BMC/Intel-BMC/linux.git/arch/parisc, branch dev-4.4

parisc: Ensure consistent state when switching to kernel stack at syscall entry

2016-11-10T15:36:34+00:00

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 Signed-off-by: Helge Deller Signed-off-by: Greg Kroah-Hartman

parisc: Increase initial kernel mapping size

2016-10-28T07:01:27+00:00

commit 65bf34f59594c11f13d371c5334a6a0a385cd7ae upstream. Increase the initial kernel default page mapping size for 64-bit kernels to 64 MB and for 32-bit kernels to 32 MB. Due to the additional support of ftrace, tracepoint and huge pages the kernel size can exceed the sizes we used up to now. Signed-off-by: Helge Deller Signed-off-by: Greg Kroah-Hartman

parisc: Fix kernel memory layout regarding position of __gp

2016-10-28T07:01:27+00:00

commit f8850abb7ba68229838014b3409460e576751c6d upstream. Architecturally we need to keep __gp below 0x1000000. But because of ftrace and tracepoint support, the RO_DATA_SECTION now gets much bigger than it was before. By moving the linkage tables before RO_DATA_SECTION we can avoid that __gp gets positioned at a too high address. Signed-off-by: Helge Deller Signed-off-by: Greg Kroah-Hartman

parisc: Increase KERNEL_INITIAL_SIZE for 32-bit SMP kernels

2016-10-28T07:01:26+00:00

commit 690d097c00c88fa9d93d198591e184164b1d8c20 upstream. Increase the initial kernel default page mapping size for SMP kernels to 32MB and add a runtime check which panics early if the kernel is bigger than the initial mapping size. This fixes boot crashes of 32bit SMP kernels. Due to the introduction of huge page support in kernel 4.4 and it's required initial kernel layout in memory, a 32bit SMP kernel usually got bigger (in layout, not size) than 16MB. Signed-off-by: Helge Deller Signed-off-by: Greg Kroah-Hartman

parisc: fix copy_from_user()

2016-09-24T08:07:45+00:00

commit aace880feea38875fbc919761b77e5732a3659ef upstream. Signed-off-by: Al Viro Signed-off-by: Greg Kroah-Hartman

parisc: Fix order of EREFUSED define in errno.h

2016-09-07T06:32:36+00:00

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 Signed-off-by: Greg Kroah-Hartman

parisc: Fix pagefault crash in unaligned __get_user() call

2016-06-24T17:18:20+00:00

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 #include #include 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 Signed-off-by: Greg Kroah-Hartman

parisc: Unbreak handling exceptions from kernel modules

2016-04-20T06:41:52+00:00

commit 2ef4dfd9d9f288943e249b78365a69e3ea3ec072 upstream. Handling exceptions from modules never worked on parisc. It was just masked by the fact that exceptions from modules don't happen during normal use. When a module triggers an exception in get_user() we need to load the main kernel dp value before accessing the exception_data structure, and afterwards restore the original dp value of the module on exit. Noticed-by: Mikulas Patocka Signed-off-by: Helge Deller Signed-off-by: Greg Kroah-Hartman

parisc: Fix kernel crash with reversed copy_from_user()

2016-04-20T06:41:52+00:00

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 Cc: Kees Cook Signed-off-by: Greg Kroah-Hartman

parisc: Avoid function pointers for kernel exception routines

2016-04-20T06:41:52+00:00

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 Signed-off-by: Greg Kroah-Hartman