* [PATCH v6 01/16] powerpc/watchpoint: Rename current DAWR macros
2020-05-14 11:17 [PATCH v6 00/16] powerpc/watchpoint: Preparation for more than one watchpoint Ravi Bangoria
@ 2020-05-14 11:17 ` Ravi Bangoria
2020-05-14 11:17 ` [PATCH v6 02/16] powerpc/watchpoint: Add SPRN macros for second DAWR Ravi Bangoria
` (15 subsequent siblings)
16 siblings, 0 replies; 18+ messages in thread
From: Ravi Bangoria @ 2020-05-14 11:17 UTC (permalink / raw)
To: mpe, mikey
Cc: apopple, paulus, npiggin, christophe.leroy, naveen.n.rao, peterz,
jolsa, oleg, fweisbec, mingo, linuxppc-dev, linux-kernel,
ravi.bangoria
Power10 is introducing second DAWR. Use real register names from ISA
for current macros:
s/SPRN_DAWR/SPRN_DAWR0/
s/SPRN_DAWRX/SPRN_DAWRX0/
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Reviewed-by: Michael Neuling <mikey@neuling.org>
---
arch/powerpc/include/asm/reg.h | 4 ++--
arch/powerpc/kernel/dawr.c | 4 ++--
arch/powerpc/kvm/book3s_hv.c | 12 ++++++------
arch/powerpc/kvm/book3s_hv_rmhandlers.S | 18 +++++++++---------
arch/powerpc/xmon/xmon.c | 2 +-
5 files changed, 20 insertions(+), 20 deletions(-)
diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h
index f95eb8f97756..60a21b6b2057 100644
--- a/arch/powerpc/include/asm/reg.h
+++ b/arch/powerpc/include/asm/reg.h
@@ -283,14 +283,14 @@
#define CTRL_CT1 0x40000000 /* thread 1 */
#define CTRL_TE 0x00c00000 /* thread enable */
#define CTRL_RUNLATCH 0x1
-#define SPRN_DAWR 0xB4
+#define SPRN_DAWR0 0xB4
#define SPRN_RPR 0xBA /* Relative Priority Register */
#define SPRN_CIABR 0xBB
#define CIABR_PRIV 0x3
#define CIABR_PRIV_USER 1
#define CIABR_PRIV_SUPER 2
#define CIABR_PRIV_HYPER 3
-#define SPRN_DAWRX 0xBC
+#define SPRN_DAWRX0 0xBC
#define DAWRX_USER __MASK(0)
#define DAWRX_KERNEL __MASK(1)
#define DAWRX_HYP __MASK(2)
diff --git a/arch/powerpc/kernel/dawr.c b/arch/powerpc/kernel/dawr.c
index cc14aa6c4a1b..e91b613bf137 100644
--- a/arch/powerpc/kernel/dawr.c
+++ b/arch/powerpc/kernel/dawr.c
@@ -39,8 +39,8 @@ int set_dawr(struct arch_hw_breakpoint *brk)
if (ppc_md.set_dawr)
return ppc_md.set_dawr(dawr, dawrx);
- mtspr(SPRN_DAWR, dawr);
- mtspr(SPRN_DAWRX, dawrx);
+ mtspr(SPRN_DAWR0, dawr);
+ mtspr(SPRN_DAWRX0, dawrx);
return 0;
}
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 93493f0cbfe8..db07199f0977 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -3392,8 +3392,8 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
int trap;
unsigned long host_hfscr = mfspr(SPRN_HFSCR);
unsigned long host_ciabr = mfspr(SPRN_CIABR);
- unsigned long host_dawr = mfspr(SPRN_DAWR);
- unsigned long host_dawrx = mfspr(SPRN_DAWRX);
+ unsigned long host_dawr = mfspr(SPRN_DAWR0);
+ unsigned long host_dawrx = mfspr(SPRN_DAWRX0);
unsigned long host_psscr = mfspr(SPRN_PSSCR);
unsigned long host_pidr = mfspr(SPRN_PID);
@@ -3422,8 +3422,8 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
mtspr(SPRN_SPURR, vcpu->arch.spurr);
if (dawr_enabled()) {
- mtspr(SPRN_DAWR, vcpu->arch.dawr);
- mtspr(SPRN_DAWRX, vcpu->arch.dawrx);
+ mtspr(SPRN_DAWR0, vcpu->arch.dawr);
+ mtspr(SPRN_DAWRX0, vcpu->arch.dawrx);
}
mtspr(SPRN_CIABR, vcpu->arch.ciabr);
mtspr(SPRN_IC, vcpu->arch.ic);
@@ -3475,8 +3475,8 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
(local_paca->kvm_hstate.fake_suspend << PSSCR_FAKE_SUSPEND_LG));
mtspr(SPRN_HFSCR, host_hfscr);
mtspr(SPRN_CIABR, host_ciabr);
- mtspr(SPRN_DAWR, host_dawr);
- mtspr(SPRN_DAWRX, host_dawrx);
+ mtspr(SPRN_DAWR0, host_dawr);
+ mtspr(SPRN_DAWRX0, host_dawrx);
mtspr(SPRN_PID, host_pidr);
/*
diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index 780a499c7114..70de3325d0e9 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -707,8 +707,8 @@ BEGIN_FTR_SECTION
END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)
BEGIN_FTR_SECTION
mfspr r5, SPRN_CIABR
- mfspr r6, SPRN_DAWR
- mfspr r7, SPRN_DAWRX
+ mfspr r6, SPRN_DAWR0
+ mfspr r7, SPRN_DAWRX0
mfspr r8, SPRN_IAMR
std r5, STACK_SLOT_CIABR(r1)
std r6, STACK_SLOT_DAWR(r1)
@@ -803,8 +803,8 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_207S)
beq 1f
ld r5, VCPU_DAWR(r4)
ld r6, VCPU_DAWRX(r4)
- mtspr SPRN_DAWR, r5
- mtspr SPRN_DAWRX, r6
+ mtspr SPRN_DAWR0, r5
+ mtspr SPRN_DAWRX0, r6
1:
ld r7, VCPU_CIABR(r4)
ld r8, VCPU_TAR(r4)
@@ -1766,8 +1766,8 @@ BEGIN_FTR_SECTION
* If the DAWR doesn't work, it's ok to write these here as
* this value should always be zero
*/
- mtspr SPRN_DAWR, r6
- mtspr SPRN_DAWRX, r7
+ mtspr SPRN_DAWR0, r6
+ mtspr SPRN_DAWRX0, r7
END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
BEGIN_FTR_SECTION
ld r5, STACK_SLOT_TID(r1)
@@ -2577,8 +2577,8 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
mfmsr r6
andi. r6, r6, MSR_DR /* in real mode? */
bne 4f
- mtspr SPRN_DAWR, r4
- mtspr SPRN_DAWRX, r5
+ mtspr SPRN_DAWR0, r4
+ mtspr SPRN_DAWRX0, r5
4: li r3, 0
blr
@@ -3329,7 +3329,7 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_300)
mtspr SPRN_AMR, r0
mtspr SPRN_IAMR, r0
mtspr SPRN_CIABR, r0
- mtspr SPRN_DAWRX, r0
+ mtspr SPRN_DAWRX0, r0
BEGIN_MMU_FTR_SECTION
b 4f
diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
index d1a79f9e0566..effb10c2e32f 100644
--- a/arch/powerpc/xmon/xmon.c
+++ b/arch/powerpc/xmon/xmon.c
@@ -1956,7 +1956,7 @@ static void dump_207_sprs(void)
printf("hfscr = %.16lx dhdes = %.16lx rpr = %.16lx\n",
mfspr(SPRN_HFSCR), mfspr(SPRN_DHDES), mfspr(SPRN_RPR));
printf("dawr = %.16lx dawrx = %.16lx ciabr = %.16lx\n",
- mfspr(SPRN_DAWR), mfspr(SPRN_DAWRX), mfspr(SPRN_CIABR));
+ mfspr(SPRN_DAWR0), mfspr(SPRN_DAWRX0), mfspr(SPRN_CIABR));
#endif
}
--
2.26.2
^ permalink raw reply related [flat|nested] 18+ messages in thread* [PATCH v6 02/16] powerpc/watchpoint: Add SPRN macros for second DAWR
2020-05-14 11:17 [PATCH v6 00/16] powerpc/watchpoint: Preparation for more than one watchpoint Ravi Bangoria
2020-05-14 11:17 ` [PATCH v6 01/16] powerpc/watchpoint: Rename current DAWR macros Ravi Bangoria
@ 2020-05-14 11:17 ` Ravi Bangoria
2020-05-14 11:17 ` [PATCH v6 03/16] powerpc/watchpoint: Introduce function to get nr watchpoints dynamically Ravi Bangoria
` (14 subsequent siblings)
16 siblings, 0 replies; 18+ messages in thread
From: Ravi Bangoria @ 2020-05-14 11:17 UTC (permalink / raw)
To: mpe, mikey
Cc: apopple, paulus, npiggin, christophe.leroy, naveen.n.rao, peterz,
jolsa, oleg, fweisbec, mingo, linuxppc-dev, linux-kernel,
ravi.bangoria
Power10 is introducing second DAWR. Add SPRN_ macros for the same.
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Reviewed-by: Michael Neuling <mikey@neuling.org>
---
arch/powerpc/include/asm/reg.h | 2 ++
1 file changed, 2 insertions(+)
diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h
index 60a21b6b2057..054f8a71d686 100644
--- a/arch/powerpc/include/asm/reg.h
+++ b/arch/powerpc/include/asm/reg.h
@@ -284,6 +284,7 @@
#define CTRL_TE 0x00c00000 /* thread enable */
#define CTRL_RUNLATCH 0x1
#define SPRN_DAWR0 0xB4
+#define SPRN_DAWR1 0xB5
#define SPRN_RPR 0xBA /* Relative Priority Register */
#define SPRN_CIABR 0xBB
#define CIABR_PRIV 0x3
@@ -291,6 +292,7 @@
#define CIABR_PRIV_SUPER 2
#define CIABR_PRIV_HYPER 3
#define SPRN_DAWRX0 0xBC
+#define SPRN_DAWRX1 0xBD
#define DAWRX_USER __MASK(0)
#define DAWRX_KERNEL __MASK(1)
#define DAWRX_HYP __MASK(2)
--
2.26.2
^ permalink raw reply related [flat|nested] 18+ messages in thread* [PATCH v6 03/16] powerpc/watchpoint: Introduce function to get nr watchpoints dynamically
2020-05-14 11:17 [PATCH v6 00/16] powerpc/watchpoint: Preparation for more than one watchpoint Ravi Bangoria
2020-05-14 11:17 ` [PATCH v6 01/16] powerpc/watchpoint: Rename current DAWR macros Ravi Bangoria
2020-05-14 11:17 ` [PATCH v6 02/16] powerpc/watchpoint: Add SPRN macros for second DAWR Ravi Bangoria
@ 2020-05-14 11:17 ` Ravi Bangoria
2020-05-14 11:17 ` [PATCH v6 04/16] powerpc/watchpoint/ptrace: Return actual num of available watchpoints Ravi Bangoria
` (13 subsequent siblings)
16 siblings, 0 replies; 18+ messages in thread
From: Ravi Bangoria @ 2020-05-14 11:17 UTC (permalink / raw)
To: mpe, mikey
Cc: apopple, paulus, npiggin, christophe.leroy, naveen.n.rao, peterz,
jolsa, oleg, fweisbec, mingo, linuxppc-dev, linux-kernel,
ravi.bangoria
So far we had only one watchpoint, so we have hardcoded HBP_NUM to 1.
But Power10 is introducing 2nd DAWR and thus kernel should be able to
dynamically find actual number of watchpoints supported by hw it's
running on. Introduce function for the same. Also convert HBP_NUM macro
to HBP_NUM_MAX, which will now represent maximum number of watchpoints
supported by Powerpc.
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Reviewed-by: Michael Neuling <mikey@neuling.org>
---
arch/powerpc/include/asm/cputable.h | 6 +++++-
arch/powerpc/include/asm/hw_breakpoint.h | 5 +++++
arch/powerpc/include/asm/processor.h | 2 +-
arch/powerpc/kernel/hw_breakpoint.c | 2 +-
4 files changed, 12 insertions(+), 3 deletions(-)
diff --git a/arch/powerpc/include/asm/cputable.h b/arch/powerpc/include/asm/cputable.h
index 40a4d3c6fd99..c67b94f3334c 100644
--- a/arch/powerpc/include/asm/cputable.h
+++ b/arch/powerpc/include/asm/cputable.h
@@ -614,7 +614,11 @@ enum {
};
#endif /* __powerpc64__ */
-#define HBP_NUM 1
+/*
+ * Maximum number of hw breakpoint supported on powerpc. Number of
+ * breakpoints supported by actual hw might be less than this.
+ */
+#define HBP_NUM_MAX 1
#endif /* !__ASSEMBLY__ */
diff --git a/arch/powerpc/include/asm/hw_breakpoint.h b/arch/powerpc/include/asm/hw_breakpoint.h
index f2f8d8aa8e3b..518b41eef924 100644
--- a/arch/powerpc/include/asm/hw_breakpoint.h
+++ b/arch/powerpc/include/asm/hw_breakpoint.h
@@ -43,6 +43,11 @@ struct arch_hw_breakpoint {
#define DABR_MAX_LEN 8
#define DAWR_MAX_LEN 512
+static inline int nr_wp_slots(void)
+{
+ return HBP_NUM_MAX;
+}
+
#ifdef CONFIG_HAVE_HW_BREAKPOINT
#include <linux/kdebug.h>
#include <asm/reg.h>
diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h
index 5ab202055d5a..f209c5703ee2 100644
--- a/arch/powerpc/include/asm/processor.h
+++ b/arch/powerpc/include/asm/processor.h
@@ -180,7 +180,7 @@ struct thread_struct {
int fpexc_mode; /* floating-point exception mode */
unsigned int align_ctl; /* alignment handling control */
#ifdef CONFIG_HAVE_HW_BREAKPOINT
- struct perf_event *ptrace_bps[HBP_NUM];
+ struct perf_event *ptrace_bps[HBP_NUM_MAX];
/*
* Helps identify source of single-step exception and subsequent
* hw-breakpoint enablement
diff --git a/arch/powerpc/kernel/hw_breakpoint.c b/arch/powerpc/kernel/hw_breakpoint.c
index 423603c92c0f..01f07d91df70 100644
--- a/arch/powerpc/kernel/hw_breakpoint.c
+++ b/arch/powerpc/kernel/hw_breakpoint.c
@@ -39,7 +39,7 @@ static DEFINE_PER_CPU(struct perf_event *, bp_per_reg);
int hw_breakpoint_slots(int type)
{
if (type == TYPE_DATA)
- return HBP_NUM;
+ return nr_wp_slots();
return 0; /* no instruction breakpoints available */
}
--
2.26.2
^ permalink raw reply related [flat|nested] 18+ messages in thread* [PATCH v6 04/16] powerpc/watchpoint/ptrace: Return actual num of available watchpoints
2020-05-14 11:17 [PATCH v6 00/16] powerpc/watchpoint: Preparation for more than one watchpoint Ravi Bangoria
` (2 preceding siblings ...)
2020-05-14 11:17 ` [PATCH v6 03/16] powerpc/watchpoint: Introduce function to get nr watchpoints dynamically Ravi Bangoria
@ 2020-05-14 11:17 ` Ravi Bangoria
2020-05-14 11:17 ` [PATCH v6 05/16] powerpc/watchpoint: Provide DAWR number to set_dawr Ravi Bangoria
` (12 subsequent siblings)
16 siblings, 0 replies; 18+ messages in thread
From: Ravi Bangoria @ 2020-05-14 11:17 UTC (permalink / raw)
To: mpe, mikey
Cc: apopple, paulus, npiggin, christophe.leroy, naveen.n.rao, peterz,
jolsa, oleg, fweisbec, mingo, linuxppc-dev, linux-kernel,
ravi.bangoria
User can ask for num of available watchpoints(dbginfo.num_data_bps)
using ptrace(PPC_PTRACE_GETHWDBGINFO). Return actual number of
available watchpoints on the machine rather than hardcoded 1.
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Reviewed-by: Michael Neuling <mikey@neuling.org>
---
arch/powerpc/kernel/ptrace/ptrace-noadv.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/powerpc/kernel/ptrace/ptrace-noadv.c b/arch/powerpc/kernel/ptrace/ptrace-noadv.c
index f87e7c5c3bf3..12962302d6a4 100644
--- a/arch/powerpc/kernel/ptrace/ptrace-noadv.c
+++ b/arch/powerpc/kernel/ptrace/ptrace-noadv.c
@@ -44,7 +44,7 @@ void ppc_gethwdinfo(struct ppc_debug_info *dbginfo)
dbginfo->version = 1;
dbginfo->num_instruction_bps = 0;
if (ppc_breakpoint_available())
- dbginfo->num_data_bps = 1;
+ dbginfo->num_data_bps = nr_wp_slots();
else
dbginfo->num_data_bps = 0;
dbginfo->num_condition_regs = 0;
--
2.26.2
^ permalink raw reply related [flat|nested] 18+ messages in thread* [PATCH v6 05/16] powerpc/watchpoint: Provide DAWR number to set_dawr
2020-05-14 11:17 [PATCH v6 00/16] powerpc/watchpoint: Preparation for more than one watchpoint Ravi Bangoria
` (3 preceding siblings ...)
2020-05-14 11:17 ` [PATCH v6 04/16] powerpc/watchpoint/ptrace: Return actual num of available watchpoints Ravi Bangoria
@ 2020-05-14 11:17 ` Ravi Bangoria
2020-05-14 11:17 ` [PATCH v6 06/16] powerpc/watchpoint: Provide DAWR number to __set_breakpoint Ravi Bangoria
` (11 subsequent siblings)
16 siblings, 0 replies; 18+ messages in thread
From: Ravi Bangoria @ 2020-05-14 11:17 UTC (permalink / raw)
To: mpe, mikey
Cc: apopple, paulus, npiggin, christophe.leroy, naveen.n.rao, peterz,
jolsa, oleg, fweisbec, mingo, linuxppc-dev, linux-kernel,
ravi.bangoria
Introduce new parameter 'nr' to set_dawr() which indicates which DAWR
should be programed.
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Reviewed-by: Michael Neuling <mikey@neuling.org>
---
arch/powerpc/include/asm/hw_breakpoint.h | 4 ++--
arch/powerpc/kernel/dawr.c | 15 ++++++++++-----
arch/powerpc/kernel/process.c | 2 +-
3 files changed, 13 insertions(+), 8 deletions(-)
diff --git a/arch/powerpc/include/asm/hw_breakpoint.h b/arch/powerpc/include/asm/hw_breakpoint.h
index 518b41eef924..5b3b02834e0b 100644
--- a/arch/powerpc/include/asm/hw_breakpoint.h
+++ b/arch/powerpc/include/asm/hw_breakpoint.h
@@ -104,10 +104,10 @@ static inline bool dawr_enabled(void)
{
return dawr_force_enable;
}
-int set_dawr(struct arch_hw_breakpoint *brk);
+int set_dawr(int nr, struct arch_hw_breakpoint *brk);
#else
static inline bool dawr_enabled(void) { return false; }
-static inline int set_dawr(struct arch_hw_breakpoint *brk) { return -1; }
+static inline int set_dawr(int nr, struct arch_hw_breakpoint *brk) { return -1; }
#endif
#endif /* __KERNEL__ */
diff --git a/arch/powerpc/kernel/dawr.c b/arch/powerpc/kernel/dawr.c
index e91b613bf137..8114ad3a8574 100644
--- a/arch/powerpc/kernel/dawr.c
+++ b/arch/powerpc/kernel/dawr.c
@@ -16,7 +16,7 @@
bool dawr_force_enable;
EXPORT_SYMBOL_GPL(dawr_force_enable);
-int set_dawr(struct arch_hw_breakpoint *brk)
+int set_dawr(int nr, struct arch_hw_breakpoint *brk)
{
unsigned long dawr, dawrx, mrd;
@@ -39,15 +39,20 @@ int set_dawr(struct arch_hw_breakpoint *brk)
if (ppc_md.set_dawr)
return ppc_md.set_dawr(dawr, dawrx);
- mtspr(SPRN_DAWR0, dawr);
- mtspr(SPRN_DAWRX0, dawrx);
+ if (nr == 0) {
+ mtspr(SPRN_DAWR0, dawr);
+ mtspr(SPRN_DAWRX0, dawrx);
+ } else {
+ mtspr(SPRN_DAWR1, dawr);
+ mtspr(SPRN_DAWRX1, dawrx);
+ }
return 0;
}
static void set_dawr_cb(void *info)
{
- set_dawr(info);
+ set_dawr(0, info);
}
static ssize_t dawr_write_file_bool(struct file *file,
@@ -60,7 +65,7 @@ static ssize_t dawr_write_file_bool(struct file *file,
/* Send error to user if they hypervisor won't allow us to write DAWR */
if (!dawr_force_enable &&
firmware_has_feature(FW_FEATURE_LPAR) &&
- set_dawr(&null_brk) != H_SUCCESS)
+ set_dawr(0, &null_brk) != H_SUCCESS)
return -ENODEV;
rc = debugfs_write_file_bool(file, user_buf, count, ppos);
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index db766252238f..dc161b0adc82 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -806,7 +806,7 @@ void __set_breakpoint(struct arch_hw_breakpoint *brk)
if (dawr_enabled())
// Power8 or later
- set_dawr(brk);
+ set_dawr(0, brk);
else if (IS_ENABLED(CONFIG_PPC_8xx))
set_breakpoint_8xx(brk);
else if (!cpu_has_feature(CPU_FTR_ARCH_207S))
--
2.26.2
^ permalink raw reply related [flat|nested] 18+ messages in thread* [PATCH v6 06/16] powerpc/watchpoint: Provide DAWR number to __set_breakpoint
2020-05-14 11:17 [PATCH v6 00/16] powerpc/watchpoint: Preparation for more than one watchpoint Ravi Bangoria
` (4 preceding siblings ...)
2020-05-14 11:17 ` [PATCH v6 05/16] powerpc/watchpoint: Provide DAWR number to set_dawr Ravi Bangoria
@ 2020-05-14 11:17 ` Ravi Bangoria
2020-05-14 11:17 ` [PATCH v6 07/16] powerpc/watchpoint: Get watchpoint count dynamically while disabling them Ravi Bangoria
` (10 subsequent siblings)
16 siblings, 0 replies; 18+ messages in thread
From: Ravi Bangoria @ 2020-05-14 11:17 UTC (permalink / raw)
To: mpe, mikey
Cc: apopple, paulus, npiggin, christophe.leroy, naveen.n.rao, peterz,
jolsa, oleg, fweisbec, mingo, linuxppc-dev, linux-kernel,
ravi.bangoria
Introduce new parameter 'nr' to __set_breakpoint() which indicates
which DAWR should be programed. Also convert current_brk variable
to an array.
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Reviewed-by: Michael Neuling <mikey@neuling.org>
---
arch/powerpc/include/asm/debug.h | 2 +-
arch/powerpc/include/asm/hw_breakpoint.h | 2 +-
arch/powerpc/kernel/hw_breakpoint.c | 8 ++++----
arch/powerpc/kernel/process.c | 14 +++++++-------
arch/powerpc/kernel/signal.c | 2 +-
arch/powerpc/xmon/xmon.c | 2 +-
6 files changed, 15 insertions(+), 15 deletions(-)
diff --git a/arch/powerpc/include/asm/debug.h b/arch/powerpc/include/asm/debug.h
index 7756026b95ca..ec57daf87f40 100644
--- a/arch/powerpc/include/asm/debug.h
+++ b/arch/powerpc/include/asm/debug.h
@@ -45,7 +45,7 @@ static inline int debugger_break_match(struct pt_regs *regs) { return 0; }
static inline int debugger_fault_handler(struct pt_regs *regs) { return 0; }
#endif
-void __set_breakpoint(struct arch_hw_breakpoint *brk);
+void __set_breakpoint(int nr, struct arch_hw_breakpoint *brk);
bool ppc_breakpoint_available(void);
#ifdef CONFIG_PPC_ADV_DEBUG_REGS
extern void do_send_trap(struct pt_regs *regs, unsigned long address,
diff --git a/arch/powerpc/include/asm/hw_breakpoint.h b/arch/powerpc/include/asm/hw_breakpoint.h
index 5b3b02834e0b..1120c7d9db58 100644
--- a/arch/powerpc/include/asm/hw_breakpoint.h
+++ b/arch/powerpc/include/asm/hw_breakpoint.h
@@ -85,7 +85,7 @@ static inline void hw_breakpoint_disable(void)
brk.len = 0;
brk.hw_len = 0;
if (ppc_breakpoint_available())
- __set_breakpoint(&brk);
+ __set_breakpoint(0, &brk);
}
extern void thread_change_pc(struct task_struct *tsk, struct pt_regs *regs);
int hw_breakpoint_handler(struct die_args *args);
diff --git a/arch/powerpc/kernel/hw_breakpoint.c b/arch/powerpc/kernel/hw_breakpoint.c
index 01f07d91df70..f5472402c06d 100644
--- a/arch/powerpc/kernel/hw_breakpoint.c
+++ b/arch/powerpc/kernel/hw_breakpoint.c
@@ -64,7 +64,7 @@ int arch_install_hw_breakpoint(struct perf_event *bp)
* If so, DABR will be populated in single_step_dabr_instruction().
*/
if (current->thread.last_hit_ubp != bp)
- __set_breakpoint(info);
+ __set_breakpoint(0, info);
return 0;
}
@@ -222,7 +222,7 @@ void thread_change_pc(struct task_struct *tsk, struct pt_regs *regs)
info = counter_arch_bp(tsk->thread.last_hit_ubp);
regs->msr &= ~MSR_SE;
- __set_breakpoint(info);
+ __set_breakpoint(0, info);
tsk->thread.last_hit_ubp = NULL;
}
@@ -347,7 +347,7 @@ int hw_breakpoint_handler(struct die_args *args)
if (!(info->type & HW_BRK_TYPE_EXTRANEOUS_IRQ))
perf_bp_event(bp, regs);
- __set_breakpoint(info);
+ __set_breakpoint(0, info);
out:
rcu_read_unlock();
return rc;
@@ -380,7 +380,7 @@ static int single_step_dabr_instruction(struct die_args *args)
if (!(info->type & HW_BRK_TYPE_EXTRANEOUS_IRQ))
perf_bp_event(bp, regs);
- __set_breakpoint(info);
+ __set_breakpoint(0, info);
current->thread.last_hit_ubp = NULL;
/*
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index dc161b0adc82..f303aea61794 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -637,7 +637,7 @@ void do_break (struct pt_regs *regs, unsigned long address,
}
#endif /* CONFIG_PPC_ADV_DEBUG_REGS */
-static DEFINE_PER_CPU(struct arch_hw_breakpoint, current_brk);
+static DEFINE_PER_CPU(struct arch_hw_breakpoint, current_brk[HBP_NUM_MAX]);
#ifdef CONFIG_PPC_ADV_DEBUG_REGS
/*
@@ -714,7 +714,7 @@ EXPORT_SYMBOL_GPL(switch_booke_debug_regs);
static void set_breakpoint(struct arch_hw_breakpoint *brk)
{
preempt_disable();
- __set_breakpoint(brk);
+ __set_breakpoint(0, brk);
preempt_enable();
}
@@ -800,13 +800,13 @@ static inline int set_breakpoint_8xx(struct arch_hw_breakpoint *brk)
return 0;
}
-void __set_breakpoint(struct arch_hw_breakpoint *brk)
+void __set_breakpoint(int nr, struct arch_hw_breakpoint *brk)
{
- memcpy(this_cpu_ptr(¤t_brk), brk, sizeof(*brk));
+ memcpy(this_cpu_ptr(¤t_brk[nr]), brk, sizeof(*brk));
if (dawr_enabled())
// Power8 or later
- set_dawr(0, brk);
+ set_dawr(nr, brk);
else if (IS_ENABLED(CONFIG_PPC_8xx))
set_breakpoint_8xx(brk);
else if (!cpu_has_feature(CPU_FTR_ARCH_207S))
@@ -1174,8 +1174,8 @@ struct task_struct *__switch_to(struct task_struct *prev,
* schedule DABR
*/
#ifndef CONFIG_HAVE_HW_BREAKPOINT
- if (unlikely(!hw_brk_match(this_cpu_ptr(¤t_brk), &new->thread.hw_brk)))
- __set_breakpoint(&new->thread.hw_brk);
+ if (unlikely(!hw_brk_match(this_cpu_ptr(¤t_brk[0]), &new->thread.hw_brk)))
+ __set_breakpoint(0, &new->thread.hw_brk);
#endif /* CONFIG_HAVE_HW_BREAKPOINT */
#endif
diff --git a/arch/powerpc/kernel/signal.c b/arch/powerpc/kernel/signal.c
index a46c3fdb6853..8e29138a344a 100644
--- a/arch/powerpc/kernel/signal.c
+++ b/arch/powerpc/kernel/signal.c
@@ -272,7 +272,7 @@ static void do_signal(struct task_struct *tsk)
* triggered inside the kernel.
*/
if (tsk->thread.hw_brk.address && tsk->thread.hw_brk.type)
- __set_breakpoint(&tsk->thread.hw_brk);
+ __set_breakpoint(0, &tsk->thread.hw_brk);
#endif
/* Re-enable the breakpoints for the signal stack */
thread_change_pc(tsk, tsk->thread.regs);
diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
index effb10c2e32f..30b3e3d99c0d 100644
--- a/arch/powerpc/xmon/xmon.c
+++ b/arch/powerpc/xmon/xmon.c
@@ -954,7 +954,7 @@ static void insert_cpu_bpts(void)
brk.address = dabr.address;
brk.type = (dabr.enabled & HW_BRK_TYPE_DABR) | HW_BRK_TYPE_PRIV_ALL;
brk.len = DABR_MAX_LEN;
- __set_breakpoint(&brk);
+ __set_breakpoint(0, &brk);
}
if (iabr)
--
2.26.2
^ permalink raw reply related [flat|nested] 18+ messages in thread* [PATCH v6 07/16] powerpc/watchpoint: Get watchpoint count dynamically while disabling them
2020-05-14 11:17 [PATCH v6 00/16] powerpc/watchpoint: Preparation for more than one watchpoint Ravi Bangoria
` (5 preceding siblings ...)
2020-05-14 11:17 ` [PATCH v6 06/16] powerpc/watchpoint: Provide DAWR number to __set_breakpoint Ravi Bangoria
@ 2020-05-14 11:17 ` Ravi Bangoria
2020-05-14 11:17 ` [PATCH v6 08/16] powerpc/watchpoint: Disable all available watchpoints when !dawr_force_enable Ravi Bangoria
` (9 subsequent siblings)
16 siblings, 0 replies; 18+ messages in thread
From: Ravi Bangoria @ 2020-05-14 11:17 UTC (permalink / raw)
To: mpe, mikey
Cc: apopple, paulus, npiggin, christophe.leroy, naveen.n.rao, peterz,
jolsa, oleg, fweisbec, mingo, linuxppc-dev, linux-kernel,
ravi.bangoria
Instead of disabling only one watchpoint, get num of available
watchpoints dynamically and disable all of them.
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Reviewed-by: Michael Neuling <mikey@neuling.org>
---
arch/powerpc/include/asm/hw_breakpoint.h | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)
diff --git a/arch/powerpc/include/asm/hw_breakpoint.h b/arch/powerpc/include/asm/hw_breakpoint.h
index 1120c7d9db58..d472b2eb757e 100644
--- a/arch/powerpc/include/asm/hw_breakpoint.h
+++ b/arch/powerpc/include/asm/hw_breakpoint.h
@@ -78,14 +78,14 @@ extern void ptrace_triggered(struct perf_event *bp,
struct perf_sample_data *data, struct pt_regs *regs);
static inline void hw_breakpoint_disable(void)
{
- struct arch_hw_breakpoint brk;
-
- brk.address = 0;
- brk.type = 0;
- brk.len = 0;
- brk.hw_len = 0;
- if (ppc_breakpoint_available())
- __set_breakpoint(0, &brk);
+ int i;
+ struct arch_hw_breakpoint null_brk = {0};
+
+ if (!ppc_breakpoint_available())
+ return;
+
+ for (i = 0; i < nr_wp_slots(); i++)
+ __set_breakpoint(i, &null_brk);
}
extern void thread_change_pc(struct task_struct *tsk, struct pt_regs *regs);
int hw_breakpoint_handler(struct die_args *args);
--
2.26.2
^ permalink raw reply related [flat|nested] 18+ messages in thread* [PATCH v6 08/16] powerpc/watchpoint: Disable all available watchpoints when !dawr_force_enable
2020-05-14 11:17 [PATCH v6 00/16] powerpc/watchpoint: Preparation for more than one watchpoint Ravi Bangoria
` (6 preceding siblings ...)
2020-05-14 11:17 ` [PATCH v6 07/16] powerpc/watchpoint: Get watchpoint count dynamically while disabling them Ravi Bangoria
@ 2020-05-14 11:17 ` Ravi Bangoria
2020-05-14 11:17 ` [PATCH v6 09/16] powerpc/watchpoint: Convert thread_struct->hw_brk to an array Ravi Bangoria
` (8 subsequent siblings)
16 siblings, 0 replies; 18+ messages in thread
From: Ravi Bangoria @ 2020-05-14 11:17 UTC (permalink / raw)
To: mpe, mikey
Cc: apopple, paulus, npiggin, christophe.leroy, naveen.n.rao, peterz,
jolsa, oleg, fweisbec, mingo, linuxppc-dev, linux-kernel,
ravi.bangoria
Instead of disabling only first watchpoint, disable all available
watchpoints while clearing dawr_force_enable.
Callback function is used only for disabling watchpoint, rename it
to disable_dawrs_cb(). And null_brk parameter is not really required
while disabling watchpoint, remove it.
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Reviewed-by: Michael Neuling <mikey@neuling.org>
---
arch/powerpc/kernel/dawr.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/arch/powerpc/kernel/dawr.c b/arch/powerpc/kernel/dawr.c
index 8114ad3a8574..500f52fa4711 100644
--- a/arch/powerpc/kernel/dawr.c
+++ b/arch/powerpc/kernel/dawr.c
@@ -50,9 +50,13 @@ int set_dawr(int nr, struct arch_hw_breakpoint *brk)
return 0;
}
-static void set_dawr_cb(void *info)
+static void disable_dawrs_cb(void *info)
{
- set_dawr(0, info);
+ struct arch_hw_breakpoint null_brk = {0};
+ int i;
+
+ for (i = 0; i < nr_wp_slots(); i++)
+ set_dawr(i, &null_brk);
}
static ssize_t dawr_write_file_bool(struct file *file,
@@ -74,7 +78,7 @@ static ssize_t dawr_write_file_bool(struct file *file,
/* If we are clearing, make sure all CPUs have the DAWR cleared */
if (!dawr_force_enable)
- smp_call_function(set_dawr_cb, &null_brk, 0);
+ smp_call_function(disable_dawrs_cb, NULL, 0);
return rc;
}
--
2.26.2
^ permalink raw reply related [flat|nested] 18+ messages in thread* [PATCH v6 09/16] powerpc/watchpoint: Convert thread_struct->hw_brk to an array
2020-05-14 11:17 [PATCH v6 00/16] powerpc/watchpoint: Preparation for more than one watchpoint Ravi Bangoria
` (7 preceding siblings ...)
2020-05-14 11:17 ` [PATCH v6 08/16] powerpc/watchpoint: Disable all available watchpoints when !dawr_force_enable Ravi Bangoria
@ 2020-05-14 11:17 ` Ravi Bangoria
2020-05-14 11:17 ` [PATCH v6 10/16] powerpc/watchpoint: Use loop for thread_struct->ptrace_bps Ravi Bangoria
` (7 subsequent siblings)
16 siblings, 0 replies; 18+ messages in thread
From: Ravi Bangoria @ 2020-05-14 11:17 UTC (permalink / raw)
To: mpe, mikey
Cc: apopple, paulus, npiggin, christophe.leroy, naveen.n.rao, peterz,
jolsa, oleg, fweisbec, mingo, linuxppc-dev, linux-kernel,
ravi.bangoria
So far powerpc hw supported only one watchpoint. But Power10 is
introducing 2nd DAWR. Convert thread_struct->hw_brk into an array.
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Reviewed-by: Michael Neuling <mikey@neuling.org>
---
arch/powerpc/include/asm/processor.h | 2 +-
arch/powerpc/kernel/process.c | 60 ++++++++++++++---------
arch/powerpc/kernel/ptrace/ptrace-noadv.c | 40 ++++++++++-----
arch/powerpc/kernel/ptrace/ptrace32.c | 4 +-
arch/powerpc/kernel/signal.c | 13 +++--
5 files changed, 78 insertions(+), 41 deletions(-)
diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h
index f209c5703ee2..fba6b586e3c8 100644
--- a/arch/powerpc/include/asm/processor.h
+++ b/arch/powerpc/include/asm/processor.h
@@ -187,7 +187,7 @@ struct thread_struct {
*/
struct perf_event *last_hit_ubp;
#endif /* CONFIG_HAVE_HW_BREAKPOINT */
- struct arch_hw_breakpoint hw_brk; /* info on the hardware breakpoint */
+ struct arch_hw_breakpoint hw_brk[HBP_NUM_MAX]; /* hardware breakpoint info */
unsigned long trap_nr; /* last trap # on this thread */
u8 load_slb; /* Ages out SLB preload cache entries */
u8 load_fp;
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index f303aea61794..d94d8925711c 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -711,21 +711,49 @@ void switch_booke_debug_regs(struct debug_reg *new_debug)
EXPORT_SYMBOL_GPL(switch_booke_debug_regs);
#else /* !CONFIG_PPC_ADV_DEBUG_REGS */
#ifndef CONFIG_HAVE_HW_BREAKPOINT
-static void set_breakpoint(struct arch_hw_breakpoint *brk)
+static void set_breakpoint(int i, struct arch_hw_breakpoint *brk)
{
preempt_disable();
- __set_breakpoint(0, brk);
+ __set_breakpoint(i, brk);
preempt_enable();
}
static void set_debug_reg_defaults(struct thread_struct *thread)
{
- thread->hw_brk.address = 0;
- thread->hw_brk.type = 0;
- thread->hw_brk.len = 0;
- thread->hw_brk.hw_len = 0;
- if (ppc_breakpoint_available())
- set_breakpoint(&thread->hw_brk);
+ int i;
+ struct arch_hw_breakpoint null_brk = {0};
+
+ for (i = 0; i < nr_wp_slots(); i++) {
+ thread->hw_brk[i] = null_brk;
+ if (ppc_breakpoint_available())
+ set_breakpoint(i, &thread->hw_brk[i]);
+ }
+}
+
+static inline bool hw_brk_match(struct arch_hw_breakpoint *a,
+ struct arch_hw_breakpoint *b)
+{
+ if (a->address != b->address)
+ return false;
+ if (a->type != b->type)
+ return false;
+ if (a->len != b->len)
+ return false;
+ /* no need to check hw_len. it's calculated from address and len */
+ return true;
+}
+
+static void switch_hw_breakpoint(struct task_struct *new)
+{
+ int i;
+
+ for (i = 0; i < nr_wp_slots(); i++) {
+ if (likely(hw_brk_match(this_cpu_ptr(¤t_brk[i]),
+ &new->thread.hw_brk[i])))
+ continue;
+
+ __set_breakpoint(i, &new->thread.hw_brk[i]);
+ }
}
#endif /* !CONFIG_HAVE_HW_BREAKPOINT */
#endif /* CONFIG_PPC_ADV_DEBUG_REGS */
@@ -829,19 +857,6 @@ bool ppc_breakpoint_available(void)
}
EXPORT_SYMBOL_GPL(ppc_breakpoint_available);
-static inline bool hw_brk_match(struct arch_hw_breakpoint *a,
- struct arch_hw_breakpoint *b)
-{
- if (a->address != b->address)
- return false;
- if (a->type != b->type)
- return false;
- if (a->len != b->len)
- return false;
- /* no need to check hw_len. it's calculated from address and len */
- return true;
-}
-
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
static inline bool tm_enabled(struct task_struct *tsk)
@@ -1174,8 +1189,7 @@ struct task_struct *__switch_to(struct task_struct *prev,
* schedule DABR
*/
#ifndef CONFIG_HAVE_HW_BREAKPOINT
- if (unlikely(!hw_brk_match(this_cpu_ptr(¤t_brk[0]), &new->thread.hw_brk)))
- __set_breakpoint(0, &new->thread.hw_brk);
+ switch_hw_breakpoint(new);
#endif /* CONFIG_HAVE_HW_BREAKPOINT */
#endif
diff --git a/arch/powerpc/kernel/ptrace/ptrace-noadv.c b/arch/powerpc/kernel/ptrace/ptrace-noadv.c
index 12962302d6a4..0dbb35392dd2 100644
--- a/arch/powerpc/kernel/ptrace/ptrace-noadv.c
+++ b/arch/powerpc/kernel/ptrace/ptrace-noadv.c
@@ -67,11 +67,16 @@ int ptrace_get_debugreg(struct task_struct *child, unsigned long addr,
/* We only support one DABR and no IABRS at the moment */
if (addr > 0)
return -EINVAL;
- dabr_fake = ((child->thread.hw_brk.address & (~HW_BRK_TYPE_DABR)) |
- (child->thread.hw_brk.type & HW_BRK_TYPE_DABR));
+ dabr_fake = ((child->thread.hw_brk[0].address & (~HW_BRK_TYPE_DABR)) |
+ (child->thread.hw_brk[0].type & HW_BRK_TYPE_DABR));
return put_user(dabr_fake, datalp);
}
+/*
+ * ptrace_set_debugreg() fakes DABR and DABR is only one. So even if
+ * internal hw supports more than one watchpoint, we support only one
+ * watchpoint with this interface.
+ */
int ptrace_set_debugreg(struct task_struct *task, unsigned long addr, unsigned long data)
{
#ifdef CONFIG_HAVE_HW_BREAKPOINT
@@ -137,7 +142,7 @@ int ptrace_set_debugreg(struct task_struct *task, unsigned long addr, unsigned l
return ret;
thread->ptrace_bps[0] = bp;
- thread->hw_brk = hw_brk;
+ thread->hw_brk[0] = hw_brk;
return 0;
}
@@ -159,12 +164,24 @@ int ptrace_set_debugreg(struct task_struct *task, unsigned long addr, unsigned l
if (set_bp && (!ppc_breakpoint_available()))
return -ENODEV;
#endif /* CONFIG_HAVE_HW_BREAKPOINT */
- task->thread.hw_brk = hw_brk;
+ task->thread.hw_brk[0] = hw_brk;
return 0;
}
+static int find_empty_hw_brk(struct thread_struct *thread)
+{
+ int i;
+
+ for (i = 0; i < nr_wp_slots(); i++) {
+ if (!thread->hw_brk[i].address)
+ return i;
+ }
+ return -1;
+}
+
long ppc_set_hwdebug(struct task_struct *child, struct ppc_hw_breakpoint *bp_info)
{
+ int i;
#ifdef CONFIG_HAVE_HW_BREAKPOINT
int len = 0;
struct thread_struct *thread = &child->thread;
@@ -223,15 +240,16 @@ long ppc_set_hwdebug(struct task_struct *child, struct ppc_hw_breakpoint *bp_inf
if (bp_info->addr_mode != PPC_BREAKPOINT_MODE_EXACT)
return -EINVAL;
- if (child->thread.hw_brk.address)
+ i = find_empty_hw_brk(&child->thread);
+ if (i < 0)
return -ENOSPC;
if (!ppc_breakpoint_available())
return -ENODEV;
- child->thread.hw_brk = brk;
+ child->thread.hw_brk[i] = brk;
- return 1;
+ return i + 1;
}
long ppc_del_hwdebug(struct task_struct *child, long data)
@@ -241,7 +259,7 @@ long ppc_del_hwdebug(struct task_struct *child, long data)
struct thread_struct *thread = &child->thread;
struct perf_event *bp;
#endif /* CONFIG_HAVE_HW_BREAKPOINT */
- if (data != 1)
+ if (data < 1 || data > nr_wp_slots())
return -EINVAL;
#ifdef CONFIG_HAVE_HW_BREAKPOINT
@@ -254,11 +272,11 @@ long ppc_del_hwdebug(struct task_struct *child, long data)
}
return ret;
#else /* CONFIG_HAVE_HW_BREAKPOINT */
- if (child->thread.hw_brk.address == 0)
+ if (child->thread.hw_brk[data - 1].address == 0)
return -ENOENT;
- child->thread.hw_brk.address = 0;
- child->thread.hw_brk.type = 0;
+ child->thread.hw_brk[data - 1].address = 0;
+ child->thread.hw_brk[data - 1].type = 0;
#endif /* CONFIG_HAVE_HW_BREAKPOINT */
return 0;
diff --git a/arch/powerpc/kernel/ptrace/ptrace32.c b/arch/powerpc/kernel/ptrace/ptrace32.c
index 7976ddf29c0e..7589a9665ffb 100644
--- a/arch/powerpc/kernel/ptrace/ptrace32.c
+++ b/arch/powerpc/kernel/ptrace/ptrace32.c
@@ -259,8 +259,8 @@ long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
ret = put_user(child->thread.debug.dac1, (u32 __user *)data);
#else
dabr_fake = (
- (child->thread.hw_brk.address & (~HW_BRK_TYPE_DABR)) |
- (child->thread.hw_brk.type & HW_BRK_TYPE_DABR));
+ (child->thread.hw_brk[0].address & (~HW_BRK_TYPE_DABR)) |
+ (child->thread.hw_brk[0].type & HW_BRK_TYPE_DABR));
ret = put_user(dabr_fake, (u32 __user *)data);
#endif
break;
diff --git a/arch/powerpc/kernel/signal.c b/arch/powerpc/kernel/signal.c
index 8e29138a344a..b4143b6ff093 100644
--- a/arch/powerpc/kernel/signal.c
+++ b/arch/powerpc/kernel/signal.c
@@ -265,15 +265,20 @@ static void do_signal(struct task_struct *tsk)
return; /* no signals delivered */
}
-#ifndef CONFIG_PPC_ADV_DEBUG_REGS
/*
* Reenable the DABR before delivering the signal to
* user space. The DABR will have been cleared if it
* triggered inside the kernel.
*/
- if (tsk->thread.hw_brk.address && tsk->thread.hw_brk.type)
- __set_breakpoint(0, &tsk->thread.hw_brk);
-#endif
+ if (!IS_ENABLED(CONFIG_PPC_ADV_DEBUG_REGS)) {
+ int i;
+
+ for (i = 0; i < nr_wp_slots(); i++) {
+ if (tsk->thread.hw_brk[i].address && tsk->thread.hw_brk[i].type)
+ __set_breakpoint(i, &tsk->thread.hw_brk[i]);
+ }
+ }
+
/* Re-enable the breakpoints for the signal stack */
thread_change_pc(tsk, tsk->thread.regs);
--
2.26.2
^ permalink raw reply related [flat|nested] 18+ messages in thread* [PATCH v6 10/16] powerpc/watchpoint: Use loop for thread_struct->ptrace_bps
2020-05-14 11:17 [PATCH v6 00/16] powerpc/watchpoint: Preparation for more than one watchpoint Ravi Bangoria
` (8 preceding siblings ...)
2020-05-14 11:17 ` [PATCH v6 09/16] powerpc/watchpoint: Convert thread_struct->hw_brk to an array Ravi Bangoria
@ 2020-05-14 11:17 ` Ravi Bangoria
2020-05-14 11:17 ` [PATCH v6 11/16] powerpc/watchpoint: Introduce is_ptrace_bp() function Ravi Bangoria
` (6 subsequent siblings)
16 siblings, 0 replies; 18+ messages in thread
From: Ravi Bangoria @ 2020-05-14 11:17 UTC (permalink / raw)
To: mpe, mikey
Cc: apopple, paulus, npiggin, christophe.leroy, naveen.n.rao, peterz,
jolsa, oleg, fweisbec, mingo, linuxppc-dev, linux-kernel,
ravi.bangoria
ptrace_bps is already an array of size HBP_NUM_MAX. But we use
hardcoded index 0 while fetching/updating it. Convert such code
to loop over array.
ptrace interface to use multiple watchpoint remains same. eg:
two PPC_PTRACE_SETHWDEBUG calls will create two watchpoint if
underneath hw supports it.
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Reviewed-by: Michael Neuling <mikey@neuling.org>
---
arch/powerpc/kernel/hw_breakpoint.c | 7 ++++--
arch/powerpc/kernel/process.c | 6 ++++-
arch/powerpc/kernel/ptrace/ptrace-noadv.c | 28 +++++++++++++++++------
3 files changed, 31 insertions(+), 10 deletions(-)
diff --git a/arch/powerpc/kernel/hw_breakpoint.c b/arch/powerpc/kernel/hw_breakpoint.c
index f5472402c06d..917cca73dbc3 100644
--- a/arch/powerpc/kernel/hw_breakpoint.c
+++ b/arch/powerpc/kernel/hw_breakpoint.c
@@ -420,10 +420,13 @@ NOKPROBE_SYMBOL(hw_breakpoint_exceptions_notify);
*/
void flush_ptrace_hw_breakpoint(struct task_struct *tsk)
{
+ int i;
struct thread_struct *t = &tsk->thread;
- unregister_hw_breakpoint(t->ptrace_bps[0]);
- t->ptrace_bps[0] = NULL;
+ for (i = 0; i < nr_wp_slots(); i++) {
+ unregister_hw_breakpoint(t->ptrace_bps[i]);
+ t->ptrace_bps[i] = NULL;
+ }
}
void hw_breakpoint_pmu_read(struct perf_event *bp)
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index d94d8925711c..77ec1299e2fd 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1604,6 +1604,9 @@ int copy_thread_tls(unsigned long clone_flags, unsigned long usp,
void (*f)(void);
unsigned long sp = (unsigned long)task_stack_page(p) + THREAD_SIZE;
struct thread_info *ti = task_thread_info(p);
+#ifdef CONFIG_HAVE_HW_BREAKPOINT
+ int i;
+#endif
klp_init_thread_info(p);
@@ -1663,7 +1666,8 @@ int copy_thread_tls(unsigned long clone_flags, unsigned long usp,
p->thread.ksp_limit = (unsigned long)end_of_stack(p);
#endif
#ifdef CONFIG_HAVE_HW_BREAKPOINT
- p->thread.ptrace_bps[0] = NULL;
+ for (i = 0; i < nr_wp_slots(); i++)
+ p->thread.ptrace_bps[i] = NULL;
#endif
p->thread.fp_save_area = NULL;
diff --git a/arch/powerpc/kernel/ptrace/ptrace-noadv.c b/arch/powerpc/kernel/ptrace/ptrace-noadv.c
index 0dbb35392dd2..08cb8c1b504c 100644
--- a/arch/powerpc/kernel/ptrace/ptrace-noadv.c
+++ b/arch/powerpc/kernel/ptrace/ptrace-noadv.c
@@ -168,6 +168,19 @@ int ptrace_set_debugreg(struct task_struct *task, unsigned long addr, unsigned l
return 0;
}
+#ifdef CONFIG_HAVE_HW_BREAKPOINT
+static int find_empty_ptrace_bp(struct thread_struct *thread)
+{
+ int i;
+
+ for (i = 0; i < nr_wp_slots(); i++) {
+ if (!thread->ptrace_bps[i])
+ return i;
+ }
+ return -1;
+}
+#endif
+
static int find_empty_hw_brk(struct thread_struct *thread)
{
int i;
@@ -217,8 +230,9 @@ long ppc_set_hwdebug(struct task_struct *child, struct ppc_hw_breakpoint *bp_inf
len = 1;
else
return -EINVAL;
- bp = thread->ptrace_bps[0];
- if (bp)
+
+ i = find_empty_ptrace_bp(thread);
+ if (i < 0)
return -ENOSPC;
/* Create a new breakpoint request if one doesn't exist already */
@@ -228,13 +242,13 @@ long ppc_set_hwdebug(struct task_struct *child, struct ppc_hw_breakpoint *bp_inf
arch_bp_generic_fields(brk.type, &attr.bp_type);
bp = register_user_hw_breakpoint(&attr, ptrace_triggered, NULL, child);
- thread->ptrace_bps[0] = bp;
+ thread->ptrace_bps[i] = bp;
if (IS_ERR(bp)) {
- thread->ptrace_bps[0] = NULL;
+ thread->ptrace_bps[i] = NULL;
return PTR_ERR(bp);
}
- return 1;
+ return i + 1;
#endif /* CONFIG_HAVE_HW_BREAKPOINT */
if (bp_info->addr_mode != PPC_BREAKPOINT_MODE_EXACT)
@@ -263,10 +277,10 @@ long ppc_del_hwdebug(struct task_struct *child, long data)
return -EINVAL;
#ifdef CONFIG_HAVE_HW_BREAKPOINT
- bp = thread->ptrace_bps[0];
+ bp = thread->ptrace_bps[data - 1];
if (bp) {
unregister_hw_breakpoint(bp);
- thread->ptrace_bps[0] = NULL;
+ thread->ptrace_bps[data - 1] = NULL;
} else {
ret = -ENOENT;
}
--
2.26.2
^ permalink raw reply related [flat|nested] 18+ messages in thread* [PATCH v6 11/16] powerpc/watchpoint: Introduce is_ptrace_bp() function
2020-05-14 11:17 [PATCH v6 00/16] powerpc/watchpoint: Preparation for more than one watchpoint Ravi Bangoria
` (9 preceding siblings ...)
2020-05-14 11:17 ` [PATCH v6 10/16] powerpc/watchpoint: Use loop for thread_struct->ptrace_bps Ravi Bangoria
@ 2020-05-14 11:17 ` Ravi Bangoria
2020-05-14 11:17 ` [PATCH v6 12/16] powerpc/watchpoint: Use builtin ALIGN*() macros Ravi Bangoria
` (5 subsequent siblings)
16 siblings, 0 replies; 18+ messages in thread
From: Ravi Bangoria @ 2020-05-14 11:17 UTC (permalink / raw)
To: mpe, mikey
Cc: apopple, paulus, npiggin, christophe.leroy, naveen.n.rao, peterz,
jolsa, oleg, fweisbec, mingo, linuxppc-dev, linux-kernel,
ravi.bangoria
Introduce is_ptrace_bp() function and move the check inside the
function. It will be utilize more in later set of patches.
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Reviewed-by: Michael Neuling <mikey@neuling.org>
---
arch/powerpc/kernel/hw_breakpoint.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/kernel/hw_breakpoint.c b/arch/powerpc/kernel/hw_breakpoint.c
index 917cca73dbc3..8028a2704874 100644
--- a/arch/powerpc/kernel/hw_breakpoint.c
+++ b/arch/powerpc/kernel/hw_breakpoint.c
@@ -91,6 +91,11 @@ void arch_uninstall_hw_breakpoint(struct perf_event *bp)
hw_breakpoint_disable();
}
+static bool is_ptrace_bp(struct perf_event *bp)
+{
+ return bp->overflow_handler == ptrace_triggered;
+}
+
/*
* Perform cleanup of arch-specific counters during unregistration
* of the perf-event
@@ -325,7 +330,7 @@ int hw_breakpoint_handler(struct die_args *args)
* one-shot mode. The ptrace-ed process will receive the SIGTRAP signal
* generated in do_dabr().
*/
- if (bp->overflow_handler == ptrace_triggered) {
+ if (is_ptrace_bp(bp)) {
perf_bp_event(bp, regs);
rc = NOTIFY_DONE;
goto out;
--
2.26.2
^ permalink raw reply related [flat|nested] 18+ messages in thread* [PATCH v6 12/16] powerpc/watchpoint: Use builtin ALIGN*() macros
2020-05-14 11:17 [PATCH v6 00/16] powerpc/watchpoint: Preparation for more than one watchpoint Ravi Bangoria
` (10 preceding siblings ...)
2020-05-14 11:17 ` [PATCH v6 11/16] powerpc/watchpoint: Introduce is_ptrace_bp() function Ravi Bangoria
@ 2020-05-14 11:17 ` Ravi Bangoria
2020-05-14 11:17 ` [PATCH v6 13/16] powerpc/watchpoint: Prepare handler to handle more than one watcnhpoint Ravi Bangoria
` (4 subsequent siblings)
16 siblings, 0 replies; 18+ messages in thread
From: Ravi Bangoria @ 2020-05-14 11:17 UTC (permalink / raw)
To: mpe, mikey
Cc: apopple, paulus, npiggin, christophe.leroy, naveen.n.rao, peterz,
jolsa, oleg, fweisbec, mingo, linuxppc-dev, linux-kernel,
ravi.bangoria
Currently we calculate hw aligned start and end addresses manually.
Replace them with builtin ALIGN_DOWN() and ALIGN() macros.
So far end_addr was inclusive but this patch makes it exclusive (by
avoiding -1) for better readability.
Suggested-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Reviewed-by: Michael Neuling <mikey@neuling.org>
---
arch/powerpc/include/asm/hw_breakpoint.h | 5 +++--
arch/powerpc/kernel/hw_breakpoint.c | 12 ++++++------
arch/powerpc/kernel/process.c | 8 ++++----
arch/powerpc/kernel/ptrace/ptrace-noadv.c | 2 +-
4 files changed, 14 insertions(+), 13 deletions(-)
diff --git a/arch/powerpc/include/asm/hw_breakpoint.h b/arch/powerpc/include/asm/hw_breakpoint.h
index d472b2eb757e..add5aa076919 100644
--- a/arch/powerpc/include/asm/hw_breakpoint.h
+++ b/arch/powerpc/include/asm/hw_breakpoint.h
@@ -34,10 +34,11 @@ struct arch_hw_breakpoint {
#define HW_BRK_TYPE_PRIV_ALL (HW_BRK_TYPE_USER | HW_BRK_TYPE_KERNEL | \
HW_BRK_TYPE_HYP)
+/* Minimum granularity */
#ifdef CONFIG_PPC_8xx
-#define HW_BREAKPOINT_ALIGN 0x3
+#define HW_BREAKPOINT_SIZE 0x4
#else
-#define HW_BREAKPOINT_ALIGN 0x7
+#define HW_BREAKPOINT_SIZE 0x8
#endif
#define DABR_MAX_LEN 8
diff --git a/arch/powerpc/kernel/hw_breakpoint.c b/arch/powerpc/kernel/hw_breakpoint.c
index 8028a2704874..4366bd0c90c4 100644
--- a/arch/powerpc/kernel/hw_breakpoint.c
+++ b/arch/powerpc/kernel/hw_breakpoint.c
@@ -146,10 +146,10 @@ int arch_bp_generic_fields(int type, int *gen_bp_type)
* <---8 bytes--->
*
* In this case, we should configure hw as:
- * start_addr = address & ~HW_BREAKPOINT_ALIGN
+ * start_addr = address & ~(HW_BREAKPOINT_SIZE - 1)
* len = 16 bytes
*
- * @start_addr and @end_addr are inclusive.
+ * @start_addr is inclusive but @end_addr is exclusive.
*/
static int hw_breakpoint_validate_len(struct arch_hw_breakpoint *hw)
{
@@ -157,14 +157,14 @@ static int hw_breakpoint_validate_len(struct arch_hw_breakpoint *hw)
u16 hw_len;
unsigned long start_addr, end_addr;
- start_addr = hw->address & ~HW_BREAKPOINT_ALIGN;
- end_addr = (hw->address + hw->len - 1) | HW_BREAKPOINT_ALIGN;
- hw_len = end_addr - start_addr + 1;
+ start_addr = ALIGN_DOWN(hw->address, HW_BREAKPOINT_SIZE);
+ end_addr = ALIGN(hw->address + hw->len, HW_BREAKPOINT_SIZE);
+ hw_len = end_addr - start_addr;
if (dawr_enabled()) {
max_len = DAWR_MAX_LEN;
/* DAWR region can't cross 512 bytes boundary */
- if ((start_addr >> 9) != (end_addr >> 9))
+ if (ALIGN(start_addr, SZ_512M) != ALIGN(end_addr - 1, SZ_512M))
return -EINVAL;
} else if (IS_ENABLED(CONFIG_PPC_8xx)) {
/* 8xx can setup a range without limitation */
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 77ec1299e2fd..9b11575dcb8a 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -800,12 +800,12 @@ static inline int set_breakpoint_8xx(struct arch_hw_breakpoint *brk)
unsigned long lctrl1 = LCTRL1_CTE_GT | LCTRL1_CTF_LT | LCTRL1_CRWE_RW |
LCTRL1_CRWF_RW;
unsigned long lctrl2 = LCTRL2_LW0EN | LCTRL2_LW0LADC | LCTRL2_SLW0EN;
- unsigned long start_addr = brk->address & ~HW_BREAKPOINT_ALIGN;
- unsigned long end_addr = (brk->address + brk->len - 1) | HW_BREAKPOINT_ALIGN;
+ unsigned long start_addr = ALIGN_DOWN(brk->address, HW_BREAKPOINT_SIZE);
+ unsigned long end_addr = ALIGN(brk->address + brk->len, HW_BREAKPOINT_SIZE);
if (start_addr == 0)
lctrl2 |= LCTRL2_LW0LA_F;
- else if (end_addr == ~0U)
+ else if (end_addr == 0)
lctrl2 |= LCTRL2_LW0LA_E;
else
lctrl2 |= LCTRL2_LW0LA_EandF;
@@ -821,7 +821,7 @@ static inline int set_breakpoint_8xx(struct arch_hw_breakpoint *brk)
lctrl1 |= LCTRL1_CRWE_WO | LCTRL1_CRWF_WO;
mtspr(SPRN_CMPE, start_addr - 1);
- mtspr(SPRN_CMPF, end_addr + 1);
+ mtspr(SPRN_CMPF, end_addr);
mtspr(SPRN_LCTRL1, lctrl1);
mtspr(SPRN_LCTRL2, lctrl2);
diff --git a/arch/powerpc/kernel/ptrace/ptrace-noadv.c b/arch/powerpc/kernel/ptrace/ptrace-noadv.c
index 08cb8c1b504c..697c7e4b5877 100644
--- a/arch/powerpc/kernel/ptrace/ptrace-noadv.c
+++ b/arch/powerpc/kernel/ptrace/ptrace-noadv.c
@@ -216,7 +216,7 @@ long ppc_set_hwdebug(struct task_struct *child, struct ppc_hw_breakpoint *bp_inf
if ((unsigned long)bp_info->addr >= TASK_SIZE)
return -EIO;
- brk.address = bp_info->addr & ~HW_BREAKPOINT_ALIGN;
+ brk.address = ALIGN_DOWN(bp_info->addr, HW_BREAKPOINT_SIZE);
brk.type = HW_BRK_TYPE_TRANSLATE;
brk.len = DABR_MAX_LEN;
if (bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_READ)
--
2.26.2
^ permalink raw reply related [flat|nested] 18+ messages in thread* [PATCH v6 13/16] powerpc/watchpoint: Prepare handler to handle more than one watcnhpoint
2020-05-14 11:17 [PATCH v6 00/16] powerpc/watchpoint: Preparation for more than one watchpoint Ravi Bangoria
` (11 preceding siblings ...)
2020-05-14 11:17 ` [PATCH v6 12/16] powerpc/watchpoint: Use builtin ALIGN*() macros Ravi Bangoria
@ 2020-05-14 11:17 ` Ravi Bangoria
2020-05-14 11:17 ` [PATCH v6 14/16] powerpc/watchpoint: Don't allow concurrent perf and ptrace events Ravi Bangoria
` (3 subsequent siblings)
16 siblings, 0 replies; 18+ messages in thread
From: Ravi Bangoria @ 2020-05-14 11:17 UTC (permalink / raw)
To: mpe, mikey
Cc: apopple, paulus, npiggin, christophe.leroy, naveen.n.rao, peterz,
jolsa, oleg, fweisbec, mingo, linuxppc-dev, linux-kernel,
ravi.bangoria
Currently we assume that we have only one watchpoint supported by hw.
Get rid of that assumption and use dynamic loop instead. This should
make supporting more watchpoints very easy.
With more than one watchpoint, exception handler needs to know which
DAWR caused the exception, and hw currently does not provide it. So
we need sw logic for the same. To figure out which DAWR caused the
exception, check all different combinations of user specified range,
DAWR address range, actual access range and DAWRX constrains. For ex,
if user specified range and actual access range overlaps but DAWRX is
configured for readonly watchpoint and the instruction is store, this
DAWR must not have caused exception.
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Reviewed-by: Michael Neuling <mikey@neuling.org>
---
arch/powerpc/include/asm/processor.h | 2 +-
arch/powerpc/include/asm/sstep.h | 2 +
arch/powerpc/kernel/hw_breakpoint.c | 397 +++++++++++++++++++++------
arch/powerpc/kernel/process.c | 3 -
4 files changed, 312 insertions(+), 92 deletions(-)
diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h
index fba6b586e3c8..4e53df163b92 100644
--- a/arch/powerpc/include/asm/processor.h
+++ b/arch/powerpc/include/asm/processor.h
@@ -185,7 +185,7 @@ struct thread_struct {
* Helps identify source of single-step exception and subsequent
* hw-breakpoint enablement
*/
- struct perf_event *last_hit_ubp;
+ struct perf_event *last_hit_ubp[HBP_NUM_MAX];
#endif /* CONFIG_HAVE_HW_BREAKPOINT */
struct arch_hw_breakpoint hw_brk[HBP_NUM_MAX]; /* hardware breakpoint info */
unsigned long trap_nr; /* last trap # on this thread */
diff --git a/arch/powerpc/include/asm/sstep.h b/arch/powerpc/include/asm/sstep.h
index 9b200a5f8794..3b01c69a44aa 100644
--- a/arch/powerpc/include/asm/sstep.h
+++ b/arch/powerpc/include/asm/sstep.h
@@ -49,6 +49,8 @@ enum instruction_type {
#define INSTR_TYPE_MASK 0x1f
+#define OP_IS_LOAD(type) ((LOAD <= (type) && (type) <= LOAD_VSX) || (type) == LARX)
+#define OP_IS_STORE(type) ((STORE <= (type) && (type) <= STORE_VSX) || (type) == STCX)
#define OP_IS_LOAD_STORE(type) (LOAD <= (type) && (type) <= STCX)
/* Compute flags, ORed in with type */
diff --git a/arch/powerpc/kernel/hw_breakpoint.c b/arch/powerpc/kernel/hw_breakpoint.c
index 4366bd0c90c4..da858bc6a414 100644
--- a/arch/powerpc/kernel/hw_breakpoint.c
+++ b/arch/powerpc/kernel/hw_breakpoint.c
@@ -31,7 +31,7 @@
* Stores the breakpoints currently in use on each breakpoint address
* register for every cpu
*/
-static DEFINE_PER_CPU(struct perf_event *, bp_per_reg);
+static DEFINE_PER_CPU(struct perf_event *, bp_per_reg[HBP_NUM_MAX]);
/*
* Returns total number of data or instruction breakpoints available.
@@ -43,6 +43,17 @@ int hw_breakpoint_slots(int type)
return 0; /* no instruction breakpoints available */
}
+static bool single_step_pending(void)
+{
+ int i;
+
+ for (i = 0; i < nr_wp_slots(); i++) {
+ if (current->thread.last_hit_ubp[i])
+ return true;
+ }
+ return false;
+}
+
/*
* Install a perf counter breakpoint.
*
@@ -55,16 +66,26 @@ int hw_breakpoint_slots(int type)
int arch_install_hw_breakpoint(struct perf_event *bp)
{
struct arch_hw_breakpoint *info = counter_arch_bp(bp);
- struct perf_event **slot = this_cpu_ptr(&bp_per_reg);
+ struct perf_event **slot;
+ int i;
+
+ for (i = 0; i < nr_wp_slots(); i++) {
+ slot = this_cpu_ptr(&bp_per_reg[i]);
+ if (!*slot) {
+ *slot = bp;
+ break;
+ }
+ }
- *slot = bp;
+ if (WARN_ONCE(i == nr_wp_slots(), "Can't find any breakpoint slot"))
+ return -EBUSY;
/*
* Do not install DABR values if the instruction must be single-stepped.
* If so, DABR will be populated in single_step_dabr_instruction().
*/
- if (current->thread.last_hit_ubp != bp)
- __set_breakpoint(0, info);
+ if (!single_step_pending())
+ __set_breakpoint(i, info);
return 0;
}
@@ -80,15 +101,22 @@ int arch_install_hw_breakpoint(struct perf_event *bp)
*/
void arch_uninstall_hw_breakpoint(struct perf_event *bp)
{
- struct perf_event **slot = this_cpu_ptr(&bp_per_reg);
+ struct arch_hw_breakpoint null_brk = {0};
+ struct perf_event **slot;
+ int i;
- if (*slot != bp) {
- WARN_ONCE(1, "Can't find the breakpoint");
- return;
+ for (i = 0; i < nr_wp_slots(); i++) {
+ slot = this_cpu_ptr(&bp_per_reg[i]);
+ if (*slot == bp) {
+ *slot = NULL;
+ break;
+ }
}
- *slot = NULL;
- hw_breakpoint_disable();
+ if (WARN_ONCE(i == nr_wp_slots(), "Can't find any breakpoint slot"))
+ return;
+
+ __set_breakpoint(i, &null_brk);
}
static bool is_ptrace_bp(struct perf_event *bp)
@@ -108,8 +136,14 @@ void arch_unregister_hw_breakpoint(struct perf_event *bp)
* restoration variables to prevent dangling pointers.
* FIXME, this should not be using bp->ctx at all! Sayeth peterz.
*/
- if (bp->ctx && bp->ctx->task && bp->ctx->task != ((void *)-1L))
- bp->ctx->task->thread.last_hit_ubp = NULL;
+ if (bp->ctx && bp->ctx->task && bp->ctx->task != ((void *)-1L)) {
+ int i;
+
+ for (i = 0; i < nr_wp_slots(); i++) {
+ if (bp->ctx->task->thread.last_hit_ubp[i] == bp)
+ bp->ctx->task->thread.last_hit_ubp[i] = NULL;
+ }
+ }
}
/*
@@ -221,90 +255,211 @@ int hw_breakpoint_arch_parse(struct perf_event *bp,
void thread_change_pc(struct task_struct *tsk, struct pt_regs *regs)
{
struct arch_hw_breakpoint *info;
+ int i;
- if (likely(!tsk->thread.last_hit_ubp))
- return;
+ for (i = 0; i < nr_wp_slots(); i++) {
+ if (unlikely(tsk->thread.last_hit_ubp[i]))
+ goto reset;
+ }
+ return;
- info = counter_arch_bp(tsk->thread.last_hit_ubp);
+reset:
regs->msr &= ~MSR_SE;
- __set_breakpoint(0, info);
- tsk->thread.last_hit_ubp = NULL;
+ for (i = 0; i < nr_wp_slots(); i++) {
+ info = counter_arch_bp(__this_cpu_read(bp_per_reg[i]));
+ __set_breakpoint(i, info);
+ tsk->thread.last_hit_ubp[i] = NULL;
+ }
}
-static bool dar_within_range(unsigned long dar, struct arch_hw_breakpoint *info)
+static bool dar_in_user_range(unsigned long dar, struct arch_hw_breakpoint *info)
{
return ((info->address <= dar) && (dar - info->address < info->len));
}
-static bool
-dar_range_overlaps(unsigned long dar, int size, struct arch_hw_breakpoint *info)
+static bool dar_user_range_overlaps(unsigned long dar, int size,
+ struct arch_hw_breakpoint *info)
+{
+ return ((dar < info->address + info->len) &&
+ (dar + size > info->address));
+}
+
+static bool dar_in_hw_range(unsigned long dar, struct arch_hw_breakpoint *info)
+{
+ unsigned long hw_start_addr, hw_end_addr;
+
+ hw_start_addr = ALIGN_DOWN(info->address, HW_BREAKPOINT_SIZE);
+ hw_end_addr = ALIGN(info->address + info->len, HW_BREAKPOINT_SIZE);
+
+ return ((hw_start_addr <= dar) && (hw_end_addr > dar));
+}
+
+static bool dar_hw_range_overlaps(unsigned long dar, int size,
+ struct arch_hw_breakpoint *info)
{
- return ((dar <= info->address + info->len - 1) &&
- (dar + size - 1 >= info->address));
+ unsigned long hw_start_addr, hw_end_addr;
+
+ hw_start_addr = ALIGN_DOWN(info->address, HW_BREAKPOINT_SIZE);
+ hw_end_addr = ALIGN(info->address + info->len, HW_BREAKPOINT_SIZE);
+
+ return ((dar < hw_end_addr) && (dar + size > hw_start_addr));
}
/*
- * Handle debug exception notifications.
+ * If hw has multiple DAWR registers, we also need to check all
+ * dawrx constraint bits to confirm this is _really_ a valid event.
*/
-static bool stepping_handler(struct pt_regs *regs, struct perf_event *bp,
- struct arch_hw_breakpoint *info)
+static bool check_dawrx_constraints(struct pt_regs *regs, int type,
+ struct arch_hw_breakpoint *info)
{
- struct ppc_inst instr = ppc_inst(0);
- int ret, type, size;
- struct instruction_op op;
- unsigned long addr = info->address;
+ if (OP_IS_LOAD(type) && !(info->type & HW_BRK_TYPE_READ))
+ return false;
- if (__get_user_instr_inatomic(instr, (void __user *)regs->nip))
- goto fail;
+ if (OP_IS_STORE(type) && !(info->type & HW_BRK_TYPE_WRITE))
+ return false;
- ret = analyse_instr(&op, regs, instr);
- type = GETTYPE(op.type);
- size = GETSIZE(op.type);
+ if (is_kernel_addr(regs->nip) && !(info->type & HW_BRK_TYPE_KERNEL))
+ return false;
- if (!ret && (type == LARX || type == STCX)) {
- printk_ratelimited("Breakpoint hit on instruction that can't be emulated."
- " Breakpoint at 0x%lx will be disabled.\n", addr);
- goto disable;
- }
+ if (user_mode(regs) && !(info->type & HW_BRK_TYPE_USER))
+ return false;
+
+ return true;
+}
+
+/*
+ * Return true if the event is valid wrt dawr configuration,
+ * including extraneous exception. Otherwise return false.
+ */
+static bool check_constraints(struct pt_regs *regs, struct ppc_inst instr,
+ int type, int size, struct arch_hw_breakpoint *info)
+{
+ bool in_user_range = dar_in_user_range(regs->dar, info);
+ bool dawrx_constraints;
/*
- * If it's extraneous event, we still need to emulate/single-
- * step the instruction, but we don't generate an event.
+ * 8xx supports only one breakpoint and thus we can
+ * unconditionally return true.
*/
- if (size && !dar_range_overlaps(regs->dar, size, info))
- info->type |= HW_BRK_TYPE_EXTRANEOUS_IRQ;
+ if (IS_ENABLED(CONFIG_PPC_8xx)) {
+ if (!in_user_range)
+ info->type |= HW_BRK_TYPE_EXTRANEOUS_IRQ;
+ return true;
+ }
- /* Do not emulate user-space instructions, instead single-step them */
- if (user_mode(regs)) {
- current->thread.last_hit_ubp = bp;
- regs->msr |= MSR_SE;
+ if (unlikely(ppc_inst_equal(instr, ppc_inst(0)))) {
+ if (in_user_range)
+ return true;
+
+ if (dar_in_hw_range(regs->dar, info)) {
+ info->type |= HW_BRK_TYPE_EXTRANEOUS_IRQ;
+ return true;
+ }
return false;
}
- if (!emulate_step(regs, instr))
- goto fail;
+ dawrx_constraints = check_dawrx_constraints(regs, type, info);
- return true;
+ if (dar_user_range_overlaps(regs->dar, size, info))
+ return dawrx_constraints;
+
+ if (dar_hw_range_overlaps(regs->dar, size, info)) {
+ if (dawrx_constraints) {
+ info->type |= HW_BRK_TYPE_EXTRANEOUS_IRQ;
+ return true;
+ }
+ }
+ return false;
+}
+
+static void get_instr_detail(struct pt_regs *regs, struct ppc_inst *instr,
+ int *type, int *size, bool *larx_stcx)
+{
+ struct instruction_op op;
+
+ if (__get_user_instr_inatomic(*instr, (void __user *)regs->nip))
+ return;
+
+ analyse_instr(&op, regs, *instr);
-fail:
/*
- * We've failed in reliably handling the hw-breakpoint. Unregister
- * it and throw a warning message to let the user know about it.
+ * Set size = 8 if analyse_instr() fails. If it's a userspace
+ * watchpoint(valid or extraneous), we can notify user about it.
+ * If it's a kernel watchpoint, instruction emulation will fail
+ * in stepping_handler() and watchpoint will be disabled.
*/
- WARN(1, "Unable to handle hardware breakpoint. Breakpoint at "
- "0x%lx will be disabled.", addr);
+ *type = GETTYPE(op.type);
+ *size = !(*type == UNKNOWN) ? GETSIZE(op.type) : 8;
+ *larx_stcx = (*type == LARX || *type == STCX);
+}
+
+/*
+ * We've failed in reliably handling the hw-breakpoint. Unregister
+ * it and throw a warning message to let the user know about it.
+ */
+static void handler_error(struct perf_event *bp, struct arch_hw_breakpoint *info)
+{
+ WARN(1, "Unable to handle hardware breakpoint."
+ "Breakpoint at 0x%lx will be disabled.",
+ info->address);
+ perf_event_disable_inatomic(bp);
+}
-disable:
+static void larx_stcx_err(struct perf_event *bp, struct arch_hw_breakpoint *info)
+{
+ printk_ratelimited("Breakpoint hit on instruction that can't "
+ "be emulated. Breakpoint at 0x%lx will be "
+ "disabled.\n", info->address);
perf_event_disable_inatomic(bp);
- return false;
+}
+
+static bool stepping_handler(struct pt_regs *regs, struct perf_event **bp,
+ struct arch_hw_breakpoint **info, int *hit,
+ struct ppc_inst instr)
+{
+ int i;
+ int stepped;
+
+ /* Do not emulate user-space instructions, instead single-step them */
+ if (user_mode(regs)) {
+ for (i = 0; i < nr_wp_slots(); i++) {
+ if (!hit[i])
+ continue;
+ current->thread.last_hit_ubp[i] = bp[i];
+ info[i] = NULL;
+ }
+ regs->msr |= MSR_SE;
+ return false;
+ }
+
+ stepped = emulate_step(regs, instr);
+ if (!stepped) {
+ for (i = 0; i < nr_wp_slots(); i++) {
+ if (!hit[i])
+ continue;
+ handler_error(bp[i], info[i]);
+ info[i] = NULL;
+ }
+ return false;
+ }
+ return true;
}
int hw_breakpoint_handler(struct die_args *args)
{
+ bool err = false;
int rc = NOTIFY_STOP;
- struct perf_event *bp;
+ struct perf_event *bp[HBP_NUM_MAX] = {0};
struct pt_regs *regs = args->regs;
- struct arch_hw_breakpoint *info;
+ struct arch_hw_breakpoint *info[HBP_NUM_MAX] = {0};
+ int i;
+ int hit[HBP_NUM_MAX] = {0};
+ int nr_hit = 0;
+ bool ptrace_bp = false;
+ struct ppc_inst instr = ppc_inst(0);
+ int type = 0;
+ int size = 0;
+ bool larx_stcx = false;
/* Disable breakpoints during exception handling */
hw_breakpoint_disable();
@@ -317,12 +472,40 @@ int hw_breakpoint_handler(struct die_args *args)
*/
rcu_read_lock();
- bp = __this_cpu_read(bp_per_reg);
- if (!bp) {
+ if (!IS_ENABLED(CONFIG_PPC_8xx))
+ get_instr_detail(regs, &instr, &type, &size, &larx_stcx);
+
+ for (i = 0; i < nr_wp_slots(); i++) {
+ bp[i] = __this_cpu_read(bp_per_reg[i]);
+ if (!bp[i])
+ continue;
+
+ info[i] = counter_arch_bp(bp[i]);
+ info[i]->type &= ~HW_BRK_TYPE_EXTRANEOUS_IRQ;
+
+ if (check_constraints(regs, instr, type, size, info[i])) {
+ if (!IS_ENABLED(CONFIG_PPC_8xx) &&
+ ppc_inst_equal(instr, ppc_inst(0))) {
+ handler_error(bp[i], info[i]);
+ info[i] = NULL;
+ err = 1;
+ continue;
+ }
+
+ if (is_ptrace_bp(bp[i]))
+ ptrace_bp = true;
+ hit[i] = 1;
+ nr_hit++;
+ }
+ }
+
+ if (err)
+ goto reset;
+
+ if (!nr_hit) {
rc = NOTIFY_DONE;
goto out;
}
- info = counter_arch_bp(bp);
/*
* Return early after invoking user-callback function without restoring
@@ -330,29 +513,50 @@ int hw_breakpoint_handler(struct die_args *args)
* one-shot mode. The ptrace-ed process will receive the SIGTRAP signal
* generated in do_dabr().
*/
- if (is_ptrace_bp(bp)) {
- perf_bp_event(bp, regs);
+ if (ptrace_bp) {
+ for (i = 0; i < nr_wp_slots(); i++) {
+ if (!hit[i])
+ continue;
+ perf_bp_event(bp[i], regs);
+ info[i] = NULL;
+ }
rc = NOTIFY_DONE;
- goto out;
+ goto reset;
}
- info->type &= ~HW_BRK_TYPE_EXTRANEOUS_IRQ;
- if (IS_ENABLED(CONFIG_PPC_8xx)) {
- if (!dar_within_range(regs->dar, info))
- info->type |= HW_BRK_TYPE_EXTRANEOUS_IRQ;
- } else {
- if (!stepping_handler(regs, bp, info))
- goto out;
+ if (!IS_ENABLED(CONFIG_PPC_8xx)) {
+ if (larx_stcx) {
+ for (i = 0; i < nr_wp_slots(); i++) {
+ if (!hit[i])
+ continue;
+ larx_stcx_err(bp[i], info[i]);
+ info[i] = NULL;
+ }
+ goto reset;
+ }
+
+ if (!stepping_handler(regs, bp, info, hit, instr))
+ goto reset;
}
/*
* As a policy, the callback is invoked in a 'trigger-after-execute'
* fashion
*/
- if (!(info->type & HW_BRK_TYPE_EXTRANEOUS_IRQ))
- perf_bp_event(bp, regs);
+ for (i = 0; i < nr_wp_slots(); i++) {
+ if (!hit[i])
+ continue;
+ if (!(info[i]->type & HW_BRK_TYPE_EXTRANEOUS_IRQ))
+ perf_bp_event(bp[i], regs);
+ }
+
+reset:
+ for (i = 0; i < nr_wp_slots(); i++) {
+ if (!info[i])
+ continue;
+ __set_breakpoint(i, info[i]);
+ }
- __set_breakpoint(0, info);
out:
rcu_read_unlock();
return rc;
@@ -367,26 +571,43 @@ static int single_step_dabr_instruction(struct die_args *args)
struct pt_regs *regs = args->regs;
struct perf_event *bp = NULL;
struct arch_hw_breakpoint *info;
+ int i;
+ bool found = false;
- bp = current->thread.last_hit_ubp;
/*
* Check if we are single-stepping as a result of a
* previous HW Breakpoint exception
*/
- if (!bp)
- return NOTIFY_DONE;
+ for (i = 0; i < nr_wp_slots(); i++) {
+ bp = current->thread.last_hit_ubp[i];
+
+ if (!bp)
+ continue;
+
+ found = true;
+ info = counter_arch_bp(bp);
+
+ /*
+ * We shall invoke the user-defined callback function in the
+ * single stepping handler to confirm to 'trigger-after-execute'
+ * semantics
+ */
+ if (!(info->type & HW_BRK_TYPE_EXTRANEOUS_IRQ))
+ perf_bp_event(bp, regs);
+ current->thread.last_hit_ubp[i] = NULL;
+ }
- info = counter_arch_bp(bp);
+ if (!found)
+ return NOTIFY_DONE;
- /*
- * We shall invoke the user-defined callback function in the single
- * stepping handler to confirm to 'trigger-after-execute' semantics
- */
- if (!(info->type & HW_BRK_TYPE_EXTRANEOUS_IRQ))
- perf_bp_event(bp, regs);
+ for (i = 0; i < nr_wp_slots(); i++) {
+ bp = __this_cpu_read(bp_per_reg[i]);
+ if (!bp)
+ continue;
- __set_breakpoint(0, info);
- current->thread.last_hit_ubp = NULL;
+ info = counter_arch_bp(bp);
+ __set_breakpoint(i, info);
+ }
/*
* If the process was being single-stepped by ptrace, let the
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 9b11575dcb8a..048d64c4e115 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -629,9 +629,6 @@ void do_break (struct pt_regs *regs, unsigned long address,
if (debugger_break_match(regs))
return;
- /* Clear the breakpoint */
- hw_breakpoint_disable();
-
/* Deliver the signal to userspace */
force_sig_fault(SIGTRAP, TRAP_HWBKPT, (void __user *)address);
}
--
2.26.2
^ permalink raw reply related [flat|nested] 18+ messages in thread* [PATCH v6 14/16] powerpc/watchpoint: Don't allow concurrent perf and ptrace events
2020-05-14 11:17 [PATCH v6 00/16] powerpc/watchpoint: Preparation for more than one watchpoint Ravi Bangoria
` (12 preceding siblings ...)
2020-05-14 11:17 ` [PATCH v6 13/16] powerpc/watchpoint: Prepare handler to handle more than one watcnhpoint Ravi Bangoria
@ 2020-05-14 11:17 ` Ravi Bangoria
2020-05-14 11:17 ` [PATCH v6 15/16] powerpc/watchpoint/xmon: Don't allow breakpoint overwriting Ravi Bangoria
` (2 subsequent siblings)
16 siblings, 0 replies; 18+ messages in thread
From: Ravi Bangoria @ 2020-05-14 11:17 UTC (permalink / raw)
To: mpe, mikey
Cc: apopple, paulus, npiggin, christophe.leroy, naveen.n.rao, peterz,
jolsa, oleg, fweisbec, mingo, linuxppc-dev, linux-kernel,
ravi.bangoria
With Book3s DAWR, ptrace and perf watchpoints on powerpc behaves
differently. Ptrace watchpoint works in one-shot mode and generates
signal before executing instruction. It's ptrace user's job to
single-step the instruction and re-enable the watchpoint. OTOH, in
case of perf watchpoint, kernel emulates/single-steps the instruction
and then generates event. If perf and ptrace creates two events with
same or overlapping address ranges, it's ambiguous to decide who
should single-step the instruction. Because of this issue, don't
allow perf and ptrace watchpoint at the same time if their address
range overlaps.
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Reviewed-by: Michael Neuling <mikey@neuling.org>
---
arch/powerpc/include/asm/hw_breakpoint.h | 2 +
arch/powerpc/kernel/hw_breakpoint.c | 221 +++++++++++++++++++++++
kernel/events/hw_breakpoint.c | 16 ++
3 files changed, 239 insertions(+)
diff --git a/arch/powerpc/include/asm/hw_breakpoint.h b/arch/powerpc/include/asm/hw_breakpoint.h
index add5aa076919..f42a55eb77d2 100644
--- a/arch/powerpc/include/asm/hw_breakpoint.h
+++ b/arch/powerpc/include/asm/hw_breakpoint.h
@@ -70,6 +70,8 @@ extern int hw_breakpoint_exceptions_notify(struct notifier_block *unused,
unsigned long val, void *data);
int arch_install_hw_breakpoint(struct perf_event *bp);
void arch_uninstall_hw_breakpoint(struct perf_event *bp);
+int arch_reserve_bp_slot(struct perf_event *bp);
+void arch_release_bp_slot(struct perf_event *bp);
void arch_unregister_hw_breakpoint(struct perf_event *bp);
void hw_breakpoint_pmu_read(struct perf_event *bp);
extern void flush_ptrace_hw_breakpoint(struct task_struct *tsk);
diff --git a/arch/powerpc/kernel/hw_breakpoint.c b/arch/powerpc/kernel/hw_breakpoint.c
index da858bc6a414..80396f3f7e90 100644
--- a/arch/powerpc/kernel/hw_breakpoint.c
+++ b/arch/powerpc/kernel/hw_breakpoint.c
@@ -124,6 +124,227 @@ static bool is_ptrace_bp(struct perf_event *bp)
return bp->overflow_handler == ptrace_triggered;
}
+struct breakpoint {
+ struct list_head list;
+ struct perf_event *bp;
+ bool ptrace_bp;
+};
+
+static DEFINE_PER_CPU(struct breakpoint *, cpu_bps[HBP_NUM_MAX]);
+static LIST_HEAD(task_bps);
+
+static struct breakpoint *alloc_breakpoint(struct perf_event *bp)
+{
+ struct breakpoint *tmp;
+
+ tmp = kzalloc(sizeof(*tmp), GFP_KERNEL);
+ if (!tmp)
+ return ERR_PTR(-ENOMEM);
+ tmp->bp = bp;
+ tmp->ptrace_bp = is_ptrace_bp(bp);
+ return tmp;
+}
+
+static bool bp_addr_range_overlap(struct perf_event *bp1, struct perf_event *bp2)
+{
+ __u64 bp1_saddr, bp1_eaddr, bp2_saddr, bp2_eaddr;
+
+ bp1_saddr = ALIGN_DOWN(bp1->attr.bp_addr, HW_BREAKPOINT_SIZE);
+ bp1_eaddr = ALIGN(bp1->attr.bp_addr + bp1->attr.bp_len, HW_BREAKPOINT_SIZE);
+ bp2_saddr = ALIGN_DOWN(bp2->attr.bp_addr, HW_BREAKPOINT_SIZE);
+ bp2_eaddr = ALIGN(bp2->attr.bp_addr + bp2->attr.bp_len, HW_BREAKPOINT_SIZE);
+
+ return (bp1_saddr < bp2_eaddr && bp1_eaddr > bp2_saddr);
+}
+
+static bool alternate_infra_bp(struct breakpoint *b, struct perf_event *bp)
+{
+ return is_ptrace_bp(bp) ? !b->ptrace_bp : b->ptrace_bp;
+}
+
+static bool can_co_exist(struct breakpoint *b, struct perf_event *bp)
+{
+ return !(alternate_infra_bp(b, bp) && bp_addr_range_overlap(b->bp, bp));
+}
+
+static int task_bps_add(struct perf_event *bp)
+{
+ struct breakpoint *tmp;
+
+ tmp = alloc_breakpoint(bp);
+ if (IS_ERR(tmp))
+ return PTR_ERR(tmp);
+
+ list_add(&tmp->list, &task_bps);
+ return 0;
+}
+
+static void task_bps_remove(struct perf_event *bp)
+{
+ struct list_head *pos, *q;
+
+ list_for_each_safe(pos, q, &task_bps) {
+ struct breakpoint *tmp = list_entry(pos, struct breakpoint, list);
+
+ if (tmp->bp == bp) {
+ list_del(&tmp->list);
+ kfree(tmp);
+ break;
+ }
+ }
+}
+
+/*
+ * If any task has breakpoint from alternate infrastructure,
+ * return true. Otherwise return false.
+ */
+static bool all_task_bps_check(struct perf_event *bp)
+{
+ struct breakpoint *tmp;
+
+ list_for_each_entry(tmp, &task_bps, list) {
+ if (!can_co_exist(tmp, bp))
+ return true;
+ }
+ return false;
+}
+
+/*
+ * If same task has breakpoint from alternate infrastructure,
+ * return true. Otherwise return false.
+ */
+static bool same_task_bps_check(struct perf_event *bp)
+{
+ struct breakpoint *tmp;
+
+ list_for_each_entry(tmp, &task_bps, list) {
+ if (tmp->bp->hw.target == bp->hw.target &&
+ !can_co_exist(tmp, bp))
+ return true;
+ }
+ return false;
+}
+
+static int cpu_bps_add(struct perf_event *bp)
+{
+ struct breakpoint **cpu_bp;
+ struct breakpoint *tmp;
+ int i = 0;
+
+ tmp = alloc_breakpoint(bp);
+ if (IS_ERR(tmp))
+ return PTR_ERR(tmp);
+
+ cpu_bp = per_cpu_ptr(cpu_bps, bp->cpu);
+ for (i = 0; i < nr_wp_slots(); i++) {
+ if (!cpu_bp[i]) {
+ cpu_bp[i] = tmp;
+ break;
+ }
+ }
+ return 0;
+}
+
+static void cpu_bps_remove(struct perf_event *bp)
+{
+ struct breakpoint **cpu_bp;
+ int i = 0;
+
+ cpu_bp = per_cpu_ptr(cpu_bps, bp->cpu);
+ for (i = 0; i < nr_wp_slots(); i++) {
+ if (!cpu_bp[i])
+ continue;
+
+ if (cpu_bp[i]->bp == bp) {
+ kfree(cpu_bp[i]);
+ cpu_bp[i] = NULL;
+ break;
+ }
+ }
+}
+
+static bool cpu_bps_check(int cpu, struct perf_event *bp)
+{
+ struct breakpoint **cpu_bp;
+ int i;
+
+ cpu_bp = per_cpu_ptr(cpu_bps, cpu);
+ for (i = 0; i < nr_wp_slots(); i++) {
+ if (cpu_bp[i] && !can_co_exist(cpu_bp[i], bp))
+ return true;
+ }
+ return false;
+}
+
+static bool all_cpu_bps_check(struct perf_event *bp)
+{
+ int cpu;
+
+ for_each_online_cpu(cpu) {
+ if (cpu_bps_check(cpu, bp))
+ return true;
+ }
+ return false;
+}
+
+/*
+ * We don't use any locks to serialize accesses to cpu_bps or task_bps
+ * because are already inside nr_bp_mutex.
+ */
+int arch_reserve_bp_slot(struct perf_event *bp)
+{
+ int ret;
+
+ /* ptrace breakpoint */
+ if (is_ptrace_bp(bp)) {
+ if (all_cpu_bps_check(bp))
+ return -ENOSPC;
+
+ if (same_task_bps_check(bp))
+ return -ENOSPC;
+
+ return task_bps_add(bp);
+ }
+
+ /* perf breakpoint */
+ if (is_kernel_addr(bp->attr.bp_addr))
+ return 0;
+
+ if (bp->hw.target && bp->cpu == -1) {
+ if (same_task_bps_check(bp))
+ return -ENOSPC;
+
+ return task_bps_add(bp);
+ } else if (!bp->hw.target && bp->cpu != -1) {
+ if (all_task_bps_check(bp))
+ return -ENOSPC;
+
+ return cpu_bps_add(bp);
+ }
+
+ if (same_task_bps_check(bp))
+ return -ENOSPC;
+
+ ret = cpu_bps_add(bp);
+ if (ret)
+ return ret;
+ ret = task_bps_add(bp);
+ if (ret)
+ cpu_bps_remove(bp);
+
+ return ret;
+}
+
+void arch_release_bp_slot(struct perf_event *bp)
+{
+ if (!is_kernel_addr(bp->attr.bp_addr)) {
+ if (bp->hw.target)
+ task_bps_remove(bp);
+ if (bp->cpu != -1)
+ cpu_bps_remove(bp);
+ }
+}
+
/*
* Perform cleanup of arch-specific counters during unregistration
* of the perf-event
diff --git a/kernel/events/hw_breakpoint.c b/kernel/events/hw_breakpoint.c
index 3cc8416ec844..b48d7039a015 100644
--- a/kernel/events/hw_breakpoint.c
+++ b/kernel/events/hw_breakpoint.c
@@ -213,6 +213,15 @@ toggle_bp_slot(struct perf_event *bp, bool enable, enum bp_type_idx type,
list_del(&bp->hw.bp_list);
}
+__weak int arch_reserve_bp_slot(struct perf_event *bp)
+{
+ return 0;
+}
+
+__weak void arch_release_bp_slot(struct perf_event *bp)
+{
+}
+
/*
* Function to perform processor-specific cleanup during unregistration
*/
@@ -270,6 +279,7 @@ static int __reserve_bp_slot(struct perf_event *bp, u64 bp_type)
struct bp_busy_slots slots = {0};
enum bp_type_idx type;
int weight;
+ int ret;
/* We couldn't initialize breakpoint constraints on boot */
if (!constraints_initialized)
@@ -294,6 +304,10 @@ static int __reserve_bp_slot(struct perf_event *bp, u64 bp_type)
if (slots.pinned + (!!slots.flexible) > nr_slots[type])
return -ENOSPC;
+ ret = arch_reserve_bp_slot(bp);
+ if (ret)
+ return ret;
+
toggle_bp_slot(bp, true, type, weight);
return 0;
@@ -317,6 +331,8 @@ static void __release_bp_slot(struct perf_event *bp, u64 bp_type)
enum bp_type_idx type;
int weight;
+ arch_release_bp_slot(bp);
+
type = find_slot_idx(bp_type);
weight = hw_breakpoint_weight(bp);
toggle_bp_slot(bp, false, type, weight);
--
2.26.2
^ permalink raw reply related [flat|nested] 18+ messages in thread* [PATCH v6 15/16] powerpc/watchpoint/xmon: Don't allow breakpoint overwriting
2020-05-14 11:17 [PATCH v6 00/16] powerpc/watchpoint: Preparation for more than one watchpoint Ravi Bangoria
` (13 preceding siblings ...)
2020-05-14 11:17 ` [PATCH v6 14/16] powerpc/watchpoint: Don't allow concurrent perf and ptrace events Ravi Bangoria
@ 2020-05-14 11:17 ` Ravi Bangoria
2020-05-14 11:17 ` [PATCH v6 16/16] powerpc/watchpoint/xmon: Support 2nd DAWR Ravi Bangoria
2020-05-20 11:00 ` [PATCH v6 00/16] powerpc/watchpoint: Preparation for more than one watchpoint Michael Ellerman
16 siblings, 0 replies; 18+ messages in thread
From: Ravi Bangoria @ 2020-05-14 11:17 UTC (permalink / raw)
To: mpe, mikey
Cc: apopple, paulus, npiggin, christophe.leroy, naveen.n.rao, peterz,
jolsa, oleg, fweisbec, mingo, linuxppc-dev, linux-kernel,
ravi.bangoria
Xmon allows overwriting breakpoints because it's supported by only
one DAWR. But with multiple DAWRs, overwriting becomes ambiguous
or unnecessary complicated. So let's not allow it.
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Reviewed-by: Michael Neuling <mikey@neuling.org>
---
arch/powerpc/xmon/xmon.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
index 30b3e3d99c0d..094bf4715f2c 100644
--- a/arch/powerpc/xmon/xmon.c
+++ b/arch/powerpc/xmon/xmon.c
@@ -1399,6 +1399,10 @@ bpt_cmds(void)
printf("Hardware data breakpoint not supported on this cpu\n");
break;
}
+ if (dabr.enabled) {
+ printf("Couldn't find free breakpoint register\n");
+ break;
+ }
mode = 7;
cmd = inchar();
if (cmd == 'r')
--
2.26.2
^ permalink raw reply related [flat|nested] 18+ messages in thread* [PATCH v6 16/16] powerpc/watchpoint/xmon: Support 2nd DAWR
2020-05-14 11:17 [PATCH v6 00/16] powerpc/watchpoint: Preparation for more than one watchpoint Ravi Bangoria
` (14 preceding siblings ...)
2020-05-14 11:17 ` [PATCH v6 15/16] powerpc/watchpoint/xmon: Don't allow breakpoint overwriting Ravi Bangoria
@ 2020-05-14 11:17 ` Ravi Bangoria
2020-05-20 11:00 ` [PATCH v6 00/16] powerpc/watchpoint: Preparation for more than one watchpoint Michael Ellerman
16 siblings, 0 replies; 18+ messages in thread
From: Ravi Bangoria @ 2020-05-14 11:17 UTC (permalink / raw)
To: mpe, mikey
Cc: apopple, paulus, npiggin, christophe.leroy, naveen.n.rao, peterz,
jolsa, oleg, fweisbec, mingo, linuxppc-dev, linux-kernel,
ravi.bangoria
Add support for 2nd DAWR in xmon. With this, we can have two
simultaneous breakpoints from xmon.
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Reviewed-by: Michael Neuling <mikey@neuling.org>
---
arch/powerpc/xmon/xmon.c | 101 ++++++++++++++++++++++++++-------------
1 file changed, 69 insertions(+), 32 deletions(-)
diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
index 094bf4715f2c..de585204d1d2 100644
--- a/arch/powerpc/xmon/xmon.c
+++ b/arch/powerpc/xmon/xmon.c
@@ -112,7 +112,7 @@ struct bpt {
#define BP_DABR 4
static struct bpt bpts[NBPTS];
-static struct bpt dabr;
+static struct bpt dabr[HBP_NUM_MAX];
static struct bpt *iabr;
static unsigned bpinstr = 0x7fe00008; /* trap */
@@ -784,10 +784,17 @@ static int xmon_sstep(struct pt_regs *regs)
static int xmon_break_match(struct pt_regs *regs)
{
+ int i;
+
if ((regs->msr & (MSR_IR|MSR_PR|MSR_64BIT)) != (MSR_IR|MSR_64BIT))
return 0;
- if (dabr.enabled == 0)
- return 0;
+ for (i = 0; i < nr_wp_slots(); i++) {
+ if (dabr[i].enabled)
+ goto found;
+ }
+ return 0;
+
+found:
xmon_core(regs, 0);
return 1;
}
@@ -948,13 +955,16 @@ static void insert_bpts(void)
static void insert_cpu_bpts(void)
{
+ int i;
struct arch_hw_breakpoint brk;
- if (dabr.enabled) {
- brk.address = dabr.address;
- brk.type = (dabr.enabled & HW_BRK_TYPE_DABR) | HW_BRK_TYPE_PRIV_ALL;
- brk.len = DABR_MAX_LEN;
- __set_breakpoint(0, &brk);
+ for (i = 0; i < nr_wp_slots(); i++) {
+ if (dabr[i].enabled) {
+ brk.address = dabr[i].address;
+ brk.type = (dabr[i].enabled & HW_BRK_TYPE_DABR) | HW_BRK_TYPE_PRIV_ALL;
+ brk.len = 8;
+ __set_breakpoint(i, &brk);
+ }
}
if (iabr)
@@ -1366,6 +1376,35 @@ static long check_bp_loc(unsigned long addr)
return 1;
}
+static int find_free_data_bpt(void)
+{
+ int i;
+
+ for (i = 0; i < nr_wp_slots(); i++) {
+ if (!dabr[i].enabled)
+ return i;
+ }
+ printf("Couldn't find free breakpoint register\n");
+ return -1;
+}
+
+static void print_data_bpts(void)
+{
+ int i;
+
+ for (i = 0; i < nr_wp_slots(); i++) {
+ if (!dabr[i].enabled)
+ continue;
+
+ printf(" data "REG" [", dabr[i].address);
+ if (dabr[i].enabled & 1)
+ printf("r");
+ if (dabr[i].enabled & 2)
+ printf("w");
+ printf("]\n");
+ }
+}
+
static char *breakpoint_help_string =
"Breakpoint command usage:\n"
"b show breakpoints\n"
@@ -1399,10 +1438,9 @@ bpt_cmds(void)
printf("Hardware data breakpoint not supported on this cpu\n");
break;
}
- if (dabr.enabled) {
- printf("Couldn't find free breakpoint register\n");
+ i = find_free_data_bpt();
+ if (i < 0)
break;
- }
mode = 7;
cmd = inchar();
if (cmd == 'r')
@@ -1411,15 +1449,15 @@ bpt_cmds(void)
mode = 6;
else
termch = cmd;
- dabr.address = 0;
- dabr.enabled = 0;
- if (scanhex(&dabr.address)) {
- if (!is_kernel_addr(dabr.address)) {
+ dabr[i].address = 0;
+ dabr[i].enabled = 0;
+ if (scanhex(&dabr[i].address)) {
+ if (!is_kernel_addr(dabr[i].address)) {
printf(badaddr);
break;
}
- dabr.address &= ~HW_BRK_TYPE_DABR;
- dabr.enabled = mode | BP_DABR;
+ dabr[i].address &= ~HW_BRK_TYPE_DABR;
+ dabr[i].enabled = mode | BP_DABR;
}
force_enable_xmon();
@@ -1458,7 +1496,9 @@ bpt_cmds(void)
for (i = 0; i < NBPTS; ++i)
bpts[i].enabled = 0;
iabr = NULL;
- dabr.enabled = 0;
+ for (i = 0; i < nr_wp_slots(); i++)
+ dabr[i].enabled = 0;
+
printf("All breakpoints cleared\n");
break;
}
@@ -1492,14 +1532,7 @@ bpt_cmds(void)
if (xmon_is_ro || !scanhex(&a)) {
/* print all breakpoints */
printf(" type address\n");
- if (dabr.enabled) {
- printf(" data "REG" [", dabr.address);
- if (dabr.enabled & 1)
- printf("r");
- if (dabr.enabled & 2)
- printf("w");
- printf("]\n");
- }
+ print_data_bpts();
for (bp = bpts; bp < &bpts[NBPTS]; ++bp) {
if (!bp->enabled)
continue;
@@ -1959,8 +1992,13 @@ static void dump_207_sprs(void)
printf("hfscr = %.16lx dhdes = %.16lx rpr = %.16lx\n",
mfspr(SPRN_HFSCR), mfspr(SPRN_DHDES), mfspr(SPRN_RPR));
- printf("dawr = %.16lx dawrx = %.16lx ciabr = %.16lx\n",
- mfspr(SPRN_DAWR0), mfspr(SPRN_DAWRX0), mfspr(SPRN_CIABR));
+ printf("dawr0 = %.16lx dawrx0 = %.16lx\n",
+ mfspr(SPRN_DAWR0), mfspr(SPRN_DAWRX0));
+ if (nr_wp_slots() > 1) {
+ printf("dawr1 = %.16lx dawrx1 = %.16lx\n",
+ mfspr(SPRN_DAWR1), mfspr(SPRN_DAWRX1));
+ }
+ printf("ciabr = %.16lx\n", mfspr(SPRN_CIABR));
#endif
}
@@ -3909,10 +3947,9 @@ static void clear_all_bpt(void)
bpts[i].enabled = 0;
/* Clear any data or iabr breakpoints */
- if (iabr || dabr.enabled) {
- iabr = NULL;
- dabr.enabled = 0;
- }
+ iabr = NULL;
+ for (i = 0; i < nr_wp_slots(); i++)
+ dabr[i].enabled = 0;
}
#ifdef CONFIG_DEBUG_FS
--
2.26.2
^ permalink raw reply related [flat|nested] 18+ messages in thread* Re: [PATCH v6 00/16] powerpc/watchpoint: Preparation for more than one watchpoint
2020-05-14 11:17 [PATCH v6 00/16] powerpc/watchpoint: Preparation for more than one watchpoint Ravi Bangoria
` (15 preceding siblings ...)
2020-05-14 11:17 ` [PATCH v6 16/16] powerpc/watchpoint/xmon: Support 2nd DAWR Ravi Bangoria
@ 2020-05-20 11:00 ` Michael Ellerman
16 siblings, 0 replies; 18+ messages in thread
From: Michael Ellerman @ 2020-05-20 11:00 UTC (permalink / raw)
To: mikey, Ravi Bangoria, mpe
Cc: jolsa, fweisbec, paulus, naveen.n.rao, mingo, oleg, peterz,
apopple, linux-kernel, christophe.leroy, linuxppc-dev, npiggin
On Thu, 14 May 2020 16:47:25 +0530, Ravi Bangoria wrote:
> So far, powerpc Book3S code has been written with an assumption of
> only one watchpoint. But Power10[1] is introducing second watchpoint
> register (DAWR). Even though this patchset does not enable 2nd DAWR,
> it makes the infrastructure ready so that enabling 2nd DAWR should
> just be a matter of changing count.
>
> Existing functionality works fine with the patchset. I've tested it
> with perf, ptrace(gdb), xmon. All hw-breakpoint selftests are passing
> as well. And I've build tested for 8xx and 'AMCC 44x, 46x or 47x'.
>
> [...]
Applied to powerpc/next.
[01/16] powerpc/watchpoint: Rename current DAWR macros
https://git.kernel.org/powerpc/c/09f82b063aa9c248a3ef919aeec361054e7b044a
[02/16] powerpc/watchpoint: Add SPRN macros for second DAWR
https://git.kernel.org/powerpc/c/4a4ec2289a5d748cb64ff67ca8d74535a76a8436
[03/16] powerpc/watchpoint: Introduce function to get nr watchpoints dynamically
https://git.kernel.org/powerpc/c/a6ba44e8799230e36c8ab06fda7f77f421e9e795
[04/16] powerpc/watchpoint/ptrace: Return actual num of available watchpoints
https://git.kernel.org/powerpc/c/45093b382e0ac25c206b4dcd210c6be1f5e56e60
[05/16] powerpc/watchpoint: Provide DAWR number to set_dawr
https://git.kernel.org/powerpc/c/a18b834625d345bfa89c4e2754dd6cbb0133c4d7
[06/16] powerpc/watchpoint: Provide DAWR number to __set_breakpoint
https://git.kernel.org/powerpc/c/4a8a9379f2af4c9928529b3959bc2d8f7023c6bc
[07/16] powerpc/watchpoint: Get watchpoint count dynamically while disabling them
https://git.kernel.org/powerpc/c/c2919132734f29a7a33e1339bef8a67b11f322eb
[08/16] powerpc/watchpoint: Disable all available watchpoints when !dawr_force_enable
https://git.kernel.org/powerpc/c/22a214e461c5cc9428b86915d9cfcf84c6e11ad7
[09/16] powerpc/watchpoint: Convert thread_struct->hw_brk to an array
https://git.kernel.org/powerpc/c/303e6a9ddcdc168e92253c78cdb4bbe1e10d78b3
[10/16] powerpc/watchpoint: Use loop for thread_struct->ptrace_bps
https://git.kernel.org/powerpc/c/6b424efa119d5ea06b15ff240dddc3b4b9f9cdfb
[11/16] powerpc/watchpoint: Introduce is_ptrace_bp() function
https://git.kernel.org/powerpc/c/c9e82aeb197df2d93b1b4234bc0c80943fa594e8
[12/16] powerpc/watchpoint: Use builtin ALIGN*() macros
https://git.kernel.org/powerpc/c/e68ef121c1f4c38edf87a3354661ceb99d522729
[13/16] powerpc/watchpoint: Prepare handler to handle more than one watchpoint
https://git.kernel.org/powerpc/c/74c6881019b7d56c327fffc268d97adb5eb1b4f9
[14/16] powerpc/watchpoint: Don't allow concurrent perf and ptrace events
https://git.kernel.org/powerpc/c/29da4f91c0c1fbda12b8a31be0d564930208c92e
[15/16] powerpc/watchpoint/xmon: Don't allow breakpoint overwriting
https://git.kernel.org/powerpc/c/514db915e7b33e7eaf8e40192b93380f79b319b5
[16/16] powerpc/watchpoint/xmon: Support 2nd DAWR
https://git.kernel.org/powerpc/c/30df74d67d48949da87e3a5b57c381763e8fd526
cheers
^ permalink raw reply [flat|nested] 18+ messages in thread