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authorMichael Holzheu <holzheu@linux.vnet.ibm.com>2015-12-17 19:06:02 +0100
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2015-12-18 14:43:21 +0100
commit272fa59ccb4fc802af28b1d699c2463db6a71bf7 (patch)
tree9c8bb0a6d3691063fac0f41198ff3fca43bd879e /arch
parent2bc53b8046ce9a1543204b6c6da1ab95e4caac76 (diff)
downloadlinux-272fa59ccb4fc802af28b1d699c2463db6a71bf7.tar.bz2
s390/dis: Fix handling of format specifiers
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>
Diffstat (limited to 'arch')
-rw-r--r--arch/s390/kernel/dis.c17
1 files changed, 12 insertions, 5 deletions
diff --git a/arch/s390/kernel/dis.c b/arch/s390/kernel/dis.c
index 8140d10c6785..6e72961608f0 100644
--- a/arch/s390/kernel/dis.c
+++ b/arch/s390/kernel/dis.c
@@ -1920,16 +1920,23 @@ static int print_insn(char *buffer, unsigned char *code, unsigned long addr)
}
if (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)
- ptr += sprintf(ptr, "%%r%i", value);
+ ptr += sprintf(ptr, "%%%%r%i", value);
else if (operand->flags & OPERAND_FPR)
- ptr += sprintf(ptr, "%%f%i", value);
+ ptr += sprintf(ptr, "%%%%f%i", value);
else if (operand->flags & OPERAND_AR)
- ptr += sprintf(ptr, "%%a%i", value);
+ ptr += sprintf(ptr, "%%%%a%i", value);
else if (operand->flags & OPERAND_CR)
- ptr += sprintf(ptr, "%%c%i", value);
+ ptr += sprintf(ptr, "%%%%c%i", value);
else if (operand->flags & OPERAND_VR)
- ptr += sprintf(ptr, "%%v%i", value);
+ ptr += sprintf(ptr, "%%%%v%i", value);
else if (operand->flags & OPERAND_PCREL)
ptr += sprintf(ptr, "%lx", (signed int) value
+ addr);