* Matt Fleming <matt@xxxxxxxxxxxxxxxxxxx> wrote: > > > + npages = (_end - _text) >> PAGE_SHIFT; > > > > You really need to PFN_ALIGN _end and _text. Has been wrong in the > > existing code as well. > > Hmm... very good point. So I think we should instead guarantee that _end and _text are page aligned. _text is already page aligned: SECTIONS { #ifdef CONFIG_X86_32 . = LOAD_OFFSET + LOAD_PHYSICAL_ADDR; phys_startup_32 = startup_32 - LOAD_OFFSET; #else . = __START_KERNEL; phys_startup_64 = startup_64 - LOAD_OFFSET; #endif /* Text and read-only data */ .text : AT(ADDR(.text) - LOAD_OFFSET) { _text = .; The reason for aligning _end as well is that we already page-align the BSS and BRK sections of the kernel and its various section boundary symbols: /* BSS */ . = ALIGN(PAGE_SIZE); .bss : AT(ADDR(.bss) - LOAD_OFFSET) { __bss_start = .; *(.bss..page_aligned) *(.bss) . = ALIGN(PAGE_SIZE); __bss_stop = .; } . = ALIGN(PAGE_SIZE); .brk : AT(ADDR(.brk) - LOAD_OFFSET) { __brk_base = .; . += 64 * 1024; /* 64k alignment slop space */ *(.brk_reservation) /* areas brk users have reserved */ __brk_limit = .; } _end = .; STABS_DEBUG DWARF_DEBUG _end is the only odd one out, so we should align it as well - because it's easy to make such pfn conversion bugs. This will also make it easier to mark STABS_DEBUG and DWARF_DEBUG as read-only, which they should fundamentally be I think. Alternatively they could be moved to the read-only section - at which point _end becomes page aligned 'for free'. Thanks, Ingo -- To unsubscribe from this list: send the line "unsubscribe linux-efi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html