Minix/minix
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

Added function read_cpu_flags() that returns current cpu flags as a

Browse Source 
long.  This is used to check for interrupts being disabled at the time
of a lock() call, if enabled in config.h. The number of times this
happens is then counted in the kinfo structure. These events (recursive
lockings) lead to nasty race conditions.
This commit is contained in:
Ben Gras
2005-06-20 14:53:13 +00:00
parent c60302c1e7
commit 3eeff022fb
4 changed files with 23 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

13
kernel/klib386.s
View File

@@ -32,6 +32,7 @@
.define _idle_task ! task executed when there is no work
.define _level0 ! call a function at level 0
.define _read_tsc ! read the cycle counter (Pentium and up)
.define _read_cpu_flags ! read the cpu flags
! The routines only guarantee to preserve the registers the C compiler
! expects to be preserved (ebx, esi, edi, ebp, esp, segment registers, and
@@ -546,3 +547,15 @@ _read_tsc:
pop ebp
ret
!*===========================================================================*
!* read_flags *
!*===========================================================================*
! PUBLIC unsigned long read_cpu_flags(void);
! Read the cycle counter of the CPU. Pentium and up.
.align 16
_read_cpu_flags:
pushf
mov eax, (esp)
popf
ret