[fpc-devel] Dr Memory Interpretation

[Jonas Maebe]

On 11 Aug 2014, at 15:38, mark diener wrote:

> Anybody have greater experience with Dr Memory to know what errors are
> actually real and which errors are valid in the latests releases of
> lazarus/fpc.


* Not actual errors:

Error #1: UNADDRESSABLE ACCESS: reading 0x04c491c3-0x04c491c4 1  
byte(s) within 0x04c491c0-0x04c491c4
# 0 FPC_PCHAR_TO_SHORTSTR                                 [C:/pdev/ 
rpztestminimum//rpztestminimum.lpr:21]

Error #2: UNADDRESSABLE ACCESS: reading 0x0508cf61-0x0508cf64 3  
byte(s) within 0x0508cf60-0x0508cf64
# 0 SYSTEM_SMALLFORWARDMOVE_3

Error #3: UNADDRESSABLE ACCESS: reading 0x050ee701-0x050ee704 3  
byte(s) within 0x050ee700-0x050ee704
# 0 SYSUTILS_STRSCAN$PCHAR$CHAR$ 
$PCHAR                                         [C:/pdev/ 
rpztestminimum//rpztestminimum.lpr:21]


* No idea, but probably not real errors since otherwise the program  
would crash:

Error #4: UNADDRESSABLE ACCESS: writing 0x00000020-0x00000024 4  
byte(s) within 0x00000020-0x04c5c950
# 0 system call NtUserBuildPropList parameter #1

Error #5: UNADDRESSABLE ACCESS: writing 0x00000020-0x00000024 4  
byte(s) within 0x00000020-0x04c5c950
# 0 system call NtUserBuildPropList parameter #1

Error #6: UNADDRESSABLE ACCESS: writing 0x00000020-0x00000024 4  
byte(s) within 0x00000020-0x04c5ceb0
# 0 system call NtUserBuildPropList parameter #1

Error #7: UNADDRESSABLE ACCESS: writing 0x00000020-0x00000024 4  
byte(s) within 0x00000020-0x04c5ceb0
# 0 system call NtUserBuildPropList parameter #1


* Probably not an actual error (see my mail in the other thread)

Error #8: POSSIBLE LEAK 64 direct bytes 0x04c489d0-0x04c48a10 + 0  
indirect bytes
# 0 replace_RtlAllocateHeap                          [d: 
\drmemory_package\common\alloc_replace.c:3076]


You'll have to ask help on the Dr Memory mailing list regarding errors  
#4 - #7. For the false positives #1 - #3 and #8 (and similar ones to  
#8), you'll have to create a suppression file: http://www.drmemory.org/docs/page_suppress.html


Jonas