[PATCH 4.2 104/110] arm64: compat: fix stxr failure case in SWP emulation

4.2-stable review patch. If anyone has any objections, please let me know. -- From: Will Deacon commit 589cb22bbedacf325951014c07a35a2b01ca57f6 upstream. If the STXR instruction fails in the SWP emulation code, we leave *data overwritten with the loaded value, therefore

[PATCH 4.2 104/110] arm64: compat: fix stxr failure case in SWP emulation

4.2-stable review patch. If anyone has any objections, please let me know. -- From: Will Deacon commit 589cb22bbedacf325951014c07a35a2b01ca57f6 upstream. If the STXR instruction fails in the SWP emulation code, we leave *data overwritten with the loaded