| Message ID | 20131115113216.GA7777@osiris (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Quoting Heiko Carstens (2013-11-15 06:32:16) > On Thu, Nov 14, 2013 at 12:19:52PM -0500, Chris Mason wrote: > > Hi Linus, > > > > Please pull my for-linus branch: > > > > git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs.git for-linus > > > > This is our usual merge window set of bug fixes, performance > > improvements and cleanups. Miao Xie has some really nice optimizations > > for writeback. > > > > Josef also expanded our sanity checks quite a bit; these make up a big > > chunk of the new lines. > > Hmm.. b19e68439375 "btrfs: Remove redundant local zero structure" seems to > use the empty_zero_page incorrectly and causes this compile warning on s390: > > CC fs/btrfs/ioctl.o > fs/btrfs/ioctl.c: In function 'btrfs_is_empty_uuid': > fs/btrfs/ioctl.c:372:2: warning: passing argument 2 of 'memcmp' makes pointer from > integer without a cast [enabled by default] > return !memcmp(uuid, empty_zero_page, BTRFS_UUID_SIZE); > ^ > > In fact there seem to be two more incorrect usages in the kernel. The patch > below is not really tested. Thanks Heiko, I'll make a new pull with the btrfs part of this. -chris -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Quoting Chris Mason (2013-11-15 07:21:31) > Quoting Heiko Carstens (2013-11-15 06:32:16) > > On Thu, Nov 14, 2013 at 12:19:52PM -0500, Chris Mason wrote: > > > Hi Linus, > > > > > > Please pull my for-linus branch: > > > > > > git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs.git for-linus > > > > > > This is our usual merge window set of bug fixes, performance > > > improvements and cleanups. Miao Xie has some really nice optimizations > > > for writeback. > > > > > > Josef also expanded our sanity checks quite a bit; these make up a big > > > chunk of the new lines. > > > > Hmm.. b19e68439375 "btrfs: Remove redundant local zero structure" seems to > > use the empty_zero_page incorrectly and causes this compile warning on s390: > > > > CC fs/btrfs/ioctl.o > > fs/btrfs/ioctl.c: In function 'btrfs_is_empty_uuid': > > fs/btrfs/ioctl.c:372:2: warning: passing argument 2 of 'memcmp' makes pointer from > > integer without a cast [enabled by default] > > return !memcmp(uuid, empty_zero_page, BTRFS_UUID_SIZE); > > ^ > > > > In fact there seem to be two more incorrect usages in the kernel. The patch > > below is not really tested. > > Thanks Heiko, > > I'll make a new pull with the btrfs part of this. Or something slightly different ;) BUG: unable to handle kernel paging request at 0000000001ba6000 IP: [<ffffffff812b3656>] memcmp+0xf/0x22 -chris -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Fri, Nov 15, 2013 at 2:40 PM, Chris Mason <chris.mason@fusionio.com> wrote: > Quoting Chris Mason (2013-11-15 07:21:31) >> Quoting Heiko Carstens (2013-11-15 06:32:16) >> > On Thu, Nov 14, 2013 at 12:19:52PM -0500, Chris Mason wrote: >> > > Hi Linus, >> > > >> > > Please pull my for-linus branch: >> > > >> > > git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs.git for-linus >> > > >> > > This is our usual merge window set of bug fixes, performance >> > > improvements and cleanups. Miao Xie has some really nice optimizations >> > > for writeback. >> > > >> > > Josef also expanded our sanity checks quite a bit; these make up a big >> > > chunk of the new lines. >> > >> > Hmm.. b19e68439375 "btrfs: Remove redundant local zero structure" seems to >> > use the empty_zero_page incorrectly and causes this compile warning on s390: >> > >> > CC fs/btrfs/ioctl.o >> > fs/btrfs/ioctl.c: In function 'btrfs_is_empty_uuid': >> > fs/btrfs/ioctl.c:372:2: warning: passing argument 2 of 'memcmp' makes pointer from >> > integer without a cast [enabled by default] >> > return !memcmp(uuid, empty_zero_page, BTRFS_UUID_SIZE); >> > ^ >> > >> > In fact there seem to be two more incorrect usages in the kernel. The patch >> > below is not really tested. >> >> Thanks Heiko, >> >> I'll make a new pull with the btrfs part of this. > > Or something slightly different ;) > > BUG: unable to handle kernel paging request at 0000000001ba6000 > IP: [<ffffffff812b3656>] memcmp+0xf/0x22 I was just going to comment that + const void *zero_page = (const void *) page_to_phys(ZERO_PAGE(0)); won't fly. You can't just cast a physical address to "void *". Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Fri, Nov 15, 2013 at 02:42:08PM +0100, Geert Uytterhoeven wrote: > On Fri, Nov 15, 2013 at 2:40 PM, Chris Mason <chris.mason@fusionio.com> wrote: > > Quoting Chris Mason (2013-11-15 07:21:31) > >> Quoting Heiko Carstens (2013-11-15 06:32:16) > >> > On Thu, Nov 14, 2013 at 12:19:52PM -0500, Chris Mason wrote: > >> > > Hi Linus, > >> > > > >> > > Please pull my for-linus branch: > >> > > > >> > > git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs.git for-linus > >> > > > >> > > This is our usual merge window set of bug fixes, performance > >> > > improvements and cleanups. Miao Xie has some really nice optimizations > >> > > for writeback. > >> > > > >> > > Josef also expanded our sanity checks quite a bit; these make up a big > >> > > chunk of the new lines. > >> > > >> > Hmm.. b19e68439375 "btrfs: Remove redundant local zero structure" seems to > >> > use the empty_zero_page incorrectly and causes this compile warning on s390: > >> > > >> > CC fs/btrfs/ioctl.o > >> > fs/btrfs/ioctl.c: In function 'btrfs_is_empty_uuid': > >> > fs/btrfs/ioctl.c:372:2: warning: passing argument 2 of 'memcmp' makes pointer from > >> > integer without a cast [enabled by default] > >> > return !memcmp(uuid, empty_zero_page, BTRFS_UUID_SIZE); > >> > ^ > >> > > >> > In fact there seem to be two more incorrect usages in the kernel. The patch > >> > below is not really tested. > >> > >> Thanks Heiko, > >> > >> I'll make a new pull with the btrfs part of this. > > > > Or something slightly different ;) > > > > BUG: unable to handle kernel paging request at 0000000001ba6000 > > IP: [<ffffffff812b3656>] memcmp+0xf/0x22 > > I was just going to comment that > > + const void *zero_page = (const void *) page_to_phys(ZERO_PAGE(0)); > > won't fly. You can't just cast a physical address to "void *". Ouch.. I think that only works on s390 because we have a 1:1 mapping for physical to virtual addresses in kernel space due to our split address spaces. So for btrfs and kvm it should be page_to_virt(), and for the dma_map_single() case I have no idea. :) -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Fri, Nov 15, 2013 at 03:57:23PM +0100, Heiko Carstens wrote: > On Fri, Nov 15, 2013 at 02:42:08PM +0100, Geert Uytterhoeven wrote: > > On Fri, Nov 15, 2013 at 2:40 PM, Chris Mason <chris.mason@fusionio.com> wrote: > > > Quoting Chris Mason (2013-11-15 07:21:31) > > >> Quoting Heiko Carstens (2013-11-15 06:32:16) > > >> > On Thu, Nov 14, 2013 at 12:19:52PM -0500, Chris Mason wrote: > > >> > > Hi Linus, > > >> > > > > >> > > Please pull my for-linus branch: > > >> > > > > >> > > git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs.git for-linus > > >> > > > > >> > > This is our usual merge window set of bug fixes, performance > > >> > > improvements and cleanups. Miao Xie has some really nice optimizations > > >> > > for writeback. > > >> > > > > >> > > Josef also expanded our sanity checks quite a bit; these make up a big > > >> > > chunk of the new lines. > > >> > > > >> > Hmm.. b19e68439375 "btrfs: Remove redundant local zero structure" seems to > > >> > use the empty_zero_page incorrectly and causes this compile warning on s390: > > >> > > > >> > CC fs/btrfs/ioctl.o > > >> > fs/btrfs/ioctl.c: In function 'btrfs_is_empty_uuid': > > >> > fs/btrfs/ioctl.c:372:2: warning: passing argument 2 of 'memcmp' makes pointer from > > >> > integer without a cast [enabled by default] > > >> > return !memcmp(uuid, empty_zero_page, BTRFS_UUID_SIZE); > > >> > ^ > > >> > > > >> > In fact there seem to be two more incorrect usages in the kernel. The patch > > >> > below is not really tested. > > >> > > >> Thanks Heiko, > > >> > > >> I'll make a new pull with the btrfs part of this. > > > > > > Or something slightly different ;) > > > > > > BUG: unable to handle kernel paging request at 0000000001ba6000 > > > IP: [<ffffffff812b3656>] memcmp+0xf/0x22 > > > > I was just going to comment that > > > > + const void *zero_page = (const void *) page_to_phys(ZERO_PAGE(0)); > > > > won't fly. You can't just cast a physical address to "void *". > > Ouch.. I think that only works on s390 because we have a 1:1 mapping for > physical to virtual addresses in kernel space due to our split address spaces. > > So for btrfs and kvm it should be page_to_virt(), and for the dma_map_single() > case I have no idea. :) Can you send updated patch for kvm please? -- Gleb. -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/spi/spi-fsl-cpm.c b/drivers/spi/spi-fsl-cpm.c index 54b06376f03c..3807bbf8a48f 100644 --- a/drivers/spi/spi-fsl-cpm.c +++ b/drivers/spi/spi-fsl-cpm.c @@ -280,6 +280,7 @@ static unsigned long fsl_spi_cpm_get_pram(struct mpc8xxx_spi *mspi) int fsl_spi_cpm_init(struct mpc8xxx_spi *mspi) { + const void *zero_page = (const void *) page_to_phys(ZERO_PAGE(0)); struct device *dev = mspi->dev; struct device_node *np = dev->of_node; const u32 *iprop; @@ -324,7 +325,7 @@ int fsl_spi_cpm_init(struct mpc8xxx_spi *mspi) goto err_bds; } - mspi->dma_dummy_tx = dma_map_single(dev, empty_zero_page, PAGE_SIZE, + mspi->dma_dummy_tx = dma_map_single(dev, zero_page, PAGE_SIZE, DMA_TO_DEVICE); if (dma_mapping_error(dev, mspi->dma_dummy_tx)) { dev_err(dev, "unable to map dummy tx buffer\n"); diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 1d04b5559e61..83f2b3e4fbf0 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -368,8 +368,10 @@ static noinline int btrfs_ioctl_fitrim(struct file *file, void __user *arg) int btrfs_is_empty_uuid(u8 *uuid) { + const void *zero_page = (const void *) page_to_phys(ZERO_PAGE(0)); + BUILD_BUG_ON(BTRFS_UUID_SIZE > PAGE_SIZE); - return !memcmp(uuid, empty_zero_page, BTRFS_UUID_SIZE); + return !memcmp(uuid, zero_page, BTRFS_UUID_SIZE); } static noinline int create_subvol(struct inode *dir, diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 662f34c3287e..01edf1c19332 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -1615,8 +1615,9 @@ EXPORT_SYMBOL_GPL(kvm_read_guest_cached); int kvm_clear_guest_page(struct kvm *kvm, gfn_t gfn, int offset, int len) { - return kvm_write_guest_page(kvm, gfn, (const void *) empty_zero_page, - offset, len); + const void *zero_page = (const void *) page_to_phys(ZERO_PAGE(0)); + + return kvm_write_guest_page(kvm, gfn, zero_page, offset, len); } EXPORT_SYMBOL_GPL(kvm_clear_guest_page);