kernel.git/arch/m68k/kernel/traps.c, branch linux-6.19.y

m68k: kernel: Use str_read_write() helper function

2024-11-06T14:10:14Z

Remove hard-coded strings by using the str_read_write() helper function and remove some unnecessary negations. Compile-tested only. Signed-off-by: Thorsten Blum Reviewed-by: Geert Uytterhoeven Link: https://lore.kernel.org/20241020205758.332095-1-thorsten.blum@linux.dev Signed-off-by: Geert Uytterhoeven

m68k: kernel: Fix indentation by 7 spaces in traps.c

2023-10-16T12:30:39Z

Indentation should use TABs, not spaces. Signed-off-by: Geert Uytterhoeven Link: https://lore.kernel.org/r/d1b38c9d389c1135f7856cf5f90852c2f1584c50.1696602993.git.geert@linux-m68k.org

m68k: sun3/3x: Add and use "sun3.h"

2023-10-06T08:03:04Z

When building with W=1: arch/m68k/sun3/idprom.c:86:6: warning: no previous prototype for ‘sun3_get_model’ [-Wmissing-prototypes] 86 | void sun3_get_model(char *model) | ^~~~~~~~~~~~~~ arch/m68k/sun3/config.c:53:24: warning: no previous prototype for ‘sun3_init’ [-Wmissing-prototypes] 53 | asmlinkage void __init sun3_init(void) | ^~~~~~~~~ arch/m68k/sun3/mmu_emu.c:117:6: warning: no previous prototype for ‘print_pte_vaddr’ [-Wmissing-prototypes] 117 | void print_pte_vaddr (unsigned long vaddr) | ^~~~~~~~~~~~~~~ arch/m68k/sun3/mmu_emu.c:126:13: warning: no previous prototype for ‘mmu_emu_init’ [-Wmissing-prototypes] 126 | void __init mmu_emu_init(unsigned long bootmem_end) | ^~~~~~~~~~~~ arch/m68k/sun3/mmu_emu.c:353:5: warning: no previous prototype for ‘mmu_emu_handle_fault’ [-Wmissing-prototypes] 353 | int mmu_emu_handle_fault (unsigned long vaddr, int read_flag, int kernel_fault) | ^~~~~~~~~~~~~~~~~~~~ arch/m68k/sun3/leds.c:6:6: warning: no previous prototype for ‘sun3_leds’ [-Wmissing-prototypes] 6 | void sun3_leds(unsigned char byte) | ^~~~~~~~~ arch/m68k/sun3/intersil.c:27:5: warning: no previous prototype for ‘sun3_hwclk’ [-Wmissing-prototypes] 27 | int sun3_hwclk(int set, struct rtc_time *t) | ^~~~~~~~~~ arch/m68k/sun3x/config.c:30:6: warning: no previous prototype for ‘sun3_leds’ [-Wmissing-prototypes] 30 | void sun3_leds(unsigned char byte) | ^~~~~~~~~ Fix this by introducing a new header file "sun3.h" for holding the prototypes of functions implemented in arch/m68k/sun3/ and arch/m68k/sun3x/. Signed-off-by: Geert Uytterhoeven Acked-by: Arnd Bergmann Link: https://lore.kernel.org/r/87856ef9ef8955f459fb691faca921c0a688bc80.1694613528.git.geert@linux-m68k.org

m68k: mm: Add and use "fault.h"

2023-10-06T08:03:02Z

When building with W=1: arch/m68k/mm/fault.c:22:5: warning: no previous prototype for ‘send_fault_sig’ [-Wmissing-prototypes] 22 | int send_fault_sig(struct pt_regs *regs) | ^~~~~~~~~~~~~~ arch/m68k/mm/fault.c:68:5: warning: no previous prototype for ‘do_page_fault’ [-Wmissing-prototypes] 68 | int do_page_fault(struct pt_regs *regs, unsigned long address, | ^~~~~~~~~~~~~ Fix this by introducing a new header file "fault.h" for holding the prototypes of functions implemented in arch/m68k/mm/fault.c. Signed-off-by: Geert Uytterhoeven Acked-by: Arnd Bergmann Link: https://lore.kernel.org/r/ef004b8cfe4aac892aa0fb7714c2ed81a02a9b89.1694613528.git.geert@linux-m68k.org

m68k: kernel: Add and use "traps.h"

2023-10-06T08:03:01Z

When building with W=1: arch/m68k/kernel/traps.c:754:17: warning: no previous prototype for ‘buserr_c’ [-Wmissing-prototypes] 754 | asmlinkage void buserr_c(struct frame *fp) | ^~~~~~~~ arch/m68k/kernel/traps.c:1140:17: warning: no previous prototype for ‘set_esp0’ [-Wmissing-prototypes] 1140 | asmlinkage void set_esp0(unsigned long ssp) | ^~~~~~~~ arch/m68k/kernel/traps.c:1155:17: warning: no previous prototype for ‘fpemu_signal’ [-Wmissing-prototypes] 1155 | asmlinkage void fpemu_signal(int signal, int code, void *addr) | ^~~~~~~~~~~~ arch/m68k/kernel/traps.c:1149:17: warning: no previous prototype for ‘fpsp040_die’ [-Wmissing-prototypes] 1149 | asmlinkage void fpsp040_die(void) | ^~~~~~~~~~~ Fix this by introducing a new header file "traps.h" for holding the prototypes of functions implemented in arch/m68k/kernel/traps.c. Signed-off-by: Geert Uytterhoeven Acked-by: Arnd Bergmann Link: https://lore.kernel.org/r/652cbbb1c9e339980a86068ebdd0a69362324af8.1694613528.git.geert@linux-m68k.org

m68k: kernel: Make bad_super_trap() static

2023-10-06T08:03:01Z

When building with W=1: arch/m68k/kernel/traps.c:968:6: warning: no previous prototype for ‘bad_super_trap’ [-Wmissing-prototypes] 968 | void bad_super_trap (struct frame *fp) | ^~~~~~~~~~~~~~ Fix this by making bad_super_trap() static. There was never a user outside arch/m68k/kernel/traps.c. Signed-off-by: Geert Uytterhoeven Acked-by: Arnd Bergmann Link: https://lore.kernel.org/r/1e0b67a355d7e1bcb40811eced41d3080e8f4d20.1694613528.git.geert@linux-m68k.org

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: Add common forward declaration for show_registers()

2022-07-12T08:48:21Z

There are several forward declarations for show_registers() in C source files. Replace these by a single common forward declaration in , and include where needed. Signed-off-by: Geert Uytterhoeven Reviewed-by: Laurent Vivier Link: https://lore.kernel.org/r/d5b6a7f9af3e82f0ccb67edac09d9ee45d457932.1657114791.git.geert@linux-m68k.org

exit: Add and use make_task_dead.

2021-12-13T18:04:45Z

There are two big uses of do_exit. The first is it's design use to be the guts of the exit(2) system call. The second use is to terminate a task after something catastrophic has happened like a NULL pointer in kernel code. Add a function make_task_dead that is initialy exactly the same as do_exit to cover the cases where do_exit is called to handle catastrophic failure. In time this can probably be reduced to just a light wrapper around do_task_dead. For now keep it exactly the same so that there will be no behavioral differences introducing this new concept. Replace all of the uses of do_exit that use it for catastraphic task cleanup with make_task_dead to make it clear what the code is doing. As part of this rename rewind_stack_do_exit rewind_stack_and_make_dead. Signed-off-by: "Eric W. Biederman"

signal: Replace force_fatal_sig with force_exit_sig when in doubt

2021-11-19T15:15:58Z

Recently to prevent issues with SECCOMP_RET_KILL and similar signals being changed before they are delivered SA_IMMUTABLE was added. Unfortunately this broke debuggers[1][2] which reasonably expect to be able to trap synchronous SIGTRAP and SIGSEGV even when the target process is not configured to handle those signals. Add force_exit_sig and use it instead of force_fatal_sig where historically the code has directly called do_exit. This has the implementation benefits of going through the signal exit path (including generating core dumps) without the danger of allowing userspace to ignore or change these signals. This avoids userspace regressions as older kernels exited with do_exit which debuggers also can not intercept. In the future is should be possible to improve the quality of implementation of the kernel by changing some of these force_exit_sig calls to force_fatal_sig. That can be done where it matters on a case-by-case basis with careful analysis. Reported-by: Kyle Huey Reported-by: kernel test robot [1] https://lkml.kernel.org/r/CAP045AoMY4xf8aC_4QU_-j7obuEPYgTcnQQP3Yxk=2X90jtpjw@mail.gmail.com [2] https://lkml.kernel.org/r/20211117150258.GB5403@xsang-OptiPlex-9020 Fixes: 00b06da29cf9 ("signal: Add SA_IMMUTABLE to ensure forced siganls do not get changed") Fixes: a3616a3c0272 ("signal/m68k: Use force_sigsegv(SIGSEGV) in fpsp040_die") Fixes: 83a1f27ad773 ("signal/powerpc: On swapcontext failure force SIGSEGV") Fixes: 9bc508cf0791 ("signal/s390: Use force_sigsegv in default_trap_handler") Fixes: 086ec444f866 ("signal/sparc32: In setup_rt_frame and setup_fram use force_fatal_sig") Fixes: c317d306d550 ("signal/sparc32: Exit with a fatal signal when try_to_clear_window_buffer fails") Fixes: 695dd0d634df ("signal/x86: In emulate_vsyscall force a signal instead of calling do_exit") Fixes: 1fbd60df8a85 ("signal/vm86_32: Properly send SIGSEGV when the vm86 state cannot be saved.") Fixes: 941edc5bf174 ("exit/syscall_user_dispatch: Send ordinary signals on failure") Link: https://lkml.kernel.org/r/871r3dqfv8.fsf_-_@email.froward.int.ebiederm.org Reviewed-by: Kees Cook Tested-by: Kees Cook Tested-by: Kyle Huey Signed-off-by: "Eric W. Biederman"