Add dump_all_pmcs

2 files changed, 73 insertions, 1 deletions

diff --git a/Makefile b/Makefile
index 7a319fd..31f09b8 100644
--- a/Makefile
+++ b/Makefile
@@ -4,7 +4,7 @@ SIMPLE_C_TARGETS := dump-vsyscall context_switch_latency kernel_pf user_visible_
 
 SIMPLE_CC_TARGETS := evil-clock-test
 
-SPLIT_C_TARGETS := dump-vdso dump-vvar syscall_exit_regs sigreturn
+SPLIT_C_TARGETS := dump-vdso dump-vvar syscall_exit_regs sigreturn test_mremap_vdso dump_all_pmcs
 SPLIT_CC_TARGETS := timing_test test_vsyscall test_vdso_parser
 
 ALL_TARGETS := $(SIMPLE_C_TARGETS) $(SIMPLE_CC_TARGETS) $(SPLIT_C_TARGETS:%=%_64) $(SPLIT_CC_TARGETS:%=%_64) $(SPLIT_C_TARGETS:%=%_32) $(SPLIT_CC_TARGETS:%=%_32) syscall32_from_64
diff --git a/dump_all_pmcs.c b/dump_all_pmcs.c
new file mode 100644
index 0000000..be7a043
--- /dev/null
+++ b/dump_all_pmcs.c
@@ -0,0 +1,72 @@
+#define _GNU_SOURCE
+
+#include <stdio.h>
+#include <sys/prctl.h>
+#include <asm/prctl.h>
+#include <sys/ucontext.h>
+#include <unistd.h>
+#include <errno.h>
+#include <signal.h>
+#include <string.h>
+#include <err.h>
+
+static volatile sig_atomic_t got_sigbus = 0;
+
+static void sethandler(int sig, void (*handler)(int, siginfo_t *, void *),
+		       int flags)
+{
+	struct sigaction sa;
+	memset(&sa, 0, sizeof(sa));
+	sa.sa_sigaction = handler;
+	sa.sa_flags = SA_SIGINFO | flags;
+	sigemptyset(&sa.sa_mask);
+	if (sigaction(sig, &sa, 0))
+		err(1, "sigaction");
+}
+
+#ifdef __x86_64__
+# define REG_IP REG_RIP
+#else
+# define REG_IP REG_EIP
+#endif
+
+extern const char rdpmc_insn[];
+
+static void sigsegv(int sig, siginfo_t *si, void *ctx_void)
+{
+	ucontext_t *ctx = (ucontext_t*)ctx_void;
+
+	if (ctx->uc_mcontext.gregs[REG_IP] == (unsigned long)rdpmc_insn) {
+		got_sigbus = 1;
+		ctx->uc_mcontext.gregs[REG_IP] += 2;
+	} else {
+		raise(SIGABRT);
+	}
+}
+
+__attribute__((noinline, noclone)) static void do_rdpmc(unsigned int ecx)
+{
+	unsigned int eax, edx;
+
+	got_sigbus = 0;
+
+	asm volatile ("rdpmc_insn: rdpmc" : "=a" (eax), "=d" (edx) : "c" (ecx));
+
+	if (got_sigbus)
+		return;
+
+	printf("PMC 0x%08X: 0x%08X%08X\n", ecx, edx, eax);
+}
+
+int main()
+{
+	sethandler(SIGSEGV, sigsegv, 0);
+
+	for (unsigned int i = 0; i < 4096; i++)
+		do_rdpmc(i);
+
+	for (unsigned int i = 0; i < 4096; i++)
+		do_rdpmc(i | (1<<30));
+
+	return 0;
+}