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| author | Lai Jiangshan <laijs@linux.alibaba.com> | 2020-05-30 00:27:29 +0300 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2020-06-11 16:15:20 +0300 |
| commit | d390e6de89d30402bd06056c40cea72328aec9b1 (patch) | |
| tree | 1d0fa0ab07ae9095223732d9b4ac7698336f7d5e | |
| parent | 998c2034c6a36bd48284e8c8f945a6c6ffc0e3f0 (diff) | |
| download | linux-d390e6de89d30402bd06056c40cea72328aec9b1.tar.xz | |
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
| -rw-r--r-- | arch/x86/kernel/hw_breakpoint.c | 13 |
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, |