selftests/powerpc: Add subpage protection self test.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>

mpe: Fix compile errors and formatting. Add tempfile logic to Makefile.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

3 files changed, 228 insertions, 3 deletions

diff --git a/tools/testing/selftests/powerpc/mm/.gitignore b/tools/testing/selftests/powerpc/mm/.gitignore
index 156f4e89c2f1..b43ade0ec861 100644
--- a/tools/testing/selftests/powerpc/mm/.gitignore
+++ b/tools/testing/selftests/powerpc/mm/.gitignore
@@ -1 +1,3 @@
 hugetlb_vs_thp_test
+subpage_prot
+tempfile
diff --git a/tools/testing/selftests/powerpc/mm/Makefile b/tools/testing/selftests/powerpc/mm/Makefile
index 357ccbd6bad9..a14c538dd7f8 100644
--- a/tools/testing/selftests/powerpc/mm/Makefile
+++ b/tools/testing/selftests/powerpc/mm/Makefile
@@ -1,9 +1,9 @@
 noarg:
         $(MAKE) -C ../
 
-PROGS := hugetlb_vs_thp_test
+PROGS := hugetlb_vs_thp_test subpage_prot
 
-all: $(PROGS)
+all: $(PROGS) tempfile
 
 $(PROGS): ../harness.c
 
@@ -12,7 +12,10 @@ run_tests: all
                 ./$$PROG; \
         done;
 
+tempfile:
+        dd if=/dev/zero of=tempfile bs=64k count=1
+
 clean:
-        rm -f $(PROGS)
+        rm -f $(PROGS) tempfile
 
 .PHONY: all run_tests clean
diff --git a/tools/testing/selftests/powerpc/mm/subpage_prot.c b/tools/testing/selftests/powerpc/mm/subpage_prot.c
new file mode 100644
index 000000000000..440180ff8089
--- /dev/null
+++ b/tools/testing/selftests/powerpc/mm/subpage_prot.c
@@ -0,0 +1,220 @@
+/*
+ * Copyright IBM Corp.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of version 2.1 of the GNU Lesser General Public License
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it would be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ */
+
+#include <assert.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <signal.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/mman.h>
+#include <sys/ptrace.h>
+#include <sys/syscall.h>
+#include <ucontext.h>
+#include <unistd.h>
+
+#include "utils.h"
+
+char *file_name;
+
+int in_test;
+volatile int faulted;
+volatile void *dar;
+int errors;
+
+static void segv(int signum, siginfo_t *info, void *ctxt_v)
+{
+        ucontext_t *ctxt = (ucontext_t *)ctxt_v;
+        struct pt_regs *regs = ctxt->uc_mcontext.regs;
+
+        if (!in_test) {
+                fprintf(stderr, "Segfault outside of test !\n");
+                exit(1);
+        }
+
+        faulted = 1;
+        dar = (void *)regs->dar;
+        regs->nip += 4;
+}
+
+static inline void do_read(const volatile void *addr)
+{
+        int ret;
+
+        asm volatile("lwz %0,0(%1); twi 0,%0,0; isync;\n"
+                     : "=r" (ret) : "r" (addr) : "memory");
+}
+
+static inline void do_write(const volatile void *addr)
+{
+        int val = 0x1234567;
+
+        asm volatile("stw %0,0(%1); sync; \n"
+                     : : "r" (val), "r" (addr) : "memory");
+}
+
+static inline void check_faulted(void *addr, long page, long subpage, int write)
+{
+        int want_fault = (subpage == ((page + 3) % 16));
+
+        if (write)
+                want_fault |= (subpage == ((page + 1) % 16));
+
+        if (faulted != want_fault) {
+                printf("Failed at 0x%p (p=%ld,sp=%ld,w=%d), want=%s, got=%s !\n",
+                       addr, page, subpage, write,
+                       want_fault ? "fault" : "pass",
+                       faulted ? "fault" : "pass");
+                ++errors;
+        }
+
+        if (faulted) {
+                if (dar != addr) {
+                        printf("Fault expected at 0x%p and happened at 0x%p !\n",
+                               addr, dar);
+                }
+                faulted = 0;
+                asm volatile("sync" : : : "memory");
+        }
+}
+
+static int run_test(void *addr, unsigned long size)
+{
+        unsigned int *map;
+        long i, j, pages, err;
+
+        pages = size / 0x10000;
+        map = malloc(pages * 4);
+        assert(map);
+
+        /*
+         * for each page, mark subpage i % 16 read only and subpage
+         * (i + 3) % 16 inaccessible
+         */
+        for (i = 0; i < pages; i++) {
+                map[i] = (0x40000000 >> (((i + 1) * 2) % 32)) |
+                        (0xc0000000 >> (((i + 3) * 2) % 32));
+        }
+
+        err = syscall(__NR_subpage_prot, addr, size, map);
+        if (err) {
+                perror("subpage_perm");
+                return 1;
+        }
+        free(map);
+
+        in_test = 1;
+        errors = 0;
+        for (i = 0; i < pages; i++) {
+                for (j = 0; j < 16; j++, addr += 0x1000) {
+                        do_read(addr);
+                        check_faulted(addr, i, j, 0);
+                        do_write(addr);
+                        check_faulted(addr, i, j, 1);
+                }
+        }
+
+        in_test = 0;
+        if (errors) {
+                printf("%d errors detected\n", errors);
+                return 1;
+        }
+
+        return 0;
+}
+
+int test_anon(void)
+{
+        unsigned long align;
+        struct sigaction act = {
+                .sa_sigaction = segv,
+                .sa_flags = SA_SIGINFO
+        };
+        void *mallocblock;
+        unsigned long mallocsize;
+
+        if (getpagesize() != 0x10000) {
+                fprintf(stderr, "Kernel page size must be 64K!\n");
+                return 1;
+        }
+
+        sigaction(SIGSEGV, &act, NULL);
+
+        mallocsize = 4 * 16 * 1024 * 1024;
+
+        FAIL_IF(posix_memalign(&mallocblock, 64 * 1024, mallocsize));
+
+        align = (unsigned long)mallocblock;
+        if (align & 0xffff)
+                align = (align | 0xffff) + 1;
+
+        mallocblock = (void *)align;
+
+        printf("allocated malloc block of 0x%lx bytes at 0x%p\n",
+               mallocsize, mallocblock);
+
+        printf("testing malloc block...\n");
+
+        return run_test(mallocblock, mallocsize);
+}
+
+int test_file(void)
+{
+        struct sigaction act = {
+                .sa_sigaction = segv,
+                .sa_flags = SA_SIGINFO
+        };
+        void *fileblock;
+        off_t filesize;
+        int fd;
+
+        fd = open(file_name, O_RDWR);
+        if (fd == -1) {
+                perror("failed to open file");
+                return 1;
+        }
+        sigaction(SIGSEGV, &act, NULL);
+
+        filesize = lseek(fd, 0, SEEK_END);
+        if (filesize & 0xffff)
+                filesize &= ~0xfffful;
+
+        fileblock = mmap(NULL, filesize, PROT_READ | PROT_WRITE,
+                         MAP_SHARED, fd, 0);
+        if (fileblock == MAP_FAILED) {
+                perror("failed to map file");
+                return 1;
+        }
+        printf("allocated %s for 0x%lx bytes at 0x%p\n",
+               file_name, filesize, fileblock);
+
+        printf("testing file map...\n");
+
+        return run_test(fileblock, filesize);
+}
+
+int main(int argc, char *argv[])
+{
+        test_harness(test_anon, "subpage_prot_anon");
+
+        if (argc > 1)
+                file_name = argv[1];
+        else
+                file_name = "tempfile";
+
+        test_harness(test_file, "subpage_prot_file");
+
+        return 0;
+}