powerpc/ftrace: Fix ABIv2 issues with __ftrace_make_call (24a1bdc3) · Commits · 戴 / test

arch/powerpc/kernel/ftrace.c

+19 −21

Original line number	Diff line number	Diff line
		@@ -292,19 +292,24 @@ static int
		__ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
		{
		unsigned int op[2];
		unsigned long ip = rec->ip;
		void ip = (void )rec->ip;

		/* read where this goes */
		if (probe_kernel_read(op, (void )ip, MCOUNT_INSN_SIZE 2))
		if (probe_kernel_read(op, ip, sizeof(op)))
		return -EFAULT;

		/*
		* It should be pointing to two nops or
		* b +8; ld r2,40(r1)
		* We expect to see:
		*
		* b +8
		* ld r2,XX(r1)
		*
		* The load offset is different depending on the ABI. For simplicity
		* just mask it out when doing the compare.
		*/
		if (((op[0] != 0x48000008) \|\| (op[1] != 0xe8410028)) &&
		((op[0] != PPC_INST_NOP) \|\| (op[1] != PPC_INST_NOP))) {
		printk(KERN_ERR "Expected NOPs but have %x %x\n", op[0], op[1]);
		if ((op[0] != 0x48000008) \|\| ((op[1] & 0xffff00000) != 0xe8410000)) {
		printk(KERN_ERR "Unexpected call sequence: %x %x\n",
		op[0], op[1]);
		return -EINVAL;
		}

		@@ -314,23 +319,16 @@ __ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
		return -EINVAL;
		}

		/* create the branch to the trampoline */
		op[0] = create_branch((unsigned int *)ip,
		rec->arch.mod->arch.tramp, BRANCH_SET_LINK);
		if (!op[0]) {
		printk(KERN_ERR "REL24 out of range!\n");
		/* Ensure branch is within 24 bits */
		if (create_branch(ip, rec->arch.mod->arch.tramp, BRANCH_SET_LINK)) {
		printk(KERN_ERR "Branch out of range");
		return -EINVAL;
		}

		/* ld r2,40(r1) */
		op[1] = 0xe8410028;

		pr_devel("write to %lx\n", rec->ip);

		if (probe_kernel_write((void )ip, op, MCOUNT_INSN_SIZE 2))
		return -EPERM;

		flush_icache_range(ip, ip + 8);
		if (patch_branch(ip, rec->arch.mod->arch.tramp, BRANCH_SET_LINK)) {
		printk(KERN_ERR "REL24 out of range!\n");
		return -EINVAL;
		}

		return 0;
		}

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