| 491,6 → 491,12 |
|---|
| andcc %g1, TSTATE_PRIV_BIT, %g0 ! if we are not returning to userspace..., |
| bnz 1f ! ...skip restoring userspace windows |
| nop |
| |
| /* |
| * Spills and fills will be processed by the {spill,fill}_1_normal |
| * handlers. |
| */ |
| wrpr %g0, WSTATE_OTHER(0) | WSTATE_NORMAL(1), %wstate |
| |
| rdpr %cwp, %g1 |
| rdpr %otherwin, %g2 |
| 545,7 → 551,9 |
|---|
| */ |
| wrpr %g1, 0, %cwp |
| add %g4, %g2, %g2 |
| mov NWINDOW - 2, %g1 |
| cmp %g2, NWINDOW - 2 |
| bg 2f ! fix the CANRESTORE=NWINDOW-1 anomaly |
| mov NWINDOW - 2, %g1 ! use dealy slot for both cases |
| sub %g1, %g2, %g1 |
| |
| wrpr %g0, 0, %otherwin |
| 553,12 → 561,39 |
|---|
| wrpr %g2, 0, %canrestore ! OTHERWIN + windows in the buffer |
| wrpr %g2, 0, %cleanwin ! avoid information leak |
| |
| 1: |
| restore |
| retry |
| |
| /* |
| * Spills and fills will be processed by the {spill,fill}_1_normal |
| * handlers. |
| * We got here in order to avoid inconsistency of the window state registers. |
| * If the: |
| * |
| * save %g6, -PREEMPTIBLE_HANDLER_STACK_FRAME_SIZE, %sp |
| * |
| * instruction trapped and spilled a register window into the userspace |
| * window buffer, we have just restored NWINDOW - 1 register windows. |
| * However, CANRESTORE can be only NWINDOW - 2 at most. |
| * |
| * The solution is to manually switch to (CWP - 1) mod NWINDOW |
| * and set the window state registers so that: |
| * |
| * CANRESTORE = NWINDOW - 2 |
| * CLEANWIN = NWINDOW - 2 |
| * CANSAVE = 0 |
| * OTHERWIN = 0 |
| * |
| * The RESTORE isntruction is therfore to be skipped. |
| */ |
| wrpr %g0, WSTATE_OTHER(0) | WSTATE_NORMAL(1), %wstate |
| 2: |
| wrpr %g0, 0, %otherwin |
| wrpr %g0, 0, %cansave |
| wrpr %g1, 0, %canrestore |
| wrpr %g1, 0, %cleanwin |
| |
| 1: |
| restore |
| rdpr %cwp, %g1 |
| dec %g1 |
| and %g1, NWINDOW - 1, %g1 |
| wrpr %g1, 0, %cwp ! CWP-- |
| |
| retry |