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-rw-r--r--arch/x86/kernel/perf_regs.c15
-rw-r--r--include/linux/perf_event.h35
-rw-r--r--include/linux/perf_regs.h6
-rw-r--r--kernel/events/core.c66
4 files changed, 119 insertions, 3 deletions
diff --git a/arch/x86/kernel/perf_regs.c b/arch/x86/kernel/perf_regs.c
index 3d6923528b1c..c5a3e5cfe07f 100644
--- a/arch/x86/kernel/perf_regs.c
+++ b/arch/x86/kernel/perf_regs.c
@@ -1,5 +1,7 @@
#include <linux/errno.h>
#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/perf_event.h>
#include <linux/bug.h>
#include <linux/stddef.h>
#include <asm/perf_regs.h>
@@ -71,6 +73,11 @@ int perf_reg_validate(u64 mask)
return 0;
}
+
+u64 perf_reg_abi(struct task_struct *task)
+{
+ return PERF_SAMPLE_REGS_ABI_32;
+}
#else /* CONFIG_X86_64 */
#define REG_NOSUPPORT ((1ULL << PERF_REG_X86_DS) | \
(1ULL << PERF_REG_X86_ES) | \
@@ -87,4 +94,12 @@ int perf_reg_validate(u64 mask)
return 0;
}
+
+u64 perf_reg_abi(struct task_struct *task)
+{
+ if (test_tsk_thread_flag(task, TIF_IA32))
+ return PERF_SAMPLE_REGS_ABI_32;
+ else
+ return PERF_SAMPLE_REGS_ABI_64;
+}
#endif /* CONFIG_X86_32 */
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 7602ccb3f40e..3d4d84745f07 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -130,8 +130,9 @@ enum perf_event_sample_format {
PERF_SAMPLE_STREAM_ID = 1U << 9,
PERF_SAMPLE_RAW = 1U << 10,
PERF_SAMPLE_BRANCH_STACK = 1U << 11,
+ PERF_SAMPLE_REGS_USER = 1U << 12,
- PERF_SAMPLE_MAX = 1U << 12, /* non-ABI */
+ PERF_SAMPLE_MAX = 1U << 13, /* non-ABI */
};
/*
@@ -163,6 +164,15 @@ enum perf_branch_sample_type {
PERF_SAMPLE_BRANCH_HV)
/*
+ * Values to determine ABI of the registers dump.
+ */
+enum perf_sample_regs_abi {
+ PERF_SAMPLE_REGS_ABI_NONE = 0,
+ PERF_SAMPLE_REGS_ABI_32 = 1,
+ PERF_SAMPLE_REGS_ABI_64 = 2,
+};
+
+/*
* The format of the data returned by read() on a perf event fd,
* as specified by attr.read_format:
*
@@ -194,6 +204,7 @@ enum perf_event_read_format {
#define PERF_ATTR_SIZE_VER0 64 /* sizeof first published struct */
#define PERF_ATTR_SIZE_VER1 72 /* add: config2 */
#define PERF_ATTR_SIZE_VER2 80 /* add: branch_sample_type */
+#define PERF_ATTR_SIZE_VER3 88 /* add: sample_regs_user */
/*
* Hardware event_id to monitor via a performance monitoring event:
@@ -271,7 +282,13 @@ struct perf_event_attr {
__u64 bp_len;
__u64 config2; /* extension of config1 */
};
- __u64 branch_sample_type; /* enum branch_sample_type */
+ __u64 branch_sample_type; /* enum perf_branch_sample_type */
+
+ /*
+ * Defines set of user regs to dump on samples.
+ * See asm/perf_regs.h for details.
+ */
+ __u64 sample_regs_user;
};
/*
@@ -548,6 +565,9 @@ enum perf_event_type {
* char data[size];}&& PERF_SAMPLE_RAW
*
* { u64 from, to, flags } lbr[nr];} && PERF_SAMPLE_BRANCH_STACK
+ *
+ * { u64 abi; # enum perf_sample_regs_abi
+ * u64 regs[weight(mask)]; } && PERF_SAMPLE_REGS_USER
* };
*/
PERF_RECORD_SAMPLE = 9,
@@ -609,6 +629,7 @@ struct perf_guest_info_callbacks {
#include <linux/static_key.h>
#include <linux/atomic.h>
#include <linux/sysfs.h>
+#include <linux/perf_regs.h>
#include <asm/local.h>
struct perf_callchain_entry {
@@ -654,6 +675,11 @@ struct perf_branch_stack {
struct perf_branch_entry entries[0];
};
+struct perf_regs_user {
+ __u64 abi;
+ struct pt_regs *regs;
+};
+
struct task_struct;
/*
@@ -1133,6 +1159,7 @@ struct perf_sample_data {
struct perf_callchain_entry *callchain;
struct perf_raw_record *raw;
struct perf_branch_stack *br_stack;
+ struct perf_regs_user regs_user;
};
static inline void perf_sample_data_init(struct perf_sample_data *data,
@@ -1142,7 +1169,9 @@ static inline void perf_sample_data_init(struct perf_sample_data *data,
data->addr = addr;
data->raw = NULL;
data->br_stack = NULL;
- data->period = period;
+ data->period = period;
+ data->regs_user.abi = PERF_SAMPLE_REGS_ABI_NONE;
+ data->regs_user.regs = NULL;
}
extern void perf_output_sample(struct perf_output_handle *handle,
diff --git a/include/linux/perf_regs.h b/include/linux/perf_regs.h
index a2f1a98f7839..3c73d5fe18be 100644
--- a/include/linux/perf_regs.h
+++ b/include/linux/perf_regs.h
@@ -5,6 +5,7 @@
#include <asm/perf_regs.h>
u64 perf_reg_value(struct pt_regs *regs, int idx);
int perf_reg_validate(u64 mask);
+u64 perf_reg_abi(struct task_struct *task);
#else
static inline u64 perf_reg_value(struct pt_regs *regs, int idx)
{
@@ -15,5 +16,10 @@ static inline int perf_reg_validate(u64 mask)
{
return mask ? -ENOSYS : 0;
}
+
+static inline u64 perf_reg_abi(struct task_struct *task)
+{
+ return PERF_SAMPLE_REGS_ABI_NONE;
+}
#endif /* CONFIG_HAVE_PERF_REGS */
#endif /* _LINUX_PERF_REGS_H */
diff --git a/kernel/events/core.c b/kernel/events/core.c
index b7935fcec7d9..d3ce97525b9f 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -3756,6 +3756,37 @@ int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks *cbs)
}
EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks);
+static void
+perf_output_sample_regs(struct perf_output_handle *handle,
+ struct pt_regs *regs, u64 mask)
+{
+ int bit;
+
+ for_each_set_bit(bit, (const unsigned long *) &mask,
+ sizeof(mask) * BITS_PER_BYTE) {
+ u64 val;
+
+ val = perf_reg_value(regs, bit);
+ perf_output_put(handle, val);
+ }
+}
+
+static void perf_sample_regs_user(struct perf_regs_user *regs_user,
+ struct pt_regs *regs)
+{
+ if (!user_mode(regs)) {
+ if (current->mm)
+ regs = task_pt_regs(current);
+ else
+ regs = NULL;
+ }
+
+ if (regs) {
+ regs_user->regs = regs;
+ regs_user->abi = perf_reg_abi(current);
+ }
+}
+
static void __perf_event_header__init_id(struct perf_event_header *header,
struct perf_sample_data *data,
struct perf_event *event)
@@ -4016,6 +4047,23 @@ void perf_output_sample(struct perf_output_handle *handle,
perf_output_put(handle, nr);
}
}
+
+ if (sample_type & PERF_SAMPLE_REGS_USER) {
+ u64 abi = data->regs_user.abi;
+
+ /*
+ * If there are no regs to dump, notice it through
+ * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
+ */
+ perf_output_put(handle, abi);
+
+ if (abi) {
+ u64 mask = event->attr.sample_regs_user;
+ perf_output_sample_regs(handle,
+ data->regs_user.regs,
+ mask);
+ }
+ }
}
void perf_prepare_sample(struct perf_event_header *header,
@@ -4067,6 +4115,20 @@ void perf_prepare_sample(struct perf_event_header *header,
}
header->size += size;
}
+
+ if (sample_type & PERF_SAMPLE_REGS_USER) {
+ /* regs dump ABI info */
+ int size = sizeof(u64);
+
+ perf_sample_regs_user(&data->regs_user, regs);
+
+ if (data->regs_user.regs) {
+ u64 mask = event->attr.sample_regs_user;
+ size += hweight64(mask) * sizeof(u64);
+ }
+
+ header->size += size;
+ }
}
static void perf_event_output(struct perf_event *event,
@@ -6142,6 +6204,10 @@ static int perf_copy_attr(struct perf_event_attr __user *uattr,
attr->branch_sample_type = mask;
}
}
+
+ if (attr->sample_type & PERF_SAMPLE_REGS_USER)
+ ret = perf_reg_validate(attr->sample_regs_user);
+
out:
return ret;