s390/dis: Fix handling of format specifiers (272fa59c) · Commits · 戴 / test

The print_insn() function returns strings like "lghi %r1,0". To escape the '%' character in sprintf() a second '%' is used. For example "lghi %%r1,0" is converted into "lghi %r1,0". After print_insn() the output string is passed to printk(). Because format specifiers like "%r" or "%f" are ignored by printk() this works by chance most of the time. But for instructions with control registers like "lctl %c6,%c6,780" this fails because printk() interprets "%c" as character format specifier. Fix this problem and escape the '%' characters twice. For example "lctl %%%%c6,%%%%c6,780" is then converted by sprintf() into "lctl %%c6,%%c6,780" and by printk() into "lctl %c6,%c6,780". Signed-off-by:

Michael Holzheu <holzheu@linux.vnet.ibm.com> Cc: stable@vger.kernel.org Signed-off-by:

Martin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/kernel/dis.c

+12 −5

Original line number	Original line	Diff line number	Diff line
	@@ -1920,16 +1920,23 @@ static int print_insn(char buffer, unsigned char code, unsigned long addr)
	}		}
	if (separator)		if (separator)
	ptr += sprintf(ptr, "%c", separator);		ptr += sprintf(ptr, "%c", separator);
			/*
			* Use four '%' characters below because of the
			* following two conversions:
			*
			* 1) sprintf: %%%%r -> %%r
			* 2) printk : %%r -> %r
			*/
	if (operand->flags & OPERAND_GPR)		if (operand->flags & OPERAND_GPR)
	ptr += sprintf(ptr, "%%r%i", value);		ptr += sprintf(ptr, "%%%%r%i", value);
	else if (operand->flags & OPERAND_FPR)		else if (operand->flags & OPERAND_FPR)
	ptr += sprintf(ptr, "%%f%i", value);		ptr += sprintf(ptr, "%%%%f%i", value);
	else if (operand->flags & OPERAND_AR)		else if (operand->flags & OPERAND_AR)
	ptr += sprintf(ptr, "%%a%i", value);		ptr += sprintf(ptr, "%%%%a%i", value);
	else if (operand->flags & OPERAND_CR)		else if (operand->flags & OPERAND_CR)
	ptr += sprintf(ptr, "%%c%i", value);		ptr += sprintf(ptr, "%%%%c%i", value);
	else if (operand->flags & OPERAND_VR)		else if (operand->flags & OPERAND_VR)
	ptr += sprintf(ptr, "%%v%i", value);		ptr += sprintf(ptr, "%%%%v%i", value);
	else if (operand->flags & OPERAND_PCREL)		else if (operand->flags & OPERAND_PCREL)
	ptr += sprintf(ptr, "%lx", (signed int) value		ptr += sprintf(ptr, "%lx", (signed int) value
	+ addr);		+ addr);

Admin message