#
199cc14c |
|
11-Mar-2024 |
Jinyang He <hejinyang@loongson.cn> |
LoongArch: Add kernel livepatching support The arch-specified function ftrace_regs_set_instruction_pointer() has been implemented in arch/loongarch/include/asm/ftrace.h, so here only implement arch_stack_walk_reliable() function. Here are the test logs: [root@linux fedora]# cat /proc/cmdline BOOT_IMAGE=/vmlinuz-6.8.0-rc2 root=/dev/sda3 [root@linux fedora]# modprobe livepatch-sample [root@linux fedora]# cat /proc/cmdline this has been live patched [root@linux fedora]# echo 0 > /sys/kernel/livepatch/livepatch_sample/enabled [root@linux fedora]# rmmod livepatch_sample [root@linux fedora]# cat /proc/cmdline BOOT_IMAGE=/vmlinuz-6.8.0-rc2 root=/dev/sda3 [root@linux fedora]# dmesg -t | tail -5 livepatch: enabling patch 'livepatch_sample' livepatch: 'livepatch_sample': starting patching transition livepatch: 'livepatch_sample': patching complete livepatch: 'livepatch_sample': starting unpatching transition livepatch: 'livepatch_sample': unpatching complete Signed-off-by: Jinyang He <hejinyang@loongson.cn> Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
|
#
cb8a2ef0 |
|
11-Mar-2024 |
Tiezhu Yang <yangtiezhu@loongson.cn> |
LoongArch: Add ORC stack unwinder support The kernel CONFIG_UNWINDER_ORC option enables the ORC unwinder, which is similar in concept to a DWARF unwinder. The difference is that the format of the ORC data is much simpler than DWARF, which in turn allows the ORC unwinder to be much simpler and faster. The ORC data consists of unwind tables which are generated by objtool. After analyzing all the code paths of a .o file, it determines information about the stack state at each instruction address in the file and outputs that information to the .orc_unwind and .orc_unwind_ip sections. The per-object ORC sections are combined at link time and are sorted and post-processed at boot time. The unwinder uses the resulting data to correlate instruction addresses with their stack states at run time. Most of the logic are similar with x86, in order to get ra info before ra is saved into stack, add ra_reg and ra_offset into orc_entry. At the same time, modify some arch-specific code to silence the objtool warnings. Co-developed-by: Jinyang He <hejinyang@loongson.cn> Signed-off-by: Jinyang He <hejinyang@loongson.cn> Co-developed-by: Youling Tang <tangyouling@loongson.cn> Signed-off-by: Youling Tang <tangyouling@loongson.cn> Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
|
#
97ceddbc |
|
09-Dec-2023 |
Jinyang He <hejinyang@loongson.cn> |
LoongArch: Set unwind stack type to unknown rather than set error flag During unwinding, unwind_done() is used as an end condition. Normally it unwind to the user stack and then set the stack type to unknown, which is a normal exit. When something unexpected happens in unwind process and we cannot unwind anymore, we should set the error flag, and also set the stack type to unknown to indicate that the unwind process can not continue. The error flag emphasizes that the unwind process produce an unexpected error. There is no unexpected things when we unwind the PT_REGS in the top of IRQ stack and find out that is an user mode PT_REGS. Thus, we should not set error flag and just set stack type to unknown. Reported-by: Hengqi Chen <hengqi.chen@gmail.com> Acked-by: Hengqi Chen <hengqi.chen@gmail.com> Signed-off-by: Jinyang He <hejinyang@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
|
#
95bb5b61 |
|
06-Sep-2023 |
Enze Li <lienze@kylinos.cn> |
LoongArch: Get partial stack information when providing regs parameter Currently, arch_stack_walk() can only get the full stack information including NMI. This is because the implementation of arch_stack_walk() is forced to ignore the information passed by the regs parameter and use the current stack information instead. For some detection systems like KFENCE, only partial stack information is needed. In particular, the stack frame where the interrupt occurred. To support KFENCE, this patch modifies the implementation of the arch_stack_walk() function so that if this function is called with the regs argument passed, it retains all the stack information in regs and uses it to provide accurate information. Before this patch: [ 1.531195 ] ================================================================== [ 1.531442 ] BUG: KFENCE: out-of-bounds read in stack_trace_save_regs+0x48/0x6c [ 1.531442 ] [ 1.531900 ] Out-of-bounds read at 0xffff800012267fff (1B left of kfence-#12): [ 1.532046 ] stack_trace_save_regs+0x48/0x6c [ 1.532169 ] kfence_report_error+0xa4/0x528 [ 1.532276 ] kfence_handle_page_fault+0x124/0x270 [ 1.532388 ] no_context+0x50/0x94 [ 1.532453 ] do_page_fault+0x1a8/0x36c [ 1.532524 ] tlb_do_page_fault_0+0x118/0x1b4 [ 1.532623 ] test_out_of_bounds_read+0xa0/0x1d8 [ 1.532745 ] kunit_generic_run_threadfn_adapter+0x1c/0x28 [ 1.532854 ] kthread+0x124/0x130 [ 1.532922 ] ret_from_kernel_thread+0xc/0xa4 <snip> After this patch: [ 1.320220 ] ================================================================== [ 1.320401 ] BUG: KFENCE: out-of-bounds read in test_out_of_bounds_read+0xa8/0x1d8 [ 1.320401 ] [ 1.320898 ] Out-of-bounds read at 0xffff800012257fff (1B left of kfence-#10): [ 1.321134 ] test_out_of_bounds_read+0xa8/0x1d8 [ 1.321264 ] kunit_generic_run_threadfn_adapter+0x1c/0x28 [ 1.321392 ] kthread+0x124/0x130 [ 1.321459 ] ret_from_kernel_thread+0xc/0xa4 <snip> Suggested-by: Jinyang He <hejinyang@loongson.cn> Signed-off-by: Enze Li <lienze@kylinos.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
|
#
370a3b8f |
|
18-Apr-2023 |
Tiezhu Yang <yangtiezhu@loongson.cn> |
LoongArch: Check unwind_error() in arch_stack_walk() We can see the following messages with CONFIG_PROVE_LOCKING=y on LoongArch: BUG: MAX_STACK_TRACE_ENTRIES too low! turning off the locking correctness validator. This is because stack_trace_save() returns a big value after call arch_stack_walk(), here is the call trace: save_trace() stack_trace_save() arch_stack_walk() stack_trace_consume_entry() arch_stack_walk() should return immediately if unwind_next_frame() failed, no need to do the useless loops to increase the value of c->len in stack_trace_consume_entry(), then we can fix the above problem. Cc: stable@vger.kernel.org Reported-by: Guenter Roeck <linux@roeck-us.net> Link: https://lore.kernel.org/all/8a44ad71-68d2-4926-892f-72bfc7a67e2a@roeck-us.net/ Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
|
#
4d7bf939 |
|
06-Aug-2022 |
Qing Zhang <zhangqing@loongson.cn> |
LoongArch: Add USER_STACKTRACE support To get the best stacktrace output, you can compile your userspace programs with frame pointers (at least glibc + the app you are tracing). 1, export "CC = gcc -fno-omit-frame-pointer"; 2, compile your programs with "CC"; 3, use uprobe to get stacktrace output. ... echo 'p:malloc /usr/lib64/libc.so.6:0x0a4704 size=%r4:u64' > uprobe_events echo 'p:free /usr/lib64/libc.so.6:0x0a4d50 ptr=%r4:x64' >> uprobe_events echo 'comm == "demo"' > ./events/uprobes/malloc/filter echo 'comm == "demo"' > ./events/uprobes/free/filter echo 1 > ./options/userstacktrace echo 1 > ./options/sym-userobj ... Signed-off-by: Qing Zhang <zhangqing@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
|
#
93a4fa62 |
|
06-Aug-2022 |
Qing Zhang <zhangqing@loongson.cn> |
LoongArch: Add STACKTRACE support 1. Use common arch_stack_walk() infrastructure to avoid duplicated code and avoid taking care of the stack storage and filtering. 2. Add sched_ra (means sched return address) and sched_cfa (means sched call frame address) to thread_info, and store them in switch_to(). 3. Add __get_wchan() implementation. Now we can print the process stack and wait channel by cat /proc/*/stack and /proc/*/wchan. Signed-off-by: Qing Zhang <zhangqing@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
|