diff options
| author | bsd <bsd@FreeBSD.org> | 2001-07-19 04:37:27 +0000 |
|---|---|---|
| committer | bsd <bsd@FreeBSD.org> | 2001-07-19 04:37:27 +0000 |
| commit | 8e847a512321399ee40f1f1ec78e84d3cd35ee43 (patch) | |
| tree | 68f3e83d564cef4db6f8398ca94b4e5ddfd6590d | |
| parent | 7e154a8df47fef85a555745479d72a8d59f3921b (diff) | |
| download | FreeBSD-src-8e847a512321399ee40f1f1ec78e84d3cd35ee43.zip FreeBSD-src-8e847a512321399ee40f1f1ec78e84d3cd35ee43.tar.gz | |
swtch.s: During context save, use the correct bit mask for clearing
the non-reserved bits of dr7.
During context restore, load dr7 in such a way as to not
disturb reserved bits.
machdep.c: Don't explicitly disallow the setting of the reserved bits
in dr7 since we now keep from setting them when we load dr7
from the PCB.
This allows one to write back the dr7 value obtained from
the system without triggering an EINVAL (one of the
reserved bits always seems to be set after taking a trace
trap).
MFC after: 7 days
| -rw-r--r-- | sys/amd64/amd64/cpu_switch.S | 10 | ||||
| -rw-r--r-- | sys/amd64/amd64/machdep.c | 3 | ||||
| -rw-r--r-- | sys/amd64/amd64/swtch.s | 10 | ||||
| -rw-r--r-- | sys/i386/i386/machdep.c | 3 | ||||
| -rw-r--r-- | sys/i386/i386/swtch.s | 10 |
5 files changed, 24 insertions, 12 deletions
diff --git a/sys/amd64/amd64/cpu_switch.S b/sys/amd64/amd64/cpu_switch.S index 180b87b..0f2f7a8 100644 --- a/sys/amd64/amd64/cpu_switch.S +++ b/sys/amd64/amd64/cpu_switch.S @@ -104,7 +104,7 @@ ENTRY(cpu_switch) jz 1f /* no, skip over */ movl %dr7,%eax /* yes, do the save */ movl %eax,PCB_DR7(%edx) - andl $0x0000ff00, %eax /* disable all watchpoints */ + andl $0x0000fc00, %eax /* disable all watchpoints */ movl %eax,%dr7 movl %dr6,%eax movl %eax,PCB_DR6(%edx) @@ -271,7 +271,13 @@ cpu_switch_load_gs: movl %eax,%dr1 movl PCB_DR0(%edx),%eax movl %eax,%dr0 - movl PCB_DR7(%edx),%eax + movl %dr7,%eax /* load dr7 so as not to disturb */ + andl $0x0000fc00,%eax /* reserved bits */ + pushl %ebx + movl PCB_DR7(%edx),%ebx + andl $~0x0000fc00,%ebx + orl %ebx,%eax + popl %ebx movl %eax,%dr7 1: ret diff --git a/sys/amd64/amd64/machdep.c b/sys/amd64/amd64/machdep.c index 7e9a4dd..c12e676 100644 --- a/sys/amd64/amd64/machdep.c +++ b/sys/amd64/amd64/machdep.c @@ -2314,9 +2314,6 @@ set_dbregs(p, dbregs) if ((dbregs->dr7 & mask1) == mask2) return (EINVAL); - if (dbregs->dr7 & 0x0000fc00) - return (EINVAL); - pcb = &p->p_addr->u_pcb; /* diff --git a/sys/amd64/amd64/swtch.s b/sys/amd64/amd64/swtch.s index 180b87b..0f2f7a8 100644 --- a/sys/amd64/amd64/swtch.s +++ b/sys/amd64/amd64/swtch.s @@ -104,7 +104,7 @@ ENTRY(cpu_switch) jz 1f /* no, skip over */ movl %dr7,%eax /* yes, do the save */ movl %eax,PCB_DR7(%edx) - andl $0x0000ff00, %eax /* disable all watchpoints */ + andl $0x0000fc00, %eax /* disable all watchpoints */ movl %eax,%dr7 movl %dr6,%eax movl %eax,PCB_DR6(%edx) @@ -271,7 +271,13 @@ cpu_switch_load_gs: movl %eax,%dr1 movl PCB_DR0(%edx),%eax movl %eax,%dr0 - movl PCB_DR7(%edx),%eax + movl %dr7,%eax /* load dr7 so as not to disturb */ + andl $0x0000fc00,%eax /* reserved bits */ + pushl %ebx + movl PCB_DR7(%edx),%ebx + andl $~0x0000fc00,%ebx + orl %ebx,%eax + popl %ebx movl %eax,%dr7 1: ret diff --git a/sys/i386/i386/machdep.c b/sys/i386/i386/machdep.c index 7e9a4dd..c12e676 100644 --- a/sys/i386/i386/machdep.c +++ b/sys/i386/i386/machdep.c @@ -2314,9 +2314,6 @@ set_dbregs(p, dbregs) if ((dbregs->dr7 & mask1) == mask2) return (EINVAL); - if (dbregs->dr7 & 0x0000fc00) - return (EINVAL); - pcb = &p->p_addr->u_pcb; /* diff --git a/sys/i386/i386/swtch.s b/sys/i386/i386/swtch.s index 180b87b..0f2f7a8 100644 --- a/sys/i386/i386/swtch.s +++ b/sys/i386/i386/swtch.s @@ -104,7 +104,7 @@ ENTRY(cpu_switch) jz 1f /* no, skip over */ movl %dr7,%eax /* yes, do the save */ movl %eax,PCB_DR7(%edx) - andl $0x0000ff00, %eax /* disable all watchpoints */ + andl $0x0000fc00, %eax /* disable all watchpoints */ movl %eax,%dr7 movl %dr6,%eax movl %eax,PCB_DR6(%edx) @@ -271,7 +271,13 @@ cpu_switch_load_gs: movl %eax,%dr1 movl PCB_DR0(%edx),%eax movl %eax,%dr0 - movl PCB_DR7(%edx),%eax + movl %dr7,%eax /* load dr7 so as not to disturb */ + andl $0x0000fc00,%eax /* reserved bits */ + pushl %ebx + movl PCB_DR7(%edx),%ebx + andl $~0x0000fc00,%ebx + orl %ebx,%eax + popl %ebx movl %eax,%dr7 1: ret |
