linux.git/arch/s390/lib/string.c, branch v4.12

s390: Audit and remove any remaining unnecessary uses of module.h

2017-02-17T06:40:41+00:00

Historically a lot of these existed because we did not have
a distinction between what was modular code and what was providing
support to modules via EXPORT_SYMBOL and friends.  That changed
when we forked out support for the latter into the export.h file.

This means we should be able to reduce the usage of module.h
in code that is obj-y Makefile or bool Kconfig.  The advantage
in doing so is that module.h itself sources about 15 other headers;
adding significantly to what we feed cpp, and it can obscure what
headers we are effectively using.

Since module.h was the source for init.h (for __init) and for
export.h (for EXPORT_SYMBOL) we consider each change instance
for the presence of either and replace as needed.  An instance
where module_param was used without moduleparam.h was also fixed,
as well as implicit use of ptrace.h and string.h headers.

Signed-off-by: Paul Gortmaker 
Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky

s390/lib: add missing memory barriers to string inline assemblies

2016-12-14T15:33:41+00:00

We have a couple of inline assemblies like memchr() and strlen() that
read from memory, but tell the compiler only they need the addresses
of the strings they access.
This allows the compiler to omit the initialization of such strings
and therefore generate broken code. Add the missing memory barrier to
all string related inline assemblies to fix this potential issue. It
looks like the compiler currently does not generate broken code due to
these bugs.

Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky

s390/lib: fix memcmp and strstr

2016-08-08T13:41:31+00:00

if two string compare equal the clcle instruction will update the
string addresses to point _after_ the string. This might already
be on a different page, so we should not use these pointer to
calculate the difference as in that case the calculation of the
difference can cause oopses.

The return value of memcmp does not need the difference, we
can just reuse the condition code and return for CC=1 (All bytes
compared, first operand low) -1 and for CC=2 (All bytes compared,
first operand high) +1
strstr also does not need the diff.
While fixing this, make the common function clcle "correct on its
own" by using l1 instead of l2 for the first length. strstr will
call this with l2 for both strings.

Signed-off-by: Christian Borntraeger 
Fixes: db7f5eef3dc0 ("s390/lib: use basic blocks for inline assemblies")
Reviewed-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky

s390/lib: use basic blocks for inline assemblies

2016-06-28T07:32:28+00:00

Use only simple inline assemblies which consist of a single basic
block if the register asm construct is being used.

Otherwise gcc would generate broken code if the compiler option
--sanitize-coverage=trace-pc would be used.

Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky

s390/string: provide asm lib functions for memcpy and memcmp

2012-09-26T13:44:50+00:00

Our memcpy and memcmp variants were implemented by calling the corresponding
gcc builtin variants.
However gcc is free to replace a call to __builtin_memcmp with a call to memcmp
which, when called, will result in an endless recursion within memcmp.
So let's provide asm variants and also fix the variants that are used for
uncompressing the kernel image.
In addition remove all other occurences of builtin function calls.

Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky

s390/comments: unify copyright messages and remove file names

2012-07-20T09:15:04+00:00

Remove the file name from the comment at top of many files. In most
cases the file name was wrong anyway, so it's rather pointless.

Also unify the IBM copyright statement. We did have a lot of sightly
different statements and wanted to change them one after another
whenever a file gets touched. However that never happened. Instead
people start to take the old/"wrong" statements to use as a template
for new files.
So unify all of them in one go.

Signed-off-by: Heiko Carstens

[S390] use compiler builtin versions of strlen/strcpy/strcat

2009-03-26T14:24:24+00:00

Use builtin variants if gcc 4 or newer is used to compile the kernel.
Generates better code than the asm variants.

Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky

[S390] Fix sparse warnings.

2006-07-12T14:41:55+00:00

Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky

Linux-2.6.12-rc2

2005-04-16T22:20:36+00:00

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!