From afb778a2a85ab4ac883638e309442f454f158692 Mon Sep 17 00:00:00 2001 From: Markus Metzger Date: Fri, 14 Feb 2014 09:25:40 +0100 Subject: [PATCH] btrace: identify cpu Add a struct for identifying a processor and use it in linux-btrace.c when identifying the processor we're running on. We will need this feature for the new btrace format. 2015-02-09 Markus Metzger * common/btrace-common.h (btrace_cpu_vendor, btrace_cpu): New. * nat/linux-btrace.c: (btrace_this_cpu): New. (cpu_supports_bts): Call btrace_this_cpu. (intel_supports_bts): Add cpu parameter. --- gdb/ChangeLog | 7 ++++ gdb/common/btrace-common.h | 28 +++++++++++++++ gdb/nat/linux-btrace.c | 70 ++++++++++++++++++++++++++------------ 3 files changed, 83 insertions(+), 22 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 40c6a516b8c..89521dab1ac 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,10 @@ +2015-02-09 Markus Metzger + + * common/btrace-common.h (btrace_cpu_vendor, btrace_cpu): New. + * nat/linux-btrace.c: (btrace_this_cpu): New. + (cpu_supports_bts): Call btrace_this_cpu. + (intel_supports_bts): Add cpu parameter. + 2015-02-09 Markus Metzger * btrace.h (btrace_insn_class): New. diff --git a/gdb/common/btrace-common.h b/gdb/common/btrace-common.h index bb151091991..ba99a067e2c 100644 --- a/gdb/common/btrace-common.h +++ b/gdb/common/btrace-common.h @@ -61,6 +61,34 @@ enum btrace_format BTRACE_FORMAT_BTS }; +/* An enumeration of cpu vendors. */ + +enum btrace_cpu_vendor +{ + /* We do not know this vendor. */ + CV_UNKNOWN, + + /* Intel. */ + CV_INTEL +}; + +/* A cpu identifier. */ + +struct btrace_cpu +{ + /* The processor vendor. */ + enum btrace_cpu_vendor vendor; + + /* The cpu family. */ + unsigned short family; + + /* The cpu model. */ + unsigned char model; + + /* The cpu stepping. */ + unsigned char stepping; +}; + /* A BTS configuration. */ struct btrace_config_bts diff --git a/gdb/nat/linux-btrace.c b/gdb/nat/linux-btrace.c index 62c0acf9db4..3093a5cf8c7 100644 --- a/gdb/nat/linux-btrace.c +++ b/gdb/nat/linux-btrace.c @@ -59,6 +59,41 @@ struct perf_event_sample struct perf_event_bts bts; }; +/* Identify the cpu we're running on. */ +static struct btrace_cpu +btrace_this_cpu (void) +{ + struct btrace_cpu cpu; + unsigned int eax, ebx, ecx, edx; + int ok; + + memset (&cpu, 0, sizeof (cpu)); + + ok = x86_cpuid (0, &eax, &ebx, &ecx, &edx); + if (ok != 0) + { + if (ebx == signature_INTEL_ebx && ecx == signature_INTEL_ecx + && edx == signature_INTEL_edx) + { + unsigned int cpuid, ignore; + + ok = x86_cpuid (1, &cpuid, &ignore, &ignore, &ignore); + if (ok != 0) + { + cpu.vendor = CV_INTEL; + + cpu.family = (cpuid >> 8) & 0xf; + cpu.model = (cpuid >> 4) & 0xf; + + if (cpu.family == 0x6) + cpu.model += (cpuid >> 12) & 0xf0; + } + } + } + + return cpu; +} + /* Return non-zero if there is new data in PEVENT; zero otherwise. */ static int @@ -302,22 +337,12 @@ kernel_supports_bts (void) /* Check whether an Intel cpu supports BTS. */ static int -intel_supports_bts (void) +intel_supports_bts (const struct btrace_cpu *cpu) { - unsigned int cpuid, model, family; - - if (!x86_cpuid (1, &cpuid, NULL, NULL, NULL)) - return 0; - - family = (cpuid >> 8) & 0xf; - model = (cpuid >> 4) & 0xf; - - switch (family) + switch (cpu->family) { case 0x6: - model += (cpuid >> 12) & 0xf0; - - switch (model) + switch (cpu->model) { case 0x1a: /* Nehalem */ case 0x1f: @@ -345,17 +370,18 @@ intel_supports_bts (void) static int cpu_supports_bts (void) { - unsigned int ebx, ecx, edx; + struct btrace_cpu cpu; - if (!x86_cpuid (0, NULL, &ebx, &ecx, &edx)) - return 0; - - if (ebx == signature_INTEL_ebx && ecx == signature_INTEL_ecx - && edx == signature_INTEL_edx) - return intel_supports_bts (); + cpu = btrace_this_cpu (); + switch (cpu.vendor) + { + default: + /* Don't know about others. Let's assume they do. */ + return 1; - /* Don't know about others. Let's assume they do. */ - return 1; + case CV_INTEL: + return intel_supports_bts (&cpu); + } } /* Check whether the linux target supports BTS. */ -- 2.30.2