[PATCH] Thumb-2: Correctly handle undefined instructions in the kernel
From: catalin.marinas@arm.com (Catalin Marinas)
Date: 2009-09-18 22:33:46
Subsystem:
arm port, the rest · Maintainers:
Russell King, Linus Torvalds
VFP instructions in the kernel may trigger undefined exceptions if VFP hardware is not present. This patch corrects the loading of such Thumb-2 instructions. It also marks the "no_fp" label as a function so that the linker generate a Thumb address. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> --- arch/arm/kernel/entry-armv.S | 12 +++++++++++- 1 files changed, 11 insertions(+), 1 deletions(-)
diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S
index a332bc7..0a2ba51 100644
--- a/arch/arm/kernel/entry-armv.S
+++ b/arch/arm/kernel/entry-armv.S@@ -272,7 +272,15 @@ __und_svc: @ @ r0 - instruction @ +#ifndef CONFIG_THUMB2_KERNEL ldr r0, [r2, #-4] +#else + ldrh r0, [r2, #-2] @ Thumb instruction at LR - 2 + and r9, r0, #0xf800 + cmp r9, #0xe800 @ 32-bit instruction if xx >= 0 + ldrhhs r9, [r2] @ bottom 16 bits + orrhs r0, r9, r0, lsl #16 +#endif adr r9, BSYM(1f) bl call_fpe
@@ -678,7 +686,9 @@ ENTRY(fp_enter) .word no_fp .previous -no_fp: mov pc, lr +ENTRY(no_fp) + mov pc, lr +ENDPROC(no_fp) __und_usr_unknown: enable_irq