The phys_addr_t per_cpu_ptr_to_phys() function ignores the offset within a page, whenever not using a simple translation using __pa(). Without this patch /sys/devices/system/cpu/cpu*/crash_notes shows incorrect values, which breaks kdump. Other things may also be broken. Signed-off-by: Petr Tesarik <ptesarik@xxxxxxx> diff --git a/mm/percpu.c b/mm/percpu.c index 3bb810a..1a1b5ac 100644 --- a/mm/percpu.c +++ b/mm/percpu.c @@ -998,6 +998,7 @@ phys_addr_t per_cpu_ptr_to_phys(void *addr) bool in_first_chunk = false; unsigned long first_low, first_high; unsigned int cpu; + phys_addr_t page_addr; /* * The following test on unit_low/high isn't strictly @@ -1023,9 +1024,10 @@ phys_addr_t per_cpu_ptr_to_phys(void *addr) if (!is_vmalloc_addr(addr)) return __pa(addr); else - return page_to_phys(vmalloc_to_page(addr)); + page_addr = page_to_phys(vmalloc_to_page(addr)); } else - return page_to_phys(pcpu_addr_to_page(addr)); + page_addr = page_to_phys(pcpu_addr_to_page(addr)); + return page_addr + offset_in_page(addr); } /** -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>