On Thu, Feb 26, 2015 at 8:19 PM, Wang Nan <wangn...@huawei.com> wrote: > As early_trap_init() doesn't use IST, replace set_intr_gate_ist() and > set_system_intr_gate_ist() with their standard counterparts. > > set_intr_gate() requires a trace_debug symbol which we don't have and > won't use. This patch seprates set_intr_gate() into 2 parts, and uses > base version in early_trap_init(). > > Signed-off-by: Wang Nan <wangn...@huawei.com>
Looks good to me. Ingo? --Andy > --- > > Hi Andy Lutomirski, > > This patch should be less tricky than previous one [1]. I also tried > to renaming all set_intr_gate(), but it causes too many code changes, > so I think you will be satisfied with this one. > > Thank you! > > [1] https://lkml.org/lkml/2015/2/26/770 > > --- > arch/x86/include/asm/desc.h | 7 ++++++- > arch/x86/kernel/traps.c | 20 ++++++++++++-------- > 2 files changed, 18 insertions(+), 9 deletions(-) > > diff --git a/arch/x86/include/asm/desc.h b/arch/x86/include/asm/desc.h > index a94b82e..a0bf89f 100644 > --- a/arch/x86/include/asm/desc.h > +++ b/arch/x86/include/asm/desc.h > @@ -376,11 +376,16 @@ static inline void _set_gate(int gate, unsigned type, > void *addr, > * Pentium F0 0F bugfix can have resulted in the mapped > * IDT being write-protected. > */ > -#define set_intr_gate(n, addr) \ > +#define set_intr_gate_notrace(n, addr) \ > do { \ > BUG_ON((unsigned)n > 0xFF); \ > _set_gate(n, GATE_INTERRUPT, (void *)addr, 0, 0, \ > __KERNEL_CS); \ > + } while (0) > + > +#define set_intr_gate(n, addr) \ > + do { \ > + set_intr_gate_notrace(n, addr); \ > _trace_set_gate(n, GATE_INTERRUPT, (void *)trace_##addr,\ > 0, 0, __KERNEL_CS); \ > } while (0) > diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c > index 4281988..9965bd1 100644 > --- a/arch/x86/kernel/traps.c > +++ b/arch/x86/kernel/traps.c > @@ -926,16 +926,20 @@ dotraplinkage void do_iret_error(struct pt_regs *regs, > long error_code) > void __init early_trap_init(void) > { > /* > - * Don't set ist to DEBUG_STACK as it doesn't work until TSS is > - * ready in cpu_init() <-- trap_init(). Before trap_init(), CPU > - * runs at ring 0 so it is impossible to hit an invalid stack. > - * Using the original stack works well enough at this early > - * stage. DEBUG_STACK will be equipped after cpu_init() in > + * Don't use IST to set DEBUG_STACK as it doesn't work until TSS > + * is ready in cpu_init() <-- trap_init(). Before trap_init(), > + * CPU runs at ring 0 so it is impossible to hit an invalid > + * stack. Using the original stack works well enough at this > + * early stage. DEBUG_STACK will be equipped after cpu_init() in > * trap_init(). > + * > + * We don't need to set trace_idt_table like set_intr_gate(), > + * since we don't have trace_debug and it will be reset to > + * 'debug' in trap_init() by set_intr_gate_ist(). > */ > - set_intr_gate_ist(X86_TRAP_DB, &debug, 0); > + set_intr_gate_notrace(X86_TRAP_DB, debug); > /* int3 can be called from all */ > - set_system_intr_gate_ist(X86_TRAP_BP, &int3, 0); > + set_system_intr_gate(X86_TRAP_BP, &int3); > #ifdef CONFIG_X86_32 > set_intr_gate(X86_TRAP_PF, page_fault); > #endif > @@ -1015,7 +1019,7 @@ void __init trap_init(void) > > /* > * X86_TRAP_DB and X86_TRAP_BP have been set > - * in early_trap_init(). However, DEBUG_STACK works only after > + * in early_trap_init(). However, ITS works only after > * cpu_init() loads TSS. See comments in early_trap_init(). > */ > set_intr_gate_ist(X86_TRAP_DB, &debug, DEBUG_STACK); > -- > 1.8.4 > -- Andy Lutomirski AMA Capital Management, LLC -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
