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 (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 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
linaro-kernel@lists.linaro.org
-
Vijay Kilari -
Will Deacon