[PATCH 04/11] Define the virtual space of KASan's shadow region
From: Ard Biesheuvel <hidden>
Date: 2017-10-16 12:14:59
Also in:
linux-mm, lkml
On 16 October 2017 at 12:42, Liuwenliang (Lamb) [off-list ref] wrote:
quoted hunk ↗ jump to hunk
On 10/16/2017 07:03 PM, Abbott Liu wrote:quoted
arch/arm/kernel/entry-armv.S:348: Error: selected processor does not support `movw r1,#:lower16:((((0xC0000000-0x01000000)>>3)+((0xC0000000-0x01000000)-(1<<29))))' in ARM modequoted
arch/arm/kernel/entry-armv.S:348: Error: selected processor does not support `movt r1,#:upper16:((((0xC0000000-0x01000000)>>3)+((0xC0000000-0x01000000)-(1<<29))))' in ARM mode Thanks for building test. This error can be solved by following code:--- a/arch/arm/kernel/entry-armv.S +++ b/arch/arm/kernel/entry-armv.S@@ -188,8 +188,7 @@ ENDPROC(__und_invalid) get_thread_info tsk ldr r0, [tsk, #TI_ADDR_LIMIT] #ifdef CONFIG_KASAN - movw r1, #:lower16:TASK_SIZE - movt r1, #:upper16:TASK_SIZE + ldr r1, =TASK_SIZE #else mov r1, #TASK_SIZE #endif
This is unnecessary: ldr r1, =TASK_SIZE will be converted to a mov instruction by the assembler if the value of TASK_SIZE fits its 12-bit immediate field. So please remove the whole #ifdef, and just use ldr r1, =xxx
quoted hunk ↗ jump to hunk
@@ -446,7 +445,12 @@ ENDPROC(__fiq_abt) @ if it was interrupted in a critical region. Here we @ perform a quick test inline since it should be false @ 99.9999% of the time. The rest is done out of line. +#if CONFIG_KASAN + ldr r0, =TASK_SIZE + cmp r4, r0 +#else cmp r4, #TASK_SIZE +#endif blhs kuser_cmpxchg64_fixup #endif #endifmovt,movw can only be used in ARMv6*, ARMv7 instruction set. But ldr can be used in ARMv4*, ARMv5T*, ARMv6*, ARMv7. Maybe the performance is going to fall down by using ldr, but I think the influence of performance is very limited.