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| author | Michael Holzheu <holzheu@linux.vnet.ibm.com> | 2015-12-17 21:06:02 +0300 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2016-01-23 00:40:06 +0300 |
| commit | 45f32e359d36dd045e4af0d1bea8bbbafd81eeb7 (patch) | |
| tree | 10b5a2fac9e6fdef6c04750ff7a0739f363a35b4 /arch/s390 | |
| parent | fa41a0adbc216e18afe7a2dd4386f614899a0653 (diff) | |
| download | linux-45f32e359d36dd045e4af0d1bea8bbbafd81eeb7.tar.xz | |
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>
Diffstat (limited to 'arch/s390')
| -rw-r--r-- | arch/s390/kernel/dis.c | 15 |
1 files changed, 11 insertions, 4 deletions
diff --git a/arch/s390/kernel/dis.c b/arch/s390/kernel/dis.c index 45df6d456aa1..847ea1598f12 100644 --- a/arch/s390/kernel/dis.c +++ b/arch/s390/kernel/dis.c @@ -1503,14 +1503,21 @@ 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); |