linux-stable.git/arch/parisc, branch linux-3.12.y Linux kernel stable tree parisc: Don't use BITS_PER_LONG in userspace-exported swab.h header 2017-02-15T10:56:08+00:00 Helge Deller deller@gmx.de 2017-01-28T10:52:02+00:00 e24ff9832c2eba6a5db36a306c3f58cc3719446b commit 2ad5d52d42810bed95100a3d912679d8864421ec upstream. In swab.h the "#if BITS_PER_LONG > 32" breaks compiling userspace programs if BITS_PER_LONG is #defined by userspace with the sizeof() compiler builtin. Solve this problem by using __BITS_PER_LONG instead. Since we now #include asm/bitsperlong.h avoid further potential userspace pollution by moving the #define of SHIFT_PER_LONG to bitops.h which is not exported to userspace. This patch unbreaks compiling qemu on hppa/parisc. Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Jiri Slaby <jslaby@suse.cz> 
commit 2ad5d52d42810bed95100a3d912679d8864421ec upstream.

In swab.h the "#if BITS_PER_LONG > 32" breaks compiling userspace programs if
BITS_PER_LONG is #defined by userspace with the sizeof() compiler builtin.

Solve this problem by using __BITS_PER_LONG instead.  Since we now
#include asm/bitsperlong.h avoid further potential userspace pollution
by moving the #define of SHIFT_PER_LONG to bitops.h which is not
exported to userspace.

This patch unbreaks compiling qemu on hppa/parisc.

Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
parisc: Ensure consistent state when switching to kernel stack at syscall entry 2016-11-24T15:23:25+00:00 John David Anglin dave.anglin@bell.net 2016-10-29T03:00:34+00:00 d9e82de839095cbd4ccaff50850c5165ca7993af commit 6ed518328d0189e0fdf1bb7c73290d546143ea66 upstream. We have one critical section in the syscall entry path in which we switch from the userspace stack to kernel stack. In the event of an external interrupt, the interrupt code distinguishes between those two states by analyzing the value of sr7. If sr7 is zero, it uses the kernel stack. Therefore it's important, that the value of sr7 is in sync with the currently enabled stack. This patch now disables interrupts while executing the critical section. This prevents the interrupt handler to possibly see an inconsistent state which in the worst case can lead to crashes. Interestingly, in the syscall exit path interrupts were already disabled in the critical section which switches back to the userspace stack. Signed-off-by: John David Anglin <dave.anglin@bell.net> Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Jiri Slaby <jslaby@suse.cz> 
commit 6ed518328d0189e0fdf1bb7c73290d546143ea66 upstream.

We have one critical section in the syscall entry path in which we switch from
the userspace stack to kernel stack. In the event of an external interrupt, the
interrupt code distinguishes between those two states by analyzing the value of
sr7. If sr7 is zero, it uses the kernel stack. Therefore it's important, that
the value of sr7 is in sync with the currently enabled stack.

This patch now disables interrupts while executing the critical section.  This
prevents the interrupt handler to possibly see an inconsistent state which in
the worst case can lead to crashes.

Interestingly, in the syscall exit path interrupts were already disabled in the
critical section which switches back to the userspace stack.

Signed-off-by: John David Anglin <dave.anglin@bell.net>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
parisc: fix copy_from_user() 2016-09-29T09:14:36+00:00 Al Viro viro@zeniv.linux.org.uk 2016-08-20T23:03:37+00:00 503b87d3d3f77158e2879b4221f3cc38cef6faf6 commit aace880feea38875fbc919761b77e5732a3659ef upstream. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Jiri Slaby <jslaby@suse.cz> 
commit aace880feea38875fbc919761b77e5732a3659ef upstream.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
parisc: Fix order of EREFUSED define in errno.h 2016-09-21T11:40:07+00:00 Helge Deller deller@gmx.de 2016-08-20T09:51:38+00:00 7af0891d048a9a5f960571869935d20666ff4fc9 commit 3eb53b20d7bd1374598cfb1feaa081fcac0e76cd upstream. When building gccgo in userspace, errno.h gets parsed and the go include file sysinfo.go is generated. Since EREFUSED is defined to the same value as ECONNREFUSED, and ECONNREFUSED is defined later on in errno.h, this leads to go complaining that EREFUSED isn't defined yet. Fix this trivial problem by moving the define of EREFUSED down after ECONNREFUSED in errno.h (and clean up the indenting while touching this line). Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Jiri Slaby <jslaby@suse.cz> 
commit 3eb53b20d7bd1374598cfb1feaa081fcac0e76cd upstream.

When building gccgo in userspace, errno.h gets parsed and the go include file
sysinfo.go is generated.

Since EREFUSED is defined to the same value as ECONNREFUSED, and ECONNREFUSED
is defined later on in errno.h, this leads to go complaining that EREFUSED
isn't defined yet.

Fix this trivial problem by moving the define of EREFUSED down after
ECONNREFUSED in errno.h (and clean up the indenting while touching this line).

Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
parisc: Fix pagefault crash in unaligned __get_user() call 2016-07-12T09:27:48+00:00 Helge Deller deller@gmx.de 2016-06-04T15:21:33+00:00 22079c65db043d6440d2d00347556291dab779fc commit 8b78f260887df532da529f225c49195d18fef36b upstream. One of the debian buildd servers had this crash in the syslog without any other information: Unaligned handler failed, ret = -2 clock_adjtime (pid 22578): Unaligned data reference (code 28) CPU: 1 PID: 22578 Comm: clock_adjtime Tainted: G E 4.5.0-2-parisc64-smp #1 Debian 4.5.4-1 task: 000000007d9960f8 ti: 00000001bde7c000 task.ti: 00000001bde7c000 YZrvWESTHLNXBCVMcbcbcbcbOGFRQPDI PSW: 00001000000001001111100000001111 Tainted: G E r00-03 000000ff0804f80f 00000001bde7c2b0 00000000402d2be8 00000001bde7c2b0 r04-07 00000000409e1fd0 00000000fa6f7fff 00000001bde7c148 00000000fa6f7fff r08-11 0000000000000000 00000000ffffffff 00000000fac9bb7b 000000000002b4d4 r12-15 000000000015241c 000000000015242c 000000000000002d 00000000fac9bb7b r16-19 0000000000028800 0000000000000001 0000000000000070 00000001bde7c218 r20-23 0000000000000000 00000001bde7c210 0000000000000002 0000000000000000 r24-27 0000000000000000 0000000000000000 00000001bde7c148 00000000409e1fd0 r28-31 0000000000000001 00000001bde7c320 00000001bde7c350 00000001bde7c218 sr00-03 0000000001200000 0000000001200000 0000000000000000 0000000001200000 sr04-07 0000000000000000 0000000000000000 0000000000000000 0000000000000000 IASQ: 0000000000000000 0000000000000000 IAOQ: 00000000402d2e84 00000000402d2e88 IIR: 0ca0d089 ISR: 0000000001200000 IOR: 00000000fa6f7fff CPU: 1 CR30: 00000001bde7c000 CR31: ffffffffffffffff ORIG_R28: 00000002369fe628 IAOQ[0]: compat_get_timex+0x2dc/0x3c0 IAOQ[1]: compat_get_timex+0x2e0/0x3c0 RP(r2): compat_get_timex+0x40/0x3c0 Backtrace: [<00000000402d4608>] compat_SyS_clock_adjtime+0x40/0xc0 [<0000000040205024>] syscall_exit+0x0/0x14 This means the userspace program clock_adjtime called the clock_adjtime() syscall and then crashed inside the compat_get_timex() function. Syscalls should never crash programs, but instead return EFAULT. The IIR register contains the executed instruction, which disassebles into "ldw 0(sr3,r5),r9". This load-word instruction is part of __get_user() which tried to read the word at %r5/IOR (0xfa6f7fff). This means the unaligned handler jumped in. The unaligned handler is able to emulate all ldw instructions, but it fails if it fails to read the source e.g. because of page fault. The following program reproduces the problem: #define _GNU_SOURCE #include <unistd.h> #include <sys/syscall.h> #include <sys/mman.h> int main(void) { /* allocate 8k */ char *ptr = mmap(NULL, 2*4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0); /* free second half (upper 4k) and make it invalid. */ munmap(ptr+4096, 4096); /* syscall where first int is unaligned and clobbers into invalid memory region */ /* syscall should return EFAULT */ return syscall(__NR_clock_adjtime, 0, ptr+4095); } To fix this issue we simply need to check if the faulting instruction address is in the exception fixup table when the unaligned handler failed. If it is, call the fixup routine instead of crashing. While looking at the unaligned handler I found another issue as well: The target register should not be modified if the handler was unsuccessful. Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Jiri Slaby <jslaby@suse.cz> 
commit 8b78f260887df532da529f225c49195d18fef36b upstream.

One of the debian buildd servers had this crash in the syslog without
any other information:

 Unaligned handler failed, ret = -2
 clock_adjtime (pid 22578): Unaligned data reference (code 28)
 CPU: 1 PID: 22578 Comm: clock_adjtime Tainted: G  E  4.5.0-2-parisc64-smp #1 Debian 4.5.4-1
 task: 000000007d9960f8 ti: 00000001bde7c000 task.ti: 00000001bde7c000

      YZrvWESTHLNXBCVMcbcbcbcbOGFRQPDI
 PSW: 00001000000001001111100000001111 Tainted: G            E
 r00-03  000000ff0804f80f 00000001bde7c2b0 00000000402d2be8 00000001bde7c2b0
 r04-07  00000000409e1fd0 00000000fa6f7fff 00000001bde7c148 00000000fa6f7fff
 r08-11  0000000000000000 00000000ffffffff 00000000fac9bb7b 000000000002b4d4
 r12-15  000000000015241c 000000000015242c 000000000000002d 00000000fac9bb7b
 r16-19  0000000000028800 0000000000000001 0000000000000070 00000001bde7c218
 r20-23  0000000000000000 00000001bde7c210 0000000000000002 0000000000000000
 r24-27  0000000000000000 0000000000000000 00000001bde7c148 00000000409e1fd0
 r28-31  0000000000000001 00000001bde7c320 00000001bde7c350 00000001bde7c218
 sr00-03  0000000001200000 0000000001200000 0000000000000000 0000000001200000
 sr04-07  0000000000000000 0000000000000000 0000000000000000 0000000000000000

 IASQ: 0000000000000000 0000000000000000 IAOQ: 00000000402d2e84 00000000402d2e88
  IIR: 0ca0d089    ISR: 0000000001200000  IOR: 00000000fa6f7fff
  CPU:        1   CR30: 00000001bde7c000 CR31: ffffffffffffffff
  ORIG_R28: 00000002369fe628
  IAOQ[0]: compat_get_timex+0x2dc/0x3c0
  IAOQ[1]: compat_get_timex+0x2e0/0x3c0
  RP(r2): compat_get_timex+0x40/0x3c0
 Backtrace:
  [<00000000402d4608>] compat_SyS_clock_adjtime+0x40/0xc0
  [<0000000040205024>] syscall_exit+0x0/0x14

This means the userspace program clock_adjtime called the clock_adjtime()
syscall and then crashed inside the compat_get_timex() function.
Syscalls should never crash programs, but instead return EFAULT.

The IIR register contains the executed instruction, which disassebles
into "ldw 0(sr3,r5),r9".
This load-word instruction is part of __get_user() which tried to read the word
at %r5/IOR (0xfa6f7fff). This means the unaligned handler jumped in.  The
unaligned handler is able to emulate all ldw instructions, but it fails if it
fails to read the source e.g. because of page fault.

The following program reproduces the problem:

#define _GNU_SOURCE
#include <unistd.h>
#include <sys/syscall.h>
#include <sys/mman.h>

int main(void) {
        /* allocate 8k */
        char *ptr = mmap(NULL, 2*4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
        /* free second half (upper 4k) and make it invalid. */
        munmap(ptr+4096, 4096);
        /* syscall where first int is unaligned and clobbers into invalid memory region */
        /* syscall should return EFAULT */
        return syscall(__NR_clock_adjtime, 0, ptr+4095);
}

To fix this issue we simply need to check if the faulting instruction address
is in the exception fixup table when the unaligned handler failed. If it
is, call the fixup routine instead of crashing.

While looking at the unaligned handler I found another issue as well: The
target register should not be modified if the handler was unsuccessful.

Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
parisc: Fix kernel crash with reversed copy_from_user() 2016-04-20T06:40:09+00:00 Helge Deller deller@gmx.de 2016-04-08T16:18:48+00:00 168d26de82bf018acec1768ddf1f818e434d00be commit ef72f3110d8b19f4c098a0bff7ed7d11945e70c6 upstream. The kernel module testcase (lib/test_user_copy.c) exhibited a kernel crash on parisc if the parameters for copy_from_user were reversed ("illegal reversed copy_to_user" testcase). Fix this potential crash by checking the fault handler if the faulting address is in the exception table. Signed-off-by: Helge Deller <deller@gmx.de> Cc: Kees Cook <keescook@chromium.org> Signed-off-by: Jiri Slaby <jslaby@suse.cz> 
commit ef72f3110d8b19f4c098a0bff7ed7d11945e70c6 upstream.

The kernel module testcase (lib/test_user_copy.c) exhibited a kernel
crash on parisc if the parameters for copy_from_user were reversed
("illegal reversed copy_to_user" testcase).

Fix this potential crash by checking the fault handler if the faulting
address is in the exception table.

Signed-off-by: Helge Deller <deller@gmx.de>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
parisc: Avoid function pointers for kernel exception routines 2016-04-20T06:40:09+00:00 Helge Deller deller@gmx.de 2016-04-08T16:11:33+00:00 b13667443e6ccdec329773cc70bb5962d62c159d commit e3893027a300927049efc1572f852201eb785142 upstream. We want to avoid the kernel module loader to create function pointers for the kernel fixup routines of get_user() and put_user(). Changing the external reference from function type to int type fixes this. This unbreaks exception handling for get_user() and put_user() when called from a kernel module. Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Jiri Slaby <jslaby@suse.cz> 
commit e3893027a300927049efc1572f852201eb785142 upstream.

We want to avoid the kernel module loader to create function pointers
for the kernel fixup routines of get_user() and put_user(). Changing
the external reference from function type to int type fixes this.

This unbreaks exception handling for get_user() and put_user() when
called from a kernel module.

Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
parisc: Fix __ARCH_SI_PREAMBLE_SIZE 2016-02-15T16:07:50+00:00 Helge Deller deller@gmx.de 2016-01-10T08:30:42+00:00 db8d9cd9aa8846b9395be6af85c1e7713943bcb2 commit e60fc5aa608eb38b47ba4ee058f306f739eb70a0 upstream. On a 64bit kernel build the compiler aligns the _sifields union in the struct siginfo_t on a 64bit address. The __ARCH_SI_PREAMBLE_SIZE define compensates for this alignment and thus fixes the wait testcase of the strace package. The symptoms of a wrong __ARCH_SI_PREAMBLE_SIZE value is that _sigchld.si_stime variable is missed to be copied and thus after a copy_siginfo() will have uninitialized values. Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Jiri Slaby <jslaby@suse.cz> 
commit e60fc5aa608eb38b47ba4ee058f306f739eb70a0 upstream.

On a 64bit kernel build the compiler aligns the _sifields union in the
struct siginfo_t on a 64bit address. The __ARCH_SI_PREAMBLE_SIZE define
compensates for this alignment and thus fixes the wait testcase of the
strace package.

The symptoms of a wrong __ARCH_SI_PREAMBLE_SIZE value is that
_sigchld.si_stime variable is missed to be copied and thus after a
copy_siginfo() will have uninitialized values.

Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
parisc: Fix syscall restarts 2016-02-15T16:07:50+00:00 Helge Deller deller@gmx.de 2015-12-21T09:03:30+00:00 70e2633a6757510fea72f305e49b49d40b39eab3 commit 71a71fb5374a23be36a91981b5614590b9e722c3 upstream. On parisc syscalls which are interrupted by signals sometimes failed to restart and instead returned -ENOSYS which in the worst case lead to userspace crashes. A similiar problem existed on MIPS and was fixed by commit e967ef02 ("MIPS: Fix restart of indirect syscalls"). On parisc the current syscall restart code assumes that all syscall callers load the syscall number in the delay slot of the ble instruction. That's how it is e.g. done in the unistd.h header file: ble 0x100(%sr2, %r0) ldi #syscall_nr, %r20 Because of that assumption the current code never restored %r20 before returning to userspace. This assumption is at least not true for code which uses the glibc syscall() function, which instead uses this syntax: ble 0x100(%sr2, %r0) copy regX, %r20 where regX depend on how the compiler optimizes the code and register usage. This patch fixes this problem by adding code to analyze how the syscall number is loaded in the delay branch and - if needed - copy the syscall number to regX prior returning to userspace for the syscall restart. Signed-off-by: Helge Deller <deller@gmx.de> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: Jiri Slaby <jslaby@suse.cz> 
commit 71a71fb5374a23be36a91981b5614590b9e722c3 upstream.

On parisc syscalls which are interrupted by signals sometimes failed to
restart and instead returned -ENOSYS which in the worst case lead to
userspace crashes.
A similiar problem existed on MIPS and was fixed by commit e967ef02
("MIPS: Fix restart of indirect syscalls").

On parisc the current syscall restart code assumes that all syscall
callers load the syscall number in the delay slot of the ble
instruction. That's how it is e.g. done in the unistd.h header file:
	ble 0x100(%sr2, %r0)
	ldi #syscall_nr, %r20
Because of that assumption the current code never restored %r20 before
returning to userspace.

This assumption is at least not true for code which uses the glibc
syscall() function, which instead uses this syntax:
	ble 0x100(%sr2, %r0)
	copy regX, %r20
where regX depend on how the compiler optimizes the code and register
usage.

This patch fixes this problem by adding code to analyze how the syscall
number is loaded in the delay branch and - if needed - copy the syscall
number to regX prior returning to userspace for the syscall restart.

Signed-off-by: Helge Deller <deller@gmx.de>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
parisc: Drop unused MADV_xxxK_PAGES flags from asm/mman.h 2016-02-15T16:07:50+00:00 Helge Deller deller@gmx.de 2015-11-22T11:14:14+00:00 7248da879ceaa8aa0195f39975470b1cd947eca0 commit dcbf0d299c00ed4f82ea8d6e359ad88a5182f9b8 upstream. Drop the MADV_xxK_PAGES flags, which were never used and were from a proposed API which was never integrated into the generic Linux kernel code. Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Jiri Slaby <jslaby@suse.cz> 
commit dcbf0d299c00ed4f82ea8d6e359ad88a5182f9b8 upstream.

Drop the MADV_xxK_PAGES flags, which were never used and were from a proposed
API which was never integrated into the generic Linux kernel code.

Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>