Re: [PATCH v7 11/11] arm64: scs: add shadow stacks for SDEI
From: James Morse <james.morse@arm.com>
Date: 2020-02-11 13:57:35
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Hi Sami, On 28/01/2020 18:49, Sami Tolvanen wrote:
This change adds per-CPU shadow call stacks for the SDEI handler. Similarly to how the kernel stacks are handled, we add separate shadow stacks for normal and critical events.
Reviewed-by: James Morse <james.morse@arm.com> Tested-by: James Morse <james.morse@arm.com>
quoted hunk ↗ jump to hunk
diff --git a/arch/arm64/kernel/scs.c b/arch/arm64/kernel/scs.c index eaadf5430baa..dddb7c56518b 100644 --- a/arch/arm64/kernel/scs.c +++ b/arch/arm64/kernel/scs.c
+static int scs_alloc_percpu(unsigned long * __percpu *ptr, int cpu)
+{
+ unsigned long *p;
+
+ p = __vmalloc_node_range(PAGE_SIZE, SCS_SIZE,
+ VMALLOC_START, VMALLOC_END,
+ GFP_SCS, PAGE_KERNEL,
+ 0, cpu_to_node(cpu),
+ __builtin_return_address(0));(What makes this arch specific? arm64 has its own calls like this for the regular vmap stacks because it plays tricks with the alignment. Here the alignment requirement comes from the core SCS code... Would another architecture implement these scs_alloc_percpu()/scs_free_percpu() differently?) Thanks, James _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel