The following commit has been merged into the x86/entry branch of tip: Commit-ID: 83f7a80367e99cca0023be95538635abacec07ae Gitweb: https://git.kernel.org/tip/83f7a80367e99cca0023be95538635abacec07ae Author: Lai Jiangshan <la...@linux.alibaba.com> AuthorDate: Fri, 29 May 2020 23:27:29 +02:00 Committer: Thomas Gleixner <t...@linutronix.de> CommitterDate: Sat, 30 May 2020 10:00:05 +02:00
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 <la...@linux.alibaba.com> Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org> Signed-off-by: Thomas Gleixner <t...@linutronix.de> Link: https://lkml.kernel.org/r/20200526014221.2119-2-la...@linux.alibaba.com Link: https://lkml.kernel.org/r/20200529213320.784524...@infradead.org --- arch/x86/kernel/hw_breakpoint.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/hw_breakpoint.c b/arch/x86/kernel/hw_breakpoint.c index 9ddf441..c149c7b 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,
