arm64: fix wrong check of on_sdei_stack in nmi context

When doing unwind_frame() in the context of pseudo nmi (need enable
CONFIG_ARM64_PSEUDO_NMI), reaching the bottom of the stack (fp == 0,
pc != 0), function on_sdei_stack() will return true while the sdei acpi
table is not inited in fact. This will cause a "NULL pointer dereference"
oops when going on.

Reviewed-by: Julien Thierry <julien.thierry@arm.com>
Signed-off-by: Wei Li <liwei391@huawei.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

diff --git a/arch/arm64/kernel/sdei.c b/arch/arm64/kernel/sdei.c
index 5ba4465e44f09028c89fb190b7d65927635a9d10..ea94cf8f9dc6d15f58a7c8e298eba6d8bfdecede 100644 (file)
--- a/arch/arm64/kernel/sdei.c
+++ b/arch/arm64/kernel/sdei.c
@@ -94,6 +94,9 @@ static bool on_sdei_normal_stack(unsigned long sp, struct stack_info *info)
        unsigned long low = (unsigned long)raw_cpu_read(sdei_stack_normal_ptr);
        unsigned long high = low + SDEI_STACK_SIZE;
 
+       if (!low)
+               return false;
+
        if (sp < low || sp >= high)
                return false;
 
@@ -111,6 +114,9 @@ static bool on_sdei_critical_stack(unsigned long sp, struct stack_info *info)
        unsigned long low = (unsigned long)raw_cpu_read(sdei_stack_critical_ptr);
        unsigned long high = low + SDEI_STACK_SIZE;
 
+       if (!low)
+               return false;
+
        if (sp < low || sp >= high)
                return false;