Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
Groups > linux.kernel > #1485417
| From | Al Viro <viro@ZenIV.linux.org.uk> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: Runtime failure running sh:qemu in -next due to 'sh: fix copy_from_user()' |
| Date | 2016-09-17 01:10 +0200 |
| Message-ID | <siaqB-2Wo-5@gated-at.bofh.it> (permalink) |
| References | <si6Q2-uW-19@gated-at.bofh.it> <si7j4-FB-31@gated-at.bofh.it> <si8oO-1p6-21@gated-at.bofh.it> <si91v-1Sg-1@gated-at.bofh.it> <sia7g-2Am-5@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On Fri, Sep 16, 2016 at 03:47:04PM -0700, Guenter Roeck wrote: > Adding pr_info() just before the "if (unlikely..." fixes the problem. > > Commenting out the "if (unlikely())" code fixes the problem. > > Using a new variable "unsigned long x" for the return code instead of > re-using __copy_size fixes the problem. > > Replacing "return __copy_size;" with "return __copy_size & 0xffffffff;" > fixes the problem. > > The problem only seems to be seen if the copy size length is odd (more > specifically, the failing copy always has a length of 25 bytes). > > No idea what is going on. Bug in __copy_user() ? Compiler bug ? Definitely a compiler bug. __kernel_size_t is 32 bits on sh; that & 0xffffffff should've been optimized away, for crying out loud!
Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread
Runtime failure running sh:qemu in -next due to 'sh: fix copy_from_user()' Guenter Roeck <linux@roeck-us.net> - 2016-09-16 21:20 +0200
Re: Runtime failure running sh:qemu in -next due to 'sh: fix copy_from_user()' Al Viro <viro@ZenIV.linux.org.uk> - 2016-09-16 21:50 +0200
Re: Runtime failure running sh:qemu in -next due to 'sh: fix copy_from_user()' Guenter Roeck <linux@roeck-us.net> - 2016-09-16 23:00 +0200
Re: Runtime failure running sh:qemu in -next due to 'sh: fix copy_from_user()' Al Viro <viro@ZenIV.linux.org.uk> - 2016-09-16 23:40 +0200
Re: Runtime failure running sh:qemu in -next due to 'sh: fix copy_from_user()' Rich Felker <dalias@libc.org> - 2016-09-16 23:50 +0200
Re: Runtime failure running sh:qemu in -next due to 'sh: fix copy_from_user()' Guenter Roeck <linux@roeck-us.net> - 2016-09-17 00:50 +0200
Re: Runtime failure running sh:qemu in -next due to 'sh: fix copy_from_user()' Rich Felker <dalias@libc.org> - 2016-09-17 01:40 +0200
Re: Runtime failure running sh:qemu in -next due to 'sh: fix copy_from_user()' Guenter Roeck <linux@roeck-us.net> - 2016-09-17 04:30 +0200
Re: Runtime failure running sh:qemu in -next due to 'sh: fix copy_from_user()' Guenter Roeck <linux@roeck-us.net> - 2016-09-17 04:30 +0200
Re: Runtime failure running sh:qemu in -next due to 'sh: fix copy_from_user()' Rob Landley <rob@landley.net> - 2016-09-18 06:50 +0200
Re: Runtime failure running sh:qemu in -next due to 'sh: fix copy_from_user()' Rich Felker <dalias@libc.org> - 2016-09-18 17:20 +0200
Re: Runtime failure running sh:qemu in -next due to 'sh: fix copy_from_user()' Guenter Roeck <linux@roeck-us.net> - 2016-09-17 00:50 +0200
Re: Runtime failure running sh:qemu in -next due to 'sh: fix copy_from_user()' Al Viro <viro@ZenIV.linux.org.uk> - 2016-09-17 01:10 +0200
Re: Runtime failure running sh:qemu in -next due to 'sh: fix copy_from_user()' Al Viro <viro@ZenIV.linux.org.uk> - 2016-09-16 22:10 +0200
Re: Runtime failure running sh:qemu in -next due to 'sh: fix copy_from_user()' Guenter Roeck <linux@roeck-us.net> - 2016-09-16 22:40 +0200
Re: Runtime failure running sh:qemu in -next due to 'sh: fix copy_from_user()' lsorense@csclub.uwaterloo.ca (Lennart Sorensen) - 2016-09-16 22:50 +0200
Re: Runtime failure running sh:qemu in -next due to 'sh: fix copy_from_user()' Al Viro <viro@ZenIV.linux.org.uk> - 2016-09-16 23:30 +0200
csiph-web