| Message ID | 20220517180605.109867-1-nalanzeyu@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | linux-user: fix ioctl() arguments printing in strace support | expand |
diff --git a/linux-user/user-internals.h b/linux-user/user-internals.h index ddc260e465..550d16e2dd 100644 --- a/linux-user/user-internals.h +++ b/linux-user/user-internals.h @@ -35,7 +35,7 @@ typedef abi_long do_ioctl_fn(const IOCTLEntry *ie, uint8_t *buf_temp, int fd, int cmd, abi_long arg); struct IOCTLEntry { - int target_cmd; + unsigned int target_cmd; unsigned int host_cmd; const char *name; int access;
When both of the following conditions are satisfied, ioctl() arguments printing in strace support is not working: - highest bit of ioctl() request command is 1 - sizeof abi_long is 8 bytes print_ioctl() and print_syscall_ret_ioctl() find IOCTLEntry by this way: /* ie->target_cmd is int, arg1 is abi_long, both are signed */ for (ie = ioctl_entries; ie->target_cmd != 0; ie++) if (ie->target_cmd == arg1) break; Operator "==" will convert target_cmd to abi_long by sign extension, resulting in a negative number, will not match any ioctl request number. This patch simply changes type of target_cmd to unsigned int, avoids sign extension. ioctl command values are 32-bit constants, explain highest bit as sign bit is pointless. Signed-off-by: Yan Cangang <nalanzeyu@gmail.com> --- linux-user/user-internals.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)