Add initial support for -D_FORTIFY_SOURCE to bionic for the
following functions:
* memcpy
* memmove
* strcpy
* strcat
* strncpy
* strncat
This change adds a new version of the above functions which passes
the size of the destination buffer to __builtin___*_chk.
If the compiler can determine, at compile time, that the destination
buffer is large enough, or the destination buffer can point to an object
of unknown size, then the check call is bypassed.
If the compiler can't make a compile time decision, then it calls
the __*_chk() function, which does a runtime buffer size check
These options are only enabled if the code is compiled with
-D_FORTIFY_SOURCE=1 or 2, and only when optimizations are enabled.
Please see
* http://gcc.gnu.org/onlinedocs/gcc/Object-Size-Checking.html
* http://gcc.gnu.org/ml/gcc-patches/2004-09/msg02055.html
for additional details on FORTIFY_SOURCE.
Testing: Compiled the entire Android tree with -D_FORTIFY_SOURCE=1,
and verified that everything appears to be working properly.
Also created a test buffer overflow, and verified that it was
caught by this change.
Change-Id: I4fddb445bafe92b16845b22458d72e6dedd24fbc
This patch is a rewrite of libc.debug.malloc = 10 (chk_malloc). It provides
the same features as the original (poison freed memory, detect heap overruns
and underruns), except that it provides more debugging information whenever it
detects a problem.
In addition to the original features, the new chk_malloc() implementation
detects multiple frees within a given range of the last N allocations, N being
configurable via the system property libc.debug.malloc.backlog.
Finally, this patch keeps track of all outstanding memory allocations. On
program exit, we walk that list and report each outstanding allocation.
(There is support (not enabled) for a scanner thread periodically walks over
the list of outstanding allocations as well as the backlog of recently-freed
allocations, checking for heap-usage errors.)
Feature overview:
1) memory leaks
2) multiple frees
3) use after free
4) overrun
Implementation:
-- for each allocation, there is a:
1) stack trace at the time the allocation is made
2) if the memory is freed, there is also a stack trace at the point
3) a front and rear guard (fence)
4) the stack traces are kept together with the allocation
-- the following lists and maintained
1) all outstanding memory allocations
3) a backlog of allocations what are freed; when you call free(), instead of
actually freed, the allocation is moved to this backlog;
4) when the backlog of allocations gets full, the oldest entry gets evicted
from it; at that point, the allocation is checked for overruns or
use-after-free errors, and then actually freed.
5) when the program exits, the list of outstanding allocations and the
backlog are inspected for errors, then freed;
To use this, set the following system properties before running the process or
processes you want to inspect:
libc.malloc.debug.backlog # defaults to 100
libc.malloc.debug 10
When a problem is detected, you will see the following on logcat for a multiple
free:
E/libc ( 7233): +++ ALLOCATION 0x404b9278 SIZE 10 BYTES MULTIPLY FREED!
E/libc ( 7233): +++ ALLOCATION 0x404b9278 SIZE 10 ALLOCATED HERE:
E/libc ( 7233): *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
E/libc ( 7233): #00 pc 0000c35a /system/lib/libc_malloc_debug_leak.so
E/libc ( 7233): #01 pc 0000c658 /system/lib/libc_malloc_debug_leak.so
E/libc ( 7233): #02 pc 00016d80 /system/lib/libc.so
E/libc ( 7233): #03 pc 4009647c /system/bin/malloctest
E/libc ( 7233): #04 pc 00016f24 /system/lib/libc.so
E/libc ( 7233): +++ ALLOCATION 0x404b9278 SIZE 10 FIRST FREED HERE:
E/libc ( 7233): *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
E/libc ( 7233): #00 pc 0000c35a /system/lib/libc_malloc_debug_leak.so
E/libc ( 7233): #01 pc 0000c7d2 /system/lib/libc_malloc_debug_leak.so
E/libc ( 7233): #02 pc 00016d94 /system/lib/libc.so
E/libc ( 7233): #03 pc 40096490 /system/bin/malloctest
E/libc ( 7233): #04 pc 00016f24 /system/lib/libc.so
E/libc ( 7233): +++ ALLOCATION 0x404b9278 SIZE 10 NOW BEING FREED HERE:
E/libc ( 7233): *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
E/libc ( 7233): #00 pc 0000c35a /system/lib/libc_malloc_debug_leak.so
E/libc ( 7233): #01 pc 0000c6ac /system/lib/libc_malloc_debug_leak.so
E/libc ( 7233): #02 pc 00016d94 /system/lib/libc.so
E/libc ( 7233): #03 pc 400964a0 /system/bin/malloctest
E/libc ( 7233): #04 pc 00016f24 /system/lib/libc.so
The following for a heap overrun and underrun:
E/libc ( 7233): +++ REAR GUARD MISMATCH [10, 11)
E/libc ( 7233): +++ ALLOCATION 0x404b9198 SIZE 10 HAS A CORRUPTED REAR GUARD
E/libc ( 7233): +++ ALLOCATION 0x404b9198 SIZE 10 ALLOCATED HERE:
E/libc ( 7233): *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
E/libc ( 7233): #00 pc 0000c35a /system/lib/libc_malloc_debug_leak.so
E/libc ( 7233): #01 pc 0000c658 /system/lib/libc_malloc_debug_leak.so
E/libc ( 7233): #02 pc 00016d80 /system/lib/libc.so
E/libc ( 7233): #03 pc 40096438 /system/bin/malloctest
E/libc ( 7233): #04 pc 00016f24 /system/lib/libc.so
E/libc ( 7233): +++ ALLOCATION 0x404b9198 SIZE 10 FREED HERE:
E/libc ( 7233): *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
E/libc ( 7233): #00 pc 0000c35a /system/lib/libc_malloc_debug_leak.so
E/libc ( 7233): #01 pc 0000c7d2 /system/lib/libc_malloc_debug_leak.so
E/libc ( 7233): #02 pc 00016d94 /system/lib/libc.so
E/libc ( 7233): #03 pc 40096462 /system/bin/malloctest
E/libc ( 7233): #04 pc 00016f24 /system/lib/libc.so
E/libc ( 7233): +++ ALLOCATION 0x404b9358 SIZE 10 HAS A CORRUPTED FRONT GUARD
E/libc ( 7233): +++ ALLOCATION 0x404b9358 SIZE 10 ALLOCATED HERE:
E/libc ( 7233): *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
E/libc ( 7233): #00 pc 0000c35a /system/lib/libc_malloc_debug_leak.so
E/libc ( 7233): #01 pc 0000c658 /system/lib/libc_malloc_debug_leak.so
E/libc ( 7233): #02 pc 00016d80 /system/lib/libc.so
E/libc ( 7233): #03 pc 400964ba /system/bin/malloctest
E/libc ( 7233): #04 pc 00016f24 /system/lib/libc.so
E/libc ( 7233): +++ ALLOCATION 0x404b9358 SIZE 10 FREED HERE:
E/libc ( 7233): *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
E/libc ( 7233): #00 pc 0000c35a /system/lib/libc_malloc_debug_leak.so
E/libc ( 7233): #01 pc 0000c7d2 /system/lib/libc_malloc_debug_leak.so
E/libc ( 7233): #02 pc 00016d94 /system/lib/libc.so
E/libc ( 7233): #03 pc 400964e4 /system/bin/malloctest
E/libc ( 7233): #04 pc 00016f24 /system/lib/libc.so
The following for a memory leak:
E/libc ( 7233): +++ THERE ARE 1 LEAKED ALLOCATIONS
E/libc ( 7233): +++ DELETING 4096 BYTES OF LEAKED MEMORY AT 0x404b95e8 (1 REMAINING)
E/libc ( 7233): +++ ALLOCATION 0x404b95e8 SIZE 4096 ALLOCATED HERE:
E/libc ( 7233): *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
E/libc ( 7233): #00 pc 0000c35a /system/lib/libc_malloc_debug_leak.so
E/libc ( 7233): #01 pc 0000c658 /system/lib/libc_malloc_debug_leak.so
E/libc ( 7233): #02 pc 00016d80 /system/lib/libc.so
E/libc ( 7233): #03 pc 0001bc94 /system/lib/libc.so
E/libc ( 7233): #04 pc 0001edf6 /system/lib/libc.so
E/libc ( 7233): #05 pc 0001b80a /system/lib/libc.so
E/libc ( 7233): #06 pc 0001c086 /system/lib/libc.so
E/libc ( 7233): #07 pc 40096402 /system/bin/malloctest
E/libc ( 7233): #08 pc 00016f24 /system/lib/libc.so
Change-Id: Ic440e9d05a01e2ea86b25e8998714e88bc2d16e0
Signed-off-by: Iliyan Malchev <malchev@google.com>
libc.debug.malloc.program provides an additional level of control over which
processes to enable libc.debug.malloc functionality for. The string value of
libc.debug.malloc.program is matched against the program name; if the value of
libc.debug.malloc.program is a substring of the program name, then malloc debug
is applied to that program at whatever level libc.debug.malloc specifies.
If lib.debug.malloc.program is not specified, then libc.debug.malloc has the
same effect as before.
For example, to enable libc.deubug.malloc = 10 only to the mediaserver, do the
following:
adb root # necessary for setprop
adb setprop libc.debug.malloc.program mediaserver
adb setprop libc.debug.malloc 10
adb kill -9 $(pid mediaserver)
Change-Id: I6f01c12f033c8e2e015d73025369d7f1685ba200
Signed-off-by: Iliyan Malchev <malchev@google.com>
crtbegin_dynamic and crtbegin_static are essentially identical,
minus a few trivial differences (comments and whitespace).
Eliminate duplicates.
Change-Id: Ic9fae6bc9695004974493b53bfc07cd3bb904480
Also, fixes SIGSEV during calculation of si->phdr in load_library(),
which is caused by accessing PHDR area, which is not guaranteed to be
loaded.
Note that this usually does not happen because program header area is
covered by immediately following PT_LOAD entry. But it does not hold
always.
Bug: 6561258
Change-Id: Ie376253c773b5420279ca89044e81b1aad5a5736
For example:
@@@ ABORTING: INVALID HEAP ADDRESS IN dlfree addr=0x5c3bfbd0
Fatal signal 11 (SIGSEGV) at 0xdeadbaad (code=1), thread 2942
The addr=0x5c3bfbd0 part is new.
Change-Id: I8670144b2b0a3a6182384150d762c97dfee5452f
For example:
@@@ ABORTING: INVALID HEAP ADDRESS IN dlfree addr=0x5c3bfbd0
Fatal signal 11 (SIGSEGV) at 0xdeadbaad (code=1), thread 2942
The addr=0x5c3bfbd0 part is new.
Change-Id: I8670144b2b0a3a6182384150d762c97dfee5452f
Previously, the linker always loaded itself into the same
location in memory, which inhibited the effectiveness of Android's
ASLR implementation. Modify the linker code so it can be relocatable
and link itself at runtime.
Change-Id: Ia80273d7a00ff648b4da545f4b69debee6343968
Use LOCAL_NO_CRT to prevent linking against crtbegin.o, rather than
messing with build rules. This also prevents linking against crtend.o,
which isn't needed for the linker.
Change-Id: I0c5b9999be7e8676560fe145c1c033ffce8db4d1
The computation of si->base assumed that the first entry in the
program header table is a PT_PHDR. This results in the dynamic
linker crashing with a SIGSEGV/MAPERR when trying to load some
of the NDK unit test programs, which happen to have an EXIDX
header first, followed byu a PHDR one.
This patch fixes the computation by parsing the program header
table, looking explicitely for the PHDR entry. This fixes the
load of the NDK unit test programs, and doesn't affect system
libraries.
Change-Id: Id18ea6037dbe950b5abbbce816c2960321f0b81d
Modify the dynamic linker so that executables can be loaded
at locations other than 0x00000000.
Modify crtbegin* so that non-PIC compilant "thumb interwork
veneers" are not created by the linker.
Bug: 5323301
Change-Id: Iece0272e2b708c79034f302c20160e1fe9029588
