diff options
| author | cinap_lenrek <cinap_lenrek@felloff.net> | 2014-02-08 03:50:41 +0100 |
|---|---|---|
| committer | cinap_lenrek <cinap_lenrek@felloff.net> | 2014-02-08 03:50:41 +0100 |
| commit | 6b146c70c2863bf1e9d5c4a35cbd8426c5a161e7 (patch) | |
| tree | 0c683fb3d4ab300d91acfe33415974a152212ab4 /sys/src/9/port/devproc.c | |
| parent | 43212f64320c2e136eb3d4adb5d3e8c31c637386 (diff) | |
pc64: handle negative file offsets when accessing kernel memory with devproc
file offset is 64 bit signed integer, negative offsets
are invalid and rejected by the kernel. to still access
kernel memory on amd64, we unconditionally clear the sign
bit of the 64 bit offset in libmach and devproc sign
extends the offset back to a 64 bit address.
Diffstat (limited to 'sys/src/9/port/devproc.c')
| -rw-r--r-- | sys/src/9/port/devproc.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/sys/src/9/port/devproc.c b/sys/src/9/port/devproc.c index 57ebebb1a..c49f5f677 100644 --- a/sys/src/9/port/devproc.c +++ b/sys/src/9/port/devproc.c @@ -708,6 +708,10 @@ procread(Chan *c, void *va, long n, vlong off) Waitq *wq; a = va; + + /* sign extend 63 bit to 64 bit */ + off <<= 1; + off >>= 1; offset = off; if(c->qid.type & QTDIR) |