From: Felix Willgerodt <felix.willgerodt@intel.com>
To: markus.t.metzger@intel.com, gdb-patches@sourceware.org
Subject: [PATCH v4 08/10] btrace, linux: Enable ptwrite packets.
Date: Fri, 6 May 2022 13:40:08 +0200 [thread overview]
Message-ID: <20220506114010.134106-8-felix.willgerodt@intel.com> (raw)
In-Reply-To: <20220506114010.134106-1-felix.willgerodt@intel.com>
Enable ptwrite in the PT config, if it is supported by the kernel.
---
gdb/nat/linux-btrace.c | 29 +++++++++++++++++++++++++++++
gdb/record-btrace.c | 5 +++++
2 files changed, 34 insertions(+)
diff --git a/gdb/nat/linux-btrace.c b/gdb/nat/linux-btrace.c
index b0d6dcd7cf1..53f1a468bcc 100644
--- a/gdb/nat/linux-btrace.c
+++ b/gdb/nat/linux-btrace.c
@@ -415,6 +415,29 @@ cpu_supports_bts (void)
}
}
+/* Check whether the linux target supports Intel Processor Trace PTWRITE. */
+
+static bool
+linux_supports_ptwrite ()
+{
+ static const char filename[]
+ = "/sys/bus/event_source/devices/intel_pt/caps/ptwrite";
+ gdb_file_up file = gdb_fopen_cloexec (filename, "r");
+
+ if (file.get () == nullptr)
+ return false;
+
+ int status, found = fscanf (file.get (), "%d", &status);
+
+ if (found != 1)
+ {
+ warning (_("Failed to determine ptwrite support from %s."), filename);
+ return false;
+ }
+
+ return status == 1;
+}
+
/* The perf_event_open syscall failed. Try to print a helpful error
message. */
@@ -624,6 +647,12 @@ linux_enable_pt (ptid_t ptid, const struct btrace_config_pt *conf)
pt->attr.exclude_hv = 1;
pt->attr.exclude_idle = 1;
+ if (conf->ptwrite && linux_supports_ptwrite ())
+ {
+ pt->attr.config |= 0x1000;
+ tinfo->conf.pt.ptwrite = conf->ptwrite;
+ }
+
errno = 0;
scoped_fd fd (syscall (SYS_perf_event_open, &pt->attr, pid, -1, -1, 0));
if (fd.get () < 0)
diff --git a/gdb/record-btrace.c b/gdb/record-btrace.c
index 1bfb9c1d876..799a9ea96ee 100644
--- a/gdb/record-btrace.c
+++ b/gdb/record-btrace.c
@@ -3289,4 +3289,9 @@ to see the actual buffer size."), NULL, show_record_pt_buffer_size_value,
record_btrace_conf.bts.size = 64 * 1024;
record_btrace_conf.pt.size = 16 * 1024;
+#if (LIBIPT_VERSION >= 0x200)
+ record_btrace_conf.pt.ptwrite = true;
+#else
+ record_btrace_conf.pt.ptwrite = false;
+#endif
}
--
2.34.1
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Registered Address: Am Campeon 10, 85579 Neubiberg, Germany
Tel: +49 89 99 8853-0, www.intel.de <http://www.intel.de>
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next prev parent reply other threads:[~2022-05-06 11:41 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-05-06 11:40 [PATCH v4 01/10] btrace: Introduce auxiliary instructions Felix Willgerodt
2022-05-06 11:40 ` [PATCH v4 02/10] btrace: Enable auxiliary instructions in record instruction-history Felix Willgerodt
2022-05-06 11:46 ` Eli Zaretskii
2022-05-06 11:40 ` [PATCH v4 03/10] btrace: Enable auxiliary instructions in record function-call-history Felix Willgerodt
2022-05-06 11:48 ` Eli Zaretskii
2022-05-06 11:40 ` [PATCH v4 04/10] btrace: Handle stepping and goto for auxiliary instructions Felix Willgerodt
2022-05-06 11:40 ` [PATCH v4 05/10] python: Introduce gdb.RecordAuxiliary class Felix Willgerodt
2022-05-06 11:49 ` Eli Zaretskii
2022-05-06 11:40 ` [PATCH v4 06/10] python: Add clear() to gdb.Record Felix Willgerodt
2022-05-06 11:50 ` Eli Zaretskii
2022-05-10 13:42 ` Willgerodt, Felix
2022-05-10 14:04 ` Eli Zaretskii
2022-05-11 8:22 ` Willgerodt, Felix
2022-05-11 11:43 ` Eli Zaretskii
2022-05-06 11:40 ` [PATCH v4 07/10] btrace, gdbserver: Add ptwrite to btrace_config_pt Felix Willgerodt
2022-05-06 11:53 ` Eli Zaretskii
2022-05-10 13:42 ` Willgerodt, Felix
2022-05-06 11:40 ` Felix Willgerodt [this message]
2022-05-06 11:40 ` [PATCH v4 09/10] btrace, python: Enable ptwrite listener registration Felix Willgerodt
2022-05-06 11:40 ` [PATCH v4 10/10] btrace: Extend ptwrite event decoding Felix Willgerodt
2022-05-06 12:04 ` Eli Zaretskii
2022-05-10 13:43 ` Willgerodt, Felix
2022-05-10 14:11 ` Eli Zaretskii
2022-05-11 8:19 ` Willgerodt, Felix
2022-05-06 11:47 ` [PATCH v4 01/10] btrace: Introduce auxiliary instructions Eli Zaretskii
2022-05-10 13:42 ` Willgerodt, Felix
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