From: James Hogan <james.hogan@imgtec.com> To: "Michael S. Tsirkin" <mst@redhat.com>, <linux-kernel@vger.kernel.org> Cc: Arnd Bergmann <arnd@arndb.de>, <linux-arch@vger.kernel.org>, <linux-metag@vger.kernel.org> Subject: Re: [PATCH repost 09/16] metag/uaccess: fix sparse errors Date: Fri, 2 Jan 2015 15:41:02 +0000 [thread overview] Message-ID: <54A6BC0E.50008@imgtec.com> (raw) In-Reply-To: <1419499661-8566-10-git-send-email-mst@redhat.com> [-- Attachment #1: Type: text/plain, Size: 5653 bytes --] Hi, On 25/12/14 09:29, Michael S. Tsirkin wrote: > virtio wants to read bitwise types from userspace using get_user. At the > moment this triggers sparse errors, since the value is passed through an > integer. > > Fix that up using __force. I still see these sparse warnings with metag even with your patch: CHECK drivers/vhost/vhost.c drivers/vhost/vhost.c:1004:13: warning: cast from restricted __virtio16 drivers/vhost/vhost.c:1004:13: warning: cast from restricted __virtio16 drivers/vhost/vhost.c:1004:13: warning: cast from restricted __virtio16 drivers/vhost/vhost.c:1004:13: warning: cast from restricted __virtio16 drivers/vhost/vhost.c:1022:13: warning: cast from restricted __virtio16 drivers/vhost/vhost.c:1022:13: warning: cast from restricted __virtio16 drivers/vhost/vhost.c:1022:13: warning: cast from restricted __virtio16 drivers/vhost/vhost.c:1022:13: warning: cast from restricted __virtio16 drivers/vhost/vhost.c:1373:21: warning: cast from restricted __virtio32 drivers/vhost/vhost.c:1373:21: warning: cast from restricted __virtio32 drivers/vhost/vhost.c:1373:21: warning: cast from restricted __virtio32 drivers/vhost/vhost.c:1373:21: warning: cast from restricted __virtio32 drivers/vhost/vhost.c:1377:21: warning: cast from restricted __virtio32 drivers/vhost/vhost.c:1377:21: warning: cast from restricted __virtio32 drivers/vhost/vhost.c:1377:21: warning: cast from restricted __virtio32 drivers/vhost/vhost.c:1377:21: warning: cast from restricted __virtio32 drivers/vhost/vhost.c:1425:13: warning: cast from restricted __virtio16 drivers/vhost/vhost.c:1425:13: warning: cast from restricted __virtio16 drivers/vhost/vhost.c:1425:13: warning: cast from restricted __virtio16 drivers/vhost/vhost.c:1425:13: warning: cast from restricted __virtio16 Which something like the following hunk fixes in a similar way to yours: diff --git a/arch/metag/include/asm/uaccess.h b/arch/metag/include/asm/uaccess.h index 0748b0a97986..594497053748 100644 --- a/arch/metag/include/asm/uaccess.h +++ b/arch/metag/include/asm/uaccess.h @@ -112,13 +112,17 @@ do { \ retval = 0; \ switch (size) { \ case 1: \ - retval = __put_user_asm_b((unsigned int)x, ptr); break; \ + retval = __put_user_asm_b((__force unsigned int)x, ptr); \ + break; \ case 2: \ - retval = __put_user_asm_w((unsigned int)x, ptr); break; \ + retval = __put_user_asm_w((__force unsigned int)x, ptr); \ + break; \ case 4: \ - retval = __put_user_asm_d((unsigned int)x, ptr); break; \ + retval = __put_user_asm_d((__force unsigned int)x, ptr); \ + break; \ case 8: \ - retval = __put_user_asm_l((unsigned long long)x, ptr); break; \ + retval = __put_user_asm_l((__force unsigned long long)x, ptr); \ + break; \ default: \ __put_user_bad(); \ } As far as I understand it, using __force on the value (as opposed to the pointer) is safe here, in the sense of not masking any genuine defects. Do you agree? Do you want to apply that hunk with your patch too? Note, this change also suppresses warnings for writing a pointer to userland due to the casts to unsigned int / unsigned long long, such as the following (each 4 times due to 4 cases above): kernel/signal.c:2740:25: warning: cast removes address space of expression kernel/signal.c:2747:24: warning: cast removes address space of expression kernel/signal.c:2760:24: warning: cast removes address space of expression kernel/signal.c:2761:24: warning: cast removes address space of expression kernel/signal.c:2775:24: warning: cast removes address space of expression kernel/signal.c:2779:24: warning: cast removes address space of expression kernel/signal.c:3202:25: warning: cast removes address space of expression kernel/signal.c:3225:17: warning: cast removes address space of expression kernel/futex.c:2769:16: warning: cast removes address space of expression > > Signed-off-by: Michael S. Tsirkin <mst@redhat.com> > --- > arch/metag/include/asm/uaccess.h | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/arch/metag/include/asm/uaccess.h b/arch/metag/include/asm/uaccess.h > index 0748b0a..c314b45 100644 > --- a/arch/metag/include/asm/uaccess.h > +++ b/arch/metag/include/asm/uaccess.h > @@ -135,7 +135,7 @@ extern long __get_user_bad(void); > ({ \ > long __gu_err, __gu_val; \ > __get_user_size(__gu_val, (ptr), (size), __gu_err); \ > - (x) = (__typeof__(*(ptr)))__gu_val; \ > + (x) = (__force __typeof__(*(ptr)))__gu_val; \ Can you adjust the position of the \ to line up please > __gu_err; \ > }) > > @@ -145,7 +145,7 @@ extern long __get_user_bad(void); > const __typeof__(*(ptr)) __user *__gu_addr = (ptr); \ > if (access_ok(VERIFY_READ, __gu_addr, size)) \ > __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \ > - (x) = (__typeof__(*(ptr)))__gu_val; \ > + (x) = (__force __typeof__(*(ptr)))__gu_val; \ same here (this one causes a checkpatch error due to 80 column limit) > __gu_err; \ > }) > > With those changes, Acked-by: James Hogan <james.hogan@imgtec.com> Cheers James [-- Attachment #2: OpenPGP digital signature --] [-- Type: application/pgp-signature, Size: 819 bytes --]
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From: James Hogan <james.hogan@imgtec.com> To: "Michael S. Tsirkin" <mst@redhat.com>, linux-kernel@vger.kernel.org Cc: Arnd Bergmann <arnd@arndb.de>, linux-arch@vger.kernel.org, linux-metag@vger.kernel.org Subject: Re: [PATCH repost 09/16] metag/uaccess: fix sparse errors Date: Fri, 2 Jan 2015 15:41:02 +0000 [thread overview] Message-ID: <54A6BC0E.50008@imgtec.com> (raw) In-Reply-To: <1419499661-8566-10-git-send-email-mst@redhat.com> [-- Attachment #1: Type: text/plain, Size: 5653 bytes --] Hi, On 25/12/14 09:29, Michael S. Tsirkin wrote: > virtio wants to read bitwise types from userspace using get_user. At the > moment this triggers sparse errors, since the value is passed through an > integer. > > Fix that up using __force. I still see these sparse warnings with metag even with your patch: CHECK drivers/vhost/vhost.c drivers/vhost/vhost.c:1004:13: warning: cast from restricted __virtio16 drivers/vhost/vhost.c:1004:13: warning: cast from restricted __virtio16 drivers/vhost/vhost.c:1004:13: warning: cast from restricted __virtio16 drivers/vhost/vhost.c:1004:13: warning: cast from restricted __virtio16 drivers/vhost/vhost.c:1022:13: warning: cast from restricted __virtio16 drivers/vhost/vhost.c:1022:13: warning: cast from restricted __virtio16 drivers/vhost/vhost.c:1022:13: warning: cast from restricted __virtio16 drivers/vhost/vhost.c:1022:13: warning: cast from restricted __virtio16 drivers/vhost/vhost.c:1373:21: warning: cast from restricted __virtio32 drivers/vhost/vhost.c:1373:21: warning: cast from restricted __virtio32 drivers/vhost/vhost.c:1373:21: warning: cast from restricted __virtio32 drivers/vhost/vhost.c:1373:21: warning: cast from restricted __virtio32 drivers/vhost/vhost.c:1377:21: warning: cast from restricted __virtio32 drivers/vhost/vhost.c:1377:21: warning: cast from restricted __virtio32 drivers/vhost/vhost.c:1377:21: warning: cast from restricted __virtio32 drivers/vhost/vhost.c:1377:21: warning: cast from restricted __virtio32 drivers/vhost/vhost.c:1425:13: warning: cast from restricted __virtio16 drivers/vhost/vhost.c:1425:13: warning: cast from restricted __virtio16 drivers/vhost/vhost.c:1425:13: warning: cast from restricted __virtio16 drivers/vhost/vhost.c:1425:13: warning: cast from restricted __virtio16 Which something like the following hunk fixes in a similar way to yours: diff --git a/arch/metag/include/asm/uaccess.h b/arch/metag/include/asm/uaccess.h index 0748b0a97986..594497053748 100644 --- a/arch/metag/include/asm/uaccess.h +++ b/arch/metag/include/asm/uaccess.h @@ -112,13 +112,17 @@ do { \ retval = 0; \ switch (size) { \ case 1: \ - retval = __put_user_asm_b((unsigned int)x, ptr); break; \ + retval = __put_user_asm_b((__force unsigned int)x, ptr); \ + break; \ case 2: \ - retval = __put_user_asm_w((unsigned int)x, ptr); break; \ + retval = __put_user_asm_w((__force unsigned int)x, ptr); \ + break; \ case 4: \ - retval = __put_user_asm_d((unsigned int)x, ptr); break; \ + retval = __put_user_asm_d((__force unsigned int)x, ptr); \ + break; \ case 8: \ - retval = __put_user_asm_l((unsigned long long)x, ptr); break; \ + retval = __put_user_asm_l((__force unsigned long long)x, ptr); \ + break; \ default: \ __put_user_bad(); \ } As far as I understand it, using __force on the value (as opposed to the pointer) is safe here, in the sense of not masking any genuine defects. Do you agree? Do you want to apply that hunk with your patch too? Note, this change also suppresses warnings for writing a pointer to userland due to the casts to unsigned int / unsigned long long, such as the following (each 4 times due to 4 cases above): kernel/signal.c:2740:25: warning: cast removes address space of expression kernel/signal.c:2747:24: warning: cast removes address space of expression kernel/signal.c:2760:24: warning: cast removes address space of expression kernel/signal.c:2761:24: warning: cast removes address space of expression kernel/signal.c:2775:24: warning: cast removes address space of expression kernel/signal.c:2779:24: warning: cast removes address space of expression kernel/signal.c:3202:25: warning: cast removes address space of expression kernel/signal.c:3225:17: warning: cast removes address space of expression kernel/futex.c:2769:16: warning: cast removes address space of expression > > Signed-off-by: Michael S. Tsirkin <mst@redhat.com> > --- > arch/metag/include/asm/uaccess.h | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/arch/metag/include/asm/uaccess.h b/arch/metag/include/asm/uaccess.h > index 0748b0a..c314b45 100644 > --- a/arch/metag/include/asm/uaccess.h > +++ b/arch/metag/include/asm/uaccess.h > @@ -135,7 +135,7 @@ extern long __get_user_bad(void); > ({ \ > long __gu_err, __gu_val; \ > __get_user_size(__gu_val, (ptr), (size), __gu_err); \ > - (x) = (__typeof__(*(ptr)))__gu_val; \ > + (x) = (__force __typeof__(*(ptr)))__gu_val; \ Can you adjust the position of the \ to line up please > __gu_err; \ > }) > > @@ -145,7 +145,7 @@ extern long __get_user_bad(void); > const __typeof__(*(ptr)) __user *__gu_addr = (ptr); \ > if (access_ok(VERIFY_READ, __gu_addr, size)) \ > __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \ > - (x) = (__typeof__(*(ptr)))__gu_val; \ > + (x) = (__force __typeof__(*(ptr)))__gu_val; \ same here (this one causes a checkpatch error due to 80 column limit) > __gu_err; \ > }) > > With those changes, Acked-by: James Hogan <james.hogan@imgtec.com> Cheers James [-- Attachment #2: OpenPGP digital signature --] [-- Type: application/pgp-signature, Size: 819 bytes --]
next prev parent reply other threads:[~2015-01-02 15:41 UTC|newest] Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top 2014-12-25 9:28 [PATCH repost 00/16] uaccess: fix sparse warning on get_user for bitwise types Michael S. Tsirkin 2014-12-25 9:28 ` [PATCH repost 01/16] x86/uaccess: fix sparse errors Michael S. Tsirkin 2014-12-25 9:28 ` [PATCH repost 02/16] alpha/uaccess: " Michael S. Tsirkin 2014-12-25 9:28 ` [PATCH repost 03/16] arm64/uaccess: " Michael S. Tsirkin 2014-12-25 9:28 ` Michael S. Tsirkin 2015-01-23 15:33 ` Catalin Marinas 2015-01-23 15:33 ` Catalin Marinas 2015-01-23 15:33 ` Catalin Marinas 2015-01-23 15:42 ` Will Deacon 2015-01-23 15:42 ` Will Deacon 2015-01-23 15:42 ` Will Deacon 2015-01-23 16:35 ` Catalin Marinas 2015-01-23 16:35 ` Catalin Marinas 2015-01-23 16:35 ` Catalin Marinas 2014-12-25 9:28 ` [PATCH repost 04/16] avr32/uaccess: " Michael S. Tsirkin 2014-12-25 9:28 ` [PATCH repost 05/16] blackfin/uaccess: " Michael S. Tsirkin 2014-12-25 9:28 ` [PATCH repost 06/16] cris/uaccess: " Michael S. Tsirkin 2014-12-25 9:28 ` [PATCH repost 07/16] ia64/uaccess: " Michael S. Tsirkin 2014-12-25 9:28 ` Michael S. Tsirkin 2014-12-25 9:28 ` [PATCH repost 08/16] m32r/uaccess: " Michael S. Tsirkin 2014-12-25 9:29 ` [PATCH repost 09/16] metag/uaccess: " Michael S. Tsirkin 2015-01-02 15:41 ` James Hogan [this message] 2015-01-02 15:41 ` James Hogan 2015-01-04 10:52 ` Michael S. Tsirkin 2015-01-05 9:44 ` James Hogan 2015-01-05 9:44 ` James Hogan 2015-01-05 13:00 ` Michael S. Tsirkin 2015-01-05 14:47 ` James Hogan 2015-01-06 10:00 ` Michael S. Tsirkin 2014-12-25 9:29 ` [PATCH repost 10/16] microblaze/uaccess: " Michael S. Tsirkin 2014-12-25 9:29 ` [PATCH repost 11/16] openrisc/uaccess: " Michael S. Tsirkin 2014-12-25 9:29 ` Michael S. Tsirkin 2014-12-25 9:29 ` [PATCH repost 12/16] parisc/uaccess: " Michael S. Tsirkin 2014-12-25 22:37 ` Helge Deller 2014-12-27 16:14 ` Michael S. Tsirkin 2014-12-31 17:17 ` James Bottomley 2014-12-31 18:38 ` Michael S. Tsirkin 2014-12-31 20:23 ` James Bottomley 2014-12-25 9:29 ` [PATCH repost 13/16] sh/uaccess: " Michael S. Tsirkin 2014-12-25 9:29 ` Michael S. Tsirkin 2014-12-25 9:29 ` [PATCH repost 14/16] sparc/uaccess: " Michael S. Tsirkin 2014-12-25 9:29 ` Michael S. Tsirkin 2014-12-25 9:30 ` [PATCH repost 15/16] " Michael S. Tsirkin 2014-12-25 9:30 ` Michael S. Tsirkin 2014-12-25 23:39 ` David Miller 2014-12-25 23:39 ` David Miller 2014-12-28 10:21 ` Michael S. Tsirkin 2014-12-28 10:21 ` Michael S. Tsirkin 2014-12-25 9:30 ` [PATCH repost 16/16] m68k/uaccess: " Michael S. Tsirkin
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