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| author | Maksim E. Kozlov <maksim.e.kozlov@gmail.com> | 2019-06-05 22:22:36 +0300 |
|---|---|---|
| committer | Sebastian Huber <sebastian.huber@embedded-brains.de> | 2019-06-06 08:40:47 +0200 |
| commit | a38187051863cf4a423c4f00669c6786bc8ff60d (patch) | |
| tree | 81e6089217b4802e70585f491f19707acecc3db8 /cpukit/score | |
| parent | sparc: Improve _CPU_Context_validate() (diff) | |
| download | rtems-a38187051863cf4a423c4f00669c6786bc8ff60d.tar.bz2 | |
sparc: Fix missed restoring of PSR in syscall_lazy_fp_switch
It is needed to restore PSR just before return because condition
codes are dirty after the CMP instructions and this may cause
undefined program behavior after returning from the switching
procedure (on following branch instruction, for example).
Close #3756.
Diffstat (limited to 'cpukit/score')
| -rw-r--r-- | cpukit/score/cpu/sparc/syscall.S | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/cpukit/score/cpu/sparc/syscall.S b/cpukit/score/cpu/sparc/syscall.S index 603ed7a738..4f4ef32c53 100644 --- a/cpukit/score/cpu/sparc/syscall.S +++ b/cpukit/score/cpu/sparc/syscall.S @@ -241,12 +241,23 @@ SYM(syscall_lazy_fp_switch): .Lfp_restore_done: + /* + * Restore condition codes. PSR[EF] is 1 here. Take PSR write delay + * into account (maximum is three instructions). + */ + mov %l0, %psr + nop + /* Now, retry the floating point instruction with PSR[EF] == 1 */ jmp %l1 rett %l2 .Lillegal_use_of_floating_point_unit: + /* + * There is no need to restore the condition codes here, since + * _Internal_error() does not return. + */ sethi %hi(_Internal_error), %l1 or %l1, %lo(_Internal_error), %l1 mov 38, %i0 |