From mboxrd@z Thu Jan 1 00:00:00 1970 From: yalin.wang2010@gmail.com (yalin wang) Date: Fri, 24 Jul 2015 19:53:14 +0800 Subject: [RFC] arm64:use set_fixmap_offset to make it more clear In-Reply-To: <20150724100724.GA4348@leverpostej> References: <20150723130344.GC27052@e104818-lin.cambridge.arm.com> <9E910A45-D4AB-44F6-878F-3CB2372B3660@gmail.com> <20150724095618.GB23074@leverpostej> <20150724100724.GA4348@leverpostej> Message-ID: <11F09FCC-E973-44E9-BDBF-88F8F27D4601@gmail.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org > ? 2015?7?24??18:07?Mark Rutland ??? > > On Fri, Jul 24, 2015 at 10:56:18AM +0100, Mark Rutland wrote: >> On Fri, Jul 24, 2015 at 04:56:59AM +0100, yalin wang wrote: >>> >>>> On Jul 23, 2015, at 21:03, Catalin Marinas wrote: >>>> >>>> On Thu, Jul 23, 2015 at 07:45:53PM +0800, yalin wang wrote: >>>>> A little change to patch_map() function, >>>>> use set_fixmap_offset() to make code more clear. >>>>> >>>>> Signed-off-by: yalin wang >>>>> --- >>>>> arch/arm64/kernel/insn.c | 5 ++--- >>>>> 1 file changed, 2 insertions(+), 3 deletions(-) >>>>> >>>>> diff --git a/arch/arm64/kernel/insn.c b/arch/arm64/kernel/insn.c >>>>> index dd9671c..7dafd5a 100644 >>>>> --- a/arch/arm64/kernel/insn.c >>>>> +++ b/arch/arm64/kernel/insn.c >>>>> @@ -101,9 +101,8 @@ static void __kprobes *patch_map(void *addr, int fixmap) >>>>> return addr; >>>>> >>>>> BUG_ON(!page); >>>>> - set_fixmap(fixmap, page_to_phys(page)); >>>>> - >>>>> - return (void *) (__fix_to_virt(fixmap) + (uintaddr & ~PAGE_MASK)); >>>>> + return (void *)set_fixmap_offset(fixmap, page_to_phys(page) + >>>>> + (addr & ~PAGE_MASK)); >>>> >>>> It looks fine. Do you get any compiler warning for the automatic pointer >>>> to long conversion? You may want to add some explicit casts, otherwise: >>>> >>>> Acked-by: Catalin Marinas >>> i have build it, there is no warning about this change. :) >> >> I see no warnings with defconfig, but there's an (unrelated) set of warnings if >> CONFIG_DEBUG_SET_MODULE_RONX or CONFIG_DEBUG_RODATA are enabled: > > Actually they aren't unrelated after all. the unsigned long addr in > __set_fixmap_offset shadows the void* addr from patch_map making the > types match. > > With a few underscores addrd to __set_fixmap_offset's addr, I get the > following regarding patch_map: > > ---- > In file included from ./arch/arm64/include/asm/fixmap.h:85:0, > from arch/arm64/kernel/insn.c:32: > arch/arm64/kernel/insn.c: In function ?patch_map?: > arch/arm64/kernel/insn.c:105:10: error: invalid operands to binary & (have ?void *? and ?long unsigned int?) > (addr & ~PAGE_MASK)); > ^ > include/asm-generic/fixmap.h:73:20: note: in definition of macro ?__set_fixmap_offset? > __set_fixmap(idx, phys, flags); \ > ^ > arch/arm64/kernel/insn.c:104:17: note: in expansion of macro ?set_fixmap_offset? > return (void *)set_fixmap_offset(fixmap, page_to_phys(page) + > ^ > arch/arm64/kernel/insn.c:105:10: error: invalid operands to binary & (have ?void *? and ?long unsigned int?) > (addr & ~PAGE_MASK)); > ^ > include/asm-generic/fixmap.h:74:32: note: in definition of macro ?__set_fixmap_offset? > __addr = fix_to_virt(idx) + ((phys) & (PAGE_SIZE - 1)); \ > ^ > arch/arm64/kernel/insn.c:104:17: note: in expansion of macro ?set_fixmap_offset? > return (void *)set_fixmap_offset(fixmap, page_to_phys(page) + > ^ > make[1]: *** [arch/arm64/kernel/insn.o] Error 1 > make: *** [arch/arm64/kernel/insn.o] Error 2 > ---- > > we need both the cast in patch_map, and an update to __set_fixmap_offset to > prevent the name clash. > > Thanks, > Mark. i see, i will send V2 to solve this. Thanks