other: 0.164
device: 0.164
semantic: 0.160
performance: 0.107
graphic: 0.060
files: 0.055
network: 0.049
PID: 0.048
permissions: 0.039
vnc: 0.036
socket: 0.034
debug: 0.032
boot: 0.028
KVM: 0.024
debug: 0.494
other: 0.103
files: 0.091
PID: 0.050
semantic: 0.048
network: 0.035
socket: 0.030
performance: 0.029
device: 0.026
vnc: 0.023
boot: 0.022
permissions: 0.019
graphic: 0.019
KVM: 0.011

util/path.c/follow_path() does not handle "/" well

Hello,

I noticed that qemu does not handle "/" very well in follow_path().

Specifically, I was trying to run gdbserver under qemu, and it failed inside its implementation of __getcwd.

Indeed it does something like
  if (__lstat ("/", &st) < 0)
.....
and then loops from current dir toward the top using lstat("..")

On qemu side, lstat forwards the request to follow_path() in util/path.c, and when passed "/", it returns the path in QEMU_LD_PREFIX (which was the top of my sysroot).
OTHT, the series of lstat("..") finally reaches the real device root because it's not recognized as "/" in follow_path(), so this is inconsistent and __getcwd fails.

I suppose there's a good reason for returning QEMU_LD_PREFIX when asking for "/", but why is it so?

If there's no good reason, maybe the behaviour could be changed to map "/" to "/" ?

Thanks


This is an automated cleanup. This bug report has been moved to QEMU's
new bug tracker on gitlab.com and thus gets marked as 'expired' now.
Please continue with the discussion here:

 https://gitlab.com/qemu-project/qemu/-/issues/162