* with our redzone usage.
*
* [ prev sp ] <-------------
- * [ nv gpr save area ] 6*8 |
+ * [ nv gpr save area ] 5*8 |
* [ tail_call_cnt ] 8 |
- * [ local_tmp_var ] 8 |
+ * [ local_tmp_var ] 16 |
* fp (r31) --> [ ebpf stack space ] upto 512 |
* [ frame header ] 32/112 |
* sp (r1) ---> [ stack pointer ] --------------
*/
/* for gpr non volatile registers BPG_REG_6 to 10 */
-#define BPF_PPC_STACK_SAVE (6*8)
+#define BPF_PPC_STACK_SAVE (5*8)
/* for bpf JIT code internal usage */
-#define BPF_PPC_STACK_LOCALS 16
+#define BPF_PPC_STACK_LOCALS 24
/* stack frame excluding BPF stack, ensure this is quadword aligned */
#define BPF_PPC_STACKFRAME (STACK_FRAME_MIN_SIZE + \
BPF_PPC_STACK_LOCALS + BPF_PPC_STACK_SAVE)
#include <linux/if_vlan.h>
#include <asm/kprobes.h>
#include <linux/bpf.h>
+#include <asm/security_features.h>
#include "bpf_jit64.h"
* [ 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)
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)
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 */
static 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;
* BPF_ST NOSPEC (speculation barrier)
*/
case BPF_ST | BPF_NOSPEC:
+ if (!security_ftr_enabled(SEC_FTR_FAVOUR_SECURITY) ||
+ (!security_ftr_enabled(SEC_FTR_L1D_FLUSH_PR) &&
+ (!security_ftr_enabled(SEC_FTR_L1D_FLUSH_HV) || !cpu_has_feature(CPU_FTR_HVMODE))))
+ break;
+
+ switch (stf_barrier) {
+ case STF_BARRIER_EIEIO:
+ EMIT(0x7c0006ac | 0x02000000);
+ break;
+ case STF_BARRIER_SYNC_ORI:
+ EMIT(PPC_INST_SYNC);
+ EMIT(PPC_RAW_LD(b2p[TMP_REG_1], 13, 0));
+ EMIT(PPC_RAW_ORI(31, 31, 0));
+ break;
+ case STF_BARRIER_FALLBACK:
+ EMIT(PPC_INST_MFLR | ___PPC_RT(b2p[TMP_REG_1]));
+ PPC_LI64(12, dereference_kernel_function_descriptor(bpf_stf_barrier));
+ EMIT(PPC_RAW_MTCTR(12));
+ EMIT(PPC_INST_BCTR | 0x1);
+ EMIT(PPC_RAW_MTLR(b2p[TMP_REG_1]));
+ break;
+ case STF_BARRIER_NONE:
+ break;
+ }
break;
/*