| Message ID | CALicx6tx9aLmXpai5SFzZeR6cfu7NKF7WipZWY1nrKGBcA-oGA@mail.gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wed, Jan 22, 2014 at 10:01 AM, Vijay Kilari <vijay.kilari@gmail.com> wrote: > On Wed, Jan 22, 2014 at 12:06 AM, Will Deacon <will.deacon@arm.com> wrote: >> On Tue, Jan 21, 2014 at 02:10:14PM +0000, Vijay Kilari wrote: >>> Hi Will, >> >> Hello Vijay, >> >>> On Mon, Jan 20, 2014 at 3:53 PM, Will Deacon <will.deacon@arm.com> wrote: >>> > Well, the warnings are one thing but the 100 miles of backtrace output that >>> > appear on every boot (and I think end in an oops) are probably more >>> > important to fix. Please enable CONFIG_KGDB_TESTS and >>> > CONFIG_KGDB_TESTS_ON_BOOT and take a look. >>> > >>> >>> I could manage to run KGDB boot tests if I run from sysfs after complete boot >>> >>> echo V1F1000 > /sys/module/kgdbts/parameters/kgdbts >>> >>> Here the value of PSTATE is 80000145, which means PSTATE.D is unmasked >>> hence it works fine. >>> >>> If I run during boot by enabling CONFIG_KGDB_TESTS_ON_BOOT, >>> the step debug test fail because value of PSTATE is 80000345. >>> If I force PSTATE.D to 0, it works fine >>> >>> In debug_monitors.c file, only PSTATE.SS & MDSCR.KDE/MDE is managed >>> but not PSTATE.D >>> >>> Can you please let me know if where PSTATE.D is managed in arm64? >> >> That's a good point: I think we wait until our first exception before they >> are unmasked. Perhaps we should: >> >> (1) Move local_dbg_{save,restore} from debug-monitors.h into irqflags.h local_dbg_save is setting bit #8 it should be bit #9? #define local_dbg_save(flags) \ do { \ typecheck(unsigned long, flags); \ asm volatile( \ "mrs %0, daif // local_dbg_save\n" \ "msr daifset, #8" \ : "=r" (flags) : : "memory"); \ } while (0) >> (2) Add local_dbg_enable/local_dbg_disable macros >> (3) Add a call to local_dbg_enable in the clear_os_lock function after the >> isb(). >> >> Does that work for you? > > Yes, only after first exception occurs the PSTATE.D is unmasked. > > I have patched (temp) as below and now KGDB boot tests pass > > diff --git a/arch/arm64/include/asm/debug-monitors.h > b/arch/arm64/include/asm/debug-monitors.h > index aff3a76..ea2bc46 100644 > --- a/arch/arm64/include/asm/debug-monitors.h > +++ b/arch/arm64/include/asm/debug-monitors.h > @@ -64,6 +111,24 @@ struct task_struct; > > #define DBG_ARCH_ID_RESERVED 0 /* In case of ptrace ABI updates. */ > > +#define local_dbg_enable() > \ > + do { > \ > + asm volatile( > \ > + "msr daifclr, #9 // > arch_local_irq_disable" \ > + : > \ > + : > \ > + : "memory"); > \ > + } while (0) > + > +#define local_dbg_disable() > \ > + do { > \ > + asm volatile( > \ > + "msr daifset, #9 // > arch_local_irq_disable" \ > + : > \ > + : > \ > + : "memory"); > \ > + } while (0) > + > struct step_hook { > struct list_head node; > int (*fn)(struct pt_regs *regs, unsigned int insn, unsigned long addr); > > diff --git a/arch/arm64/kernel/debug-monitors.c > b/arch/arm64/kernel/debug-monitors.c > index f8b90c0..d0e55f7 100644 > --- a/arch/arm64/kernel/debug-monitors.c > +++ b/arch/arm64/kernel/debug-monitors.c > @@ -139,6 +142,7 @@ static void clear_os_lock(void *unused) > { > asm volatile("msr oslar_el1, %0" : : "r" (0)); > isb(); > + local_dbg_enable(); > } > > > boot test: > > [32927.161317] msgmni has been set to 1870 > [32927.212747] alg: No test for stdrng (krng) > [32927.213953] Key type asymmetric registered > [32927.214899] Asymmetric key parser 'x509' registered > [32927.220029] Block layer SCSI generic (bsg) driver version 0.4 > loaded (major 253) > [32927.225824] io scheduler noop registered > [32927.226764] io scheduler deadline registered > [32927.230714] io scheduler cfq registered (default) > [32927.237895] Serial: 8250/16550 driver, 4 ports, IRQ sharing disabled > [32927.266066] kgdb: Registered I/O driver kgdbts. > [32927.266419] kgdb: Waiting for connection from remote gdb... > [32927.268598] kgdbts:RUN plant and detach test > [32927.270683] kgdbts:RUN sw breakpoint test > [32927.287659] kgdbts:RUN bad memory access test > [32927.290322] kgdbts:RUN singlestep test 1000 iterations > [32927.330342] kgdbts:RUN singlestep [0/1000] > [32931.286356] kgdbts:RUN singlestep [100/1000] > [32935.242536] kgdbts:RUN singlestep [200/1000] > [32939.205392] kgdbts:RUN singlestep [300/1000] > [32943.169522] kgdbts:RUN singlestep [400/1000] > [32947.231868] kgdbts:RUN singlestep [500/1000] > [32951.188008] kgdbts:RUN singlestep [600/1000] > [32955.332243] kgdbts:RUN singlestep [700/1000] > [32959.467109] kgdbts:RUN singlestep [800/1000] > [32963.430888] kgdbts:RUN singlestep [900/1000] > [32967.346992] kgdbts:RUN do_fork for 100 breakpoints > > kgdb test using sysfs: > > ~ # echo V1F1000 > /sys/module/kgdbts/parameters/kgdbts > [33231.554237] kgdb: Registered I/O driver kgdbts. > [33231.554677] kgdbts:RUN plant and detach test > [33231.557072] kgdbts:RUN sw breakpoint test > [33231.576980] kgdbts:RUN bad memory access test > [33231.580022] kgdbts:RUN singlestep test 1000 iterations > [33231.627056] kgdbts:RUN singlestep [0/1000] > [33235.954027] kgdbts:RUN singlestep [100/1000] > [33240.429086] kgdbts:RUN singlestep [200/1000] > [33244.687118] kgdbts:RUN singlestep [300/1000] > [33248.945191] kgdbts:RUN singlestep [400/1000] > [33253.203751] kgdbts:RUN singlestep [500/1000] > [33257.462019] kgdbts:RUN singlestep [600/1000] > [33261.817809] kgdbts:RUN singlestep [700/1000] > [33266.081268] kgdbts:RUN singlestep [800/1000] > [33270.339813] kgdbts:RUN singlestep [900/1000] > [33274.712404] kgdbts:RUN do_fork for 1000 breakpoints > ~ # > > This works for me. Should I patch it or will you send a patch for this? > > PS: cc to mailing list missed >> >> Will
On Wed, Jan 22, 2014 at 07:50:46AM +0000, Vijay Kilari wrote: > On Wed, Jan 22, 2014 at 10:01 AM, Vijay Kilari <vijay.kilari@gmail.com> wrote: > >>> On Mon, Jan 20, 2014 at 3:53 PM, Will Deacon <will.deacon@arm.com> wrote: > >> That's a good point: I think we wait until our first exception before they > >> are unmasked. Perhaps we should: > >> > >> (1) Move local_dbg_{save,restore} from debug-monitors.h into irqflags.h > > local_dbg_save is setting bit #8 it should be bit #9? > > #define local_dbg_save(flags) > \ > do { > \ > typecheck(unsigned long, flags); > \ > asm volatile( > \ > "mrs %0, daif // > local_dbg_save\n" \ > "msr daifset, #8" That uses daifset, so #8 is bit 3 which is D. > >> (2) Add local_dbg_enable/local_dbg_disable macros > >> (3) Add a call to local_dbg_enable in the clear_os_lock function after the > >> isb(). > >> > >> Does that work for you? > > > > Yes, only after first exception occurs the PSTATE.D is unmasked. > > > > I have patched (temp) as below and now KGDB boot tests pass > > > > diff --git a/arch/arm64/include/asm/debug-monitors.h > > b/arch/arm64/include/asm/debug-monitors.h > > index aff3a76..ea2bc46 100644 > > --- a/arch/arm64/include/asm/debug-monitors.h > > +++ b/arch/arm64/include/asm/debug-monitors.h > > @@ -64,6 +111,24 @@ struct task_struct; > > > > #define DBG_ARCH_ID_RESERVED 0 /* In case of ptrace ABI updates. */ > > > > +#define local_dbg_enable() > > \ > > + do { > > \ > > + asm volatile( > > \ > > + "msr daifclr, #9 // I think this is going to unmask fiq as well... Will
diff --git a/arch/arm64/include/asm/debug-monitors.h b/arch/arm64/include/asm/debug-monitors.h index aff3a76..ea2bc46 100644 --- a/arch/arm64/include/asm/debug-monitors.h +++ b/arch/arm64/include/asm/debug-monitors.h @@ -64,6 +111,24 @@ struct task_struct; #define DBG_ARCH_ID_RESERVED 0 /* In case of ptrace ABI updates. */ +#define local_dbg_enable() \ + do { \ + asm volatile( \ + "msr daifclr, #9 // arch_local_irq_disable" \ + : \ + : \ + : "memory"); \ + } while (0) + +#define local_dbg_disable() \ + do { \ + asm volatile( \ + "msr daifset, #9 // arch_local_irq_disable" \ + : \ + : \ + : "memory"); \ + } while (0) + struct step_hook { struct list_head node; int (*fn)(struct pt_regs *regs, unsigned int insn, unsigned long addr); diff --git a/arch/arm64/kernel/debug-monitors.c b/arch/arm64/kernel/debug-monitors.c index f8b90c0..d0e55f7 100644 --- a/arch/arm64/kernel/debug-monitors.c +++ b/arch/arm64/kernel/debug-monitors.c @@ -139,6 +142,7 @@ static void clear_os_lock(void *unused) { asm volatile("msr oslar_el1, %0" : : "r" (0)); isb(); + local_dbg_enable(); }