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@@ -0,0 +1,776 @@
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+/*
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+ * BPF Jit compiler for s390.
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+ *
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+ * Copyright IBM Corp. 2012
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+ *
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+ * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
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+ */
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+#include <linux/moduleloader.h>
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+#include <linux/netdevice.h>
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+#include <linux/filter.h>
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+#include <asm/cacheflush.h>
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+#include <asm/processor.h>
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+#include <asm/facility.h>
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+
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+/*
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+ * Conventions:
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+ * %r2 = skb pointer
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+ * %r3 = offset parameter
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+ * %r4 = scratch register / length parameter
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+ * %r5 = BPF A accumulator
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+ * %r8 = return address
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+ * %r9 = save register for skb pointer
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+ * %r10 = skb->data
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+ * %r11 = skb->len - skb->data_len (headlen)
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+ * %r12 = BPF X accumulator
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+ * %r13 = literal pool pointer
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+ * 0(%r15) - 63(%r15) scratch memory array with BPF_MEMWORDS
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+ */
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+int bpf_jit_enable __read_mostly;
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+
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+/*
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+ * assembly code in arch/x86/net/bpf_jit.S
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+ */
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+extern u8 sk_load_word[], sk_load_half[], sk_load_byte[], sk_load_byte_msh[];
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+extern u8 sk_load_word_ind[], sk_load_half_ind[], sk_load_byte_ind[];
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+
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+struct bpf_jit {
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+ unsigned int seen;
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+ u8 *start;
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+ u8 *prg;
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+ u8 *mid;
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+ u8 *lit;
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+ u8 *end;
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+ u8 *base_ip;
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+ u8 *ret0_ip;
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+ u8 *exit_ip;
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+ unsigned int off_load_word;
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+ unsigned int off_load_half;
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+ unsigned int off_load_byte;
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+ unsigned int off_load_bmsh;
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+ unsigned int off_load_iword;
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+ unsigned int off_load_ihalf;
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+ unsigned int off_load_ibyte;
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+};
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+
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+#define BPF_SIZE_MAX 4096 /* Max size for program */
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+
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+#define SEEN_DATAREF 1 /* might call external helpers */
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+#define SEEN_XREG 2 /* ebx is used */
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+#define SEEN_MEM 4 /* use mem[] for temporary storage */
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+#define SEEN_RET0 8 /* pc_ret0 points to a valid return 0 */
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+#define SEEN_LITERAL 16 /* code uses literals */
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+#define SEEN_LOAD_WORD 32 /* code uses sk_load_word */
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+#define SEEN_LOAD_HALF 64 /* code uses sk_load_half */
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+#define SEEN_LOAD_BYTE 128 /* code uses sk_load_byte */
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+#define SEEN_LOAD_BMSH 256 /* code uses sk_load_byte_msh */
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+#define SEEN_LOAD_IWORD 512 /* code uses sk_load_word_ind */
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+#define SEEN_LOAD_IHALF 1024 /* code uses sk_load_half_ind */
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+#define SEEN_LOAD_IBYTE 2048 /* code uses sk_load_byte_ind */
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+
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+#define EMIT2(op) \
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+({ \
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+ if (jit->prg + 2 <= jit->mid) \
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+ *(u16 *) jit->prg = op; \
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+ jit->prg += 2; \
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+})
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+
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+#define EMIT4(op) \
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+({ \
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+ if (jit->prg + 4 <= jit->mid) \
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+ *(u32 *) jit->prg = op; \
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+ jit->prg += 4; \
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+})
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+
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+#define EMIT4_DISP(op, disp) \
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+({ \
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+ unsigned int __disp = (disp) & 0xfff; \
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+ EMIT4(op | __disp); \
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+})
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+
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+#define EMIT4_IMM(op, imm) \
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+({ \
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+ unsigned int __imm = (imm) & 0xffff; \
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+ EMIT4(op | __imm); \
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+})
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+
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+#define EMIT4_PCREL(op, pcrel) \
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+({ \
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+ long __pcrel = ((pcrel) >> 1) & 0xffff; \
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+ EMIT4(op | __pcrel); \
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+})
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+
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+#define EMIT6(op1, op2) \
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+({ \
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+ if (jit->prg + 6 <= jit->mid) { \
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+ *(u32 *) jit->prg = op1; \
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+ *(u16 *) (jit->prg + 4) = op2; \
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+ } \
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+ jit->prg += 6; \
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+})
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+
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+#define EMIT6_DISP(op1, op2, disp) \
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+({ \
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+ unsigned int __disp = (disp) & 0xfff; \
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+ EMIT6(op1 | __disp, op2); \
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+})
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+
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+#define EMIT6_IMM(op, imm) \
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+({ \
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+ unsigned int __imm = (imm); \
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+ EMIT6(op | (__imm >> 16), __imm & 0xffff); \
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+})
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+
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+#define EMIT_CONST(val) \
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+({ \
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+ unsigned int ret; \
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+ ret = (unsigned int) (jit->lit - jit->base_ip); \
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+ jit->seen |= SEEN_LITERAL; \
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+ if (jit->lit + 4 <= jit->end) \
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+ *(u32 *) jit->lit = val; \
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+ jit->lit += 4; \
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+ ret; \
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+})
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+
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+#define EMIT_FN_CONST(bit, fn) \
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+({ \
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+ unsigned int ret; \
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+ ret = (unsigned int) (jit->lit - jit->base_ip); \
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+ if (jit->seen & bit) { \
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+ jit->seen |= SEEN_LITERAL; \
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+ if (jit->lit + 8 <= jit->end) \
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+ *(void **) jit->lit = fn; \
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+ jit->lit += 8; \
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+ } \
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+ ret; \
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+})
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+
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+static void bpf_jit_prologue(struct bpf_jit *jit)
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+{
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+ /* Save registers and create stack frame if necessary */
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+ if (jit->seen & SEEN_DATAREF) {
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+ /* stmg %r8,%r15,88(%r15) */
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+ EMIT6(0xeb8ff058, 0x0024);
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+ /* lgr %r14,%r15 */
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+ EMIT4(0xb90400ef);
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+ /* ahi %r15,<offset> */
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+ EMIT4_IMM(0xa7fa0000, (jit->seen & SEEN_MEM) ? -112 : -80);
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+ /* stg %r14,152(%r15) */
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+ EMIT6(0xe3e0f098, 0x0024);
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+ } else if ((jit->seen & SEEN_XREG) && (jit->seen & SEEN_LITERAL))
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+ /* stmg %r12,%r13,120(%r15) */
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+ EMIT6(0xebcdf078, 0x0024);
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+ else if (jit->seen & SEEN_XREG)
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+ /* stg %r12,120(%r15) */
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+ EMIT6(0xe3c0f078, 0x0024);
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+ else if (jit->seen & SEEN_LITERAL)
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+ /* stg %r13,128(%r15) */
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+ EMIT6(0xe3d0f080, 0x0024);
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+
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+ /* Setup literal pool */
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+ if (jit->seen & SEEN_LITERAL) {
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+ /* basr %r13,0 */
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+ EMIT2(0x0dd0);
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+ jit->base_ip = jit->prg;
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+ }
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+ jit->off_load_word = EMIT_FN_CONST(SEEN_LOAD_WORD, sk_load_word);
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+ jit->off_load_half = EMIT_FN_CONST(SEEN_LOAD_HALF, sk_load_half);
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+ jit->off_load_byte = EMIT_FN_CONST(SEEN_LOAD_BYTE, sk_load_byte);
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+ jit->off_load_bmsh = EMIT_FN_CONST(SEEN_LOAD_BMSH, sk_load_byte_msh);
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+ jit->off_load_iword = EMIT_FN_CONST(SEEN_LOAD_IWORD, sk_load_word_ind);
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+ jit->off_load_ihalf = EMIT_FN_CONST(SEEN_LOAD_IHALF, sk_load_half_ind);
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+ jit->off_load_ibyte = EMIT_FN_CONST(SEEN_LOAD_IBYTE, sk_load_byte_ind);
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+
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+ /* Filter needs to access skb data */
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+ if (jit->seen & SEEN_DATAREF) {
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+ /* l %r11,<len>(%r2) */
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+ EMIT4_DISP(0x58b02000, offsetof(struct sk_buff, len));
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+ /* s %r11,<data_len>(%r2) */
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+ EMIT4_DISP(0x5bb02000, offsetof(struct sk_buff, data_len));
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+ /* lg %r10,<data>(%r2) */
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+ EMIT6_DISP(0xe3a02000, 0x0004,
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+ offsetof(struct sk_buff, data));
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+ }
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+}
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+
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+static void bpf_jit_epilogue(struct bpf_jit *jit)
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+{
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+ /* Return 0 */
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+ if (jit->seen & SEEN_RET0) {
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+ jit->ret0_ip = jit->prg;
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+ /* lghi %r2,0 */
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+ EMIT4(0xa7290000);
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+ }
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+ jit->exit_ip = jit->prg;
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+ /* Restore registers */
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+ if (jit->seen & SEEN_DATAREF)
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+ /* lmg %r8,%r15,<offset>(%r15) */
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+ EMIT6_DISP(0xeb8ff000, 0x0004,
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+ (jit->seen & SEEN_MEM) ? 200 : 168);
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+ else if ((jit->seen & SEEN_XREG) && (jit->seen & SEEN_LITERAL))
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+ /* lmg %r12,%r13,120(%r15) */
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+ EMIT6(0xebcdf078, 0x0004);
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+ else if (jit->seen & SEEN_XREG)
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+ /* lg %r12,120(%r15) */
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+ EMIT6(0xe3c0f078, 0x0004);
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+ else if (jit->seen & SEEN_LITERAL)
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+ /* lg %r13,128(%r15) */
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+ EMIT6(0xe3d0f080, 0x0004);
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+ /* br %r14 */
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+ EMIT2(0x07fe);
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+}
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+
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+/*
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+ * make sure we dont leak kernel information to user
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+ */
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+static void bpf_jit_noleaks(struct bpf_jit *jit, struct sock_filter *filter)
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+{
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+ /* Clear temporary memory if (seen & SEEN_MEM) */
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+ if (jit->seen & SEEN_MEM)
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+ /* xc 0(64,%r15),0(%r15) */
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+ EMIT6(0xd73ff000, 0xf000);
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+ /* Clear X if (seen & SEEN_XREG) */
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+ if (jit->seen & SEEN_XREG)
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+ /* lhi %r12,0 */
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+ EMIT4(0xa7c80000);
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+ /* Clear A if the first register does not set it. */
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+ switch (filter[0].code) {
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+ case BPF_S_LD_W_ABS:
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+ case BPF_S_LD_H_ABS:
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+ case BPF_S_LD_B_ABS:
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+ case BPF_S_LD_W_LEN:
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+ case BPF_S_LD_W_IND:
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+ case BPF_S_LD_H_IND:
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+ case BPF_S_LD_B_IND:
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+ case BPF_S_LDX_B_MSH:
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+ case BPF_S_LD_IMM:
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+ case BPF_S_LD_MEM:
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+ case BPF_S_MISC_TXA:
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+ case BPF_S_ANC_PROTOCOL:
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+ case BPF_S_ANC_PKTTYPE:
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+ case BPF_S_ANC_IFINDEX:
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+ case BPF_S_ANC_MARK:
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+ case BPF_S_ANC_QUEUE:
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+ case BPF_S_ANC_HATYPE:
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+ case BPF_S_ANC_RXHASH:
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+ case BPF_S_ANC_CPU:
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+ case BPF_S_RET_K:
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+ /* first instruction sets A register */
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+ break;
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+ default: /* A = 0 */
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+ /* lhi %r5,0 */
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+ EMIT4(0xa7580000);
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+ }
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+}
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+
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+static int bpf_jit_insn(struct bpf_jit *jit, struct sock_filter *filter,
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+ unsigned int *addrs, int i, int last)
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+{
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+ unsigned int K;
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+ int offset;
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+ unsigned int mask;
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+
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+ K = filter->k;
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+ switch (filter->code) {
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+ case BPF_S_ALU_ADD_X: /* A += X */
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+ jit->seen |= SEEN_XREG;
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+ /* ar %r5,%r12 */
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+ EMIT2(0x1a5c);
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+ break;
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+ case BPF_S_ALU_ADD_K: /* A += K */
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+ if (!K)
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+ break;
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+ if (K <= 16383)
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+ /* ahi %r5,<K> */
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+ EMIT4_IMM(0xa75a0000, K);
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+ else if (test_facility(21))
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+ /* alfi %r5,<K> */
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+ EMIT6_IMM(0xc25b0000, K);
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+ else
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+ /* a %r5,<d(K)>(%r13) */
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+ EMIT4_DISP(0x5a50d000, EMIT_CONST(K));
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+ break;
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+ case BPF_S_ALU_SUB_X: /* A -= X */
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+ jit->seen |= SEEN_XREG;
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+ /* sr %r5,%r12 */
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+ EMIT2(0x1b5c);
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+ break;
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+ case BPF_S_ALU_SUB_K: /* A -= K */
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+ if (!K)
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+ break;
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+ if (K <= 16384)
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+ /* ahi %r5,-K */
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+ EMIT4_IMM(0xa75a0000, -K);
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+ else if (test_facility(21))
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+ /* alfi %r5,-K */
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+ EMIT6_IMM(0xc25b0000, -K);
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+ else
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+ /* s %r5,<d(K)>(%r13) */
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+ EMIT4_DISP(0x5b50d000, EMIT_CONST(K));
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+ break;
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+ case BPF_S_ALU_MUL_X: /* A *= X */
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+ jit->seen |= SEEN_XREG;
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+ /* msr %r5,%r12 */
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+ EMIT4(0xb252005c);
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+ break;
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+ case BPF_S_ALU_MUL_K: /* A *= K */
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+ if (K <= 16383)
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+ /* mhi %r5,K */
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+ EMIT4_IMM(0xa75c0000, K);
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+ else if (test_facility(34))
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+ /* msfi %r5,<K> */
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+ EMIT6_IMM(0xc2510000, K);
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+ else
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+ /* ms %r5,<d(K)>(%r13) */
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+ EMIT4_DISP(0x7150d000, EMIT_CONST(K));
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+ break;
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+ case BPF_S_ALU_DIV_X: /* A /= X */
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+ jit->seen |= SEEN_XREG | SEEN_RET0;
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+ /* ltr %r12,%r12 */
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+ EMIT2(0x12cc);
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+ /* jz <ret0> */
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+ EMIT4_PCREL(0xa7840000, (jit->ret0_ip - jit->prg));
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+ /* lhi %r4,0 */
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+ EMIT4(0xa7480000);
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+ /* dr %r4,%r12 */
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+ EMIT2(0x1d4c);
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+ break;
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+ case BPF_S_ALU_DIV_K: /* A = reciprocal_divide(A, K) */
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+ /* m %r4,<d(K)>(%r13) */
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+ EMIT4_DISP(0x5c40d000, EMIT_CONST(K));
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+ /* lr %r5,%r4 */
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+ EMIT2(0x1854);
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+ break;
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+ case BPF_S_ALU_AND_X: /* A &= X */
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+ jit->seen |= SEEN_XREG;
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+ /* nr %r5,%r12 */
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+ EMIT2(0x145c);
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+ break;
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+ case BPF_S_ALU_AND_K: /* A &= K */
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+ if (test_facility(21))
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+ /* nilf %r5,<K> */
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+ EMIT6_IMM(0xc05b0000, K);
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+ else
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+ /* n %r5,<d(K)>(%r13) */
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+ EMIT4_DISP(0x5450d000, EMIT_CONST(K));
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+ break;
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+ case BPF_S_ALU_OR_X: /* A |= X */
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+ jit->seen |= SEEN_XREG;
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+ /* or %r5,%r12 */
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+ EMIT2(0x165c);
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+ break;
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+ case BPF_S_ALU_OR_K: /* A |= K */
|
|
|
+ if (test_facility(21))
|
|
|
+ /* oilf %r5,<K> */
|
|
|
+ EMIT6_IMM(0xc05d0000, K);
|
|
|
+ else
|
|
|
+ /* o %r5,<d(K)>(%r13) */
|
|
|
+ EMIT4_DISP(0x5650d000, EMIT_CONST(K));
|
|
|
+ break;
|
|
|
+ case BPF_S_ANC_ALU_XOR_X: /* A ^= X; */
|
|
|
+ jit->seen |= SEEN_XREG;
|
|
|
+ /* xr %r5,%r12 */
|
|
|
+ EMIT2(0x175c);
|
|
|
+ break;
|
|
|
+ case BPF_S_ALU_LSH_X: /* A <<= X; */
|
|
|
+ jit->seen |= SEEN_XREG;
|
|
|
+ /* sll %r5,0(%r12) */
|
|
|
+ EMIT4(0x8950c000);
|
|
|
+ break;
|
|
|
+ case BPF_S_ALU_LSH_K: /* A <<= K */
|
|
|
+ if (K == 0)
|
|
|
+ break;
|
|
|
+ /* sll %r5,K */
|
|
|
+ EMIT4_DISP(0x89500000, K);
|
|
|
+ break;
|
|
|
+ case BPF_S_ALU_RSH_X: /* A >>= X; */
|
|
|
+ jit->seen |= SEEN_XREG;
|
|
|
+ /* srl %r5,0(%r12) */
|
|
|
+ EMIT4(0x8850c000);
|
|
|
+ break;
|
|
|
+ case BPF_S_ALU_RSH_K: /* A >>= K; */
|
|
|
+ if (K == 0)
|
|
|
+ break;
|
|
|
+ /* srl %r5,K */
|
|
|
+ EMIT4_DISP(0x88500000, K);
|
|
|
+ break;
|
|
|
+ case BPF_S_ALU_NEG: /* A = -A */
|
|
|
+ /* lnr %r5,%r5 */
|
|
|
+ EMIT2(0x1155);
|
|
|
+ break;
|
|
|
+ case BPF_S_JMP_JA: /* ip += K */
|
|
|
+ offset = addrs[i + K] + jit->start - jit->prg;
|
|
|
+ EMIT4_PCREL(0xa7f40000, offset);
|
|
|
+ break;
|
|
|
+ case BPF_S_JMP_JGT_K: /* ip += (A > K) ? jt : jf */
|
|
|
+ mask = 0x200000; /* jh */
|
|
|
+ goto kbranch;
|
|
|
+ case BPF_S_JMP_JGE_K: /* ip += (A >= K) ? jt : jf */
|
|
|
+ mask = 0xa00000; /* jhe */
|
|
|
+ goto kbranch;
|
|
|
+ case BPF_S_JMP_JEQ_K: /* ip += (A == K) ? jt : jf */
|
|
|
+ mask = 0x800000; /* je */
|
|
|
+kbranch: /* Emit compare if the branch targets are different */
|
|
|
+ if (filter->jt != filter->jf) {
|
|
|
+ if (K <= 16383)
|
|
|
+ /* chi %r5,<K> */
|
|
|
+ EMIT4_IMM(0xa75e0000, K);
|
|
|
+ else if (test_facility(21))
|
|
|
+ /* clfi %r5,<K> */
|
|
|
+ EMIT6_IMM(0xc25f0000, K);
|
|
|
+ else
|
|
|
+ /* c %r5,<d(K)>(%r13) */
|
|
|
+ EMIT4_DISP(0x5950d000, EMIT_CONST(K));
|
|
|
+ }
|
|
|
+branch: if (filter->jt == filter->jf) {
|
|
|
+ if (filter->jt == 0)
|
|
|
+ break;
|
|
|
+ /* j <jt> */
|
|
|
+ offset = addrs[i + filter->jt] + jit->start - jit->prg;
|
|
|
+ EMIT4_PCREL(0xa7f40000, offset);
|
|
|
+ break;
|
|
|
+ }
|
|
|
+ if (filter->jt != 0) {
|
|
|
+ /* brc <mask>,<jt> */
|
|
|
+ offset = addrs[i + filter->jt] + jit->start - jit->prg;
|
|
|
+ EMIT4_PCREL(0xa7040000 | mask, offset);
|
|
|
+ }
|
|
|
+ if (filter->jf != 0) {
|
|
|
+ /* brc <mask^15>,<jf> */
|
|
|
+ offset = addrs[i + filter->jf] + jit->start - jit->prg;
|
|
|
+ EMIT4_PCREL(0xa7040000 | (mask ^ 0xf00000), offset);
|
|
|
+ }
|
|
|
+ break;
|
|
|
+ case BPF_S_JMP_JSET_K: /* ip += (A & K) ? jt : jf */
|
|
|
+ mask = 0x700000; /* jnz */
|
|
|
+ /* Emit test if the branch targets are different */
|
|
|
+ if (filter->jt != filter->jf) {
|
|
|
+ if (K > 65535) {
|
|
|
+ /* lr %r4,%r5 */
|
|
|
+ EMIT2(0x1845);
|
|
|
+ /* n %r4,<d(K)>(%r13) */
|
|
|
+ EMIT4_DISP(0x5440d000, EMIT_CONST(K));
|
|
|
+ } else
|
|
|
+ /* tmll %r5,K */
|
|
|
+ EMIT4_IMM(0xa7510000, K);
|
|
|
+ }
|
|
|
+ goto branch;
|
|
|
+ case BPF_S_JMP_JGT_X: /* ip += (A > X) ? jt : jf */
|
|
|
+ mask = 0x200000; /* jh */
|
|
|
+ goto xbranch;
|
|
|
+ case BPF_S_JMP_JGE_X: /* ip += (A >= X) ? jt : jf */
|
|
|
+ mask = 0xa00000; /* jhe */
|
|
|
+ goto xbranch;
|
|
|
+ case BPF_S_JMP_JEQ_X: /* ip += (A == X) ? jt : jf */
|
|
|
+ mask = 0x800000; /* je */
|
|
|
+xbranch: /* Emit compare if the branch targets are different */
|
|
|
+ if (filter->jt != filter->jf) {
|
|
|
+ jit->seen |= SEEN_XREG;
|
|
|
+ /* cr %r5,%r12 */
|
|
|
+ EMIT2(0x195c);
|
|
|
+ }
|
|
|
+ goto branch;
|
|
|
+ case BPF_S_JMP_JSET_X: /* ip += (A & X) ? jt : jf */
|
|
|
+ mask = 0x700000; /* jnz */
|
|
|
+ /* Emit test if the branch targets are different */
|
|
|
+ if (filter->jt != filter->jf) {
|
|
|
+ jit->seen |= SEEN_XREG;
|
|
|
+ /* lr %r4,%r5 */
|
|
|
+ EMIT2(0x1845);
|
|
|
+ /* nr %r4,%r12 */
|
|
|
+ EMIT2(0x144c);
|
|
|
+ }
|
|
|
+ goto branch;
|
|
|
+ case BPF_S_LD_W_ABS: /* A = *(u32 *) (skb->data+K) */
|
|
|
+ jit->seen |= SEEN_DATAREF | SEEN_RET0 | SEEN_LOAD_WORD;
|
|
|
+ offset = jit->off_load_word;
|
|
|
+ goto load_abs;
|
|
|
+ case BPF_S_LD_H_ABS: /* A = *(u16 *) (skb->data+K) */
|
|
|
+ jit->seen |= SEEN_DATAREF | SEEN_RET0 | SEEN_LOAD_HALF;
|
|
|
+ offset = jit->off_load_half;
|
|
|
+ goto load_abs;
|
|
|
+ case BPF_S_LD_B_ABS: /* A = *(u8 *) (skb->data+K) */
|
|
|
+ jit->seen |= SEEN_DATAREF | SEEN_RET0 | SEEN_LOAD_BYTE;
|
|
|
+ offset = jit->off_load_byte;
|
|
|
+load_abs: if ((int) K < 0)
|
|
|
+ goto out;
|
|
|
+call_fn: /* lg %r1,<d(function)>(%r13) */
|
|
|
+ EMIT6_DISP(0xe310d000, 0x0004, offset);
|
|
|
+ /* l %r3,<d(K)>(%r13) */
|
|
|
+ EMIT4_DISP(0x5830d000, EMIT_CONST(K));
|
|
|
+ /* basr %r8,%r1 */
|
|
|
+ EMIT2(0x0d81);
|
|
|
+ /* jnz <ret0> */
|
|
|
+ EMIT4_PCREL(0xa7740000, (jit->ret0_ip - jit->prg));
|
|
|
+ break;
|
|
|
+ case BPF_S_LD_W_IND: /* A = *(u32 *) (skb->data+K+X) */
|
|
|
+ jit->seen |= SEEN_DATAREF | SEEN_RET0 | SEEN_LOAD_IWORD;
|
|
|
+ offset = jit->off_load_iword;
|
|
|
+ goto call_fn;
|
|
|
+ case BPF_S_LD_H_IND: /* A = *(u16 *) (skb->data+K+X) */
|
|
|
+ jit->seen |= SEEN_DATAREF | SEEN_RET0 | SEEN_LOAD_IHALF;
|
|
|
+ offset = jit->off_load_ihalf;
|
|
|
+ goto call_fn;
|
|
|
+ case BPF_S_LD_B_IND: /* A = *(u8 *) (skb->data+K+X) */
|
|
|
+ jit->seen |= SEEN_DATAREF | SEEN_RET0 | SEEN_LOAD_IBYTE;
|
|
|
+ offset = jit->off_load_ibyte;
|
|
|
+ goto call_fn;
|
|
|
+ case BPF_S_LDX_B_MSH:
|
|
|
+ /* X = (*(u8 *)(skb->data+K) & 0xf) << 2 */
|
|
|
+ jit->seen |= SEEN_RET0;
|
|
|
+ if ((int) K < 0) {
|
|
|
+ /* j <ret0> */
|
|
|
+ EMIT4_PCREL(0xa7f40000, (jit->ret0_ip - jit->prg));
|
|
|
+ break;
|
|
|
+ }
|
|
|
+ jit->seen |= SEEN_DATAREF | SEEN_LOAD_BMSH;
|
|
|
+ offset = jit->off_load_bmsh;
|
|
|
+ goto call_fn;
|
|
|
+ case BPF_S_LD_W_LEN: /* A = skb->len; */
|
|
|
+ BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, len) != 4);
|
|
|
+ /* l %r5,<d(len)>(%r2) */
|
|
|
+ EMIT4_DISP(0x58502000, offsetof(struct sk_buff, len));
|
|
|
+ break;
|
|
|
+ case BPF_S_LDX_W_LEN: /* X = skb->len; */
|
|
|
+ jit->seen |= SEEN_XREG;
|
|
|
+ /* l %r12,<d(len)>(%r2) */
|
|
|
+ EMIT4_DISP(0x58c02000, offsetof(struct sk_buff, len));
|
|
|
+ break;
|
|
|
+ case BPF_S_LD_IMM: /* A = K */
|
|
|
+ if (K <= 16383)
|
|
|
+ /* lhi %r5,K */
|
|
|
+ EMIT4_IMM(0xa7580000, K);
|
|
|
+ else if (test_facility(21))
|
|
|
+ /* llilf %r5,<K> */
|
|
|
+ EMIT6_IMM(0xc05f0000, K);
|
|
|
+ else
|
|
|
+ /* l %r5,<d(K)>(%r13) */
|
|
|
+ EMIT4_DISP(0x5850d000, EMIT_CONST(K));
|
|
|
+ break;
|
|
|
+ case BPF_S_LDX_IMM: /* X = K */
|
|
|
+ jit->seen |= SEEN_XREG;
|
|
|
+ if (K <= 16383)
|
|
|
+ /* lhi %r12,<K> */
|
|
|
+ EMIT4_IMM(0xa7c80000, K);
|
|
|
+ else if (test_facility(21))
|
|
|
+ /* llilf %r12,<K> */
|
|
|
+ EMIT6_IMM(0xc0cf0000, K);
|
|
|
+ else
|
|
|
+ /* l %r12,<d(K)>(%r13) */
|
|
|
+ EMIT4_DISP(0x58c0d000, EMIT_CONST(K));
|
|
|
+ break;
|
|
|
+ case BPF_S_LD_MEM: /* A = mem[K] */
|
|
|
+ jit->seen |= SEEN_MEM;
|
|
|
+ /* l %r5,<K>(%r15) */
|
|
|
+ EMIT4_DISP(0x5850f000,
|
|
|
+ (jit->seen & SEEN_DATAREF) ? 160 + K*4 : K*4);
|
|
|
+ break;
|
|
|
+ case BPF_S_LDX_MEM: /* X = mem[K] */
|
|
|
+ jit->seen |= SEEN_XREG | SEEN_MEM;
|
|
|
+ /* l %r12,<K>(%r15) */
|
|
|
+ EMIT4_DISP(0x58c0f000,
|
|
|
+ (jit->seen & SEEN_DATAREF) ? 160 + K*4 : K*4);
|
|
|
+ break;
|
|
|
+ case BPF_S_MISC_TAX: /* X = A */
|
|
|
+ jit->seen |= SEEN_XREG;
|
|
|
+ /* lr %r12,%r5 */
|
|
|
+ EMIT2(0x18c5);
|
|
|
+ break;
|
|
|
+ case BPF_S_MISC_TXA: /* A = X */
|
|
|
+ jit->seen |= SEEN_XREG;
|
|
|
+ /* lr %r5,%r12 */
|
|
|
+ EMIT2(0x185c);
|
|
|
+ break;
|
|
|
+ case BPF_S_RET_K:
|
|
|
+ if (K == 0) {
|
|
|
+ jit->seen |= SEEN_RET0;
|
|
|
+ if (last)
|
|
|
+ break;
|
|
|
+ /* j <ret0> */
|
|
|
+ EMIT4_PCREL(0xa7f40000, jit->ret0_ip - jit->prg);
|
|
|
+ } else {
|
|
|
+ if (K <= 16383)
|
|
|
+ /* lghi %r2,K */
|
|
|
+ EMIT4_IMM(0xa7290000, K);
|
|
|
+ else
|
|
|
+ /* llgf %r2,<K>(%r13) */
|
|
|
+ EMIT6_DISP(0xe320d000, 0x0016, EMIT_CONST(K));
|
|
|
+ /* j <exit> */
|
|
|
+ if (last && !(jit->seen & SEEN_RET0))
|
|
|
+ break;
|
|
|
+ EMIT4_PCREL(0xa7f40000, jit->exit_ip - jit->prg);
|
|
|
+ }
|
|
|
+ break;
|
|
|
+ case BPF_S_RET_A:
|
|
|
+ /* llgfr %r2,%r5 */
|
|
|
+ EMIT4(0xb9160025);
|
|
|
+ /* j <exit> */
|
|
|
+ EMIT4_PCREL(0xa7f40000, jit->exit_ip - jit->prg);
|
|
|
+ break;
|
|
|
+ case BPF_S_ST: /* mem[K] = A */
|
|
|
+ jit->seen |= SEEN_MEM;
|
|
|
+ /* st %r5,<K>(%r15) */
|
|
|
+ EMIT4_DISP(0x5050f000,
|
|
|
+ (jit->seen & SEEN_DATAREF) ? 160 + K*4 : K*4);
|
|
|
+ break;
|
|
|
+ case BPF_S_STX: /* mem[K] = X : mov %ebx,off8(%rbp) */
|
|
|
+ jit->seen |= SEEN_XREG | SEEN_MEM;
|
|
|
+ /* st %r12,<K>(%r15) */
|
|
|
+ EMIT4_DISP(0x50c0f000,
|
|
|
+ (jit->seen & SEEN_DATAREF) ? 160 + K*4 : K*4);
|
|
|
+ break;
|
|
|
+ case BPF_S_ANC_PROTOCOL: /* A = ntohs(skb->protocol); */
|
|
|
+ BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, protocol) != 2);
|
|
|
+ /* lhi %r5,0 */
|
|
|
+ EMIT4(0xa7580000);
|
|
|
+ /* icm %r5,3,<d(protocol)>(%r2) */
|
|
|
+ EMIT4_DISP(0xbf532000, offsetof(struct sk_buff, protocol));
|
|
|
+ break;
|
|
|
+ case BPF_S_ANC_IFINDEX: /* if (!skb->dev) return 0;
|
|
|
+ * A = skb->dev->ifindex */
|
|
|
+ BUILD_BUG_ON(FIELD_SIZEOF(struct net_device, ifindex) != 4);
|
|
|
+ jit->seen |= SEEN_RET0;
|
|
|
+ /* lg %r1,<d(dev)>(%r2) */
|
|
|
+ EMIT6_DISP(0xe3102000, 0x0004, offsetof(struct sk_buff, dev));
|
|
|
+ /* ltgr %r1,%r1 */
|
|
|
+ EMIT4(0xb9020011);
|
|
|
+ /* jz <ret0> */
|
|
|
+ EMIT4_PCREL(0xa7840000, jit->ret0_ip - jit->prg);
|
|
|
+ /* l %r5,<d(ifindex)>(%r1) */
|
|
|
+ EMIT4_DISP(0x58501000, offsetof(struct net_device, ifindex));
|
|
|
+ break;
|
|
|
+ case BPF_S_ANC_MARK: /* A = skb->mark */
|
|
|
+ BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, mark) != 4);
|
|
|
+ /* l %r5,<d(mark)>(%r2) */
|
|
|
+ EMIT4_DISP(0x58502000, offsetof(struct sk_buff, mark));
|
|
|
+ break;
|
|
|
+ case BPF_S_ANC_QUEUE: /* A = skb->queue_mapping */
|
|
|
+ BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, queue_mapping) != 2);
|
|
|
+ /* lhi %r5,0 */
|
|
|
+ EMIT4(0xa7580000);
|
|
|
+ /* icm %r5,3,<d(queue_mapping)>(%r2) */
|
|
|
+ EMIT4_DISP(0xbf532000, offsetof(struct sk_buff, queue_mapping));
|
|
|
+ break;
|
|
|
+ case BPF_S_ANC_HATYPE: /* if (!skb->dev) return 0;
|
|
|
+ * A = skb->dev->type */
|
|
|
+ BUILD_BUG_ON(FIELD_SIZEOF(struct net_device, type) != 2);
|
|
|
+ jit->seen |= SEEN_RET0;
|
|
|
+ /* lg %r1,<d(dev)>(%r2) */
|
|
|
+ EMIT6_DISP(0xe3102000, 0x0004, offsetof(struct sk_buff, dev));
|
|
|
+ /* ltgr %r1,%r1 */
|
|
|
+ EMIT4(0xb9020011);
|
|
|
+ /* jz <ret0> */
|
|
|
+ EMIT4_PCREL(0xa7840000, jit->ret0_ip - jit->prg);
|
|
|
+ /* lhi %r5,0 */
|
|
|
+ EMIT4(0xa7580000);
|
|
|
+ /* icm %r5,3,<d(type)>(%r1) */
|
|
|
+ EMIT4_DISP(0xbf531000, offsetof(struct net_device, type));
|
|
|
+ break;
|
|
|
+ case BPF_S_ANC_RXHASH: /* A = skb->rxhash */
|
|
|
+ BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, rxhash) != 4);
|
|
|
+ /* l %r5,<d(rxhash)>(%r2) */
|
|
|
+ EMIT4_DISP(0x58502000, offsetof(struct sk_buff, rxhash));
|
|
|
+ break;
|
|
|
+ case BPF_S_ANC_CPU: /* A = smp_processor_id() */
|
|
|
+#ifdef CONFIG_SMP
|
|
|
+ /* l %r5,<d(cpu_nr)> */
|
|
|
+ EMIT4_DISP(0x58500000, offsetof(struct _lowcore, cpu_nr));
|
|
|
+#else
|
|
|
+ /* lhi %r5,0 */
|
|
|
+ EMIT4(0xa7580000);
|
|
|
+#endif
|
|
|
+ break;
|
|
|
+ default: /* too complex, give up */
|
|
|
+ goto out;
|
|
|
+ }
|
|
|
+ addrs[i] = jit->prg - jit->start;
|
|
|
+ return 0;
|
|
|
+out:
|
|
|
+ return -1;
|
|
|
+}
|
|
|
+
|
|
|
+void bpf_jit_compile(struct sk_filter *fp)
|
|
|
+{
|
|
|
+ unsigned long size, prg_len, lit_len;
|
|
|
+ struct bpf_jit jit, cjit;
|
|
|
+ unsigned int *addrs;
|
|
|
+ int pass, i;
|
|
|
+
|
|
|
+ if (!bpf_jit_enable)
|
|
|
+ return;
|
|
|
+ addrs = kmalloc(fp->len * sizeof(*addrs), GFP_KERNEL);
|
|
|
+ if (addrs == NULL)
|
|
|
+ return;
|
|
|
+ memset(addrs, 0, fp->len * sizeof(*addrs));
|
|
|
+ memset(&jit, 0, sizeof(cjit));
|
|
|
+ memset(&cjit, 0, sizeof(cjit));
|
|
|
+
|
|
|
+ for (pass = 0; pass < 10; pass++) {
|
|
|
+ jit.prg = jit.start;
|
|
|
+ jit.lit = jit.mid;
|
|
|
+
|
|
|
+ bpf_jit_prologue(&jit);
|
|
|
+ bpf_jit_noleaks(&jit, fp->insns);
|
|
|
+ for (i = 0; i < fp->len; i++) {
|
|
|
+ if (bpf_jit_insn(&jit, fp->insns + i, addrs, i,
|
|
|
+ i == fp->len - 1))
|
|
|
+ goto out;
|
|
|
+ }
|
|
|
+ bpf_jit_epilogue(&jit);
|
|
|
+ if (jit.start) {
|
|
|
+ WARN_ON(jit.prg > cjit.prg || jit.lit > cjit.lit);
|
|
|
+ if (memcmp(&jit, &cjit, sizeof(jit)) == 0)
|
|
|
+ break;
|
|
|
+ } else if (jit.prg == cjit.prg && jit.lit == cjit.lit) {
|
|
|
+ prg_len = jit.prg - jit.start;
|
|
|
+ lit_len = jit.lit - jit.mid;
|
|
|
+ size = max_t(unsigned long, prg_len + lit_len,
|
|
|
+ sizeof(struct work_struct));
|
|
|
+ if (size >= BPF_SIZE_MAX)
|
|
|
+ goto out;
|
|
|
+ jit.start = module_alloc(size);
|
|
|
+ if (!jit.start)
|
|
|
+ goto out;
|
|
|
+ jit.prg = jit.mid = jit.start + prg_len;
|
|
|
+ jit.lit = jit.end = jit.start + prg_len + lit_len;
|
|
|
+ jit.base_ip += (unsigned long) jit.start;
|
|
|
+ jit.exit_ip += (unsigned long) jit.start;
|
|
|
+ jit.ret0_ip += (unsigned long) jit.start;
|
|
|
+ }
|
|
|
+ cjit = jit;
|
|
|
+ }
|
|
|
+ if (bpf_jit_enable > 1) {
|
|
|
+ pr_err("flen=%d proglen=%lu pass=%d image=%p\n",
|
|
|
+ fp->len, jit.end - jit.start, pass, jit.start);
|
|
|
+ if (jit.start) {
|
|
|
+ printk(KERN_ERR "JIT code:\n");
|
|
|
+ print_fn_code(jit.start, jit.mid - jit.start);
|
|
|
+ print_hex_dump(KERN_ERR, "JIT literals:\n",
|
|
|
+ DUMP_PREFIX_ADDRESS, 16, 1,
|
|
|
+ jit.mid, jit.end - jit.mid, false);
|
|
|
+ }
|
|
|
+ }
|
|
|
+ if (jit.start)
|
|
|
+ fp->bpf_func = (void *) jit.start;
|
|
|
+out:
|
|
|
+ kfree(addrs);
|
|
|
+}
|
|
|
+
|
|
|
+static void jit_free_defer(struct work_struct *arg)
|
|
|
+{
|
|
|
+ module_free(NULL, arg);
|
|
|
+}
|
|
|
+
|
|
|
+/* run from softirq, we must use a work_struct to call
|
|
|
+ * module_free() from process context
|
|
|
+ */
|
|
|
+void bpf_jit_free(struct sk_filter *fp)
|
|
|
+{
|
|
|
+ struct work_struct *work;
|
|
|
+
|
|
|
+ if (fp->bpf_func == sk_run_filter)
|
|
|
+ return;
|
|
|
+ work = (struct work_struct *)fp->bpf_func;
|
|
|
+ INIT_WORK(work, jit_free_defer);
|
|
|
+ schedule_work(work);
|
|
|
+}
|