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authorArd Biesheuvel <ard.biesheuvel@linaro.org>2013-05-24 16:23:28 +0200
committerArd Biesheuvel <ard.biesheuvel@linaro.org>2013-07-08 22:07:38 +0100
commitab3da15643469ab2d206dee3d9cfa4194ba77f25 (patch)
treee332a19c18476b01934d0d2b10551daac0abd5b6 /arch/arm/vfp/vfphw.S
parent0773d73d818702191dd568e1e20bcafc5c64661a (diff)
ARM: be strict about FP exceptions in kernel mode
The support code in vfp_support_entry does not care whether the exception that caused it to be invoked occurred in kernel mode or in user mode. However, neither condition that could trigger this exception (lazy restore and VFP bounce to support code) is currently allowable in kernel mode. In either case, print a message describing the condition before letting the undefined instruction handler run its course and trigger an oops. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Acked-by: Nicolas Pitre <nico@linaro.org>
Diffstat (limited to 'arch/arm/vfp/vfphw.S')
-rw-r--r--arch/arm/vfp/vfphw.S5
1 files changed, 5 insertions, 0 deletions
diff --git a/arch/arm/vfp/vfphw.S b/arch/arm/vfp/vfphw.S
index 8d10dc8a1e1..3e5d3115a2a 100644
--- a/arch/arm/vfp/vfphw.S
+++ b/arch/arm/vfp/vfphw.S
@@ -78,6 +78,11 @@
ENTRY(vfp_support_entry)
DBGSTR3 "instr %08x pc %08x state %p", r0, r2, r10
+ ldr r3, [sp, #S_PSR] @ Neither lazy restore nor FP exceptions
+ and r3, r3, #MODE_MASK @ are supported in kernel mode
+ teq r3, #USR_MODE
+ bne vfp_kmode_exception @ Returns through lr
+
VFPFMRX r1, FPEXC @ Is the VFP enabled?
DBGSTR1 "fpexc %08x", r1
tst r1, #FPEXC_EN