kernel.git/arch/parisc/kernel, branch linux-5.19.y

parisc: Fix userspace graphics card breakage due to pgtable special bit

2022-10-24T07:56:45Z

commit 70be49f2f6223ddd2fcddb0089a40864c37e1494 upstream. Commit df24e1783e6e ("parisc: Add vDSO support") introduced the vDSO support, for which a _PAGE_SPECIAL page table flag was needed. Since we wanted to keep every page table entry in 32-bits, this patch re-used the existing - but yet unused - _PAGE_DMB flag (which triggers a hardware break if a page is accessed) to store the special bit. But when graphics card memory is mmapped into userspace, the kernel uses vm_iomap_memory() which sets the the special flag. So, with the DMB bit set, every access to the graphics memory now triggered a hardware exception and segfaulted the userspace program. Fix this breakage by dropping the DMB bit when writing the page protection bits to the CPU TLB. In addition this patch adds a small optimization: if huge pages aren't configured (which is at least the case for 32-bit kernels), then the special bit is stored in the hpage (HUGE PAGE) bit instead. That way we can skip to reset the DMB bit. Fixes: df24e1783e6e ("parisc: Add vDSO support") Cc: # 5.18+ Signed-off-by: Helge Deller Signed-off-by: Greg Kroah-Hartman

parisc: Add runtime check to prevent PA2.0 kernels on PA1.x machines

2022-09-15T08:47:08Z

[ Upstream commit 591d2108f3abc4db9f9073cae37cf3591fd250d6 ] If a 32-bit kernel was compiled for PA2.0 CPUs, it won't be able to run on machines with PA1.x CPUs. Add a check and bail out early if a PA1.x machine is detected. Signed-off-by: Helge Deller Signed-off-by: Sasha Levin

parisc: Fix exception handler for fldw and fstw instructions

2022-08-31T15:17:59Z

commit 7ae1f5508d9a33fd58ed3059bd2d569961e3b8bd upstream. The exception handler is broken for unaligned memory acceses with fldw and fstw instructions, because it trashes or uses randomly some other floating point register than the one specified in the instruction word on loads and stores. The instruction "fldw 0(addr),%fr22L" (and the other fldw/fstw instructions) encode the target register (%fr22) in the rightmost 5 bits of the instruction word. The 7th rightmost bit of the instruction word defines if the left or right half of %fr22 should be used. While processing unaligned address accesses, the FR3() define is used to extract the offset into the local floating-point register set. But the calculation in FR3() was buggy, so that for example instead of %fr22, register %fr12 [((22 * 2) & 0x1f) = 12] was used. This bug has been since forever in the parisc kernel and I wonder why it wasn't detected earlier. Interestingly I noticed this bug just because the libime debian package failed to build on *native* hardware, while it successfully built in qemu. This patch corrects the bitshift and masking calculation in FR3(). Signed-off-by: Helge Deller Cc: Signed-off-by: Greg Kroah-Hartman

parisc: io_pgetevents_time64() needs compat syscall in 32-bit compat mode

2022-08-17T13:13:48Z

commit 6431e92fc827bdd2d28f79150d90415ba9ce0d21 upstream. For all syscalls in 32-bit compat mode on 64-bit kernels the upper 32-bits of the 64-bit registers are zeroed out, so a negative 32-bit signed value will show up as positive 64-bit signed value. This behaviour breaks the io_pgetevents_time64() syscall which expects signed 64-bit values for the "min_nr" and "nr" parameters. Fix this by switching to the compat_sys_io_pgetevents_time64() syscall, which uses "compat_long_t" types for those parameters. Cc: # v5.1+ Signed-off-by: Helge Deller Signed-off-by: Greg Kroah-Hartman

parisc: Drop pa_swapper_pg_lock spinlock

2022-08-17T13:13:48Z

commit 3fbc9a7de0564c55d8a9584c9cd2c9dfe6bd6d43 upstream. This spinlock was dropped with commit b7795074a046 ("parisc: Optimize per-pagetable spinlocks") in kernel v5.12. Remove it to silence a sparse warning. Signed-off-by: Helge Deller Reported-by: kernel test robot Cc: # v5.12+ Signed-off-by: Greg Kroah-Hartman

parisc: Fix device names in /proc/iomem

2022-08-17T13:13:48Z

commit cab56b51ec0e69128909cef4650e1907248d821b upstream. Fix the output of /proc/iomem to show the real hardware device name including the pa_pathname, e.g. "Merlin 160 Core Centronics [8:16:0]". Up to now only the pa_pathname ("[8:16.0]") was shown. Signed-off-by: Helge Deller Cc: # v4.9+ Signed-off-by: Greg Kroah-Hartman

parisc: Fix vDSO signal breakage on 32-bit kernel

2022-07-02T16:36:58Z

Addition of vDSO support for parisc in kernel v5.18 suddenly broke glibc signal testcases on a 32-bit kernel. The trampoline code (sigtramp.S) which is mapped into userspace includes an offset to the context data on the stack, which is used by gdb and glibc to get access to registers. In a 32-bit kernel we used by mistake the offset into the compat context (which is valid on a 64-bit kernel only) instead of the offset into the "native" 32-bit context. Reported-by: John David Anglin Tested-by: John David Anglin Fixes: df24e1783e6e ("parisc: Add vDSO support") CC: stable@vger.kernel.org # 5.18 Signed-off-by: Helge Deller

parisc/unaligned: Fix emulate_ldw() breakage

2022-06-27T19:30:11Z

The commit e8aa7b17fe41 broke the 32-bit load-word unalignment exception handler because it calculated the wrong amount of bits by which the value should be shifted. This patch fixes it. Signed-off-by: Helge Deller Fixes: e8aa7b17fe41 ("parisc/unaligned: Rewrite inline assembly of emulate_ldw()") Cc: stable@vger.kernel.org # v5.18

parisc: Fix flush_anon_page on PA8800/PA8900

2022-06-26T10:23:15Z

Anonymous pages are allocated with the shared mappings colouring, SHM_COLOUR. Since the alias boundary on machines with PA8800 and PA8900 processors is unknown, flush_user_cache_page() might not flush all mappings of a shared anonymous page. Flushing the whole data cache flushes all mappings. This won't fix all coherency issues with shared mappings but it seems to work well in practice. I haven't seen any random memory faults in almost a month on a rp3440 running as a debian buildd machine. There is a small preformance hit. Signed-off-by: John David Anglin Signed-off-by: Helge Deller Cc: stable@vger.kernel.org # v5.18+

Merge tag 'for-5.19/parisc-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux

2022-06-04T20:50:23Z

Pull more parisc architecture updates from Helge Deller: "A fix to prevent crash at bootup if CONFIG_SCHED_MC is enabled, and add auto-detection of primary graphics card for framebuffer driver" * tag 'for-5.19/parisc-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux: parisc/stifb: Keep track of hardware path of graphics card parisc/stifb: Implement fb_is_primary_device() parisc: fix a crash with multicore scheduler