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10 Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
Al Viro
|
a08971e948 |
futex: arch_futex_atomic_op_inuser() calling conventions change
Move access_ok() in and pagefault_enable()/pagefault_disable() out. Mechanical conversion only - some instances don't really need a separate access_ok() at all (e.g. the ones only using get_user()/put_user(), or architectures where access_ok() is always true); we'll deal with that in followups. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> |
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Linus Torvalds
|
96d4f267e4 |
Remove 'type' argument from access_ok() function
Nobody has actually used the type (VERIFY_READ vs VERIFY_WRITE) argument
of the user address range verification function since we got rid of the
old racy i386-only code to walk page tables by hand.
It existed because the original 80386 would not honor the write protect
bit when in kernel mode, so you had to do COW by hand before doing any
user access. But we haven't supported that in a long time, and these
days the 'type' argument is a purely historical artifact.
A discussion about extending 'user_access_begin()' to do the range
checking resulted this patch, because there is no way we're going to
move the old VERIFY_xyz interface to that model. And it's best done at
the end of the merge window when I've done most of my merges, so let's
just get this done once and for all.
This patch was mostly done with a sed-script, with manual fix-ups for
the cases that weren't of the trivial 'access_ok(VERIFY_xyz' form.
There were a couple of notable cases:
- csky still had the old "verify_area()" name as an alias.
- the iter_iov code had magical hardcoded knowledge of the actual
values of VERIFY_{READ,WRITE} (not that they mattered, since nothing
really used it)
- microblaze used the type argument for a debug printout
but other than those oddities this should be a total no-op patch.
I tried to fix up all architectures, did fairly extensive grepping for
access_ok() uses, and the changes are trivial, but I may have missed
something. Any missed conversion should be trivially fixable, though.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Greg Kroah-Hartman
|
b24413180f |
License cleanup: add SPDX GPL-2.0 license identifier to files with no license
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
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Jiri Slaby
|
30d6e0a419 |
futex: Remove duplicated code and fix undefined behaviour
There is code duplicated over all architecture's headers for futex_atomic_op_inuser. Namely op decoding, access_ok check for uaddr, and comparison of the result. Remove this duplication and leave up to the arches only the needed assembly which is now in arch_futex_atomic_op_inuser. This effectively distributes the Will Deacon's arm64 fix for undefined behaviour reported by UBSAN to all architectures. The fix was done in commit |
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Stephan Schreiber
|
136f39ddc5 |
Wrong asm register contraints in the futex implementation
The Linux Kernel contains some inline assembly source code which has
wrong asm register constraints in arch/ia64/include/asm/futex.h.
I observed this on Kernel 3.2.23 but it is also true on the most
recent Kernel 3.9-rc1.
File arch/ia64/include/asm/futex.h:
static inline int
futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
u32 oldval, u32 newval)
{
if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
return -EFAULT;
{
register unsigned long r8 __asm ("r8");
unsigned long prev;
__asm__ __volatile__(
" mf;; \n"
" mov %0=r0 \n"
" mov ar.ccv=%4;; \n"
"[1:] cmpxchg4.acq %1=[%2],%3,ar.ccv \n"
" .xdata4 \"__ex_table\", 1b-., 2f-. \n"
"[2:]"
: "=r" (r8), "=r" (prev)
: "r" (uaddr), "r" (newval),
"rO" ((long) (unsigned) oldval)
: "memory");
*uval = prev;
return r8;
}
}
The list of output registers is
: "=r" (r8), "=r" (prev)
The constraint "=r" means that the GCC has to maintain that these vars
are in registers and contain valid info when the program flow leaves
the assembly block (output registers).
But "=r" also means that GCC can put them in registers that are used
as input registers. Input registers are uaddr, newval, oldval on the
example.
The second assembly instruction
" mov %0=r0 \n"
is the first one which writes to a register; it sets %0 to 0. %0 means
the first register operand; it is r8 here. (The r0 is read-only and
always 0 on the Itanium; it can be used if an immediate zero value is
needed.)
This instruction might overwrite one of the other registers which are
still needed.
Whether it really happens depends on how GCC decides what registers it
uses and how it optimizes the code.
The objdump utility can give us disassembly.
The futex_atomic_cmpxchg_inatomic() function is inline, so we have to
look for a module that uses the funtion. This is the
cmpxchg_futex_value_locked() function in
kernel/futex.c:
static int cmpxchg_futex_value_locked(u32 *curval, u32 __user *uaddr,
u32 uval, u32 newval)
{
int ret;
pagefault_disable();
ret = futex_atomic_cmpxchg_inatomic(curval, uaddr, uval, newval);
pagefault_enable();
return ret;
}
Now the disassembly. At first from the Kernel package 3.2.23 which has
been compiled with GCC 4.4, remeber this Kernel seemed to work:
objdump -d linux-3.2.23/debian/build/build_ia64_none_mckinley/kernel/futex.o
0000000000000230 <cmpxchg_futex_value_locked>:
230: 0b 18 80 1b 18 21 [MMI] adds r3=3168,r13;;
236: 80 40 0d 00 42 00 adds r8=40,r3
23c: 00 00 04 00 nop.i 0x0;;
240: 0b 50 00 10 10 10 [MMI] ld4 r10=[r8];;
246: 90 08 28 00 42 00 adds r9=1,r10
24c: 00 00 04 00 nop.i 0x0;;
250: 09 00 00 00 01 00 [MMI] nop.m 0x0
256: 00 48 20 20 23 00 st4 [r8]=r9
25c: 00 00 04 00 nop.i 0x0;;
260: 08 10 80 06 00 21 [MMI] adds r2=32,r3
266: 00 00 00 02 00 00 nop.m 0x0
26c: 02 08 f1 52 extr.u r16=r33,0,61
270: 05 40 88 00 08 e0 [MLX] addp4 r8=r34,r0
276: ff ff 0f 00 00 e0 movl r15=0xfffffffbfff;;
27c: f1 f7 ff 65
280: 09 70 00 04 18 10 [MMI] ld8 r14=[r2]
286: 00 00 00 02 00 c0 nop.m 0x0
28c: f0 80 1c d0 cmp.ltu p6,p7=r15,r16;;
290: 08 40 fc 1d 09 3b [MMI] cmp.eq p8,p9=-1,r14
296: 00 00 00 02 00 40 nop.m 0x0
29c: e1 08 2d d0 cmp.ltu p10,p11=r14,r33
2a0: 56 01 10 00 40 10 [BBB] (p10) br.cond.spnt.few 2e0
<cmpxchg_futex_value_locked+0xb0>
2a6: 02 08 00 80 21 03 (p08) br.cond.dpnt.few 2b0
<cmpxchg_futex_value_locked+0x80>
2ac: 40 00 00 41 (p06) br.cond.spnt.few 2e0
<cmpxchg_futex_value_locked+0xb0>
2b0: 0a 00 00 00 22 00 [MMI] mf;;
2b6: 80 00 00 00 42 00 mov r8=r0
2bc: 00 00 04 00 nop.i 0x0
2c0: 0b 00 20 40 2a 04 [MMI] mov.m ar.ccv=r8;;
2c6: 10 1a 85 22 20 00 cmpxchg4.acq r33=[r33],r35,ar.ccv
2cc: 00 00 04 00 nop.i 0x0;;
2d0: 10 00 84 40 90 11 [MIB] st4 [r32]=r33
2d6: 00 00 00 02 00 00 nop.i 0x0
2dc: 20 00 00 40 br.few 2f0
<cmpxchg_futex_value_locked+0xc0>
2e0: 09 40 c8 f9 ff 27 [MMI] mov r8=-14
2e6: 00 00 00 02 00 00 nop.m 0x0
2ec: 00 00 04 00 nop.i 0x0;;
2f0: 0b 58 20 1a 19 21 [MMI] adds r11=3208,r13;;
2f6: 20 01 2c 20 20 00 ld4 r18=[r11]
2fc: 00 00 04 00 nop.i 0x0;;
300: 0b 88 fc 25 3f 23 [MMI] adds r17=-1,r18;;
306: 00 88 2c 20 23 00 st4 [r11]=r17
30c: 00 00 04 00 nop.i 0x0;;
310: 11 00 00 00 01 00 [MIB] nop.m 0x0
316: 00 00 00 02 00 80 nop.i 0x0
31c: 08 00 84 00 br.ret.sptk.many b0;;
The lines
2b0: 0a 00 00 00 22 00 [MMI] mf;;
2b6: 80 00 00 00 42 00 mov r8=r0
2bc: 00 00 04 00 nop.i 0x0
2c0: 0b 00 20 40 2a 04 [MMI] mov.m ar.ccv=r8;;
2c6: 10 1a 85 22 20 00 cmpxchg4.acq r33=[r33],r35,ar.ccv
2cc: 00 00 04 00 nop.i 0x0;;
are the instructions of the assembly block.
The line
2b6: 80 00 00 00 42 00 mov r8=r0
sets the r8 register to 0 and after that
2c0: 0b 00 20 40 2a 04 [MMI] mov.m ar.ccv=r8;;
prepares the 'oldvalue' for the cmpxchg but it takes it from r8. This
is wrong.
What happened here is what I explained above: An input register is
overwritten which is still needed.
The register operand constraints in futex.h are wrong.
(The problem doesn't occur when the Kernel is compiled with GCC 4.6.)
The attached patch fixes the register operand constraints in futex.h.
The code after patching of it:
static inline int
futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
u32 oldval, u32 newval)
{
if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
return -EFAULT;
{
register unsigned long r8 __asm ("r8") = 0;
unsigned long prev;
__asm__ __volatile__(
" mf;; \n"
" mov ar.ccv=%4;; \n"
"[1:] cmpxchg4.acq %1=[%2],%3,ar.ccv \n"
" .xdata4 \"__ex_table\", 1b-., 2f-. \n"
"[2:]"
: "+r" (r8), "=&r" (prev)
: "r" (uaddr), "r" (newval),
"rO" ((long) (unsigned) oldval)
: "memory");
*uval = prev;
return r8;
}
}
I also initialized the 'r8' var with the C programming language.
The _asm qualifier on the definition of the 'r8' var forces GCC to use
the r8 processor register for it.
I don't believe that we should use inline assembly for zeroing out a
local variable.
The constraint is
"+r" (r8)
what means that it is both an input register and an output register.
Note that the page fault handler will modify the r8 register which
will be the return value of the function.
The real fix is
"=&r" (prev)
The & means that GCC must not use any of the input registers to place
this output register in.
Patched the Kernel 3.2.23 and compiled it with GCC4.4:
0000000000000230 <cmpxchg_futex_value_locked>:
230: 0b 18 80 1b 18 21 [MMI] adds r3=3168,r13;;
236: 80 40 0d 00 42 00 adds r8=40,r3
23c: 00 00 04 00 nop.i 0x0;;
240: 0b 50 00 10 10 10 [MMI] ld4 r10=[r8];;
246: 90 08 28 00 42 00 adds r9=1,r10
24c: 00 00 04 00 nop.i 0x0;;
250: 09 00 00 00 01 00 [MMI] nop.m 0x0
256: 00 48 20 20 23 00 st4 [r8]=r9
25c: 00 00 04 00 nop.i 0x0;;
260: 08 10 80 06 00 21 [MMI] adds r2=32,r3
266: 20 12 01 10 40 00 addp4 r34=r34,r0
26c: 02 08 f1 52 extr.u r16=r33,0,61
270: 05 40 00 00 00 e1 [MLX] mov r8=r0
276: ff ff 0f 00 00 e0 movl r15=0xfffffffbfff;;
27c: f1 f7 ff 65
280: 09 70 00 04 18 10 [MMI] ld8 r14=[r2]
286: 00 00 00 02 00 c0 nop.m 0x0
28c: f0 80 1c d0 cmp.ltu p6,p7=r15,r16;;
290: 08 40 fc 1d 09 3b [MMI] cmp.eq p8,p9=-1,r14
296: 00 00 00 02 00 40 nop.m 0x0
29c: e1 08 2d d0 cmp.ltu p10,p11=r14,r33
2a0: 56 01 10 00 40 10 [BBB] (p10) br.cond.spnt.few 2e0
<cmpxchg_futex_value_locked+0xb0>
2a6: 02 08 00 80 21 03 (p08) br.cond.dpnt.few 2b0
<cmpxchg_futex_value_locked+0x80>
2ac: 40 00 00 41 (p06) br.cond.spnt.few 2e0
<cmpxchg_futex_value_locked+0xb0>
2b0: 0b 00 00 00 22 00 [MMI] mf;;
2b6: 00 10 81 54 08 00 mov.m ar.ccv=r34
2bc: 00 00 04 00 nop.i 0x0;;
2c0: 09 58 8c 42 11 10 [MMI] cmpxchg4.acq r11=[r33],r35,ar.ccv
2c6: 00 00 00 02 00 00 nop.m 0x0
2cc: 00 00 04 00 nop.i 0x0;;
2d0: 10 00 2c 40 90 11 [MIB] st4 [r32]=r11
2d6: 00 00 00 02 00 00 nop.i 0x0
2dc: 20 00 00 40 br.few 2f0
<cmpxchg_futex_value_locked+0xc0>
2e0: 09 40 c8 f9 ff 27 [MMI] mov r8=-14
2e6: 00 00 00 02 00 00 nop.m 0x0
2ec: 00 00 04 00 nop.i 0x0;;
2f0: 0b 88 20 1a 19 21 [MMI] adds r17=3208,r13;;
2f6: 30 01 44 20 20 00 ld4 r19=[r17]
2fc: 00 00 04 00 nop.i 0x0;;
300: 0b 90 fc 27 3f 23 [MMI] adds r18=-1,r19;;
306: 00 90 44 20 23 00 st4 [r17]=r18
30c: 00 00 04 00 nop.i 0x0;;
310: 11 00 00 00 01 00 [MIB] nop.m 0x0
316: 00 00 00 02 00 80 nop.i 0x0
31c: 08 00 84 00 br.ret.sptk.many b0;;
Much better.
There is a
270: 05 40 00 00 00 e1 [MLX] mov r8=r0
which was generated by C code r8 = 0. Below
2b6: 00 10 81 54 08 00 mov.m ar.ccv=r34
what means that oldval is no longer overwritten.
This is Debian bug#702641
(http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=702641).
The patch is applicable on Kernel 3.9-rc1, 3.2.23 and many other versions.
Signed-off-by: Stephan Schreiber <info@fs-driver.org>
Cc: stable@vger.kernel.org
Signed-off-by: Tony Luck <tony.luck@intel.com>
|
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Luck, Tony
|
c76f39bddb |
ia64: fix futex_atomic_cmpxchg_inatomic()
Michel Lespinasse cleaned up the futex calling conventions in commit
|
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David Howells
|
c140d87995 |
Disintegrate asm/system.h for IA64
Disintegrate asm/system.h for IA64. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Tony Luck <tony.luck@intel.com> cc: linux-ia64@vger.kernel.org |
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Michel Lespinasse
|
8d7718aa08 |
futex: Sanitize futex ops argument types
Change futex_atomic_op_inuser and futex_atomic_cmpxchg_inatomic prototypes to use u32 types for the futex as this is the data type the futex core code uses all over the place. Signed-off-by: Michel Lespinasse <walken@google.com> Cc: Darren Hart <darren@dvhart.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Matt Turner <mattst88@gmail.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: David Howells <dhowells@redhat.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Michal Simek <monstr@monstr.eu> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Paul Mundt <lethal@linux-sh.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> LKML-Reference: <20110311025058.GD26122@google.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> |
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Michel Lespinasse
|
37a9d912b2 |
futex: Sanitize cmpxchg_futex_value_locked API
The cmpxchg_futex_value_locked API was funny in that it returned either
the original, user-exposed futex value OR an error code such as -EFAULT.
This was confusing at best, and could be a source of livelocks in places
that retry the cmpxchg_futex_value_locked after trying to fix the issue
by running fault_in_user_writeable().
This change makes the cmpxchg_futex_value_locked API more similar to the
get_futex_value_locked one, returning an error code and updating the
original value through a reference argument.
Signed-off-by: Michel Lespinasse <walken@google.com>
Acked-by: Chris Metcalf <cmetcalf@tilera.com> [tile]
Acked-by: Tony Luck <tony.luck@intel.com> [ia64]
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Michal Simek <monstr@monstr.eu> [microblaze]
Acked-by: David Howells <dhowells@redhat.com> [frv]
Cc: Darren Hart <darren@dvhart.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <20110311024851.GC26122@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
|
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Tony Luck
|
7f30491ccd |
[IA64] Move include/asm-ia64 to arch/ia64/include/asm
After moving the the include files there were a few clean-ups: 1) Some files used #include <asm-ia64/xyz.h>, changed to <asm/xyz.h> 2) Some comments alerted maintainers to look at various header files to make matching updates if certain code were to be changed. Updated these comments to use the new include paths. 3) Some header files mentioned their own names in initial comments. Just deleted these self references. Signed-off-by: Tony Luck <tony.luck@intel.com> |