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[patch v3 16/16] btrace, x86: restrict to Atom
- From: markus dot t dot metzger at intel dot com
- To: gdb-patches at sourceware dot org
- Cc: markus dot t dot metzger at gmail dot com, jan dot kratochvil at redhat dot com, palves at redhat dot com, tromey at redhat dot com, kettenis at gnu dot org, Markus Metzger <markus dot t dot metzger at intel dot com>
- Date: Tue, 14 Aug 2012 14:59:31 +0200
- Subject: [patch v3 16/16] btrace, x86: restrict to Atom
- References: <1344949171-9545-1-git-send-email-markus.t.metzger@intel.com>
From: Markus Metzger <markus.t.metzger@intel.com>
Restrict branch tracing support to Atom processors.
2012-08-14 Markus Metzger <markus.t.metzger@intel.com>
* amd64-linux-nat.c (_initialize_amd64_linux_nat): Change supports_btrace method.
* i386-linux-nat.c (_initialize_i386_linux_nat): Change supports_btrace method.
* i386-linux-tdep.h (i386_linux_supports_btrace): New function.
* i386-linux-tdep.c: Add linux-btrace.h include.
(i386_linux_supports_btrace): New function.
gdbserver/
* linux-low.h (linux_target_ops): Add supports_btrace method.
* linux-low.c (linux_low_supports_btrace): New function.
(linux_target_ops): Change supports_btrace method.
* linux-x86-low.c (x86_supports_btrace): New function.
(the_low_target): Add supports_btrace method.
---
gdb/amd64-linux-nat.c | 2 +-
gdb/gdbserver/linux-low.c | 15 ++++++++++++++-
gdb/gdbserver/linux-low.h | 2 ++
gdb/gdbserver/linux-x86-low.c | 31 +++++++++++++++++++++++++++++++
gdb/i386-linux-nat.c | 2 +-
gdb/i386-linux-tdep.c | 34 ++++++++++++++++++++++++++++++++++
gdb/i386-linux-tdep.h | 3 +++
7 files changed, 86 insertions(+), 3 deletions(-)
diff --git a/gdb/amd64-linux-nat.c b/gdb/amd64-linux-nat.c
index 3cfa45c..b411beb 100644
--- a/gdb/amd64-linux-nat.c
+++ b/gdb/amd64-linux-nat.c
@@ -1162,7 +1162,7 @@ _initialize_amd64_linux_nat (void)
t->to_read_description = amd64_linux_read_description;
/* Add btrace methods. */
- t->to_supports_btrace = linux_supports_btrace;
+ t->to_supports_btrace = i386_linux_supports_btrace;
t->to_enable_btrace = amd64_linux_enable_btrace;
t->to_disable_btrace = amd64_linux_disable_btrace;
t->to_btrace_has_changed = linux_btrace_has_changed;
diff --git a/gdb/gdbserver/linux-low.c b/gdb/gdbserver/linux-low.c
index 20b1ca5..77ecbe0 100644
--- a/gdb/gdbserver/linux-low.c
+++ b/gdb/gdbserver/linux-low.c
@@ -5793,6 +5793,19 @@ linux_qxfer_libraries_svr4 (const char *annex, unsigned char *readbuf,
return len;
}
+/* See linux-low.h. */
+static int
+linux_low_supports_btrace (void)
+{
+ if (!linux_supports_btrace ())
+ return 0;
+
+ if (*the_low_target.supports_btrace == NULL)
+ return 0;
+
+ return (*the_low_target.supports_btrace) ();
+}
+
/* Read branch trace data for @tinfo as btrace xml document into @buffer. */
static void
linux_low_read_btrace (struct btrace_target_info *tinfo, struct buffer *buffer)
@@ -5882,7 +5895,7 @@ static struct target_ops linux_target_ops = {
linux_get_min_fast_tracepoint_insn_len,
linux_qxfer_libraries_svr4,
linux_supports_agent,
- linux_supports_btrace,
+ linux_low_supports_btrace,
linux_enable_btrace,
linux_disable_btrace,
linux_btrace_has_changed,
diff --git a/gdb/gdbserver/linux-low.h b/gdb/gdbserver/linux-low.h
index 99d882a..5768a77 100644
--- a/gdb/gdbserver/linux-low.h
+++ b/gdb/gdbserver/linux-low.h
@@ -169,6 +169,8 @@ struct linux_target_ops
for use as a fast tracepoint. */
int (*get_min_fast_tracepoint_insn_len) (void);
+ /* Returns true if the low target supports btrace. */
+ int (*supports_btrace) (void);
};
extern struct linux_target_ops the_low_target;
diff --git a/gdb/gdbserver/linux-x86-low.c b/gdb/gdbserver/linux-x86-low.c
index 1215bae..e12fccb 100644
--- a/gdb/gdbserver/linux-x86-low.c
+++ b/gdb/gdbserver/linux-x86-low.c
@@ -1859,6 +1859,36 @@ x86_get_min_fast_tracepoint_insn_len (void)
}
}
+/* See linux-low.h. */
+static int
+x86_supports_btrace (void)
+{
+ unsigned int cpuid, model, family;
+
+ __asm__ __volatile__ ("movl $1, %%eax;"
+ "cpuid;"
+ : "=a" (cpuid)
+ :: "%ebx", "%ecx", "%edx");
+
+ family = (cpuid >> 8) & 0xf;
+ model = (cpuid >> 4) & 0xf;
+
+ switch (family)
+ {
+ case 6:
+ model += (cpuid >> 12) & 0xf0;
+
+ switch (model)
+ {
+ case 28: /* Atom. */
+ case 38:
+ return 1;
+ }
+ }
+
+ return 0;
+}
+
static void
add_insns (unsigned char *start, int len)
{
@@ -3214,4 +3244,5 @@ struct linux_target_ops the_low_target =
x86_install_fast_tracepoint_jump_pad,
x86_emit_ops,
x86_get_min_fast_tracepoint_insn_len,
+ x86_supports_btrace,
};
diff --git a/gdb/i386-linux-nat.c b/gdb/i386-linux-nat.c
index 0248fd7..35bc477 100644
--- a/gdb/i386-linux-nat.c
+++ b/gdb/i386-linux-nat.c
@@ -1086,7 +1086,7 @@ _initialize_i386_linux_nat (void)
t->to_read_description = i386_linux_read_description;
/* Add btrace methods. */
- t->to_supports_btrace = linux_supports_btrace;
+ t->to_supports_btrace = i386_linux_supports_btrace;
t->to_enable_btrace = i386_linux_enable_btrace;
t->to_disable_btrace = i386_linux_disable_btrace;
t->to_btrace_has_changed = linux_btrace_has_changed;
diff --git a/gdb/i386-linux-tdep.c b/gdb/i386-linux-tdep.c
index 8475d7a..b0f7b43 100644
--- a/gdb/i386-linux-tdep.c
+++ b/gdb/i386-linux-tdep.c
@@ -37,6 +37,7 @@
#include "symtab.h"
#include "arch-utils.h"
#include "xml-syscall.h"
+#include "linux-btrace.h"
#include "i387-tdep.h"
#include "i386-xstate.h"
@@ -704,6 +705,39 @@ i386_linux_displaced_step_copy_insn (struct gdbarch *gdbarch,
return closure;
}
+/* See i386-linux-tdep.h. */
+int
+i386_linux_supports_btrace (void)
+{
+ unsigned int cpuid, model, family;
+
+ if (!linux_supports_btrace ())
+ return 0;
+
+ __asm__ __volatile__ ("movl $1, %%eax;"
+ "cpuid;"
+ : "=a" (cpuid)
+ :: "%ebx", "%ecx", "%edx");
+
+ family = (cpuid >> 8) & 0xf;
+ model = (cpuid >> 4) & 0xf;
+
+ switch (family)
+ {
+ case 6:
+ model += (cpuid >> 12) & 0xf0;
+
+ switch (model)
+ {
+ case 28: /* Atom. */
+ case 38:
+ return 1;
+ }
+ }
+
+ return 0;
+}
+
static void
i386_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
{
diff --git a/gdb/i386-linux-tdep.h b/gdb/i386-linux-tdep.h
index c3a316f..45bdece 100644
--- a/gdb/i386-linux-tdep.h
+++ b/gdb/i386-linux-tdep.h
@@ -66,4 +66,7 @@ extern struct target_desc *tdesc_i386_avx_linux;
extern int i386_linux_gregset_reg_offset[];
+/* Return 1 if target supports btrace. */
+extern int i386_linux_supports_btrace (void);
+
#endif /* i386-linux-tdep.h */
--
1.7.1