On Wed, May 08, 2019 at 09:49:05AM +0200, Peter Zijlstra wrote: > Currently pt_regs on x86_32 has an oddity in that kernel regs > (!user_mode(regs)) are short two entries (esp/ss). This means that any > code trying to use them (typically: regs->sp) needs to jump through > some unfortunate hoops. > > Change the entry code to fix this up and create a full pt_regs frame. > > This then simplifies: > > - ftrace > - kprobes > - stack unwinder > - ptrace > - kdump > - kgdb > > Hated-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> > Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx> > --- > arch/x86/entry/entry_32.S | 105 ++++++++++++++++++++++++++++++++++---- > arch/x86/include/asm/kexec.h | 17 ------ > arch/x86/include/asm/ptrace.h | 17 ------ > arch/x86/include/asm/stacktrace.h | 2 > arch/x86/kernel/crash.c | 8 -- > arch/x86/kernel/ftrace_32.S | 81 ++++++++++++++++------------- > arch/x86/kernel/kgdb.c | 8 -- > arch/x86/kernel/kprobes/common.h | 4 - > arch/x86/kernel/kprobes/core.c | 29 ++++------ > arch/x86/kernel/kprobes/opt.c | 20 ++++--- > arch/x86/kernel/process_32.c | 16 +---- > arch/x86/kernel/ptrace.c | 29 ---------- > arch/x86/kernel/time.c | 3 - > arch/x86/kernel/unwind_frame.c | 32 +---------- > arch/x86/kernel/unwind_orc.c | 2 > 15 files changed, 181 insertions(+), 192 deletions(-) Very nice diffstat. This moves all the pain to the 32-bit entry code where it belongs. -- Josh
