Merge tag 'x86_bugs_for_v6.12_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 hw mitigation updates from Borislav Petkov:

 - Add CONFIG_ option for every hw CPU mitigation. The intent is to
   support configurations and scenarios where the mitigations code is
   irrelevant

 - Other small fixlets and improvements

* tag 'x86_bugs_for_v6.12_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/bugs: Fix handling when SRSO mitigation is disabled
  x86/bugs: Add missing NO_SSB flag
  Documentation/srso: Document a method for checking safe RET operates properly
  x86/bugs: Add a separate config for GDS
  x86/bugs: Remove GDS Force Kconfig option
  x86/bugs: Add a separate config for SSB
  x86/bugs: Add a separate config for Spectre V2
  x86/bugs: Add a separate config for SRBDS
  x86/bugs: Add a separate config for Spectre v1
  x86/bugs: Add a separate config for RETBLEED
  x86/bugs: Add a separate config for L1TF
  x86/bugs: Add a separate config for MMIO Stable Data
  x86/bugs: Add a separate config for TAA
  x86/bugs: Add a separate config for MDS

2 files changed, 71 insertions, 1 deletions

diff --git a/tools/testing/selftests/x86/Makefile b/tools/testing/selftests/x86/Makefile
index 5c8757a25998..d51249f14e2f 100644
--- a/tools/testing/selftests/x86/Makefile
+++ b/tools/testing/selftests/x86/Makefile
@@ -77,7 +77,7 @@ all_32: $(BINARIES_32)
 
 all_64: $(BINARIES_64)
 
-EXTRA_CLEAN := $(BINARIES_32) $(BINARIES_64)
+EXTRA_CLEAN := $(BINARIES_32) $(BINARIES_64) srso
 
 $(BINARIES_32): $(OUTPUT)/%_32: %.c helpers.h
 	$(CC) -m32 -o $@ $(CFLAGS) $(EXTRA_CFLAGS) $< $(EXTRA_FILES) -lrt -ldl -lm
diff --git a/tools/testing/selftests/x86/srso.c b/tools/testing/selftests/x86/srso.c
new file mode 100644
index 000000000000..394ec8bdeb00
--- /dev/null
+++ b/tools/testing/selftests/x86/srso.c
@@ -0,0 +1,70 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/perf_event.h>
+#include <cpuid.h>
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/ioctl.h>
+#include <sys/syscall.h>
+#include <unistd.h>
+
+int main(void)
+{
+	struct perf_event_attr ret_attr, mret_attr;
+	long long count_rets, count_rets_mispred;
+	int rrets_fd, mrrets_fd;
+	unsigned int cpuid1_eax, b, c, d;
+
+	__cpuid(1, cpuid1_eax, b, c, d);
+
+	if (cpuid1_eax < 0x00800f00 ||
+	    cpuid1_eax > 0x00afffff) {
+		fprintf(stderr, "This needs to run on a Zen[1-4] machine (CPUID(1).EAX: 0x%x). Exiting...\n", cpuid1_eax);
+		exit(EXIT_FAILURE);
+	}
+
+	memset(&ret_attr, 0, sizeof(struct perf_event_attr));
+	memset(&mret_attr, 0, sizeof(struct perf_event_attr));
+
+	ret_attr.type = mret_attr.type = PERF_TYPE_RAW;
+	ret_attr.size = mret_attr.size = sizeof(struct perf_event_attr);
+	ret_attr.config = 0xc8;
+	mret_attr.config = 0xc9;
+	ret_attr.disabled = mret_attr.disabled = 1;
+	ret_attr.exclude_user = mret_attr.exclude_user = 1;
+	ret_attr.exclude_hv = mret_attr.exclude_hv = 1;
+
+	rrets_fd = syscall(SYS_perf_event_open, &ret_attr, 0, -1, -1, 0);
+	if (rrets_fd == -1) {
+		perror("opening retired RETs fd");
+		exit(EXIT_FAILURE);
+	}
+
+	mrrets_fd = syscall(SYS_perf_event_open, &mret_attr, 0, -1, -1, 0);
+	if (mrrets_fd == -1) {
+		perror("opening retired mispredicted RETs fd");
+		exit(EXIT_FAILURE);
+	}
+
+	ioctl(rrets_fd, PERF_EVENT_IOC_RESET, 0);
+	ioctl(mrrets_fd, PERF_EVENT_IOC_RESET, 0);
+
+	ioctl(rrets_fd, PERF_EVENT_IOC_ENABLE, 0);
+	ioctl(mrrets_fd, PERF_EVENT_IOC_ENABLE, 0);
+
+	printf("Sleeping for 10 seconds\n");
+	sleep(10);
+
+	ioctl(rrets_fd, PERF_EVENT_IOC_DISABLE, 0);
+	ioctl(mrrets_fd, PERF_EVENT_IOC_DISABLE, 0);
+
+	read(rrets_fd, &count_rets, sizeof(long long));
+	read(mrrets_fd, &count_rets_mispred, sizeof(long long));
+
+	printf("RETs: (%lld retired <-> %lld mispredicted)\n",
+		count_rets, count_rets_mispred);
+	printf("SRSO Safe-RET mitigation works correctly if both counts are almost equal.\n");
+
+	return 0;
+}