Le 23/09/2022 à 05:25, Nicholas Piggin a écrit : > Using a 32-bit constant for this marker allows it to be loaded with > two ALU instructions, like 32-bit. This avoids a TOC entry and a > TOC load that depends on the r2 value that has just been loaded from > the PACA. > > This changes the value for 32-bit as well, so both have the same > value in the low 4 bytes and 64-bit has 0xffffffff in the top bytes. > > Signed-off-by: Nicholas Piggin <npig...@gmail.com> > --- > arch/powerpc/include/asm/ptrace.h | 5 +++-- > arch/powerpc/kernel/entry_32.S | 6 +++--- > arch/powerpc/kernel/exceptions-64e.S | 8 +------- > arch/powerpc/kernel/exceptions-64s.S | 2 +- > arch/powerpc/kernel/head_64.S | 7 ------- > arch/powerpc/kernel/interrupt_64.S | 6 +++--- > 6 files changed, 11 insertions(+), 23 deletions(-) > > diff --git a/arch/powerpc/include/asm/ptrace.h > b/arch/powerpc/include/asm/ptrace.h > index a03403695cd4..49d720bb888b 100644 > --- a/arch/powerpc/include/asm/ptrace.h > +++ b/arch/powerpc/include/asm/ptrace.h > @@ -99,6 +99,9 @@ struct pt_regs > > #define STACK_FRAME_WITH_PT_REGS (STACK_FRAME_OVERHEAD + sizeof(struct > pt_regs)) > > +/* 0xffffffff8d9a988d on 64-bit */ > +#define STACK_FRAME_REGS_MARKER ASM_CONST(-0x72656773) /* 0x8d9a988d */ > +
0x72656773 is "REGS" in ASCII (Big Endian) and you can spot it immediatly in a memory dump. 0x7265677368657265 is "REGSHERE". 0x8d9a988d is not printable. Don't know if it can be a problem. Christophe
