False reports when using Clipboard about drmemory HOT 5 CLOSED

From [email protected] on May 03, 2011 06:02:22

Update: as of r273 , it still reports the uninit read and looks like it thinks the '\0' is uninitialized:
UNINITIALIZED READ: reading 0x00154945-0x00154946 1 byte(s)
while
::GlobalLock returns 0x00154940 -> "ASCII\0"

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From [email protected] on May 03, 2011 06:04:22

... and ::GlobalSize() returns 6

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From [email protected] on May 03, 2011 06:30:22

(on XP 32-bit)
::OpenClipboard results in WARNING: unhandled system call #0x11d5
::EmptyClipboard results in WARNING: unhandled system call #0x116d
::SetClipboardData results in WARNING: unhandled system call #0x114f WARNING: unhandled system call #0x11fc
::CloseClipboard results in WARNING: unhandled system call #0x11fc WARNING: unhandled system call #0x114b
::GetClipboardData -> WARNING: unhandled system call #0x1185 WARNING: unhandled system call #0x1156 WARNING: unhandled system call #0x1156

These guys look like win32k system calls http://www.woodmann.com/forum/archive/index.php/t-10295.html 114b: bf8f85a7 NtUserCloseClipboard 0
114f: bf8ea924 NtUserConvertMemHandle 2
1156: bf8f9a46 NtUserCreateLocalMemHandle 4
116d: bf8ea5a9 NtUserEmptyClipboard 0
1185: bf8f9881 NtUserGetClipboardData 2
11d5: bf8f8524 NtUserOpenClipboard 2
11fc: bf8ea848 NtUserSetClipboardData 3

Looks like we're not handling some of these correctly (off-by-one error?)

Derek, can you please take a look?

From drmemory\syscall_windows.c:
/* FIXME PR 406349: win32k.sys syscalls! currently doing memcmp to see what was written
-> could it be that GlobalLock writes all 6 bytes but the last \0 byte was already \0 and memcmp have not seen this?

Owner: [email protected]
Cc: [email protected]

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From [email protected] on May 03, 2011 07:09:25

I turned off -syscall_sentinels b/c it's risky. As an experiment try turning it on and these may go away b/c drmem will see the 0 being written.

I am in the process of adding handling for non-ntdll syscall wrappers, once done w/ ioctls.

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From [email protected] on July 15, 2011 13:02:39

This issue was closed by revision r397 .

Status: Fixed

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