Searched hist:"955 c1cab" (Results 1 – 2 of 2) sorted by relevance
| /openbmc/linux/arch/powerpc/kernel/ |
| H A D | vector.S | 955c1cab Wed Oct 23 03:40:02 CDT 2013 Paul Mackerras <paulus@samba.org> powerpc: Don't corrupt user registers on 32-bit
Commit de79f7b9f6 ("powerpc: Put FP/VSX and VR state into structures")
modified load_up_fpu() and load_up_altivec() in such a way that they
now use r7 and r8. Unfortunately, the callers of these functions on
32-bit machines then return to userspace via fast_exception_return,
which doesn't restore all of the volatile GPRs, but only r1, r3 -- r6
and r9 -- r12. This was causing userspace segfaults and other
userspace misbehaviour on 32-bit machines.
This fixes the problem by changing the register usage of load_up_fpu()
and load_up_altivec() to avoid using r7 and r8 and instead use r6 and
r10. This also adds comments to those functions saying which registers
may be used.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Tested-by: Scott Wood <scottwood@freescale.com> (on e500mc, so no altivec)
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
955c1cab Wed Oct 23 03:40:02 CDT 2013 Paul Mackerras <paulus@samba.org> powerpc: Don't corrupt user registers on 32-bit
Commit de79f7b9f6 ("powerpc: Put FP/VSX and VR state into structures")
modified load_up_fpu() and load_up_altivec() in such a way that they
now use r7 and r8. Unfortunately, the callers of these functions on
32-bit machines then return to userspace via fast_exception_return,
which doesn't restore all of the volatile GPRs, but only r1, r3 -- r6
and r9 -- r12. This was causing userspace segfaults and other
userspace misbehaviour on 32-bit machines.
This fixes the problem by changing the register usage of load_up_fpu()
and load_up_altivec() to avoid using r7 and r8 and instead use r6 and
r10. This also adds comments to those functions saying which registers
may be used.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Tested-by: Scott Wood <scottwood@freescale.com> (on e500mc, so no altivec)
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
|
| H A D | fpu.S | 955c1cab Wed Oct 23 03:40:02 CDT 2013 Paul Mackerras <paulus@samba.org> powerpc: Don't corrupt user registers on 32-bit
Commit de79f7b9f6 ("powerpc: Put FP/VSX and VR state into structures")
modified load_up_fpu() and load_up_altivec() in such a way that they
now use r7 and r8. Unfortunately, the callers of these functions on
32-bit machines then return to userspace via fast_exception_return,
which doesn't restore all of the volatile GPRs, but only r1, r3 -- r6
and r9 -- r12. This was causing userspace segfaults and other
userspace misbehaviour on 32-bit machines.
This fixes the problem by changing the register usage of load_up_fpu()
and load_up_altivec() to avoid using r7 and r8 and instead use r6 and
r10. This also adds comments to those functions saying which registers
may be used.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Tested-by: Scott Wood <scottwood@freescale.com> (on e500mc, so no altivec)
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
955c1cab Wed Oct 23 03:40:02 CDT 2013 Paul Mackerras <paulus@samba.org> powerpc: Don't corrupt user registers on 32-bit
Commit de79f7b9f6 ("powerpc: Put FP/VSX and VR state into structures")
modified load_up_fpu() and load_up_altivec() in such a way that they
now use r7 and r8. Unfortunately, the callers of these functions on
32-bit machines then return to userspace via fast_exception_return,
which doesn't restore all of the volatile GPRs, but only r1, r3 -- r6
and r9 -- r12. This was causing userspace segfaults and other
userspace misbehaviour on 32-bit machines.
This fixes the problem by changing the register usage of load_up_fpu()
and load_up_altivec() to avoid using r7 and r8 and instead use r6 and
r10. This also adds comments to those functions saying which registers
may be used.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Tested-by: Scott Wood <scottwood@freescale.com> (on e500mc, so no altivec)
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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