kernel.git/arch/m68k/kernel, branch linux-6.4.y

m68k: Fix invalid .section syntax

2023-09-13T07:47:51Z

[ Upstream commit 922a9bd138101e3e5718f0f4d40dba68ef89bb43 ] gas supports several different forms for .section for ELF targets, including: .section NAME [, "FLAGS"[, @TYPE[,FLAG_SPECIFIC_ARGUMENTS]]] and: .section "NAME"[, #FLAGS...] In several places we use a mix of these two forms: .section NAME, #FLAGS... A current development snapshot of binutils (2.40.50.20230611) treats this mixed syntax as an error. Change to consistently use: .section NAME, "FLAGS" as is used elsewhere in the kernel. Link: https://buildd.debian.org/status/fetch.php?pkg=linux&arch=m68k&ver=6.4%7Erc6-1%7Eexp1&stamp=1686907300&raw=1 Signed-off-by: Ben Hutchings Tested-by: Jan-Benedict Glaw Link: https://lore.kernel.org/r/ZIyBaueWT9jnTwRC@decadent.org.uk Signed-off-by: Geert Uytterhoeven Signed-off-by: Sasha Levin

m68k/cpu: Switch to arch_cpu_finalize_init()

2023-08-08T18:04:48Z

commit 9ceecc2589b9d7cef6b321339ed8de484eac4b20 upstream check_bugs() is about to be phased out. Switch over to the new arch_cpu_finalize_init() implementation. No functional change. Signed-off-by: Thomas Gleixner Acked-by: Geert Uytterhoeven Link: https://lore.kernel.org/r/20230613224545.254342916@linutronix.de Signed-off-by: Daniel Sneddon Signed-off-by: Greg Kroah-Hartman

m68k: Move signal frame following exception on 68020/030

2023-05-22T11:51:20Z

On 68030/020, an instruction such as, moveml %a2-%a3/%a5,%sp@- may cause a stack page fault during instruction execution (i.e. not at an instruction boundary) and produce a format 0xB exception frame. In this situation, the value of USP will be unreliable. If a signal is to be delivered following the exception, this USP value is used to calculate the location for a signal frame. This can result in a corrupted user stack. The corruption was detected in dash (actually in glibc) where it showed up as an intermittent "stack smashing detected" message and crash following signal delivery for SIGCHLD. It was hard to reproduce that failure because delivery of the signal raced with the page fault and because the kernel places an unpredictable gap of up to 7 bytes between the USP and the signal frame. A format 0xB exception frame can be produced by a bus error or an address error. The 68030 Users Manual says that address errors occur immediately upon detection during instruction prefetch. The instruction pipeline allows prefetch to overlap with other instructions, which means an address error can arise during the execution of a different instruction. So it seems likely that this patch may help in the address error case also. Reported-and-tested-by: Stan Johnson Link: https://lore.kernel.org/all/CAMuHMdW3yD22_ApemzW_6me3adq6A458u1_F0v-1EYwK_62jPA@mail.gmail.com/ Cc: Michael Schmitz Cc: Andreas Schwab Cc: stable@vger.kernel.org Co-developed-by: Michael Schmitz Signed-off-by: Michael Schmitz Signed-off-by: Finn Thain Reviewed-by: Geert Uytterhoeven Link: https://lore.kernel.org/r/9e66262a754fcba50208aa424188896cc52a1dd1.1683365892.git.fthain@linux-m68k.org Signed-off-by: Geert Uytterhoeven

m68k: kexec: Include

2023-04-21T07:53:54Z

Include reboot.h in machine_kexec.c for declaration of machine_crash_shutdown and machine_shutdown. gcc-12 with W=1 reports: arch/m68k/kernel/machine_kexec.c:26:6: warning: no previous prototype for 'machine_shutdown' [-Wmissing-prototypes] 26 | void machine_shutdown(void) | ^~~~~~~~~~~~~~~~ arch/m68k/kernel/machine_kexec.c:30:6: warning: no previous prototype for 'machine_crash_shutdown' [-Wmissing-prototypes] 30 | void machine_crash_shutdown(struct pt_regs *regs) | ^~~~~~~~~~~~~~~~~~~~~~ No functional changes intended. Compile tested only. Signed-off-by: Simon Horman Reviewed-by: Geert Uytterhoeven Link: https://lore.kernel.org/r/20230421-m68k-kexec-include-reboot-v1-1-7552963a0f25@kernel.org Signed-off-by: Geert Uytterhoeven

m68k: Only force 030 bus error if PC not in exception table

2023-03-06T13:09:42Z

__get_kernel_nofault() does copy data in supervisor mode when forcing a task backtrace log through /proc/sysrq_trigger. This is expected cause a bus error exception on e.g. NULL pointer dereferencing when logging a kernel task has no workqueue associated. This bus error ought to be ignored. Our 030 bus error handler is ill equipped to deal with this: Whenever ssw indicates a kernel mode access on a data fault, we don't even attempt to handle the fault and instead always send a SEGV signal (or panic). As a result, the check for exception handling at the fault PC (buried in send_sig_fault() which gets called from do_page_fault() eventually) is never used. In contrast, both 040 and 060 access error handlers do not care whether a fault happened on supervisor mode access, and will call do_page_fault() on those, ultimately honoring the exception table. Add a check in bus_error030 to call do_page_fault() in case we do have an entry for the fault PC in our exception table. I had attempted a fix for this earlier in 2019 that did rely on testing pagefault_disabled() (see link below) to achieve the same thing, but this patch should be more generic. Tested on 030 Atari Falcon. Reported-by: Eero Tamminen Link: https://lore.kernel.org/r/alpine.LNX.2.21.1904091023540.25@nippy.intranet Link: https://lore.kernel.org/r/63130691-1984-c423-c1f2-73bfd8d3dcd3@gmail.com Signed-off-by: Michael Schmitz Reviewed-by: Geert Uytterhoeven Link: https://lore.kernel.org/r/20230301021107.26307-1-schmitzmic@gmail.com Signed-off-by: Geert Uytterhoeven

m68k: mm: Move initrd phys_to_virt handling after paging_init()

2023-03-06T13:09:42Z

When booting with an initial ramdisk on platforms where physical memory does not start at address zero (e.g. on Amiga): initrd: 0ef0602c - 0f800000 Zone ranges: DMA [mem 0x0000000008000000-0x000000f7ffffffff] Normal empty Movable zone start for each node Early memory node ranges node 0: [mem 0x0000000008000000-0x000000000f7fffff] Initmem setup node 0 [mem 0x0000000008000000-0x000000000f7fffff] Unable to handle kernel access at virtual address (ptrval) Oops: 00000000 Modules linked in: PC: [<00201d3c>] memcmp+0x28/0x56 As phys_to_virt() relies on m68k_memoffset and module_fixup(), it must not be called before paging_init(). Hence postpone the phys_to_virt handling for the initial ramdisk until after calling paging_init(). While at it, reduce #ifdef clutter by using IS_ENABLED() instead. Fixes: 376e3fdecb0dcae2 ("m68k: Enable memtest functionality") Reported-by: Stephen Walsh Link: https://lists.debian.org/debian-68k/2022/09/msg00007.html Reported-by: John Paul Adrian Glaubitz Link: https://lore.kernel.org/r/4f45f05f377bf3f5baf88dbd5c3c8aeac59d94f0.camel@physik.fu-berlin.de Signed-off-by: Geert Uytterhoeven Acked-by: Finn Thain Link: https://lore.kernel.org/r/dff216da09ab7a60217c3fc2147e671ae07d636f.1677528627.git.geert@linux-m68k.org

Merge tag 'm68k-for-v6.3-tag1' of git://git.kernel.org/pub/scm/linux/kernel/git/geert/linux-m68k

2023-02-21T23:17:34Z

Pull m68k updates from Geert Uytterhoeven: - Add seccomp support - defconfig updates - Miscellaneous fixes and improvements * tag 'm68k-for-v6.3-tag1' of git://git.kernel.org/pub/scm/linux/kernel/git/geert/linux-m68k: m68k: /proc/hardware should depend on PROC_FS selftests/seccomp: Add m68k support m68k: Add kernel seccomp support m68k: Check syscall_trace_enter() return code m68k: defconfig: Update defconfigs for v6.2-rc3 m68k: q40: Do not initialise statics to 0

m68k: Add kernel seccomp support

2023-01-30T15:40:15Z

Add secure_computing() call to syscall_trace_enter to actually filter system calls. Add necessary arch Kconfig options, define TIF_SECCOMP trace flag and provide basic seccomp filter support in asm/syscall.h syscall_get_nr currently uses the syscall nr stored in orig_d0 because we change d0 to a default return code before starting a syscall trace. This may be inconsistent with syscall_rollback copying orig_d0 to d0 (which we never check upon return from trace). We use d0 for the return code from syscall_trace_enter in entry.S currently, and could perhaps expand that to store a new syscall number returned by the seccomp filter before executing the syscall. This clearly needs some discussion. seccomp_bpf self test on ARAnyM passes 81 out of 94 tests. Signed-off-by: Michael Schmitz Reviewed-by: Geert Uytterhoeven Link: https://lore.kernel.org/r/20230112035529.13521-3-schmitzmic@gmail.com Signed-off-by: Geert Uytterhoeven

m68k: Check syscall_trace_enter() return code

2023-01-30T15:40:15Z

Check return code of syscall_trace_enter(), and skip syscall if -1. Return code will be left at what had been set by ptrace or seccomp (in regs->d0). No regression seen in testing with strace on ARAnyM. Signed-off-by: Michael Schmitz Reviewed-by: Geert Uytterhoeven Link: https://lore.kernel.org/r/20230112035529.13521-2-schmitzmic@gmail.com Signed-off-by: Geert Uytterhoeven

objtool/idle: Validate __cpuidle code as noinstr

2023-01-13T10:48:15Z

Idle code is very like entry code in that RCU isn't available. As such, add a little validation. Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Ingo Molnar Tested-by: Tony Lindgren Tested-by: Ulf Hansson Acked-by: Geert Uytterhoeven Acked-by: Rafael J. Wysocki Acked-by: Frederic Weisbecker Link: https://lore.kernel.org/r/20230112195540.373461409@infradead.org