Automatic merge of 'next-test' into merge-test (2026-01-29 09:09)

Author: maddy-kerneldev

arch/powerpc/include/asm/kgdb.h

@@ -25,7 +25,6 @@
 
 #define BREAK_INSTR_SIZE	4
 #define BUFMAX			((NUMREGBYTES * 2) + 512)
-#define OUTBUFMAX		((NUMREGBYTES * 2) + 512)
 
 #define BREAK_INSTR		0x7d821008	/* twge r2, r2 */
 

arch/powerpc/kernel/smp.c

@@ -822,6 +822,8 @@ static int parse_thread_groups(struct device_node *dn,
 
 	count = of_property_count_u32_elems(dn, "ibm,thread-groups");
 	thread_group_array = kcalloc(count, sizeof(u32), GFP_KERNEL);
+	if (!thread_group_array)
+		return -ENOMEM;
 	ret = of_property_read_u32_array(dn, "ibm,thread-groups",
 					 thread_group_array, count);
 	if (ret)

arch/powerpc/net/bpf_jit.h

@@ -24,6 +24,7 @@
 
 #define SZL			sizeof(unsigned long)
 #define BPF_INSN_SAFETY		64
+#define BPF_PPC_TAILCALL	8
 
 #define PLANT_INSTR(d, idx, instr)					      \
 	do { if (d) { (d)[idx] = instr; } idx++; } while (0)
@@ -51,6 +52,13 @@
 		EMIT(PPC_INST_BRANCH_COND | (((cond) & 0x3ff) << 16) | (offset & 0xfffc));					\
 	} while (0)
 
+/* When constant jump offset is known prior */
+#define PPC_BCC_CONST_SHORT(cond, offset)							\
+	do {											\
+		BUILD_BUG_ON(offset < -0x8000 || offset > 0x7fff || (offset & 0x3));		\
+		EMIT(PPC_INST_BRANCH_COND | (((cond) & 0x3ff) << 16) | (offset & 0xfffc));	\
+	} while (0)
+
 /*
  * Sign-extended 32-bit immediate load
  *
@@ -72,6 +80,10 @@
 	} } while (0)
 
 #ifdef CONFIG_PPC64
+
+/* for gpr non volatile registers BPG_REG_6 to 10 */
+#define BPF_PPC_STACK_SAVE	(6 * 8)
+
 /* If dummy pass (!image), account for maximum possible instructions */
 #define PPC_LI64(d, i)		do {					      \
 	if (!image)							      \
@@ -166,6 +178,9 @@ struct codegen_context {
 	unsigned int alt_exit_addr;
 	u64 arena_vm_start;
 	u64 user_vm_start;
+	bool is_subprog;
+	bool exception_boundary;
+	bool exception_cb;
 };
 
 #define bpf_to_ppc(r)	(ctx->b2p[r])
@@ -205,6 +220,7 @@ int bpf_add_extable_entry(struct bpf_prog *fp, u32 *image, u32 *fimage, int pass
 			  struct codegen_context *ctx, int insn_idx,
 			  int jmp_off, int dst_reg, u32 code);
 
+int bpf_jit_stack_tailcallinfo_offset(struct codegen_context *ctx);
 #endif
 
 #endif

arch/powerpc/net/bpf_jit_comp.c

@@ -206,6 +206,9 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp)
 	cgctx.stack_size = round_up(fp->aux->stack_depth, 16);
 	cgctx.arena_vm_start = bpf_arena_get_kern_vm_start(fp->aux->arena);
 	cgctx.user_vm_start = bpf_arena_get_user_vm_start(fp->aux->arena);
+	cgctx.is_subprog = bpf_is_subprog(fp);
+	cgctx.exception_boundary = fp->aux->exception_boundary;
+	cgctx.exception_cb = fp->aux->exception_cb;
 
 	/* Scouting faux-generate pass 0 */
 	if (bpf_jit_build_body(fp, NULL, NULL, &cgctx, addrs, 0, false)) {
@@ -435,6 +438,16 @@ void bpf_jit_free(struct bpf_prog *fp)
 	bpf_prog_unlock_free(fp);
 }
 
+bool bpf_jit_supports_exceptions(void)
+{
+	return IS_ENABLED(CONFIG_PPC64);
+}
+
+bool bpf_jit_supports_subprog_tailcalls(void)
+{
+	return IS_ENABLED(CONFIG_PPC64);
+}
+
 bool bpf_jit_supports_kfunc_call(void)
 {
 	return true;
@@ -617,15 +630,50 @@ static int invoke_bpf_mod_ret(u32 *image, u32 *ro_image, struct codegen_context
 	return 0;
 }
 
-static void bpf_trampoline_setup_tail_call_cnt(u32 *image, struct codegen_context *ctx,
-					       int func_frame_offset, int r4_off)
+/*
+ * Refer __arch_prepare_bpf_trampoline() for stack component details.
+ *
+ * The tailcall count/reference is present in caller's stack frame. The
+ * tail_call_info is saved at the same offset on the trampoline frame
+ * for the traced function (BPF subprog/callee) to fetch it.
+ */
+static void bpf_trampoline_setup_tail_call_info(u32 *image, struct codegen_context *ctx,
+						int func_frame_offset,
+						int bpf_dummy_frame_size, int r4_off)
 {
 	if (IS_ENABLED(CONFIG_PPC64)) {
-		/* See bpf_jit_stack_tailcallcnt() */
-		int tailcallcnt_offset = 7 * 8;
+		/* See Generated stack layout */
+		int tailcallinfo_offset = BPF_PPC_TAILCALL;
+
+		/*
+		 * func_frame_offset =                                   ...(1)
+		 *      bpf_dummy_frame_size + trampoline_frame_size
+		 */
+		EMIT(PPC_RAW_LD(_R4, _R1, func_frame_offset));
+		EMIT(PPC_RAW_LD(_R3, _R4, -tailcallinfo_offset));
 
-		EMIT(PPC_RAW_LL(_R3, _R1, func_frame_offset - tailcallcnt_offset));
-		EMIT(PPC_RAW_STL(_R3, _R1, -tailcallcnt_offset));
+		/*
+		 * Setting the tail_call_info in trampoline's frame
+		 * depending on if previous frame had value or reference.
+		 */
+		EMIT(PPC_RAW_CMPLWI(_R3, MAX_TAIL_CALL_CNT));
+		PPC_BCC_CONST_SHORT(COND_GT, 8);
+		EMIT(PPC_RAW_ADDI(_R3, _R4, bpf_jit_stack_tailcallinfo_offset(ctx)));
+		/*
+		 * From ...(1) above:
+		 * trampoline_frame_bottom =                            ...(2)
+		 *      func_frame_offset - bpf_dummy_frame_size
+		 *
+		 * Using ...(2) derived above:
+		 * trampoline_tail_call_info_offset =                  ...(3)
+		 *      trampoline_frame_bottom - tailcallinfo_offset
+		 *
+		 * From ...(3):
+		 * Use trampoline_tail_call_info_offset to write reference of main's
+		 * tail_call_info in trampoline frame.
+		 */
+		EMIT(PPC_RAW_STL(_R3, _R1, (func_frame_offset - bpf_dummy_frame_size)
+								- tailcallinfo_offset));
 	} else {
 		/* See bpf_jit_stack_offsetof() and BPF_PPC_TC */
 		EMIT(PPC_RAW_LL(_R4, _R1, r4_off));
@@ -635,14 +683,11 @@ static void bpf_trampoline_setup_tail_call_cnt(u32 *image, struct codegen_contex
 static void bpf_trampoline_restore_tail_call_cnt(u32 *image, struct codegen_context *ctx,
 						 int func_frame_offset, int r4_off)
 {
-	if (IS_ENABLED(CONFIG_PPC64)) {
-		/* See bpf_jit_stack_tailcallcnt() */
-		int tailcallcnt_offset = 7 * 8;
-
-		EMIT(PPC_RAW_LL(_R3, _R1, -tailcallcnt_offset));
-		EMIT(PPC_RAW_STL(_R3, _R1, func_frame_offset - tailcallcnt_offset));
-	} else {
-		/* See bpf_jit_stack_offsetof() and BPF_PPC_TC */
+	if (IS_ENABLED(CONFIG_PPC32)) {
+		/*
+		 * Restore tailcall for 32-bit powerpc
+		 * See bpf_jit_stack_offsetof() and BPF_PPC_TC
+		 */
 		EMIT(PPC_RAW_STL(_R4, _R1, r4_off));
 	}
 }
@@ -731,6 +776,7 @@ static int __arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, void *rw_im
 	 * LR save area                 [ r0 save (64-bit)  ]   | header
 	 *                              [ r0 save (32-bit)  ]   |
 	 * dummy frame for unwind       [ back chain 1      ] --
+	 *                              [ tail_call_info    ] optional - 64-bit powerpc
 	 *                              [ padding           ] align stack frame
 	 *       r4_off                 [ r4 (tailcallcnt)  ] optional - 32-bit powerpc
 	 *       alt_lr_off             [ real lr (ool stub)] optional - actual lr
@@ -812,6 +858,14 @@ static int __arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, void *rw_im
 		}
 	}
 
+	/*
+	 * Save tailcall count pointer at the same offset on the
+	 * stack where subprogs expect it
+	 */
+	if ((flags & BPF_TRAMP_F_CALL_ORIG) &&
+		(flags & BPF_TRAMP_F_TAIL_CALL_CTX))
+		bpf_frame_size += BPF_PPC_TAILCALL;
+
 	/* Padding to align stack frame, if any */
 	bpf_frame_size = round_up(bpf_frame_size, SZL * 2);
 
@@ -913,7 +967,8 @@ static int __arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, void *rw_im
 
 		/* Replicate tail_call_cnt before calling the original BPF prog */
 		if (flags & BPF_TRAMP_F_TAIL_CALL_CTX)
-			bpf_trampoline_setup_tail_call_cnt(image, ctx, func_frame_offset, r4_off);
+			bpf_trampoline_setup_tail_call_info(image, ctx, func_frame_offset,
+								bpf_dummy_frame_size, r4_off);
 
 		/* Restore args */
 		bpf_trampoline_restore_args_stack(image, ctx, func_frame_offset, nr_regs, regs_off);