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authorMichael Holzheu <holzheu@linux.vnet.ibm.com>2015-12-17 19:06:02 +0100
committerWilly Tarreau <w@1wt.eu>2016-01-29 22:12:54 +0100
commit22a1caa0c96e94e710fcf2a9a01fdd3f091a7171 (patch)
treee7be3f75ff317d2eac3b94c4609cc043a9feea8f
parent2bafc5d56fdfebb9e74a9c6f2e50033498b7b424 (diff)
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s390/dis: Fix handling of format specifiers
commit 272fa59ccb4fc802af28b1d699c2463db6a71bf7 upstream. 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> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> [bwh: Backported to 3.2: drop the OPERAND_VR case] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> (cherry picked from commit 45f32e359d36dd045e4af0d1bea8bbbafd81eeb7) Signed-off-by: Willy Tarreau <w@1wt.eu>
-rw-r--r--arch/s390/kernel/dis.c15
1 files changed, 11 insertions, 4 deletions
diff --git a/arch/s390/kernel/dis.c b/arch/s390/kernel/dis.c
index db943a7ec513..d9dfffc38b90 100644
--- a/arch/s390/kernel/dis.c
+++ b/arch/s390/kernel/dis.c
@@ -1182,14 +1182,21 @@ 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_PCREL)
ptr += sprintf(ptr, "%lx", (signed int) value
+ addr);