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authorLai Jiangshan <laijs@linux.alibaba.com>2020-05-29 23:27:29 +0200
committerThomas Gleixner <tglx@linutronix.de>2020-06-11 15:15:20 +0200
commitd390e6de89d30402bd06056c40cea72328aec9b1 (patch)
tree1d0fa0ab07ae9095223732d9b4ac7698336f7d5e /arch
parent998c2034c6a36bd48284e8c8f945a6c6ffc0e3f0 (diff)
x86/hw_breakpoint: Add within_area() to check data breakpoints
Add a within_area() helper to checking whether the data breakpoints overlap with cpu_entry_area. It will be used to completely prevent data breakpoints on GDT, IDT, or TSS. Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20200526014221.2119-2-laijs@linux.alibaba.com Link: https://lkml.kernel.org/r/20200529213320.784524504@infradead.org
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/kernel/hw_breakpoint.c13
1 files changed, 11 insertions, 2 deletions
diff --git a/arch/x86/kernel/hw_breakpoint.c b/arch/x86/kernel/hw_breakpoint.c
index 9ddf441ccaa8..c149c7b29ac3 100644
--- a/arch/x86/kernel/hw_breakpoint.c
+++ b/arch/x86/kernel/hw_breakpoint.c
@@ -228,13 +228,22 @@ int arch_check_bp_in_kernelspace(struct arch_hw_breakpoint *hw)
}
/*
+ * Checks whether the range [addr, end], overlaps the area [base, base + size).
+ */
+static inline bool within_area(unsigned long addr, unsigned long end,
+ unsigned long base, unsigned long size)
+{
+ return end >= base && addr < (base + size);
+}
+
+/*
* Checks whether the range from addr to end, inclusive, overlaps the CPU
* entry area range.
*/
static inline bool within_cpu_entry_area(unsigned long addr, unsigned long end)
{
- return end >= CPU_ENTRY_AREA_BASE &&
- addr < (CPU_ENTRY_AREA_BASE + CPU_ENTRY_AREA_TOTAL_SIZE);
+ return within_area(addr, end, CPU_ENTRY_AREA_BASE,
+ CPU_ENTRY_AREA_TOTAL_SIZE);
}
static int arch_build_bp_info(struct perf_event *bp,

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