From 97f404ad3e53bf9ac598745066ba2f57c1da3039 Mon Sep 17 00:00:00 2001 From: "Kirill A. Shutemov" Date: Wed, 15 Nov 2017 17:36:07 +0300 Subject: x86/selftests: Add test for mapping placement for 5-level paging 5-level paging provides a 56-bit virtual address space for user space application. But the kernel defaults to mappings below the 47-bit address space boundary, which is the upper bound for 4-level paging, unless an application explicitely request it by using a mmap(2) address hint above the 47-bit boundary. The kernel prevents mappings which spawn across the 47-bit boundary unless mmap(2) was invoked with MAP_FIXED. Add a self-test that covers the corner cases of the interface and validates the correctness of the implementation. [ tglx: Massaged changelog once more ] Signed-off-by: Kirill A. Shutemov Signed-off-by: Thomas Gleixner Cc: Nicholas Piggin Cc: Andy Lutomirski Cc: linux-mm@kvack.org Cc: Linus Torvalds Link: https://lkml.kernel.org/r/20171115143607.81541-2-kirill.shutemov@linux.intel.com --- tools/testing/selftests/x86/5lvl.c | 177 +++++++++++++++++++++++++++++++++++ tools/testing/selftests/x86/Makefile | 2 +- 2 files changed, 178 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/x86/5lvl.c (limited to 'tools') diff --git a/tools/testing/selftests/x86/5lvl.c b/tools/testing/selftests/x86/5lvl.c new file mode 100644 index 000000000000..2eafdcd4c2b3 --- /dev/null +++ b/tools/testing/selftests/x86/5lvl.c @@ -0,0 +1,177 @@ +#include +#include + +#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0])) + +#define PAGE_SIZE 4096 +#define LOW_ADDR ((void *) (1UL << 30)) +#define HIGH_ADDR ((void *) (1UL << 50)) + +struct testcase { + void *addr; + unsigned long size; + unsigned long flags; + const char *msg; + unsigned int low_addr_required:1; + unsigned int keep_mapped:1; +}; + +static struct testcase testcases[] = { + { + .addr = NULL, + .size = 2 * PAGE_SIZE, + .flags = MAP_PRIVATE | MAP_ANONYMOUS, + .msg = "mmap(NULL)", + .low_addr_required = 1, + }, + { + .addr = LOW_ADDR, + .size = 2 * PAGE_SIZE, + .flags = MAP_PRIVATE | MAP_ANONYMOUS, + .msg = "mmap(LOW_ADDR)", + .low_addr_required = 1, + }, + { + .addr = HIGH_ADDR, + .size = 2 * PAGE_SIZE, + .flags = MAP_PRIVATE | MAP_ANONYMOUS, + .msg = "mmap(HIGH_ADDR)", + .keep_mapped = 1, + }, + { + .addr = HIGH_ADDR, + .size = 2 * PAGE_SIZE, + .flags = MAP_PRIVATE | MAP_ANONYMOUS, + .msg = "mmap(HIGH_ADDR) again", + .keep_mapped = 1, + }, + { + .addr = HIGH_ADDR, + .size = 2 * PAGE_SIZE, + .flags = MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED, + .msg = "mmap(HIGH_ADDR, MAP_FIXED)", + }, + { + .addr = (void*) -1, + .size = 2 * PAGE_SIZE, + .flags = MAP_PRIVATE | MAP_ANONYMOUS, + .msg = "mmap(-1)", + .keep_mapped = 1, + }, + { + .addr = (void*) -1, + .size = 2 * PAGE_SIZE, + .flags = MAP_PRIVATE | MAP_ANONYMOUS, + .msg = "mmap(-1) again", + }, + { + .addr = (void *)((1UL << 47) - PAGE_SIZE), + .size = 2 * PAGE_SIZE, + .flags = MAP_PRIVATE | MAP_ANONYMOUS, + .msg = "mmap((1UL << 47), 2 * PAGE_SIZE)", + .low_addr_required = 1, + .keep_mapped = 1, + }, + { + .addr = (void *)((1UL << 47) - PAGE_SIZE / 2), + .size = 2 * PAGE_SIZE, + .flags = MAP_PRIVATE | MAP_ANONYMOUS, + .msg = "mmap((1UL << 47), 2 * PAGE_SIZE / 2)", + .low_addr_required = 1, + .keep_mapped = 1, + }, + { + .addr = (void *)((1UL << 47) - PAGE_SIZE), + .size = 2 * PAGE_SIZE, + .flags = MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED, + .msg = "mmap((1UL << 47) - PAGE_SIZE, 2 * PAGE_SIZE, MAP_FIXED)", + }, + { + .addr = NULL, + .size = 2UL << 20, + .flags = MAP_HUGETLB | MAP_PRIVATE | MAP_ANONYMOUS, + .msg = "mmap(NULL, MAP_HUGETLB)", + .low_addr_required = 1, + }, + { + .addr = LOW_ADDR, + .size = 2UL << 20, + .flags = MAP_HUGETLB | MAP_PRIVATE | MAP_ANONYMOUS, + .msg = "mmap(LOW_ADDR, MAP_HUGETLB)", + .low_addr_required = 1, + }, + { + .addr = HIGH_ADDR, + .size = 2UL << 20, + .flags = MAP_HUGETLB | MAP_PRIVATE | MAP_ANONYMOUS, + .msg = "mmap(HIGH_ADDR, MAP_HUGETLB)", + .keep_mapped = 1, + }, + { + .addr = HIGH_ADDR, + .size = 2UL << 20, + .flags = MAP_HUGETLB | MAP_PRIVATE | MAP_ANONYMOUS, + .msg = "mmap(HIGH_ADDR, MAP_HUGETLB) again", + .keep_mapped = 1, + }, + { + .addr = HIGH_ADDR, + .size = 2UL << 20, + .flags = MAP_HUGETLB | MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED, + .msg = "mmap(HIGH_ADDR, MAP_FIXED | MAP_HUGETLB)", + }, + { + .addr = (void*) -1, + .size = 2UL << 20, + .flags = MAP_HUGETLB | MAP_PRIVATE | MAP_ANONYMOUS, + .msg = "mmap(-1, MAP_HUGETLB)", + .keep_mapped = 1, + }, + { + .addr = (void*) -1, + .size = 2UL << 20, + .flags = MAP_HUGETLB | MAP_PRIVATE | MAP_ANONYMOUS, + .msg = "mmap(-1, MAP_HUGETLB) again", + }, + { + .addr = (void *)((1UL << 47) - PAGE_SIZE), + .size = 4UL << 20, + .flags = MAP_HUGETLB | MAP_PRIVATE | MAP_ANONYMOUS, + .msg = "mmap((1UL << 47), 4UL << 20, MAP_HUGETLB)", + .low_addr_required = 1, + .keep_mapped = 1, + }, + { + .addr = (void *)((1UL << 47) - (2UL << 20)), + .size = 4UL << 20, + .flags = MAP_HUGETLB | MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED, + .msg = "mmap((1UL << 47) - (2UL << 20), 4UL << 20, MAP_FIXED | MAP_HUGETLB)", + }, +}; + +int main(int argc, char **argv) +{ + int i; + void *p; + + for (i = 0; i < ARRAY_SIZE(testcases); i++) { + struct testcase *t = testcases + i; + + p = mmap(t->addr, t->size, PROT_NONE, t->flags, -1, 0); + + printf("%s: %p - ", t->msg, p); + + if (p == MAP_FAILED) { + printf("FAILED\n"); + continue; + } + + if (t->low_addr_required && p >= (void *)(1UL << 47)) + printf("FAILED\n"); + else + printf("OK\n"); + if (!t->keep_mapped) + munmap(p, t->size); + } + return 0; +} diff --git a/tools/testing/selftests/x86/Makefile b/tools/testing/selftests/x86/Makefile index 7b1adeee4b0f..939a337128db 100644 --- a/tools/testing/selftests/x86/Makefile +++ b/tools/testing/selftests/x86/Makefile @@ -11,7 +11,7 @@ TARGETS_C_BOTHBITS := single_step_syscall sysret_ss_attrs syscall_nt ptrace_sysc TARGETS_C_32BIT_ONLY := entry_from_vm86 syscall_arg_fault test_syscall_vdso unwind_vdso \ test_FCMOV test_FCOMI test_FISTTP \ vdso_restorer -TARGETS_C_64BIT_ONLY := fsgsbase sysret_rip +TARGETS_C_64BIT_ONLY := fsgsbase sysret_rip 5lvl TARGETS_C_32BIT_ALL := $(TARGETS_C_BOTHBITS) $(TARGETS_C_32BIT_ONLY) TARGETS_C_64BIT_ALL := $(TARGETS_C_BOTHBITS) $(TARGETS_C_64BIT_ONLY) -- cgit v1.2.3 From a6400120d042397675fcf694060779d21e9e762d Mon Sep 17 00:00:00 2001 From: Dave Hansen Date: Fri, 10 Nov 2017 16:12:29 -0800 Subject: x86/mpx/selftests: Fix up weird arrays The MPX hardware data structurse are defined in a weird way: they define their size in bytes and then union that with the type with which we want to access them. Yes, this is weird, but it does work. But, new GCC's complain that we are accessing the array out of bounds. Just make it a zero-sized array so gcc will stop complaining. There was not really a bug here. Signed-off-by: Dave Hansen Acked-by: Thomas Gleixner Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Josh Poimboeuf Cc: Linus Torvalds Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/20171111001229.58A7933D@viggo.jf.intel.com Signed-off-by: Ingo Molnar --- tools/testing/selftests/x86/mpx-hw.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'tools') diff --git a/tools/testing/selftests/x86/mpx-hw.h b/tools/testing/selftests/x86/mpx-hw.h index 3f0093911f03..d1b61ab870f8 100644 --- a/tools/testing/selftests/x86/mpx-hw.h +++ b/tools/testing/selftests/x86/mpx-hw.h @@ -52,14 +52,14 @@ struct mpx_bd_entry { union { char x[MPX_BOUNDS_DIR_ENTRY_SIZE_BYTES]; - void *contents[1]; + void *contents[0]; }; } __attribute__((packed)); struct mpx_bt_entry { union { char x[MPX_BOUNDS_TABLE_ENTRY_SIZE_BYTES]; - unsigned long contents[1]; + unsigned long contents[0]; }; } __attribute__((packed)); -- cgit v1.2.3 From 91c49c2deb96ffc3c461eaae70219d89224076b7 Mon Sep 17 00:00:00 2001 From: Dave Hansen Date: Fri, 10 Nov 2017 16:12:31 -0800 Subject: x86/pkeys/selftests: Rename 'si_pkey' to 'siginfo_pkey' 'si_pkey' is now #defined to be the name of the new siginfo field that protection keys uses. Rename it not to conflict. Signed-off-by: Dave Hansen Acked-by: Thomas Gleixner Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Josh Poimboeuf Cc: Linus Torvalds Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/20171111001231.DFFC8285@viggo.jf.intel.com Signed-off-by: Ingo Molnar --- tools/testing/selftests/x86/protection_keys.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) (limited to 'tools') diff --git a/tools/testing/selftests/x86/protection_keys.c b/tools/testing/selftests/x86/protection_keys.c index 7a1cc0e56d2d..bc1b0735bb50 100644 --- a/tools/testing/selftests/x86/protection_keys.c +++ b/tools/testing/selftests/x86/protection_keys.c @@ -250,7 +250,7 @@ void signal_handler(int signum, siginfo_t *si, void *vucontext) unsigned long ip; char *fpregs; u32 *pkru_ptr; - u64 si_pkey; + u64 siginfo_pkey; u32 *si_pkey_ptr; int pkru_offset; fpregset_t fpregset; @@ -292,9 +292,9 @@ void signal_handler(int signum, siginfo_t *si, void *vucontext) si_pkey_ptr = (u32 *)(((u8 *)si) + si_pkey_offset); dprintf1("si_pkey_ptr: %p\n", si_pkey_ptr); dump_mem(si_pkey_ptr - 8, 24); - si_pkey = *si_pkey_ptr; - pkey_assert(si_pkey < NR_PKEYS); - last_si_pkey = si_pkey; + siginfo_pkey = *si_pkey_ptr; + pkey_assert(siginfo_pkey < NR_PKEYS); + last_si_pkey = siginfo_pkey; if ((si->si_code == SEGV_MAPERR) || (si->si_code == SEGV_ACCERR) || @@ -306,7 +306,7 @@ void signal_handler(int signum, siginfo_t *si, void *vucontext) dprintf1("signal pkru from xsave: %08x\n", *pkru_ptr); /* need __rdpkru() version so we do not do shadow_pkru checking */ dprintf1("signal pkru from pkru: %08x\n", __rdpkru()); - dprintf1("si_pkey from siginfo: %jx\n", si_pkey); + dprintf1("pkey from siginfo: %jx\n", siginfo_pkey); *(u64 *)pkru_ptr = 0x00000000; dprintf1("WARNING: set PRKU=0 to allow faulting instruction to continue\n"); pkru_faults++; -- cgit v1.2.3 From 7b659ee3e1fe0e8eb39730afb903c64e25490ec4 Mon Sep 17 00:00:00 2001 From: Dave Hansen Date: Fri, 10 Nov 2017 16:12:32 -0800 Subject: x86/pkeys/selftests: Fix protection keys write() warning write() is marked as having a must-check return value. Check it and abort if we fail to write an error message from a signal handler. Signed-off-by: Dave Hansen Acked-by: Thomas Gleixner Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Josh Poimboeuf Cc: Linus Torvalds Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/20171111001232.94813E58@viggo.jf.intel.com Signed-off-by: Ingo Molnar --- tools/testing/selftests/x86/pkey-helpers.h | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'tools') diff --git a/tools/testing/selftests/x86/pkey-helpers.h b/tools/testing/selftests/x86/pkey-helpers.h index 3818f25391c2..b3cb7670e026 100644 --- a/tools/testing/selftests/x86/pkey-helpers.h +++ b/tools/testing/selftests/x86/pkey-helpers.h @@ -30,6 +30,7 @@ static inline void sigsafe_printf(const char *format, ...) if (!dprint_in_signal) { vprintf(format, ap); } else { + int ret; int len = vsnprintf(dprint_in_signal_buffer, DPRINT_IN_SIGNAL_BUF_SIZE, format, ap); @@ -39,7 +40,9 @@ static inline void sigsafe_printf(const char *format, ...) */ if (len > DPRINT_IN_SIGNAL_BUF_SIZE) len = DPRINT_IN_SIGNAL_BUF_SIZE; - write(1, dprint_in_signal_buffer, len); + ret = write(1, dprint_in_signal_buffer, len); + if (ret < 0) + abort(); } va_end(ap); } -- cgit v1.2.3