On Fri, 27 Apr 2018 11:39:51 +0900 Masami Hiramatsu <mhiramat@xxxxxxxxxx> wrote: > On Thu, 26 Apr 2018 21:13:51 -0400 > Steven Rostedt <rostedt@xxxxxxxxxxx> wrote: > > > On Thu, 26 Apr 2018 17:10:03 +0900 > > Masami Hiramatsu <mhiramat@xxxxxxxxxx> wrote: > > > > > Replace %p with appropriate pointer types (or just remove it) > > > - Use %pS if possible > > > - Use %px only for the function right before BUG(). > > > - Remove unneeded error message. > > > > I'm not sure "right before BUG()" is legitimate for using %px. Why not > > still use %pS? > > Since BUG() will dump all registers and stacks which includes > raw address information and reboot the system (means reset the > kaslr base offset), I thought it may not add additional damage. BUG() has been changed to print out %pS and not the address while doing the stack dump. It only prints the address if it doesn't find a function name. For example: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.11.0-rc3-test+ #48 Hardware name: MSI MS-7823/CSM-H87M-G43 (MS-7823), BIOS V1.6 02/22/2014 Call Trace: dump_stack+0x68/0x92 lockdep_rcu_suspicious+0xf7/0x100 rcu_read_lock+0x5f/0x61 __is_insn_slot_addr+0x23/0x5c __kernel_text_address+0x4a/0x80 show_trace_log_lvl+0x157/0x296 ? module_assert_mutex_or_preempt+0x4f/0x51 show_stack+0x3d/0x3f dump_stack+0x68/0x92 __warn+0xc2/0xdd ? 0xffffffffa0026077 warn_slowpath_null+0x1d/0x1f module_assert_mutex_or_preempt+0x4f/0x51 __module_address+0x2a/0xac ? 0xffffffffa0026077 __module_text_address+0x12/0x59 ? 0xffffffffa0026077 is_module_text_address+0xe/0x16 __kernel_text_address+0x2b/0x80 ? 0xffffffffa0026077 unwind_get_return_address+0x50/0x5c > > Anyway, for this patch we can use %pS. For the next [5/7] patch, > I'm not sure %pS is good for dumping a stack address... Although it now is. -- Steve
