Commit 50428fdc authored by Jordan Niethe's avatar Jordan Niethe Committed by Michael Ellerman
Browse files

powerpc: Add a ppc_inst_as_str() helper 



There are quite a few places where instructions are printed, this is
done using a '%x' format specifier. With the introduction of prefixed
instructions, this does not work well. Currently in these places,
ppc_inst_val() is used for the value for %x so only the first word of
prefixed instructions are printed.

When the instructions are word instructions, only a single word should
be printed. For prefixed instructions both the prefix and suffix should
be printed. To accommodate both of these situations, instead of a '%x'
specifier use '%s' and introduce a helper, __ppc_inst_as_str() which
returns a char *. The char * __ppc_inst_as_str() returns is buffer that
is passed to it by the caller.

It is cumbersome to require every caller of __ppc_inst_as_str() to now
declare a buffer. To make it more convenient to use __ppc_inst_as_str(),
wrap it in a macro that uses a compound statement to allocate a buffer
on the caller's stack before calling it.

Signed-off-by: default avatarJordan Niethe <jniethe5@gmail.com>
Reviewed-by: default avatarJoel Stanley <joel@jms.id.au>
Acked-by: default avatarSegher Boessenkool <segher@kernel.crashing.org>
[mpe: Drop 0x prefix to match most existings uses, especially xmon]
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200602052728.18227-1-jniethe5@gmail.com
parent 4f825900

arch/powerpc/include/asm/inst.h

+19 −0
Original line number Diff line number Diff line
@@ -122,6 +122,25 @@ static inline u64 ppc_inst_as_u64(struct ppc_inst x) 
#endif

}



#define PPC_INST_STR_LEN sizeof("00000000 00000000")



static inline char *__ppc_inst_as_str(char str[PPC_INST_STR_LEN], struct ppc_inst x)

{

	if (ppc_inst_prefixed(x))

		sprintf(str, "%08x %08x", ppc_inst_val(x), ppc_inst_suffix(x));

	else

		sprintf(str, "%08x", ppc_inst_val(x));



	return str;

}



#define ppc_inst_as_str(x)		\

({					\

	char __str[PPC_INST_STR_LEN];	\

	__ppc_inst_as_str(__str, x);	\

	__str;				\

})



int probe_user_read_inst(struct ppc_inst *inst,

			 struct ppc_inst __user *nip);

arch/powerpc/kernel/kprobes.c

+1 −1
Original line number Diff line number Diff line
@@ -244,7 +244,7 @@ static int try_to_emulate(struct kprobe *p, struct pt_regs *regs) 
		 * So, we should never get here... but, its still

		 * good to catch them, just in case...

		 */

		printk("Can't step on instruction %x\n", ppc_inst_val(insn));

		printk("Can't step on instruction %s\n", ppc_inst_as_str(insn));

		BUG();

	} else {

		/*

arch/powerpc/kernel/trace/ftrace.c

+13 −13
Original line number Diff line number Diff line
@@ -73,8 +73,8 @@ ftrace_modify_code(unsigned long ip, struct ppc_inst old, struct ppc_inst new) 


	/* Make sure it is what we expect it to be */

	if (!ppc_inst_equal(replaced, old)) {

		pr_err("%p: replaced (%#x) != old (%#x)",

		(void *)ip, ppc_inst_val(replaced), ppc_inst_val(old));

		pr_err("%p: replaced (%s) != old (%s)",

		(void *)ip, ppc_inst_as_str(replaced), ppc_inst_as_str(old));

		return -EINVAL;

	}
@@ -137,7 +137,7 @@ __ftrace_make_nop(struct module *mod, 


	/* Make sure that that this is still a 24bit jump */

	if (!is_bl_op(op)) {

		pr_err("Not expected bl: opcode is %x\n", ppc_inst_val(op));

		pr_err("Not expected bl: opcode is %s\n", ppc_inst_as_str(op));

		return -EINVAL;

	}
@@ -172,8 +172,8 @@ __ftrace_make_nop(struct module *mod, 
	/* We expect either a mflr r0, or a std r0, LRSAVE(r1) */

	if (!ppc_inst_equal(op, ppc_inst(PPC_INST_MFLR)) &&

	    !ppc_inst_equal(op, ppc_inst(PPC_INST_STD_LR))) {

		pr_err("Unexpected instruction %08x around bl _mcount\n",

		       ppc_inst_val(op));

		pr_err("Unexpected instruction %s around bl _mcount\n",

		       ppc_inst_as_str(op));

		return -EINVAL;

	}

#else
@@ -203,7 +203,7 @@ __ftrace_make_nop(struct module *mod, 
	}



	if (!ppc_inst_equal(op,  ppc_inst(PPC_INST_LD_TOC))) {

		pr_err("Expected %08x found %08x\n", PPC_INST_LD_TOC, ppc_inst_val(op));

		pr_err("Expected %08x found %s\n", PPC_INST_LD_TOC, ppc_inst_as_str(op));

		return -EINVAL;

	}

#endif /* CONFIG_MPROFILE_KERNEL */
@@ -231,7 +231,7 @@ __ftrace_make_nop(struct module *mod, 


	/* Make sure that that this is still a 24bit jump */

	if (!is_bl_op(op)) {

		pr_err("Not expected bl: opcode is %x\n", ppc_inst_val(op));

		pr_err("Not expected bl: opcode is %s\n", ppc_inst_as_str(op));

		return -EINVAL;

	}
@@ -406,7 +406,7 @@ static int __ftrace_make_nop_kernel(struct dyn_ftrace *rec, unsigned long addr) 


	/* Make sure that that this is still a 24bit jump */

	if (!is_bl_op(op)) {

		pr_err("Not expected bl: opcode is %x\n", ppc_inst_val(op));

		pr_err("Not expected bl: opcode is %s\n", ppc_inst_as_str(op));

		return -EINVAL;

	}
@@ -533,8 +533,8 @@ __ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) 
		return -EFAULT;



	if (!expected_nop_sequence(ip, op[0], op[1])) {

		pr_err("Unexpected call sequence at %p: %x %x\n",

		ip, ppc_inst_val(op[0]), ppc_inst_val(op[1]));

		pr_err("Unexpected call sequence at %p: %s %s\n",

		ip, ppc_inst_as_str(op[0]), ppc_inst_as_str(op[1]));

		return -EINVAL;

	}
@@ -597,7 +597,7 @@ __ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) 


	/* It should be pointing to a nop */

	if (!ppc_inst_equal(op,  ppc_inst(PPC_INST_NOP))) {

		pr_err("Expected NOP but have %x\n", ppc_inst_val(op));

		pr_err("Expected NOP but have %s\n", ppc_inst_as_str(op));

		return -EINVAL;

	}
@@ -654,7 +654,7 @@ static int __ftrace_make_call_kernel(struct dyn_ftrace *rec, unsigned long addr) 
	}



	if (!ppc_inst_equal(op, ppc_inst(PPC_INST_NOP))) {

		pr_err("Unexpected call sequence at %p: %x\n", ip, ppc_inst_val(op));

		pr_err("Unexpected call sequence at %p: %s\n", ip, ppc_inst_as_str(op));

		return -EINVAL;

	}
@@ -733,7 +733,7 @@ __ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, 


	/* Make sure that that this is still a 24bit jump */

	if (!is_bl_op(op)) {

		pr_err("Not expected bl: opcode is %x\n", ppc_inst_val(op));

		pr_err("Not expected bl: opcode is %s\n", ppc_inst_as_str(op));

		return -EINVAL;

	}

arch/powerpc/lib/test_emulate_step.c

+2 −2
Original line number Diff line number Diff line
@@ -1147,7 +1147,7 @@ static int __init emulate_compute_instr(struct pt_regs *regs, 


	if (analyse_instr(&op, regs, instr) != 1 ||

	    GETTYPE(op.type) != COMPUTE) {

		pr_info("emulation failed, instruction = 0x%08x\n", ppc_inst_val(instr));

		pr_info("execution failed, instruction = %s\n", ppc_inst_as_str(instr));

		return -EFAULT;

	}
@@ -1167,7 +1167,7 @@ static int __init execute_compute_instr(struct pt_regs *regs, 
	/* Patch the NOP with the actual instruction */

	patch_instruction_site(&patch__exec_instr, instr);

	if (exec_instr(regs)) {

		pr_info("execution failed, instruction = 0x%08x\n", ppc_inst_val(instr));

		pr_info("execution failed, instruction = %s\n", ppc_inst_as_str(instr));

		return -EFAULT;

	}

arch/powerpc/xmon/xmon.c

+1 −1
Original line number Diff line number Diff line
@@ -2977,7 +2977,7 @@ generic_inst_dump(unsigned long adr, long count, int praddr, 
		dotted = 0;

		last_inst = inst;

		if (praddr)

			printf(REG"  %.8x", adr, ppc_inst_val(inst));

			printf(REG"  %s", adr, ppc_inst_as_str(inst));

		printf("\t");

		dump_func(ppc_inst_val(inst), adr);

		printf("\n");

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