Merge tag 'bpf-next-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Pull bpf updates from Alexei Starovoitov:

 - Remove usermode driver (UMD) framework (Thomas Weißschuh)

 - Introduce Strongly Connected Component (SCC) in the verifier to
   detect loops and refine register liveness (Eduard Zingerman)

 - Allow 'void *' cast using bpf_rdonly_cast() and corresponding
   '__arg_untrusted' for global function parameters (Eduard Zingerman)

 - Improve precision for BPF_ADD and BPF_SUB operations in the verifier
   (Harishankar Vishwanathan)

 - Teach the verifier that constant pointer to a map cannot be NULL
   (Ihor Solodrai)

 - Introduce BPF streams for error reporting of various conditions
   detected by BPF runtime (Kumar Kartikeya Dwivedi)

 - Teach the verifier to insert runtime speculation barrier (lfence on
   x86) to mitigate speculative execution instead of rejecting the
   programs (Luis Gerhorst)

 - Various improvements for 'veristat' (Mykyta Yatsenko)

 - For CONFIG_DEBUG_KERNEL config warn on internal verifier errors to
   improve bug detection by syzbot (Paul Chaignon)

 - Support BPF private stack on arm64 (Puranjay Mohan)

 - Introduce bpf_cgroup_read_xattr() kfunc to read xattr of cgroup's
   node (Song Liu)

 - Introduce kfuncs for read-only string opreations (Viktor Malik)

 - Implement show_fdinfo() for bpf_links (Tao Chen)

 - Reduce verifier's stack consumption (Yonghong Song)

 - Implement mprog API for cgroup-bpf programs (Yonghong Song)

* tag 'bpf-next-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (192 commits)
  selftests/bpf: Migrate fexit_noreturns case into tracing_failure test suite
  selftests/bpf: Add selftest for attaching tracing programs to functions in deny list
  bpf: Add log for attaching tracing programs to functions in deny list
  bpf: Show precise rejected function when attaching fexit/fmod_ret to __noreturn functions
  bpf: Fix various typos in verifier.c comments
  bpf: Add third round of bounds deduction
  selftests/bpf: Test invariants on JSLT crossing sign
  selftests/bpf: Test cross-sign 64bits range refinement
  selftests/bpf: Update reg_bound range refinement logic
  bpf: Improve bounds when s64 crosses sign boundary
  bpf: Simplify bounds refinement from s32
  selftests/bpf: Enable private stack tests for arm64
  bpf, arm64: JIT support for private stack
  bpf: Move bpf_jit_get_prog_name() to core.c
  bpf, arm64: Fix fp initialization for exception boundary
  umd: Remove usermode driver framework
  bpf/preload: Don't select USERMODE_DRIVER
  selftests/bpf: Fix test dynptr/test_dynptr_memset_xdp_chunks failure
  selftests/bpf: Fix test dynptr/test_dynptr_copy_xdp failure
  selftests/bpf: Increase xdp data size for arm64 64K page size
  ...

1 files changed, 59 insertions, 20 deletions

diff --git a/arch/powerpc/net/bpf_jit_comp64.c b/arch/powerpc/net/bpf_jit_comp64.c
index 5daa77aee7f7..a25a6ffe7d7c 100644
--- a/arch/powerpc/net/bpf_jit_comp64.c
+++ b/arch/powerpc/net/bpf_jit_comp64.c
@@ -370,6 +370,23 @@ static int bpf_jit_emit_tail_call(u32 *image, struct codegen_context *ctx, u32 o
 	return 0;
 }
 
+bool bpf_jit_bypass_spec_v1(void)
+{
+#if defined(CONFIG_PPC_E500) || defined(CONFIG_PPC_BOOK3S_64)
+	return !(security_ftr_enabled(SEC_FTR_FAVOUR_SECURITY) &&
+		 security_ftr_enabled(SEC_FTR_BNDS_CHK_SPEC_BAR));
+#else
+	return true;
+#endif
+}
+
+bool bpf_jit_bypass_spec_v4(void)
+{
+	return !(security_ftr_enabled(SEC_FTR_FAVOUR_SECURITY) &&
+		 security_ftr_enabled(SEC_FTR_STF_BARRIER) &&
+		 stf_barrier_type_get() != STF_BARRIER_NONE);
+}
+
 /*
  * 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()
@@ -397,6 +414,7 @@ int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, u32 *fimage, struct code
 		       u32 *addrs, int pass, bool extra_pass)
 {
 	enum stf_barrier_type stf_barrier = stf_barrier_type_get();
+	bool sync_emitted, ori31_emitted;
 	const struct bpf_insn *insn = fp->insnsi;
 	int flen = fp->len;
 	int i, ret;
@@ -789,30 +807,51 @@ emit_clear:
 
 		/*
 		 * BPF_ST NOSPEC (speculation barrier)
+		 *
+		 * The following must act as a barrier against both Spectre v1
+		 * and v4 if we requested both mitigations. Therefore, also emit
+		 * 'isync; sync' on E500 or 'ori31' on BOOK3S_64 in addition to
+		 * the insns needed for a Spectre v4 barrier.
+		 *
+		 * If we requested only !bypass_spec_v1 OR only !bypass_spec_v4,
+		 * we can skip the respective other barrier type as an
+		 * optimization.
 		 */
 		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:
+			sync_emitted = false;
+			ori31_emitted = false;
+			if (IS_ENABLED(CONFIG_PPC_E500) &&
+			    !bpf_jit_bypass_spec_v1()) {
+				EMIT(PPC_RAW_ISYNC());
 				EMIT(PPC_RAW_SYNC());
-				EMIT(PPC_RAW_LD(tmp1_reg, _R13, 0));
-				EMIT(PPC_RAW_ORI(_R31, _R31, 0));
-				break;
-			case STF_BARRIER_FALLBACK:
-				ctx->seen |= SEEN_FUNC;
-				PPC_LI64(_R12, dereference_kernel_function_descriptor(bpf_stf_barrier));
-				EMIT(PPC_RAW_MTCTR(_R12));
-				EMIT(PPC_RAW_BCTRL());
-				break;
-			case STF_BARRIER_NONE:
-				break;
+				sync_emitted = true;
 			}
+			if (!bpf_jit_bypass_spec_v4()) {
+				switch (stf_barrier) {
+				case STF_BARRIER_EIEIO:
+					EMIT(PPC_RAW_EIEIO() | 0x02000000);
+					break;
+				case STF_BARRIER_SYNC_ORI:
+					if (!sync_emitted)
+						EMIT(PPC_RAW_SYNC());
+					EMIT(PPC_RAW_LD(tmp1_reg, _R13, 0));
+					EMIT(PPC_RAW_ORI(_R31, _R31, 0));
+					ori31_emitted = true;
+					break;
+				case STF_BARRIER_FALLBACK:
+					ctx->seen |= SEEN_FUNC;
+					PPC_LI64(_R12, dereference_kernel_function_descriptor(bpf_stf_barrier));
+					EMIT(PPC_RAW_MTCTR(_R12));
+					EMIT(PPC_RAW_BCTRL());
+					break;
+				case STF_BARRIER_NONE:
+					break;
+				}
+			}
+			if (IS_ENABLED(CONFIG_PPC_BOOK3S_64) &&
+			    !bpf_jit_bypass_spec_v1() &&
+			    !ori31_emitted)
+				EMIT(PPC_RAW_ORI(_R31, _R31, 0));
 			break;
 
 		/*