On 2012-05-24 09:42, Max Filippov wrote: > On Thu, May 24, 2012 at 4:16 PM, Jan Kiszka <jan.kis...@siemens.com> wrote: >> On 2012-05-24 09:08, Max Filippov wrote: >>> On Thu, May 24, 2012 at 3:25 PM, Jan Kiszka <jan.kis...@siemens.com> wrote: >>>> On 2012-05-24 07:51, Max Filippov wrote: >>>>> On Thu, May 24, 2012 at 6:34 AM, Jan Kiszka <jan.kis...@web.de> wrote: >>>>>> From: Jan Kiszka <jan.kis...@siemens.com> >>>>>> >>>>>> tb_invalidate_phys_addr has to called with the exact physical address of >>>>>> the breakpoint we add/remove, not just the page's base address. >>>>>> Otherwise we easily fail to flush the right TB. >>>>>> >>>>>> Regression of 1e7855a558. >>>>> >>>>> Sorry, I fail to see how 1e7855a558 could introduce a regression, it >>>>> just rearranged the code. >>>>> Even more, AFAIK cpu_get_phys_page_debug returns complete physical >>>>> address, not just >>>>> physical page. Probably it has a misleading name. >>>> >>>> Unfortunately, cpu_get_phys_page_debug does NOT deliver the sub-page >>>> offset, only the page base address. >>> >>> Ok, i386 has probably the most explicit implementation, >>> let's look at the target-i386/helper.c:876 >>> >>> page_offset = (addr & TARGET_PAGE_MASK) & (page_size - 1); >>> paddr = (pte & TARGET_PAGE_MASK) + page_offset; >>> return paddr; >>> >>> that's clearly physical page plus in-page offset. >>> I can provide other samples (: >> >> "page_offset" is misleading: addr & TARGET_PAGE_MASK kills all the >> offset bits. It will only contain the relevant bits between page_size >> and TARGET_PAGE_SIZE. >> >> Check also ppc's cpu_get_phys_page_debug, it's clearer in this regard. > > Ok, for i386, ppc, microblaze (and maybe others) you're right. > What about ARM, CRIS, MIPS, SH4, xtensa (and maybe others)? > Looks like this is a long-standing discrepancy and consequently > a long-standing bug in the breakpoint_invalidate.
Not in breakpoint_invalidate as the missing offset was compensated before your commit (well, starting with c2f07f81a2 in fact). But it looks like cpu_get_phys_page_debug was broken for quite a while. Let's fix those archs to return more than page-aligned addresses. Jan -- Siemens AG, Corporate Technology, CT T DE IT 1 Corporate Competence Center Embedded Linux
