[Crash-utility] [PATCH] X86 64: fix a regression issue about kernel stack padding

The commit 48764a14bc58 may cause a regression issue when the CONFIG_X86_FRED is not enabled, this is because the SIZE(fred_frame) will call the SIZE_verify() to determine if the fred_frame is valid, otherwise it will emit an error: crash> bt 1 bt: invalid structure size: fred_frame FILE: x86_64.c LINE: 4089 FUNCTION: x86_64_low_budget_back_trace_cmd() [/home/k-hagio/bin/crash] error trace: 588df3 => 5cbc72 => 5eb3e1 => 5eb366 PID: 1 TASK: ffff9f94c024b980 CPU: 2 COMMAND: "systemd" #0 [ffffade44001bca8] __schedule at ffffffffb948ebbb #1 [ffffade44001bd10] schedule at ffffffffb948f04d #2 [ffffade44001bd20] schedule_hrtimeout_range_clock at ffffffffb9494fef #3 [ffffade44001bda8] ep_poll at ffffffffb8c91be8 #4 [ffffade44001be48] do_epoll_wait at ffffffffb8c91d11 #5 [ffffade44001be80] __x64_sys_epoll_wait at ffffffffb8c92590 #6 [ffffade44001bed0] do_syscall_64 at ffffffffb947f459 #7 [ffffade44001bf50] entry_SYSCALL_64_after_hwframe at ffffffffb96000ea 5eb366: SIZE_verify.part.42+70 5eb3e1: SIZE_verify+49 5cbc72: x86_64_low_budget_back_trace_cmd+3010 588df3: back_trace+1523 bt: invalid structure size: fred_frame FILE: x86_64.c LINE: 4089 FUNCTION: x86_64_low_budget_back_trace_cmd() Let's replace the SIZE(fred_frame) with the VALID_SIZE(fred_frame) to fix it. Fixes: 48764a14bc58 ("x86_64: fix for adding top_of_kernel_stack_padding for kernel stack") Reported-by: Kazuhito Hagio <k-hagio-ab(a)nec.com&gt; Signed-off-by: Lianbo Jiang <lijiang(a)redhat.com&gt; --- x86_64.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/x86_64.c b/x86_64.c index 6777c93e6b47..469d26b05e24 100644 --- a/x86_64.c +++ b/x86_64.c @@ -4086,7 +4086,7 @@ in_exception_stack: if (!irq_eframe && !is_kernel_thread(bt->tc->task) && (GET_STACKBASE(bt->tc->task) == bt->stackbase)) { - long stack_padding_size = SIZE(fred_frame) > 0 ? (2*8) : 0; + long stack_padding_size = VALID_SIZE(fred_frame) ? (2*8) : 0; user_mode_eframe = bt->stacktop - SIZE(pt_regs); if (last_process_stack_eframe < user_mode_eframe) x86_64_exception_frame(EFRAME_PRINT, 0, bt->stackbuf + @@ -4408,7 +4408,7 @@ in_exception_stack: if (!irq_eframe && !is_kernel_thread(bt->tc->task) && (GET_STACKBASE(bt->tc->task) == bt->stackbase)) { - long stack_padding_size = SIZE(fred_frame) > 0 ? (2*8) : 0; + long stack_padding_size = VALID_SIZE(fred_frame) ? (2*8) : 0; user_mode_eframe = bt->stacktop - SIZE(pt_regs); if (last_process_stack_eframe < user_mode_eframe) x86_64_exception_frame(EFRAME_PRINT, 0, bt->stackbuf + -- 2.45.1