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path: root/arch/powerpc/net/bpf_jit_comp64.c
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Diffstat (limited to 'arch/powerpc/net/bpf_jit_comp64.c')
-rw-r--r--arch/powerpc/net/bpf_jit_comp64.c100
1 files changed, 82 insertions, 18 deletions
diff --git a/arch/powerpc/net/bpf_jit_comp64.c b/arch/powerpc/net/bpf_jit_comp64.c
index b87a63dba9c8..8b5157ccfeba 100644
--- a/arch/powerpc/net/bpf_jit_comp64.c
+++ b/arch/powerpc/net/bpf_jit_comp64.c
@@ -15,6 +15,7 @@
#include <linux/if_vlan.h>
#include <asm/kprobes.h>
#include <linux/bpf.h>
+#include <asm/security_features.h>
#include "bpf_jit64.h"
@@ -35,9 +36,9 @@ static inline bool bpf_has_stack_frame(struct codegen_context *ctx)
* [ prev sp ] <-------------
* [ ... ] |
* sp (r1) ---> [ stack pointer ] --------------
- * [ nv gpr save area ] 6*8
+ * [ nv gpr save area ] 5*8
* [ tail_call_cnt ] 8
- * [ local_tmp_var ] 8
+ * [ local_tmp_var ] 16
* [ unused red zone ] 208 bytes protected
*/
static int bpf_jit_stack_local(struct codegen_context *ctx)
@@ -45,12 +46,12 @@ static int bpf_jit_stack_local(struct codegen_context *ctx)
if (bpf_has_stack_frame(ctx))
return STACK_FRAME_MIN_SIZE + ctx->stack_size;
else
- return -(BPF_PPC_STACK_SAVE + 16);
+ return -(BPF_PPC_STACK_SAVE + 24);
}
static int bpf_jit_stack_tailcallcnt(struct codegen_context *ctx)
{
- return bpf_jit_stack_local(ctx) + 8;
+ return bpf_jit_stack_local(ctx) + 16;
}
static int bpf_jit_stack_offsetof(struct codegen_context *ctx, int reg)
@@ -206,7 +207,7 @@ void bpf_jit_emit_func_call_rel(u32 *image, struct codegen_context *ctx, u64 fun
EMIT(PPC_RAW_BCTRL());
}
-static void bpf_jit_emit_tail_call(u32 *image, struct codegen_context *ctx, u32 out)
+static int bpf_jit_emit_tail_call(u32 *image, struct codegen_context *ctx, u32 out)
{
/*
* By now, the eBPF program has already setup parameters in r3, r4 and r5
@@ -267,13 +268,38 @@ static void bpf_jit_emit_tail_call(u32 *image, struct codegen_context *ctx, u32
bpf_jit_emit_common_epilogue(image, ctx);
EMIT(PPC_RAW_BCTR());
+
/* out: */
+ return 0;
}
+/*
+ * We spill into the redzone always, even if the bpf program has its own stackframe.
+ * Offsets hardcoded based on BPF_PPC_STACK_SAVE -- see bpf_jit_stack_local()
+ */
+void bpf_stf_barrier(void);
+
+asm (
+" .global bpf_stf_barrier ;"
+" bpf_stf_barrier: ;"
+" std 21,-64(1) ;"
+" std 22,-56(1) ;"
+" sync ;"
+" ld 21,-64(1) ;"
+" ld 22,-56(1) ;"
+" ori 31,31,0 ;"
+" .rept 14 ;"
+" b 1f ;"
+" 1: ;"
+" .endr ;"
+" blr ;"
+);
+
/* Assemble the body code between the prologue & epilogue */
int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, struct codegen_context *ctx,
u32 *addrs, bool extra_pass)
{
+ enum stf_barrier_type stf_barrier = stf_barrier_type_get();
const struct bpf_insn *insn = fp->insnsi;
int flen = fp->len;
int i, ret;
@@ -328,18 +354,25 @@ int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, struct codegen_context *
EMIT(PPC_RAW_SUB(dst_reg, dst_reg, src_reg));
goto bpf_alu32_trunc;
case BPF_ALU | BPF_ADD | BPF_K: /* (u32) dst += (u32) imm */
- case BPF_ALU | BPF_SUB | BPF_K: /* (u32) dst -= (u32) imm */
case BPF_ALU64 | BPF_ADD | BPF_K: /* dst += imm */
+ if (!imm) {
+ goto bpf_alu32_trunc;
+ } else if (imm >= -32768 && imm < 32768) {
+ EMIT(PPC_RAW_ADDI(dst_reg, dst_reg, IMM_L(imm)));
+ } else {
+ PPC_LI32(b2p[TMP_REG_1], imm);
+ EMIT(PPC_RAW_ADD(dst_reg, dst_reg, b2p[TMP_REG_1]));
+ }
+ goto bpf_alu32_trunc;
+ case BPF_ALU | BPF_SUB | BPF_K: /* (u32) dst -= (u32) imm */
case BPF_ALU64 | BPF_SUB | BPF_K: /* dst -= imm */
- if (BPF_OP(code) == BPF_SUB)
- imm = -imm;
- if (imm) {
- if (imm >= -32768 && imm < 32768)
- EMIT(PPC_RAW_ADDI(dst_reg, dst_reg, IMM_L(imm)));
- else {
- PPC_LI32(b2p[TMP_REG_1], imm);
- EMIT(PPC_RAW_ADD(dst_reg, dst_reg, b2p[TMP_REG_1]));
- }
+ if (!imm) {
+ goto bpf_alu32_trunc;
+ } else if (imm > -32768 && imm <= 32768) {
+ EMIT(PPC_RAW_ADDI(dst_reg, dst_reg, IMM_L(-imm)));
+ } else {
+ PPC_LI32(b2p[TMP_REG_1], imm);
+ EMIT(PPC_RAW_SUB(dst_reg, dst_reg, b2p[TMP_REG_1]));
}
goto bpf_alu32_trunc;
case BPF_ALU | BPF_MUL | BPF_X: /* (u32) dst *= (u32) src */
@@ -389,8 +422,14 @@ int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, struct codegen_context *
case BPF_ALU64 | BPF_DIV | BPF_K: /* dst /= imm */
if (imm == 0)
return -EINVAL;
- else if (imm == 1)
- goto bpf_alu32_trunc;
+ if (imm == 1) {
+ if (BPF_OP(code) == BPF_DIV) {
+ goto bpf_alu32_trunc;
+ } else {
+ EMIT(PPC_RAW_LI(dst_reg, 0));
+ break;
+ }
+ }
PPC_LI32(b2p[TMP_REG_1], imm);
switch (BPF_CLASS(code)) {
@@ -631,6 +670,29 @@ emit_clear:
* BPF_ST NOSPEC (speculation barrier)
*/
case BPF_ST | BPF_NOSPEC:
+ if (!security_ftr_enabled(SEC_FTR_FAVOUR_SECURITY) ||
+ !security_ftr_enabled(SEC_FTR_STF_BARRIER))
+ break;
+
+ switch (stf_barrier) {
+ case STF_BARRIER_EIEIO:
+ EMIT(PPC_RAW_EIEIO() | 0x02000000);
+ break;
+ case STF_BARRIER_SYNC_ORI:
+ EMIT(PPC_RAW_SYNC());
+ EMIT(PPC_RAW_LD(b2p[TMP_REG_1], _R13, 0));
+ EMIT(PPC_RAW_ORI(_R31, _R31, 0));
+ break;
+ case STF_BARRIER_FALLBACK:
+ EMIT(PPC_RAW_MFLR(b2p[TMP_REG_1]));
+ PPC_LI64(12, dereference_kernel_function_descriptor(bpf_stf_barrier));
+ EMIT(PPC_RAW_MTCTR(12));
+ EMIT(PPC_RAW_BCTRL());
+ EMIT(PPC_RAW_MTLR(b2p[TMP_REG_1]));
+ break;
+ case STF_BARRIER_NONE:
+ break;
+ }
break;
/*
@@ -993,7 +1055,9 @@ cond_branch:
*/
case BPF_JMP | BPF_TAIL_CALL:
ctx->seen |= SEEN_TAILCALL;
- bpf_jit_emit_tail_call(image, ctx, addrs[i + 1]);
+ ret = bpf_jit_emit_tail_call(image, ctx, addrs[i + 1]);
+ if (ret < 0)
+ return ret;
break;
default:
generated by cgit v1.2.3-58-ga151 (git 2.39.0) at 2024-11-26 06:48:03 +0000