstk ? IA32_EAX : dst_lo;
- u8 dreg_hi = dstk ? IA32_EDX : dst_hi;
+ case BPF_JMP | BPF_JSET | BPF_X:
+ case BPF_JMP32 | BPF_JSET | BPF_X: {
+ bool is_jmp64 = BPF_CLASS(insn->code) == BPF_JMP;
+ u8 dreg_lo = IA32_EAX;
+ u8 dreg_hi = IA32_EDX;
u8 sreg_lo = sstk ? IA32_ECX : src_lo;
u8 sreg_hi = sstk ? IA32_EBX : src_hi;
if (dstk) {
EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_EAX),
STACK_VAR(dst_lo));
- EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_EDX),
- STACK_VAR(dst_hi));
+ if (is_jmp64)
+ EMIT3(0x8B,
+ add_2reg(0x40, IA32_EBP,
+ IA32_EDX),
+ STACK_VAR(dst_hi));
+ } else {
+ /* mov dreg_lo,dst_lo */
+ EMIT2(0x89, add_2reg(0xC0, dreg_lo, dst_lo));
+ if (is_jmp64)
+ /* mov dreg_hi,dst_hi */
+ EMIT2(0x89,
+ add_2reg(0xC0, dreg_hi, dst_hi));
}
if (sstk) {
EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_ECX),
STACK_VAR(src_lo));
- EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_EBX),
- STACK_VAR(src_hi));
+ if (is_jmp64)
+ EMIT3(0x8B,
+ add_2reg(0x40, IA32_EBP,
+ IA32_EBX),
+ STACK_VAR(src_hi));
}
/* and dreg_lo,sreg_lo */
EMIT2(0x23, add_2reg(0xC0, sreg_lo, dreg_lo));
- /* and dreg_hi,sreg_hi */
- EMIT2(0x23, add_2reg(0xC0, sreg_hi, dreg_hi));
- /* or dreg_lo,dreg_hi */
- EMIT2(0x09, add_2reg(0xC0, dreg_lo, dreg_hi));
+ if (is_jmp64) {
+ /* and dreg_hi,sreg_hi */
+ EMIT2(0x23, add_2reg(0xC0, sreg_hi, dreg_hi));
+ /* or dreg_lo,dreg_hi */
+ EMIT2(0x09, add_2reg(0xC0, dreg_lo, dreg_hi));
+ }
goto emit_cond_jmp;
}
- case BPF_JMP | BPF_JSET | BPF_K: {
- u32 hi;
- u8 dreg_lo = dstk ? IA32_EAX : dst_lo;
- u8 dreg_hi = dstk ? IA32_EDX : dst_hi;
+ case BPF_JMP | BPF_JSET | BPF_K:
+ case BPF_JMP32 | BPF_JSET | BPF_K: {
+ bool is_jmp64 = BPF_CLASS(insn->code) == BPF_JMP;
+ u8 dreg_lo = IA32_EAX;
+ u8 dreg_hi = IA32_EDX;
u8 sreg_lo = IA32_ECX;
u8 sreg_hi = IA32_EBX;
+ u32 hi;
if (dstk) {
EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_EAX),
STACK_VAR(dst_lo));
- EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_EDX),
- STACK_VAR(dst_hi));
+ if (is_jmp64)
+ EMIT3(0x8B,
+ add_2reg(0x40, IA32_EBP,
+ IA32_EDX),
+ STACK_VAR(dst_hi));
+ } else {
+ /* mov dreg_lo,dst_lo */
+ EMIT2(0x89, add_2reg(0xC0, dreg_lo, dst_lo));
+ if (is_jmp64)
+ /* mov dreg_hi,dst_hi */
+ EMIT2(0x89,
+ add_2reg(0xC0, dreg_hi, dst_hi));
}
- hi = imm32 & (1<<31) ? (u32)~0 : 0;
/* mov ecx,imm32 */
- EMIT2_off32(0xC7, add_1reg(0xC0, IA32_ECX), imm32);
- /* mov ebx,imm32 */
- EMIT2_off32(0xC7, add_1reg(0xC0, IA32_EBX), hi);
+ EMIT2_off32(0xC7, add_1reg(0xC0, sreg_lo), imm32);
/* and dreg_lo,sreg_lo */
EMIT2(0x23, add_2reg(0xC0, sreg_lo, dreg_lo));
- /* and dreg_hi,sreg_hi */
- EMIT2(0x23, add_2reg(0xC0, sreg_hi, dreg_hi));
- /* or dreg_lo,dreg_hi */
- EMIT2(0x09, add_2reg(0xC0, dreg_lo, dreg_hi));
+ if (is_jmp64) {
+ hi = imm32 & (1 << 31) ? (u32)~0 : 0;
+ /* mov ebx,imm32 */
+ EMIT2_off32(0xC7, add_1reg(0xC0, sreg_hi), hi);
+ /* and dreg_hi,sreg_hi */
+ EMIT2(0x23, add_2reg(0xC0, sreg_hi, dreg_hi));
+ /* or dreg_lo,dreg_hi */
+ EMIT2(0x09, add_2reg(0xC0, dreg_lo, dreg_hi));
+ }
goto emit_cond_jmp;
}
case BPF_JMP | BPF_JEQ | BPF_K:
@@ -2160,89 +2319,118 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image,
case BPF_JMP | BPF_JLT | BPF_K:
case BPF_JMP | BPF_JGE | BPF_K:
case BPF_JMP | BPF_JLE | BPF_K:
+ case BPF_JMP32 | BPF_JEQ | BPF_K:
+ case BPF_JMP32 | BPF_JNE | BPF_K:
+ case BPF_JMP32 | BPF_JGT | BPF_K:
+ case BPF_JMP32 | BPF_JLT | BPF_K:
+ case BPF_JMP32 | BPF_JGE | BPF_K:
+ case BPF_JMP32 | BPF_JLE | BPF_K:
+ case BPF_JMP32 | BPF_JSGT | BPF_K:
+ case BPF_JMP32 | BPF_JSLE | BPF_K:
+ case BPF_JMP32 | BPF_JSLT | BPF_K:
+ case BPF_JMP32 | BPF_JSGE | BPF_K: {
+ bool is_jmp64 = BPF_CLASS(insn->code) == BPF_JMP;
+ u8 dreg_lo = dstk ? IA32_EAX : dst_lo;
+ u8 dreg_hi = dstk ? IA32_EDX : dst_hi;
+ u8 sreg_lo = IA32_ECX;
+ u8 sreg_hi = IA32_EBX;
+ u32 hi;
+
+ if (dstk) {
+ EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_EAX),
+ STACK_VAR(dst_lo));
+ if (is_jmp64)
+ EMIT3(0x8B,
+ add_2reg(0x40, IA32_EBP,
+ IA32_EDX),
+ STACK_VAR(dst_hi));
+ }
+
+ /* mov ecx,imm32 */
+ EMIT2_off32(0xC7, add_1reg(0xC0, IA32_ECX), imm32);
+ if (is_jmp64) {
+ hi = imm32 & (1 << 31) ? (u32)~0 : 0;
+ /* mov ebx,imm32 */
+ EMIT2_off32(0xC7, add_1reg(0xC0, IA32_EBX), hi);
+ /* cmp dreg_hi,sreg_hi */
+ EMIT2(0x39, add_2reg(0xC0, dreg_hi, sreg_hi));
+ EMIT2(IA32_JNE, 2);
+ }
+ /* cmp dreg_lo,sreg_lo */
+ EMIT2(0x39, add_2reg(0xC0, dreg_lo, sreg_lo));
+
+emit_cond_jmp: jmp_cond = get_cond_jmp_opcode(BPF_OP(code), false);
+ if (jmp_cond == COND_JMP_OPCODE_INVALID)
+ return -EFAULT;
+ jmp_offset = addrs[i + insn->off] - addrs[i];
+ if (is_imm8(jmp_offset)) {
+ EMIT2(jmp_cond, jmp_offset);
+ } else if (is_simm32(jmp_offset)) {
+ EMIT2_off32(0x0F, jmp_cond + 0x10, jmp_offset);
+ } else {
+ pr_err("cond_jmp gen bug %llx\n", jmp_offset);
+ return -EFAULT;
+ }
+ break;
+ }
case BPF_JMP | BPF_JSGT | BPF_K:
case BPF_JMP | BPF_JSLE | BPF_K:
case BPF_JMP | BPF_JSLT | BPF_K:
case BPF_JMP | BPF_JSGE | BPF_K: {
- u32 hi;
u8 dreg_lo = dstk ? IA32_EAX : dst_lo;
u8 dreg_hi = dstk ? IA32_EDX : dst_hi;
u8 sreg_lo = IA32_ECX;
u8 sreg_hi = IA32_EBX;
+ u32 hi;
if (dstk) {
EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_EAX),
STACK_VAR(dst_lo));
- EMIT3(0x8B, add_2reg(0x40, IA32_EBP, IA32_EDX),
+ EMIT3(0x8B,
+ add_2reg(0x40, IA32_EBP,
+ IA32_EDX),
STACK_VAR(dst_hi));
}
- hi = imm32 & (1<<31) ? (u32)~0 : 0;
/* mov ecx,imm32 */
EMIT2_off32(0xC7, add_1reg(0xC0, IA32_ECX), imm32);
+ hi = imm32 & (1 << 31) ? (u32)~0 : 0;
/* mov ebx,imm32 */
EMIT2_off32(0xC7, add_1reg(0xC0, IA32_EBX), hi);
-
/* cmp dreg_hi,sreg_hi */
EMIT2(0x39, add_2reg(0xC0, dreg_hi, sreg_hi));
- EMIT2(IA32_JNE, 2);
+ EMIT2(IA32_JNE, 10);
/* cmp dreg_lo,sreg_lo */
EMIT2(0x39, add_2reg(0xC0, dreg_lo, sreg_lo));
-emit_cond_jmp: /* Convert BPF opcode to x86 */
- switch (BPF_OP(code)) {
- case BPF_JEQ:
- jmp_cond = IA32_JE;
- break;
- case BPF_JSET:
- case BPF_JNE:
- jmp_cond = IA32_JNE;
- break;
- case BPF_JGT:
- /* GT is unsigned '>', JA in x86 */
- jmp_cond = IA32_JA;
- break;
- case BPF_JLT:
- /* LT is unsigned '<', JB in x86 */
- jmp_cond = IA32_JB;
- break;
- case BPF_JGE:
- /* GE is unsigned '>=', JAE in x86 */
- jmp_cond = IA32_JAE;
- break;
- case BPF_JLE:
- /* LE is unsigned '<=', JBE in x86 */
- jmp_cond = IA32_JBE;
- break;
- case BPF_JSGT:
- /* Signed '>', GT in x86 */
- jmp_cond = IA32_JG;
- break;
- case BPF_JSLT:
- /* Signed '<', LT in x86 */
- jmp_cond = IA32_JL;
- break;
- case BPF_JSGE:
- /* Signed '>=', GE in x86 */
- jmp_cond = IA32_JGE;
- break;
- case BPF_JSLE:
- /* Signed '<=', LE in x86 */
- jmp_cond = IA32_JLE;
- break;
- default: /* to silence GCC warning */
+ /*
+ * For simplicity of branch offset computation,
+ * let's use fixed jump coding here.
+ */
+emit_cond_jmp_signed: /* Check the condition for low 32-bit comparison */
+ jmp_cond = get_cond_jmp_opcode(BPF_OP(code), true);
+ if (jmp_cond == COND_JMP_OPCODE_INVALID)
+ return -EFAULT;
+ jmp_offset = addrs[i + insn->off] - addrs[i] + 8;
+ if (is_simm32(jmp_offset)) {
+ EMIT2_off32(0x0F, jmp_cond + 0x10, jmp_offset);
+ } else {
+ pr_err("cond_jmp gen bug %llx\n", jmp_offset);
return -EFAULT;
}
+ EMIT2(0xEB, 6);
+
+ /* Check the condition for high 32-bit comparison */
+ jmp_cond = get_cond_jmp_opcode(BPF_OP(code), false);
+ if (jmp_cond == COND_JMP_OPCODE_INVALID)
+ return -EFAULT;
jmp_offset = addrs[i + insn->off] - addrs[i];
- if (is_imm8(jmp_offset)) {
- EMIT2(jmp_cond, jmp_offset);
- } else if (is_simm32(jmp_offset)) {
+ if (is_simm32(jmp_offset)) {
EMIT2_off32(0x0F, jmp_cond + 0x10, jmp_offset);
} else {
pr_err("cond_jmp gen bug %llx\n", jmp_offset);
return -EFAULT;
}
-
break;
}
case BPF_JMP | BPF_JA:
@@ -2270,10 +2458,8 @@ emit_jmp:
return -EFAULT;
}
break;
- /* STX XADD: lock *(u32 *)(dst + off) += src */
- case BPF_STX | BPF_XADD | BPF_W:
- /* STX XADD: lock *(u64 *)(dst + off) += src */
- case BPF_STX | BPF_XADD | BPF_DW:
+ case BPF_STX | BPF_ATOMIC | BPF_W:
+ case BPF_STX | BPF_ATOMIC | BPF_DW:
goto notyet;
case BPF_JMP | BPF_EXIT:
if (seen_exit) {
@@ -2305,7 +2491,16 @@ notyet:
}
if (image) {
- if (unlikely(proglen + ilen > oldproglen)) {
+ /*
+ * When populating the image, assert that:
+ *
+ * i) We do not write beyond the allocated space, and
+ * ii) addrs[i] did not change from the prior run, in order
+ * to validate assumptions made for computing branch
+ * displacements.
+ */
+ if (unlikely(proglen + ilen > oldproglen ||
+ proglen + ilen != addrs[i])) {
pr_err("bpf_jit: fatal error\n");
return -EFAULT;
}
@@ -2318,6 +2513,11 @@ notyet:
return proglen;
}
+bool bpf_jit_needs_zext(void)
+{
+ return true;
+}
+
struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
{
struct bpf_binary_header *header = NULL;
@@ -2400,8 +2600,7 @@ out_image:
if (bpf_jit_enable > 1)
bpf_jit_dump(prog->len, proglen, pass + 1, image);
- if (image) {
- bpf_jit_binary_lock_ro(header);
+ if (image && !bpf_jit_binary_lock_ro(header)) {
prog->bpf_func = (void *)image;
prog->jited = 1;
prog->jited_len = proglen;
@@ -2417,3 +2616,8 @@ out:
tmp : orig_prog);
return prog;
}
+
+bool bpf_jit_supports_kfunc_call(void)
+{
+ return true;
+}
generated by cgit (git 2.34.1) at 2025-12-24 22:24:46 +0000