linux/arch/mips/math-emu
Maciej W. Rozycki 7737b20b9e MIPS: math-emu: Fix delay-slot emulation cache incoherency
Correct a cache coherency regression introduced with be1664c4 [Another
round of fixes for the fp emulator.] for the emulation frame used in
delay-slot emulation.

Two instructions are copied into the frame and as from the commit
referred a cache synchronisation call is made for the second instruction
aka `badinst' of the two only.  The `flush_cache_sigtramp' interface is
reused that guarantees that synchronisation will be made for 8 bytes or
2 instructions starting from the address requested, although if cache
lines are wider then a larger area may be synchronised.

Change the call to point to the first of the two instructions aka `emul'
instead, removing unpredictable behaviour resulting from cache
incoherency.

This bug only ever manifested itself on systems implementing 4-byte
cache lines, typically MIPS I systems, causing all kinds of weirdness.
This is because the sequence of two instructions starting from `emul' is
8-byte aligned and for 8-byte or wider cache lines the line synchronised
will span both, so the vast majority of systems have escaped unharmed.

Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9698/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-04-08 01:10:00 +02:00
..
cp1emu.c MIPS: math-emu: Factor out CFC1/CTC1 emulation 2015-04-08 01:09:15 +02:00
dp_add.c MIPS: math-emu: Reinstate sNaN quieting handlers 2015-04-08 01:09:31 +02:00
dp_cmp.c MIPS: math-emu: Remove redundant code from NaN comparison 2015-04-08 01:09:38 +02:00
dp_div.c MIPS: math-emu: Reinstate sNaN quieting handlers 2015-04-08 01:09:31 +02:00
dp_fint.c MIPS: math-emu: Cleanup coding style. 2014-05-23 15:11:15 +02:00
dp_flong.c MIPS: math-emu: Cleanup coding style. 2014-05-23 15:11:15 +02:00
dp_fsp.c MIPS: math-emu: Reinstate sNaN quieting handlers 2015-04-08 01:09:31 +02:00
dp_mul.c MIPS: math-emu: Reinstate sNaN quieting handlers 2015-04-08 01:09:31 +02:00
dp_simple.c MIPS: math-emu: Cleanup coding style. 2014-05-23 15:11:15 +02:00
dp_sqrt.c MIPS: math-emu: Reinstate sNaN quieting handlers 2015-04-08 01:09:31 +02:00
dp_sub.c MIPS: math-emu: Reinstate sNaN quieting handlers 2015-04-08 01:09:31 +02:00
dp_tint.c MIPS: math-emu: Switch to using the MIPS rounding modes. 2014-05-23 15:12:38 +02:00
dp_tlong.c MIPS: math-emu: Switch to using the MIPS rounding modes. 2014-05-23 15:12:38 +02:00
dsemul.c MIPS: math-emu: Fix delay-slot emulation cache incoherency 2015-04-08 01:10:00 +02:00
ieee754.c MIPS: math-emu: Reduce code duplication. 2014-06-26 10:47:55 +01:00
ieee754.h MIPS: math-emu: Remove dead comparison helpers 2015-04-08 01:09:42 +02:00
ieee754d.c MIPS: math-emu: Cleanup coding style. 2014-05-23 15:11:15 +02:00
ieee754dp.c MIPS: math-emu: Make NaN classifiers static 2015-04-08 01:09:47 +02:00
ieee754dp.h MIPS: math-emu: Make NaN classifiers static 2015-04-08 01:09:47 +02:00
ieee754int.h MIPS: math-emu: Optimise NaN handling in comparisons 2015-04-08 01:09:35 +02:00
ieee754sp.c MIPS: math-emu: Make NaN classifiers static 2015-04-08 01:09:47 +02:00
ieee754sp.h MIPS: math-emu: Make NaN classifiers static 2015-04-08 01:09:47 +02:00
Makefile MIPS: math-emu: Inline fpu_emulator_init_fpu() 2014-05-23 15:12:37 +02:00
me-debugfs.c MIPS: Add FPU emulator counter for emulated delay slots. 2015-04-01 17:21:57 +02:00
sp_add.c MIPS: math-emu: Reinstate sNaN quieting handlers 2015-04-08 01:09:31 +02:00
sp_cmp.c MIPS: math-emu: Remove redundant code from NaN comparison 2015-04-08 01:09:38 +02:00
sp_div.c MIPS: math-emu: Reinstate sNaN quieting handlers 2015-04-08 01:09:31 +02:00
sp_fdp.c MIPS: math-emu: Optimise qNaN handling in `ieee754sp_fdp' 2015-04-08 01:09:44 +02:00
sp_fint.c MIPS: math-emu: Cleanup coding style. 2014-05-23 15:11:15 +02:00
sp_flong.c MIPS: math-emu: Cleanup coding style. 2014-05-23 15:11:15 +02:00
sp_mul.c MIPS: math-emu: Reinstate sNaN quieting handlers 2015-04-08 01:09:31 +02:00
sp_simple.c MIPS: math-emu: Cleanup coding style. 2014-05-23 15:11:15 +02:00
sp_sqrt.c MIPS: math-emu: Reinstate sNaN quieting handlers 2015-04-08 01:09:31 +02:00
sp_sub.c MIPS: math-emu: Reinstate sNaN quieting handlers 2015-04-08 01:09:31 +02:00
sp_tint.c MIPS: math-emu: Switch to using the MIPS rounding modes. 2014-05-23 15:12:38 +02:00
sp_tlong.c MIPS: math-emu: Switch to using the MIPS rounding modes. 2014-05-23 15:12:38 +02:00