[ 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>
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>
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>
[ 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>
[ 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>
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>
[ 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>
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>
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>
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>