Commit Graph

5 Commits

Author SHA1 Message Date
Christopher Ferris
5f45d583b0 Create optimized __strcpy_chk/__strcat_chk.
This change pulls the memcpy code out into a new file so that the
__strcpy_chk and __strcat_chk can use it with an include.

The new versions of the two chk functions uses assembly versions
of strlen and memcpy to implement this check. This allows near
parity with the assembly versions of strcpy/strcat. It also means that
as memcpy implementations get faster, so do the chk functions.

Other included changes:
- Change all of the assembly labels to local labels. The other labels
  confuse gdb and mess up backtracing.
- Add .cfi_startproc and .cfi_endproc directives so that gdb is not
  confused when falling through from one function to another.
- Change all functions to use cfi directives since they are more powerful.
- Move the memcpy_chk fail code outside of the memcpy function definition
  so that backtraces work properly.
- Preserve lr before the calls to __fortify_chk_fail so that the backtrace
  actually works.

Testing:

- Ran the bionic unit tests. Verified all error messages in logs are set
  correctly.
- Ran libc_test, replacing strcpy with __strcpy_chk and replacing
  strcat with __strcat_chk.
- Ran the debugger on nexus10, nexus4, and old nexus7. Verified that the
  backtrace is correct for all fortify check failures. Also verify that
  when falling through from __memcpy_chk to memcpy that the backtrace is
  still correct. Also verified the same for __memset_chk and bzero.
  Verified the two different paths in the cortex-a9 memset routine that
  save variables to the stack still show the backtrace properly.

Bug: 9293744

(cherry-picked from 2be91915dc)

Change-Id: Ia407b74d3287d0b6af0139a90b6eb3bfaebf2155
2013-08-15 11:13:39 -07:00
Christopher Ferris
4e24dcc8d8 Optimize strcat/strcpy, small tweaks to strlen. DO NOT MERGE
Create one version of strcat/strcpy/strlen for cortex-a15/krait and another
version for cortex-a9.

Tested with the libc_test strcat/strcpy/strlen tests.
Including new tests that verify that the src for strcat/strcpy do not
overread across page boundaries.

NOTE: The handling of unaligned strcpy (same code in strcat) could probably
be optimized further such that the src is read 64 bits at a time instead of
the partial reads occurring now.

strlen improves slightly since it was recently optimized.

Performance improvements for strcpy and strcat (using an empty dest string):

cortex-a9
- Small copies vary from about 5% to 20% as the size gets above 10 bytes.
- Copies >= 1024, about a 60% improvement.
- Unaligned copies, from about 40% improvement.

cortex-a15
- Most small copies exhibit a 100% improvement, a few copies only
  improve by 20%.
- Copies >= 1024, about 150% improvement.
- Unaligned copies, about 100% improvement.

krait
- Most small copies vary widely, but on average 20% improvement, then
  the performance gets better, hitting about a 100% improvement when
  copies 64 bytes of data.
- Copies >= 1024, about 100% improvement.
- When coping MBs of data, about 50% improvement.
- Unaligned copies, about 90% improvement.

As strcat destination strings get larger in size:

cortex-a9
- about 40% improvement for small dst strings (>= 32).
- about 250% improvement for dst strings >= 1024.

cortex-a15
- about 200% improvement for small dst strings (>=32).
- about 250% improvement for dst strings >= 1024.

krait
- about 25% improvement for small dst strings (>=32).
- about 100% improvement for dst strings >=1024.

Merge from internal master.

(cherry-picked from d119b7b6f4)

Change-Id: I296463b251ef9fab004ee4dded2793feca5b547a
2013-08-08 11:13:46 -07:00
Christopher Ferris
0aa9b52efa Add new optimized strlen for arm.
This optimized version is primarily targeted at cortex-a15.

Tested on all nexus devices using the system/extras/libc_test strlen test.
Tested alignments from 1 to 32 that are powers of 2.
Tested that strlen does not cross page boundaries at all alignments.

Speed improvements listed below:

cortex-a15
- Sizes >= 32 bytes, ~75% improvement.
- Sizes >= 1024 bytes, ~250% improvement.

cortex-a9
- Sizes >= 32 bytes, ~75% improvement.
- Sizes >= 1024 bytes, ~85% improvement.

krait
- Sizes >= 32 bytes, ~95% improvement.
- Sizes >= 1024 bytes, ~160% improvement.

Merge from internal master.

(cherry-picked from 2fc0717977)

Change-Id: I1ceceb4e745fd68e9d946f96d1d42e0cdaff6ccf
2013-07-16 16:47:37 -07:00
Christopher Ferris
31dea25b8b Create arch specific versions of strcmp.
This uses the new strcmp.a15.S code as the basis for new versions
of strcmp.S.

The cortex-a15 code is the performance optimized version of strcmp.a15.S
taken with only the addition of a few pld instructions.
The cortex-a9 code is the same as the cortex-a15 code except that the
unaligned strcmp code was taken from the original strcmp.S.
The krait code is the same as the cortex-a15 code except that one path
in the unaligned strcmp code was taken from the original strcmp.S code
(the 2 byte overlap case).
The generic code is the original unmodified strmp.S from the bionic
subdirectory.

All three new versions underwent these test cases:

Strings the same, all same size:
- Both pointers double word aligned.
- One pointer double word aligned, one pointer word aligned.
- Both pointers word aligned.
- One pointer double word aligned, one pointer 1 off a word alignment.
- One pointer double word aligned, one pointer 2 off a word alignment.
- One pointer double word aligned, one pointer 3 off a word alignment.
- One pointer word aligned, one pointer 1 off a word alignment.
- One pointer word aligned, one pointer 2 off a word alignment.
- One pointer word aligned, one pointer 3 off a word alignment.
For all cases where it made sense, the two pointers were also tested
swapped.

Different strings, all same size:
- Single difference at double word boundary.
- Single difference at word boudary.
- Single difference at 1 off a word alignment.
- Single difference at 2 off a word alignment.
- Single difference at 3 off a word alignment.

Different sized strings, strings the same until the end:
- Shorter string ends on a double word boundary.
- Shorter string ends on word boundary.
- Shorter string ends at 1 off a word boundary.
- Shorter string ends at 2 off a word boundary.
- Shorter string ends at 3 off a word boundary.

For all different cases, run them through the same pointer alignment
cases when the strings are the same size.
For all cases the two pointers were also tested swapped.

Bug: 8005082

Merge from internal master.

(cherry-picked from commit a9a5870d16)

Change-Id: I4c2b98f8a50804fb98ab67f75e9d660f1315a144
2013-03-20 14:33:54 -07:00
Christopher Ferris
04954a43b3 Break bionic implementations into arch versions.
Move arch specific code for arm, mips, x86 into separate
makefiles.
In addition, add different arm cpu versions of memcpy/memset.

Bug: 8005082

Merge from internal master (acdde8c1cf).

Change-Id: I04f3d0715104fab618e1abf7cf8f7eec9bec79df
2013-03-12 14:06:08 -07:00