1 Sep
2018
1 Sep
'18
8:43 p.m.
On Sat, Sep 1, 2018 at 1:14 PM, Samuel Neves sneves@dei.uc.pt wrote:
In the __getcpu function, lsl was using the wrong target and destination registers. Luckily, the compiler tends to choose %eax for both variables, so it has been working so far.
Cc: x86@kernel.org Cc: stable@vger.kernel.org Signed-off-by: Samuel Neves sneves@dei.uc.pt
Acked-by: Andy Lutomirski luto@kernel.org Fixes: a582c540ac1b ("x86/vdso: Use RDPID in preference to LSL when available")
Whoops! I even wrote a selftest just for the offending commit, but, of course, the selftest passes :( I tested this by giving gcc some gentle encouragement to allocate different registers, and the existing code is indeed wrong and the fix indeed fixes it.
--Andy