BMC/Intel-BMC/linux.git/arch/parisc/kernel, branch dev-5.15-intel

parisc: Fix patch code locking and flushing

2022-04-13T18:59:14+00:00

[ Upstream commit a9fe7fa7d874a536e0540469f314772c054a0323 ] This change fixes the following: 1) The flags variable is not initialized. Always use raw_spin_lock_irqsave and raw_spin_unlock_irqrestore to serialize patching. 2) flush_kernel_vmap_range is primarily intended for DMA flushes. Since __patch_text_multiple is often called with interrupts disabled, it is better to directly call flush_kernel_dcache_range_asm and flush_kernel_icache_range_asm. This avoids an extra call. 3) The final call to flush_icache_range is unnecessary. Signed-off-by: John David Anglin Signed-off-by: Helge Deller Signed-off-by: Sasha Levin

parisc: Fix handling off probe non-access faults

2022-04-08T12:23:56+00:00

[ Upstream commit e00b0a2ab8ec019c344e53bfc76e31c18bb587b7 ] Currently, the parisc kernel does not fully support non-access TLB fault handling for probe instructions. In the fast path, we set the target register to zero if it is not a shadowed register. The slow path is not implemented, so we call do_page_fault. The architecture indicates that non-access faults should not cause a page fault from disk. This change adds to code to provide non-access fault support for probe instructions. It also modifies the handling of faults on userspace so that if the address lies in a valid VMA and the access type matches that for the VMA, the probe target register is set to one. Otherwise, the target register is set to zero. This was done to make probe instructions more useful for userspace. Probe instructions are not very useful if they set the target register to zero whenever a page is not present in memory. Nominally, the purpose of the probe instruction is determine whether read or write access to a given address is allowed. This fixes a problem in function pointer comparison noticed in the glibc testsuite (stdio-common/tst-vfprintf-user-type). The same problem is likely in glibc (_dl_lookup_address). V2 adds flush and lpa instruction support to handle_nadtlb_fault. Signed-off-by: John David Anglin Signed-off-by: Helge Deller Signed-off-by: Sasha Levin

parisc/unaligned: Fix ldw() and stw() unalignment handlers

2022-03-02T10:47:49+00:00

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 Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman

parisc/unaligned: Fix fldd and fstd unaligned handlers on 32-bit kernel

2022-03-02T10:47:48+00:00

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 Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman

parisc: Avoid calling faulthandler_disabled() twice

2022-01-27T10:04:55+00:00

[ 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 Signed-off-by: Helge Deller Signed-off-by: Sasha Levin

parisc: Clear stale IIR value on instruction access rights trap

2022-01-05T11:42:33+00:00

[ Upstream commit 484730e5862f6b872dca13840bed40fd7c60fa26 ] When a trap 7 (Instruction access rights) occurs, this means the CPU couldn't execute an instruction due to missing execute permissions on the memory region. In this case it seems the CPU didn't even fetched the instruction from memory and thus did not store it in the cr19 (IIR) register before calling the trap handler. So, the trap handler will find some random old stale value in cr19. This patch simply overwrites the stale IIR value with a constant magic "bad food" value (0xbaadf00d), in the hope people don't start to try to understand the various random IIR values in trap 7 dumps. Noticed-by: John David Anglin Signed-off-by: Helge Deller Signed-off-by: Sasha Levin

parisc: Correct completer in lws start

2021-12-29T11:28:53+00:00

commit 8f66fce0f46560b9e910787ff7ad0974441c4f9c upstream. The completer in the "or,ev %r1,%r30,%r30" instruction is reversed, so we are not clipping the LWS number when we are called from a 32-bit process (W=0). We need to nulify the following depdi instruction when the least-significant bit of %r30 is 1. If the %r20 register is not clipped, a user process could perform a LWS call that would branch to an undefined location in the kernel and potentially crash the machine. Signed-off-by: John David Anglin Cc: stable@vger.kernel.org # 4.19+ Signed-off-by: Helge Deller Signed-off-by: Greg Kroah-Hartman

parisc: Mark cr16 CPU clocksource unstable on all SMP machines

2021-12-08T08:04:55+00:00

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 Cc: # v5.15+ Signed-off-by: Greg Kroah-Hartman

Revert "parisc: Fix backtrace to always include init funtion names"

2021-12-01T08:04:41+00:00

commit 98400ad75e95860e9a10ec78b0b90ab66184a2ce upstream. This reverts commit 279917e27edc293eb645a25428c6ab3f3bca3f86. With the CONFIG_HARDENED_USERCOPY option enabled, this patch triggers kernel bugs at runtime: usercopy: Kernel memory overwrite attempt detected to kernel text (offset 2084839, size 6)! kernel BUG at mm/usercopy.c:99! Backtrace: IAOQ[0]: usercopy_abort+0xc4/0xe8 [<00000000406ed1c8>] __check_object_size+0x174/0x238 [<00000000407086d4>] copy_strings.isra.0+0x3e8/0x708 [<0000000040709a20>] do_execveat_common.isra.0+0x1bc/0x328 [<000000004070b760>] compat_sys_execve+0x7c/0xb8 [<0000000040303eb8>] syscall_exit+0x0/0x14 The problem is, that we have an init section of at least 2MB size which starts at _stext and is freed after bootup. If then later some kernel data is (temporarily) stored in this free memory, check_kernel_text_object() will trigger a bug since the data appears to be inside the kernel text (>=_stext) area: if (overlaps(ptr, len, _stext, _etext)) usercopy_abort("kernel text"); Signed-off-by: Helge Deller Cc: stable@kernel.org # 5.4+ Signed-off-by: Greg Kroah-Hartman

Revert "parisc: Reduce sigreturn trampoline to 3 instructions"

2021-11-25T08:48:44+00:00

commit 79df39d535c7a3770856fe9f5aba8c0ad1eebdb6 upstream. This reverts commit e4f2006f1287e7ea17660490569cff323772dac4. This patch shows problems with signal handling. Revert it for now. Signed-off-by: Helge Deller Cc: # v5.15 Signed-off-by: Greg Kroah-Hartman