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* parisc/unaligned: Fix ldw() and stw() unalignment handlersHelge Deller2022-03-021-3/+3
| | | | | | | | | | | | | | | | | commit a97279836867b1cb50a3d4f0b1bf60e0abe6d46c upstream. Fix 3 bugs: a) emulate_stw() doesn't return the error code value, so faulting instructions are not reported and aborted. b) Tell emulate_ldw() to handle fldw_l as floating point instruction c) Tell emulate_ldw() to handle ldw_m as integer instruction Signed-off-by: Helge Deller <deller@gmx.de> Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* parisc/unaligned: Fix fldd and fstd unaligned handlers on 32-bit kernelHelge Deller2022-03-021-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | commit dd2288f4a020d693360e3e8d72f8b9d9c25f5ef6 upstream. Usually the kernel provides fixup routines to emulate the fldd and fstd floating-point instructions if they load or store 8-byte from/to a not natuarally aligned memory location. On a 32-bit kernel I noticed that those unaligned handlers didn't worked and instead the application got a SEGV. While checking the code I found two problems: First, the OPCODE_FLDD_L and OPCODE_FSTD_L cases were ifdef'ed out by the CONFIG_PA20 option, and as such those weren't built on a pure 32-bit kernel. This is now fixed by moving the CONFIG_PA20 #ifdef to prevent the compilation of OPCODE_LDD_L and OPCODE_FSTD_L only, and handling the fldd and fstd instructions. The second problem are two bugs in the 32-bit inline assembly code, where the wrong registers where used. The calculation of the natural alignment used %2 (vall) instead of %3 (ior), and the first word was stored back to address %1 (valh) instead of %3 (ior). Signed-off-by: Helge Deller <deller@gmx.de> Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* parisc: Avoid calling faulthandler_disabled() twiceJohn David Anglin2022-01-271-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 9e9d4b460f23bab61672eae397417d03917d116c ] In handle_interruption(), we call faulthandler_disabled() to check whether the fault handler is not disabled. If the fault handler is disabled, we immediately call do_page_fault(). It then calls faulthandler_disabled(). If disabled, do_page_fault() attempts to fixup the exception by jumping to no_context: no_context: if (!user_mode(regs) && fixup_exception(regs)) { return; } parisc_terminate("Bad Address (null pointer deref?)", regs, code, address); Apart from the error messages, the two blocks of code perform the same function. We can avoid two calls to faulthandler_disabled() by a simple revision to the code in handle_interruption(). Note: I didn't try to fix the formatting of this code block. Signed-off-by: John David Anglin <dave.anglin@bell.net> Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
* parisc: Mark cr16 CPU clocksource unstable on all SMP machinesHelge Deller2021-12-081-19/+5
| | | | | | | | | | | | | | | | | | | | | commit afdb4a5b1d340e4afffc65daa21cc71890d7d589 upstream. In commit c8c3735997a3 ("parisc: Enhance detection of synchronous cr16 clocksources") I assumed that CPUs on the same physical core are syncronous. While booting up the kernel on two different C8000 machines, one with a dual-core PA8800 and one with a dual-core PA8900 CPU, this turned out to be wrong. The symptom was that I saw a jump in the internal clocks printed to the syslog and strange overall behaviour. On machines which have 4 cores (2 dual-cores) the problem isn't visible, because the current logic already marked the cr16 clocksource unstable in this case. This patch now marks the cr16 interval timers unstable if we have more than one CPU in the system, and it fixes this issue. Fixes: c8c3735997a3 ("parisc: Enhance detection of synchronous cr16 clocksources") Signed-off-by: Helge Deller <deller@gmx.de> Cc: <stable@vger.kernel.org> # v5.15+ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* parisc: Fix "make install" on newer debian releasesHelge Deller2021-12-081-0/+1
| | | | | | | | | | | | commit 0f9fee4cdebfbe695c297e5b603a275e2557c1cc upstream. On newer debian releases the debian-provided "installkernel" script is installed in /usr/sbin. Fix the kernel install.sh script to look for the script in this directory as well. Signed-off-by: Helge Deller <deller@gmx.de> Cc: <stable@vger.kernel.org> # v3.13+ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* parisc: Fix KBUILD_IMAGE for self-extracting kernelHelge Deller2021-12-081-0/+5
| | | | | | | | | | | | commit 1d7c29b77725d05faff6754d2f5e7c147aedcf93 upstream. Default KBUILD_IMAGE to $(boot)/bzImage if a self-extracting (CONFIG_PARISC_SELF_EXTRACT=y) kernel is to be built. This fixes the bindeb-pkg make target. Signed-off-by: Helge Deller <deller@gmx.de> Cc: <stable@vger.kernel.org> # v4.14+ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* parisc/entry: fix trace test in syscall exit pathSven Schnelle2021-11-261-1/+1
| | | | | | | | | | | | | | | | | | | | | | | commit 3ec18fc7831e7d79e2d536dd1f3bc0d3ba425e8a upstream. commit 8779e05ba8aa ("parisc: Fix ptrace check on syscall return") fixed testing of TI_FLAGS. This uncovered a bug in the test mask. syscall_restore_rfi is only used when the kernel needs to exit to usespace with single or block stepping and the recovery counter enabled. The test however used _TIF_SYSCALL_TRACE_MASK, which includes a lot of bits that shouldn't be tested here. Fix this by using TIF_SINGLESTEP and TIF_BLOCKSTEP directly. I encountered this bug by enabling syscall tracepoints. Both in qemu and on real hardware. As soon as i enabled the tracepoint (sys_exit_read, but i guess it doesn't really matter which one), i got random page faults in userspace almost immediately. Signed-off-by: Sven Schnelle <svens@stackframe.org> Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* parisc/kgdb: add kgdb_roundup() to make kgdb work with idle pollingSven Schnelle2021-11-261-2/+17
| | | | | | | | | | | | | | | | [ Upstream commit 66e29fcda1824f0427966fbee2bd2c85bf362c82 ] With idle polling, IPIs are not sent when a CPU idle, but queued and run later from do_idle(). The default kgdb_call_nmi_hook() implementation gets the pointer to struct pt_regs from get_irq_reqs(), which doesn't work in that case because it was not called from the IPI interrupt handler. Fix it by defining our own kgdb_roundup() function which sents an IPI_ENTER_KGDB. When that IPI is received on the target CPU kgdb_nmicallback() is called. Signed-off-by: Sven Schnelle <svens@stackframe.org> Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
* parisc: fix warning in flush_tlb_allSven Schnelle2021-11-261-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 1030d681319b43869e0d5b568b9d0226652d1a6f ] I've got the following splat after enabling preemption: [ 3.724721] BUG: using __this_cpu_add() in preemptible [00000000] code: swapper/0/1 [ 3.734630] caller is __this_cpu_preempt_check+0x38/0x50 [ 3.740635] CPU: 1 PID: 1 Comm: swapper/0 Not tainted 5.15.0-rc4-64bit+ #324 [ 3.744605] Hardware name: 9000/785/C8000 [ 3.744605] Backtrace: [ 3.744605] [<00000000401d9d58>] show_stack+0x74/0xb0 [ 3.744605] [<0000000040c27bd4>] dump_stack_lvl+0x10c/0x188 [ 3.744605] [<0000000040c27c84>] dump_stack+0x34/0x48 [ 3.744605] [<0000000040c33438>] check_preemption_disabled+0x178/0x1b0 [ 3.744605] [<0000000040c334f8>] __this_cpu_preempt_check+0x38/0x50 [ 3.744605] [<00000000401d632c>] flush_tlb_all+0x58/0x2e0 [ 3.744605] [<00000000401075c0>] 0x401075c0 [ 3.744605] [<000000004010b8fc>] 0x4010b8fc [ 3.744605] [<00000000401080fc>] 0x401080fc [ 3.744605] [<00000000401d5224>] do_one_initcall+0x128/0x378 [ 3.744605] [<0000000040102de8>] 0x40102de8 [ 3.744605] [<0000000040c33864>] kernel_init+0x60/0x3a8 [ 3.744605] [<00000000401d1020>] ret_from_kernel_thread+0x20/0x28 [ 3.744605] Fix this by moving the __inc_irq_stat() into the locked section. Signed-off-by: Sven Schnelle <svens@stackframe.org> Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
* parisc: Fix ptrace check on syscall returnHelge Deller2021-11-261-1/+1
| | | | | | | | | | | | | | | | | commit 8779e05ba8aaffec1829872ef9774a71f44f6580 upstream. The TIF_XXX flags are stored in the flags field in the thread_info struct (TI_FLAGS), not in the flags field of the task_struct structure (TASK_FLAGS). It seems this bug didn't generate any important side-effects, otherwise it wouldn't have went unnoticed for 12 years (since v2.6.32). Signed-off-by: Helge Deller <deller@gmx.de> Fixes: ecd3d4bc06e48 ("parisc: stop using task->ptrace for {single,block}step flags") Cc: Kyle McMartin <kyle@mcmartin.ca> Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* parisc: Use absolute_pointer() to define PAGE0Helge Deller2021-10-061-1/+1
| | | | | | | | | | | | | | [ Upstream commit 90cc7bed1ed19f869ae7221a6b41887fe762a6a3 ] Use absolute_pointer() wrapper for PAGE0 to avoid this compiler warning: arch/parisc/kernel/setup.c: In function 'start_parisc': error: '__builtin_memcmp_eq' specified bound 8 exceeds source size 0 Signed-off-by: Helge Deller <deller@gmx.de> Co-Developed-by: Guenter Roeck <linux@roeck-us.net> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
* parisc: fix crash with signals and allocaMikulas Patocka2021-09-221-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 030f653078316a9cc9ca6bd1b0234dcf858be35d upstream. I was debugging some crashes on parisc and I found out that there is a crash possibility if a function using alloca is interrupted by a signal. The reason for the crash is that the gcc alloca implementation leaves garbage in the upper 32 bits of the sp register. This normally doesn't matter (the upper bits are ignored because the PSW W-bit is clear), however the signal delivery routine in the kernel uses full 64 bits of sp and it fails with -EFAULT if the upper 32 bits are not zero. I created this program that demonstrates the problem: #include <stdlib.h> #include <unistd.h> #include <signal.h> #include <alloca.h> static __attribute__((noinline,noclone)) void aa(int *size) { void * volatile p = alloca(-*size); while (1) ; } static void handler(int sig) { write(1, "signal delivered\n", 17); _exit(0); } int main(void) { int size = -0x100; signal(SIGALRM, handler); alarm(1); aa(&size); } If you compile it with optimizations, it will crash. The "aa" function has this disassembly: 000106a0 <aa>: 106a0: 08 03 02 41 copy r3,r1 106a4: 08 1e 02 43 copy sp,r3 106a8: 6f c1 00 80 stw,ma r1,40(sp) 106ac: 37 dc 3f c1 ldo -20(sp),ret0 106b0: 0c 7c 12 90 stw ret0,8(r3) 106b4: 0f 40 10 9c ldw 0(r26),ret0 ; ret0 = 0x00000000FFFFFF00 106b8: 97 9c 00 7e subi 3f,ret0,ret0 ; ret0 = 0xFFFFFFFF0000013F 106bc: d7 80 1c 1a depwi 0,31,6,ret0 ; ret0 = 0xFFFFFFFF00000100 106c0: 0b 9e 0a 1e add,l sp,ret0,sp ; sp = 0xFFFFFFFFxxxxxxxx 106c4: e8 1f 1f f7 b,l,n 106c4 <aa+0x24>,r0 This patch fixes the bug by truncating the "usp" variable to 32 bits. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* parisc: avoid a warning on u8 cast for cmpxchg on u8 pointersGao Xiang2021-04-161-1/+1
| | | | | | | | | | | | | | | | | | | | | | commit 4d752e5af63753ab5140fc282929b98eaa4bd12e upstream. commit b344d6a83d01 ("parisc: add support for cmpxchg on u8 pointers") can generate a sparse warning ("cast truncates bits from constant value"), which has been reported several times [1] [2] [3]. The original code worked as expected, but anyway, let silence such sparse warning as what others did [4]. [1] https://lore.kernel.org/r/202104061220.nRMBwCXw-lkp@intel.com [2] https://lore.kernel.org/r/202012291914.T5Agcn99-lkp@intel.com [3] https://lore.kernel.org/r/202008210829.KVwn7Xeh%25lkp@intel.com [4] https://lore.kernel.org/r/20210315131512.133720-2-jacopo+renesas@jmondi.org Cc: Liam Beguin <liambeguin@gmail.com> Cc: Helge Deller <deller@gmx.de> Cc: stable@vger.kernel.org # v5.8+ Signed-off-by: Gao Xiang <hsiangkao@redhat.com> Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* parisc: Bump 64-bit IRQ stack size to 64 KBJohn David Anglin2021-03-071-0/+4
| | | | | | | | | | | | | | [ Upstream commit 31680c1d1595a59e17c14ec036b192a95f8e5f4a ] Bump 64-bit IRQ stack size to 64 KB. I had a kernel IRQ stack overflow on the mx3210 debian buildd machine. This patch increases the 64-bit IRQ stack size to 64 KB. The 64-bit stack size needs to be larger than the 32-bit stack size since registers are twice as big. Signed-off-by: John David Anglin <dave.anglin@bell.net> Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
* parisc: Implement __smp_store_release and __smp_load_acquire barriersJohn David Anglin2020-08-211-0/+61
| | | | | | | | | | | | | | commit e96ebd589debd9a6a793608c4ec7019c38785dea upstream. This patch implements the __smp_store_release and __smp_load_acquire barriers using ordered stores and loads. This avoids the sync instruction present in the generic implementation. Cc: <stable@vger.kernel.org> # 4.14+ Signed-off-by: Dave Anglin <dave.anglin@bell.net> Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* parisc: add support for cmpxchg on u8 pointersLiam Beguin2020-08-052-0/+14
| | | | | | | | | | | | | | | | | | | | | | [ Upstream commit b344d6a83d01c52fddbefa6b3b4764da5b1022a0 ] The kernel test bot reported[1] that using set_mask_bits on a u8 causes the following issue on parisc: hppa-linux-ld: drivers/phy/ti/phy-tusb1210.o: in function `tusb1210_probe': >> (.text+0x2f4): undefined reference to `__cmpxchg_called_with_bad_pointer' >> hppa-linux-ld: (.text+0x324): undefined reference to `__cmpxchg_called_with_bad_pointer' hppa-linux-ld: (.text+0x354): undefined reference to `__cmpxchg_called_with_bad_pointer' Add support for cmpxchg on u8 pointers. [1] https://lore.kernel.org/patchwork/patch/1272617/#1468946 Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Liam Beguin <liambeguin@gmail.com> Tested-by: Dave Anglin <dave.anglin@bell.net> Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
* parisc: Add atomic64_set_release() define to avoid CPU soft lockupsJohn David Anglin2020-07-291-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit be6577af0cef934ccb036445314072e8cb9217b9 upstream. Stalls are quite frequent with recent kernels. I enabled CONFIG_SOFTLOCKUP_DETECTOR and I caught the following stall: watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [cc1:22803] CPU: 0 PID: 22803 Comm: cc1 Not tainted 5.6.17+ #3 Hardware name: 9000/800/rp3440 IAOQ[0]: d_alloc_parallel+0x384/0x688 IAOQ[1]: d_alloc_parallel+0x388/0x688 RP(r2): d_alloc_parallel+0x134/0x688 Backtrace: [<000000004036974c>] __lookup_slow+0xa4/0x200 [<0000000040369fc8>] walk_component+0x288/0x458 [<000000004036a9a0>] path_lookupat+0x88/0x198 [<000000004036e748>] filename_lookup+0xa0/0x168 [<000000004036e95c>] user_path_at_empty+0x64/0x80 [<000000004035d93c>] vfs_statx+0x104/0x158 [<000000004035dfcc>] __do_sys_lstat64+0x44/0x80 [<000000004035e5a0>] sys_lstat64+0x20/0x38 [<0000000040180054>] syscall_exit+0x0/0x14 The code was stuck in this loop in d_alloc_parallel: 4037d414: 0e 00 10 dc ldd 0(r16),ret0 4037d418: c7 fc 5f ed bb,< ret0,1f,4037d414 <d_alloc_parallel+0x384> 4037d41c: 08 00 02 40 nop This is the inner loop of bit_spin_lock which is called by hlist_bl_unlock in d_alloc_parallel: static inline void bit_spin_lock(int bitnum, unsigned long *addr) { /* * Assuming the lock is uncontended, this never enters * the body of the outer loop. If it is contended, then * within the inner loop a non-atomic test is used to * busywait with less bus contention for a good time to * attempt to acquire the lock bit. */ preempt_disable(); #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) while (unlikely(test_and_set_bit_lock(bitnum, addr))) { preempt_enable(); do { cpu_relax(); } while (test_bit(bitnum, addr)); preempt_disable(); } #endif __acquire(bitlock); } After consideration, I realized that we must be losing bit unlocks. Then, I noticed that we missed defining atomic64_set_release(). Adding this define fixes the stalls in bit operations. Signed-off-by: Dave Anglin <dave.anglin@bell.net> Cc: stable@vger.kernel.org Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* parisc: Fix kernel panic in mem_init()Helge Deller2020-06-031-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit bf71bc16e02162388808949b179d59d0b571b965 upstream. The Debian kernel v5.6 triggers this kernel panic: Kernel panic - not syncing: Bad Address (null pointer deref?) Bad Address (null pointer deref?): Code=26 (Data memory access rights trap) at addr 0000000000000000 CPU: 0 PID: 0 Comm: swapper Not tainted 5.6.0-2-parisc64 #1 Debian 5.6.14-1 IAOQ[0]: mem_init+0xb0/0x150 IAOQ[1]: mem_init+0xb4/0x150 RP(r2): start_kernel+0x6c8/0x1190 Backtrace: [<0000000040101ab4>] start_kernel+0x6c8/0x1190 [<0000000040108574>] start_parisc+0x158/0x1b8 on a HP-PARISC rp3440 machine with this memory layout: Memory Ranges: 0) Start 0x0000000000000000 End 0x000000003fffffff Size 1024 MB 1) Start 0x0000004040000000 End 0x00000040ffdfffff Size 3070 MB Fix the crash by avoiding virt_to_page() and similar functions in mem_init() until the memory zones have been fully set up. Signed-off-by: Helge Deller <deller@gmx.de> Cc: stable@vger.kernel.org # v5.0+ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* parisc: Fix compiler warnings in debug_core.cHelge Deller2020-01-121-2/+8
| | | | | | | | | | | | | | | | | | [ Upstream commit 75cf9797006a3a9f29a3a25c1febd6842a4a9eb2 ] Fix this compiler warning: kernel/debug/debug_core.c: In function ‘kgdb_cpu_enter’: arch/parisc/include/asm/cmpxchg.h:48:3: warning: value computed is not used [-Wunused-value] 48 | ((__typeof__(*(ptr)))__xchg((unsigned long)(x), (ptr), sizeof(*(ptr)))) arch/parisc/include/asm/atomic.h:78:30: note: in expansion of macro ‘xchg’ 78 | #define atomic_xchg(v, new) (xchg(&((v)->counter), new)) | ^~~~ kernel/debug/debug_core.c:596:4: note: in expansion of macro ‘atomic_xchg’ 596 | atomic_xchg(&kgdb_active, cpu); | ^~~~~~~~~~~ Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
* parisc: Fix vmap memory leak in ioremap()/iounmap()Helge Deller2019-10-291-5/+7
| | | | | | | | | | | | | | | | | commit 513f7f747e1cba81f28a436911fba0b485878ebd upstream. Sven noticed that calling ioremap() and iounmap() multiple times leads to a vmap memory leak: vmap allocation for size 4198400 failed: use vmalloc=<size> to increase size It seems we missed calling vunmap() in iounmap(). Signed-off-by: Helge Deller <deller@gmx.de> Noticed-by: Sven Schnelle <svens@stackframe.org> Cc: <stable@vger.kernel.org> # v3.16+ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* parisc: Fix build of compressed kernel even with debug enabledHelge Deller2019-08-061-2/+2
| | | | | | | | | | | | | | | commit 3fe6c873af2f2247544debdbe51ec29f690a2ccf upstream. With debug info enabled (CONFIG_DEBUG_INFO=y) the resulting vmlinux may get that huge that we need to increase the start addresss for the decompression text section otherwise one will face a linker error. Reported-by: Sven Schnelle <svens@stackframe.org> Tested-by: Sven Schnelle <svens@stackframe.org> Cc: stable@vger.kernel.org # v4.14+ Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* parisc: Fix kernel panic due invalid values in IAOQ0 or IAOQ1Helge Deller2019-07-311-10/+18
| | | | | | | | | | | | | | | | | | | | | | commit 10835c854685393a921b68f529bf740fa7c9984d upstream. On parisc the privilege level of a process is stored in the lowest two bits of the instruction pointers (IAOQ0 and IAOQ1). On Linux we use privilege level 0 for the kernel and privilege level 3 for user-space. So userspace should not be allowed to modify IAOQ0 or IAOQ1 of a ptraced process to change it's privilege level to e.g. 0 to try to gain kernel privileges. This patch prevents such modifications by always setting the two lowest bits to one (which relates to privilege level 3 for user-space) if IAOQ0 or IAOQ1 are modified via ptrace calls in the native and compat ptrace paths. Link: https://bugs.gentoo.org/481768 Reported-by: Jeroen Roovers <jer@gentoo.org> Cc: <stable@vger.kernel.org> Tested-by: Rolf Eike Beer <eike-kernel@sf-tec.de> Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* parisc: Ensure userspace privilege for ptraced processes in regset functionsHelge Deller2019-07-311-1/+2
| | | | | | | | | | | | | | | | | | | | | commit 34c32fc603311a72cb558e5e337555434f64c27b upstream. On parisc the privilege level of a process is stored in the lowest two bits of the instruction pointers (IAOQ0 and IAOQ1). On Linux we use privilege level 0 for the kernel and privilege level 3 for user-space. So userspace should not be allowed to modify IAOQ0 or IAOQ1 of a ptraced process to change it's privilege level to e.g. 0 to try to gain kernel privileges. This patch prevents such modifications in the regset support functions by always setting the two lowest bits to one (which relates to privilege level 3 for user-space) if IAOQ0 or IAOQ1 are modified via ptrace regset calls. Link: https://bugs.gentoo.org/481768 Cc: <stable@vger.kernel.org> # v4.7+ Tested-by: Rolf Eike Beer <eike-kernel@sf-tec.de> Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* parisc: Fix compiler warnings in float emulation codeHelge Deller2019-06-251-4/+4
| | | | | | | | | | | | | [ Upstream commit 6b98d9134e14f5ef4bcf64b27eedf484ed19a1ec ] Avoid such compiler warnings: arch/parisc/math-emu/cnv_float.h:71:27: warning: ‘<<’ in boolean context, did you mean ‘<’ ? [-Wint-in-bool-context] ((Dintp1(dint_valueA) << 33 - SGL_EXP_LENGTH) || Dintp2(dint_valueB)) arch/parisc/math-emu/fcnvxf.c:257:6: note: in expansion of macro ‘Dint_isinexact_to_sgl’ if (Dint_isinexact_to_sgl(srcp1,srcp2)) { Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
* parisc: Rename LEVEL to PA_ASM_LEVEL to avoid name clash with DRBD codeHelge Deller2019-05-253-6/+6
| | | | | | | | | | | | | | commit 1829dda0e87f4462782ca81be474c7890efe31ce upstream. LEVEL is a very common word, and now after many years it suddenly clashed with another LEVEL define in the DRBD code. Rename it to PA_ASM_LEVEL instead. Reported-by: kbuild test robot <lkp@intel.com> Signed-off-by: Helge Deller <deller@gmx.de> Cc: <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* parisc: Use PA_ASM_LEVEL in boot codeHelge Deller2019-05-251-3/+3
| | | | | | | | | | | | commit bdca5d64ee92abeacd6dada0bc6f6f8e6350dd67 upstream. The LEVEL define clashed with the DRBD code. Reported-by: kbuild test robot <lkp@intel.com> Signed-off-by: Helge Deller <deller@gmx.de> Cc: <stable@vger.kernel.org> # v4.14+ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* parisc: Export running_on_qemu symbol for modulesHelge Deller2019-05-251-0/+1
| | | | | | | | | commit 3e1120f4b57bc12437048494ab56648edaa5b57d upstream. Signed-off-by: Helge Deller <deller@gmx.de> CC: stable@vger.kernel.org # v4.9+ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* parisc: regs_return_value() should return gpr28Sven Schnelle2019-04-171-1/+1
| | | | | | | | | | | | | | commit 45efd871bf0a47648f119d1b41467f70484de5bc upstream. While working on kretprobes for PA-RISC I was wondering while the kprobes sanity test always fails on kretprobes. This is caused by returning gpr20 instead of gpr28. Signed-off-by: Sven Schnelle <svens@stackframe.org> Signed-off-by: Helge Deller <deller@gmx.de> Cc: stable@vger.kernel.org # 4.14+ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* parisc: Detect QEMU earlier in boot processHelge Deller2019-04-172-6/+3
| | | | | | | | | | | | | | | | | | | commit d006e95b5561f708d0385e9677ffe2c46f2ae345 upstream. While adding LASI support to QEMU, I noticed that the QEMU detection in the kernel happens much too late. For example, when a LASI chip is found by the kernel, it registers the LASI LED driver as well. But when we run on QEMU it makes sense to avoid spending unnecessary CPU cycles, so we need to access the running_on_QEMU flag earlier than before. This patch now makes the QEMU detection the fist task of the Linux kernel by moving it to where the kernel enters the C-coding. Fixes: 310d82784fb4 ("parisc: qemu idle sleep support") Signed-off-by: Helge Deller <deller@gmx.de> Cc: stable@vger.kernel.org # v4.14+ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* parisc: Fix ptrace syscall number modificationDmitry V. Levin2019-02-271-8/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit b7dc5a071ddf69c0350396b203cba32fe5bab510 upstream. Commit 910cd32e552e ("parisc: Fix and enable seccomp filter support") introduced a regression in ptrace-based syscall tampering: when tracer changes syscall number to -1, the kernel fails to initialize %r28 with -ENOSYS and subsequently fails to return the error code of the failed syscall to userspace. This erroneous behaviour could be observed with a simple strace syscall fault injection command which is expected to print something like this: $ strace -a0 -ewrite -einject=write:error=enospc echo hello write(1, "hello\n", 6) = -1 ENOSPC (No space left on device) (INJECTED) write(2, "echo: ", 6) = -1 ENOSPC (No space left on device) (INJECTED) write(2, "write error", 11) = -1 ENOSPC (No space left on device) (INJECTED) write(2, "\n", 1) = -1 ENOSPC (No space left on device) (INJECTED) +++ exited with 1 +++ After commit 910cd32e552ea09caa89cdbe328e468979b030dd it loops printing something like this instead: write(1, "hello\n", 6../strace: Failed to tamper with process 12345: unexpectedly got no error (return value 0, error 0) ) = 0 (INJECTED) This bug was found by strace test suite. Fixes: 910cd32e552e ("parisc: Fix and enable seccomp filter support") Cc: stable@vger.kernel.org # v4.5+ Signed-off-by: Dmitry V. Levin <ldv@altlinux.org> Tested-by: Helge Deller <deller@gmx.de> Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* parisc: Fix exported address of os_hpmc handlerHelge Deller2018-11-131-2/+1
| | | | | | | | | | | | | | | | | | commit 99a3ae51d557d8e38a7aece65678a31f9db215ee upstream. In the C-code we need to put the physical address of the hpmc handler in the interrupt vector table (IVA) in order to get HPMCs working. Since on parisc64 function pointers are indirect (in fact they are function descriptors) we instead export the address as variable and not as function. This reverts a small part of commit f39cce654f9a ("parisc: Add cfi_startproc and cfi_endproc to assembly code"). Signed-off-by: Helge Deller <deller@gmx.de> Cc: <stable@vger.kernel.org> [4.9+] Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* parisc: Fix map_pages() to not overwrite existing pte entriesHelge Deller2018-11-131-6/+2
| | | | | | | | | | | | | | | | commit 3c229b3f2dd8133f61bb81d3cb018be92f4bba39 upstream. Fix a long-existing small nasty bug in the map_pages() implementation which leads to overwriting already written pte entries with zero, *if* map_pages() is called a second time with an end address which isn't aligned on a pmd boundry. This happens for example if we want to remap only the text segment read/write in order to run alternative patching on the code. Exiting the loop when we reach the end address fixes this. Cc: stable@vger.kernel.org Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* parisc: Fix address in HPMC IVAJohn David Anglin2018-11-132-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 1138b6718ff74d2a934459643e3754423d23b5e2 upstream. Helge noticed that the address of the os_hpmc handler was not being correctly calculated in the hpmc macro. As a result, PDCE_CHECK would fail to call os_hpmc: <Cpu2> e800009802e00000 0000000000000000 CC_ERR_CHECK_HPMC <Cpu2> 37000f7302e00000 8040004000000000 CC_ERR_CPU_CHECK_SUMMARY <Cpu2> f600105e02e00000 fffffff0f0c00000 CC_MC_HPMC_MONARCH_SELECTED <Cpu2> 140003b202e00000 000000000000000b CC_ERR_HPMC_STATE_ENTRY <Cpu2> 5600100b02e00000 00000000000001a0 CC_MC_OS_HPMC_LEN_ERR <Cpu2> 5600106402e00000 fffffff0f0438e70 CC_MC_BR_TO_OS_HPMC_FAILED <Cpu2> e800009802e00000 0000000000000000 CC_ERR_CHECK_HPMC <Cpu2> 37000f7302e00000 8040004000000000 CC_ERR_CPU_CHECK_SUMMARY <Cpu2> 4000109f02e00000 0000000000000000 CC_MC_HPMC_INITIATED <Cpu2> 4000101902e00000 0000000000000000 CC_MC_MULTIPLE_HPMCS <Cpu2> 030010d502e00000 0000000000000000 CC_CPU_STOP The address problem can be seen by dumping the fault vector: 0000000040159000 <fault_vector_20>: 40159000: 63 6f 77 73 stb r15,-2447(dp) 40159004: 20 63 61 6e ldil L%b747000,r3 40159008: 20 66 6c 79 ldil L%-1c3b3000,r3 ... 40159020: 08 00 02 40 nop 40159024: 20 6e 60 02 ldil L%15d000,r3 40159028: 34 63 00 00 ldo 0(r3),r3 4015902c: e8 60 c0 02 bv,n r0(r3) 40159030: 08 00 02 40 nop 40159034: 00 00 00 00 break 0,0 40159038: c0 00 70 00 bb,*< r0,sar,40159840 <fault_vector_20+0x840> 4015903c: 00 00 00 00 break 0,0 Location 40159038 should contain the physical address of os_hpmc: 000000004015d000 <os_hpmc>: 4015d000: 08 1a 02 43 copy r26,r3 4015d004: 01 c0 08 a4 mfctl iva,r4 4015d008: 48 85 00 68 ldw 34(r4),r5 This patch moves the address setup into initialize_ivt to resolve the above problem. I tested the change by dumping the HPMC entry after setup: 0000000040209020: 8000240 0000000040209024: 206a2004 0000000040209028: 34630ac0 000000004020902c: e860c002 0000000040209030: 8000240 0000000040209034: 1bdddce6 0000000040209038: 15d000 000000004020903c: 1a0 Signed-off-by: John David Anglin <dave.anglin@bell.net> Cc: <stable@vger.kernel.org> Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* parisc: Remove unnecessary barriers from spinlock.hJohn David Anglin2018-08-241-6/+2
| | | | | | | | | | | | | | | | | | | | commit 3b885ac1dc35b87a39ee176a6c7e2af9c789d8b8 upstream. Now that mb() is an instruction barrier, it will slow performance if we issue unnecessary barriers. The spinlock defines have a number of unnecessary barriers.  The __ldcw() define is both a hardware and compiler barrier.  The mb() barriers in the routines using __ldcw() serve no purpose. The only barrier needed is the one in arch_spin_unlock().  We need to ensure all accesses are complete prior to releasing the lock. Signed-off-by: John David Anglin <dave.anglin@bell.net> Cc: stable@vger.kernel.org # 4.0+ Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* parisc: Remove ordered stores from syscall.SJohn David Anglin2018-08-241-12/+12
| | | | | | | | | | | | | | | | | commit 7797167ffde1f00446301cb22b37b7c03194cfaf upstream. Now that we use a sync prior to releasing the locks in syscall.S, we don't need the PA 2.0 ordered stores used to release some locks.  Using an ordered store, potentially slows the release and subsequent code. There are a number of other ordered stores and loads that serve no purpose.  I have converted these to normal stores. Signed-off-by: John David Anglin <dave.anglin@bell.net> Cc: stable@vger.kernel.org # 4.0+ Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* parisc: Define mb() and add memory barriers to assembler unlock sequencesJohn David Anglin2018-08-154-0/+39
| | | | | | | | | | | | | | | | | | | | | | | | | commit fedb8da96355f5f64353625bf96dc69423ad1826 upstream. For years I thought all parisc machines executed loads and stores in order. However, Jeff Law recently indicated on gcc-patches that this is not correct. There are various degrees of out-of-order execution all the way back to the PA7xxx processor series (hit-under-miss). The PA8xxx series has full out-of-order execution for both integer operations, and loads and stores. This is described in the following article: http://web.archive.org/web/20040214092531/http://www.cpus.hp.com/technical_references/advperf.shtml For this reason, we need to define mb() and to insert a memory barrier before the store unlocking spinlocks. This ensures that all memory accesses are complete prior to unlocking. The ldcw instruction performs the same function on entry. Signed-off-by: John David Anglin <dave.anglin@bell.net> Cc: stable@vger.kernel.org # 4.0+ Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* parisc: Enable CONFIG_MLONGCALLS by defaultHelge Deller2018-08-151-1/+1
| | | | | | | | | | | | | commit 66509a276c8c1d19ee3f661a41b418d101c57d29 upstream. Enable the -mlong-calls compiler option by default, because otherwise in most cases linking the vmlinux binary fails due to truncations of R_PARISC_PCREL22F relocations. This fixes building the 64-bit defconfig. Cc: stable@vger.kernel.org # 4.0+ Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* parisc: Move setup_profiling_timer() out of init sectionHelge Deller2018-06-211-2/+1
| | | | | | | | | | | | [ Upstream commit 01f56832cfb6fcc204e7203f46841b6185ebd574 ] No other architecture has setup_profiling_timer() in the init section, thus on parisc we face this section mismatch warning: Reference from the function devm_device_add_group() to the function .init.text:setup_profiling_timer() Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* parisc: drivers.c: Fix section mismatchesHelge Deller2018-06-211-3/+4
| | | | | | | | | | | | | | [ Upstream commit b819439fea305a0bfd6ca23a7994fd1a8847c0d8 ] Fix two section mismatches in drivers.c: 1) Section mismatch in reference from the function alloc_tree_node() to the function .init.text:create_tree_node(). 2) Section mismatch in reference from the function walk_native_bus() to the function .init.text:alloc_pa_dev(). Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* parisc: time: Convert read_persistent_clock() to read_persistent_clock64()Baolin Wang2018-06-211-1/+1
| | | | | | | | | | | | | | | | [ Upstream commit f76cdd00ef0e39d880139b074e3b247594dff95a ] The read_persistent_clock() uses a timespec, which is not year 2038 safe on 32bit systems. On parisc architecture, we have implemented generic RTC drivers that can be used to compensate the system suspend time, but the RTC time can not represent the nanosecond resolution, so this patch just converts to read_persistent_clock64() with timespec64. Signed-off-by: Baolin Wang <baolin.wang@linaro.org> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* parisc: Fix HPMC handler by increasing size to multiple of 16 bytesHelge Deller2018-04-191-1/+5
| | | | | | | | | | | | | commit d5654e156bc4d68a87bbaa6d7e020baceddf6e68 upstream. Make sure that the HPMC (High Priority Machine Check) handler is 16-byte aligned and that it's length in the IVT is a multiple of 16 bytes. Otherwise PDC may decide not to call the HPMC crash handler. Signed-off-by: Helge Deller <deller@gmx.de> Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* parisc: Fix out of array access in match_pci_device()Helge Deller2018-04-191-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 615b2665fd20c327b631ff1e79426775de748094 upstream. As found by the ubsan checker, the value of the 'index' variable can be out of range for the bc[] array: UBSAN: Undefined behaviour in arch/parisc/kernel/drivers.c:655:21 index 6 is out of range for type 'char [6]' Backtrace: [<104fa850>] __ubsan_handle_out_of_bounds+0x68/0x80 [<1019d83c>] check_parent+0xc0/0x170 [<1019d91c>] descend_children+0x30/0x6c [<1059e164>] device_for_each_child+0x60/0x98 [<1019cd54>] parse_tree_node+0x40/0x54 [<1019d86c>] check_parent+0xf0/0x170 [<1019d91c>] descend_children+0x30/0x6c [<1059e164>] device_for_each_child+0x60/0x98 [<1019d938>] descend_children+0x4c/0x6c [<1059e164>] device_for_each_child+0x60/0x98 [<1019cd54>] parse_tree_node+0x40/0x54 [<1019cffc>] hwpath_to_device+0xa4/0xc4 Signed-off-by: Helge Deller <deller@gmx.de> Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* parisc: Handle case where flush_cache_range is called with no contextJohn David Anglin2018-03-211-9/+32
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 9ef0f88fe5466c2ca1d2975549ba6be502c464c1 upstream. Just when I had decided that flush_cache_range() was always called with a valid context, Helge reported two cases where the "BUG_ON(!vma->vm_mm->context);" was hit on the phantom buildd: kernel BUG at /mnt/sdb6/linux/linux-4.15.4/arch/parisc/kernel/cache.c:587! CPU: 1 PID: 3254 Comm: kworker/1:2 Tainted: G D 4.15.0-1-parisc64-smp #1 Debian 4.15.4-1+b1 Workqueue: events free_ioctx   IAOQ[0]: flush_cache_range+0x164/0x168   IAOQ[1]: flush_cache_page+0x0/0x1c8   RP(r2): unmap_page_range+0xae8/0xb88 Backtrace:   [<00000000404a6980>] unmap_page_range+0xae8/0xb88   [<00000000404a6ae0>] unmap_single_vma+0xc0/0x188   [<00000000404a6cdc>] zap_page_range_single+0x134/0x1f8   [<00000000404a702c>] unmap_mapping_range+0x1cc/0x208   [<0000000040461518>] truncate_pagecache+0x98/0x108   [<0000000040461624>] truncate_setsize+0x9c/0xb8   [<00000000405d7f30>] put_aio_ring_file+0x80/0x100   [<00000000405d803c>] aio_free_ring+0x8c/0x290   [<00000000405d82c0>] free_ioctx+0x80/0x180   [<0000000040284e6c>] process_one_work+0x21c/0x668   [<00000000402854c4>] worker_thread+0x20c/0x778   [<0000000040291d44>] kthread+0x2d4/0x2e0   [<0000000040204020>] end_fault_vector+0x20/0xc0 This indicates that we need to handle the no context case in flush_cache_range() as we do in flush_cache_mm(). In thinking about this, I realized that we don't need to flush the TLB when there is no context. So, I added context checks to the large flush cases in flush_cache_mm() and flush_cache_range(). The large flush case occurs frequently in flush_cache_mm() and the change should improve fork performance. The v2 version of this change removes the BUG_ON from flush_cache_page() by skipping the TLB flush when there is no context.  I also added code to flush the TLB in flush_cache_mm() and flush_cache_range() when we have a context that's not current.  Now all three routines handle TLB flushes in a similar manner. Signed-off-by: John David Anglin <dave.anglin@bell.net> Cc: stable@vger.kernel.org # 4.9+ Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* parisc: Fix ordering of cache and TLB flushesJohn David Anglin2018-03-083-26/+54
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 0adb24e03a124b79130c9499731936b11ce2677d upstream. The change to flush_kernel_vmap_range() wasn't sufficient to avoid the SMP stalls.  The problem is some drivers call these routines with interrupts disabled.  Interrupts need to be enabled for flush_tlb_all() and flush_cache_all() to work.  This version adds checks to ensure interrupts are not disabled before calling routines that need IPI interrupts.  When interrupts are disabled, we now drop into slower code. The attached change fixes the ordering of cache and TLB flushes in several cases.  When we flush the cache using the existing PTE/TLB entries, we need to flush the TLB after doing the cache flush.  We don't need to do this when we flush the entire instruction and data caches as these flushes don't use the existing TLB entries.  The same is true for tmpalias region flushes. The flush_kernel_vmap_range() and invalidate_kernel_vmap_range() routines have been updated. Secondly, we added a new purge_kernel_dcache_range_asm() routine to pacache.S and use it in invalidate_kernel_vmap_range().  Nominally, purges are faster than flushes as the cache lines don't have to be written back to memory. Hopefully, this is sufficient to resolve the remaining problems due to cache speculation.  So far, testing indicates that this is the case.  I did work up a patch using tmpalias flushes, but there is a performance hit because we need the physical address for each page, and we also need to sequence access to the tmpalias flush code.  This increases the probability of stalls. Signed-off-by: John David Anglin <dave.anglin@bell.net> Cc: stable@vger.kernel.org # 4.9+ Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* parisc: Reduce irq overhead when run in qemuHelge Deller2018-03-081-4/+5
| | | | | | | | | | | | | | | | | commit 636a415bcc7f4fd020ece8fd5fc648c4cef19c34 upstream. When run under QEMU, calling mfctl(16) creates some overhead because the qemu timer has to be scaled and moved into the register. This patch reduces the number of calls to mfctl(16) by moving the calls out of the loops. Additionally, increase the minimal time interval to 8000 cycles instead of 500 to compensate possible QEMU delays when delivering interrupts. Signed-off-by: Helge Deller <deller@gmx.de> Cc: stable@vger.kernel.org # 4.14+ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* parisc: Use cr16 interval timers unconditionally on qemuHelge Deller2018-03-082-1/+3
| | | | | | | | | | | | commit 5ffa8518851f1401817c15d2a7eecc0373c26ff9 upstream. When running on qemu we know that the (emulated) cr16 cpu-internal clocks are syncronized. So let's use them unconditionally on qemu. Signed-off-by: Helge Deller <deller@gmx.de> Cc: stable@vger.kernel.org # 4.14+ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* parisc: Reduce thread stack to 16 kbJohn David Anglin2018-03-031-0/+5
| | | | | | | | | | | | | | [ Upstream commit da57c5414f49ef9e4bcb9ae0bbafd1d650b31411 ] In testing, I found that the thread stack can be 16 kB when using an irq stack. Without it, the thread stack needs to be 32 kB. Currently, the irq stack is 32 kB. While it probably could be 16 kB, I would prefer to leave it as is for safety. Signed-off-by: John David Anglin <dave.anglin@bell.net> Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* parisc: qemu idle sleep supportHelge Deller2018-01-101-0/+39
| | | | | | | | | | | | | | | | commit 310d82784fb4d60c80569f5ca9f53a7f3bf1d477 upstream. Add qemu idle sleep support when running under qemu with SeaBIOS PDC firmware. Like the power architecture we use the "or" assembler instructions, which translate to nops on real hardware, to indicate that qemu shall idle sleep. Signed-off-by: Helge Deller <deller@gmx.de> Cc: Richard Henderson <rth@twiddle.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* parisc: Fix alignment of pa_tlb_lock in assembly on 32-bit SMP kernelHelge Deller2018-01-103-4/+20
| | | | | | | | | | | | | | | | | | | | commit 88776c0e70be0290f8357019d844aae15edaa967 upstream. Qemu for PARISC reported on a 32bit SMP parisc kernel strange failures about "Not-handled unaligned insn 0x0e8011d6 and 0x0c2011c9." Those opcodes evaluate to the ldcw() assembly instruction which requires (on 32bit) an alignment of 16 bytes to ensure atomicity. As it turns out, qemu is correct and in our assembly code in entry.S and pacache.S we don't pay attention to the required alignment. This patch fixes the problem by aligning the lock offset in assembly code in the same manner as we do in our C-code. Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Revert "parisc: Re-enable interrupts early"John David Anglin2017-12-291-3/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 9352aeada4d8d8753fc0e414fbfe8fdfcb68a12c upstream. This reverts commit 5c38602d83e584047906b41b162ababd4db4106d. Interrupts can't be enabled early because the register saves are done on the thread stack prior to switching to the IRQ stack. This caused stack overflows and the thread stack needed increasing to 32k. Even then, stack overflows still occasionally occurred. Background: Even with a 32 kB thread stack, I have seen instances where the thread stack overflowed on the mx3210 buildd. Detection of stack overflow only occurs when we have an external interrupt. When an external interrupt occurs, we switch to the thread stack if we are not already on a kernel stack. Then, registers and specials are saved to the kernel stack. The bug occurs in intr_return where interrupts are reenabled prior to returning from the interrupt. This was done incase we need to schedule or deliver signals. However, it introduces the possibility that multiple external interrupts may occur on the thread stack and cause a stack overflow. These might not be detected and cause the kernel to misbehave in random ways. This patch changes the code back to only reenable interrupts when we are going to schedule or deliver signals. As a result, we generally return from an interrupt before reenabling interrupts. This minimizes the growth of the thread stack. Fixes: 5c38602d83e5 ("parisc: Re-enable interrupts early") Signed-off-by: John David Anglin <dave.anglin@bell.net> Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>