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[50.39.100.161]) by smtp.gmail.com with ESMTPSA id s83-v6sm640937qki.20.2018.07.17.06.50.30 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 17 Jul 2018 06:50:32 -0700 (PDT) From: Ram Pai To: shuahkh@osg.samsung.com, linux-kselftest@vger.kernel.org Subject: [PATCH v14 14/22] selftests/vm: Introduce generic abstractions Date: Tue, 17 Jul 2018 06:49:17 -0700 Message-Id: <1531835365-32387-15-git-send-email-linuxram@us.ibm.com> X-Mailer: git-send-email 1.7.1 In-Reply-To: <1531835365-32387-1-git-send-email-linuxram@us.ibm.com> References: <1531835365-32387-1-git-send-email-linuxram@us.ibm.com> X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.27 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-arch@vger.kernel.org, fweimer@redhat.com, dave.hansen@intel.com, x86@kernel.org, linuxram@us.ibm.com, mhocko@kernel.org, linux-mm@kvack.org, mingo@redhat.com, aneesh.kumar@linux.vnet.ibm.com, bauerman@linux.vnet.ibm.com, msuchanek@suse.de, linuxppc-dev@lists.ozlabs.org Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" Introduce generic abstractions and provide architecture specific implementation for the abstractions. cc: Dave Hansen cc: Florian Weimer Signed-off-by: Ram Pai Signed-off-by: Thiago Jung Bauermann --- tools/testing/selftests/vm/pkey-helpers.h | 16 ++++- tools/testing/selftests/vm/pkey-powerpc.h | 93 ++++++++++++++++++++++++++ tools/testing/selftests/vm/pkey-x86.h | 15 ++++ tools/testing/selftests/vm/protection_keys.c | 52 ++++++++------ 4 files changed, 153 insertions(+), 23 deletions(-) create mode 100644 tools/testing/selftests/vm/pkey-powerpc.h diff --git a/tools/testing/selftests/vm/pkey-helpers.h b/tools/testing/selftests/vm/pkey-helpers.h index 52a1152..321bbbd 100644 --- a/tools/testing/selftests/vm/pkey-helpers.h +++ b/tools/testing/selftests/vm/pkey-helpers.h @@ -74,8 +74,13 @@ static inline void sigsafe_printf(const char *format, ...) } \ } while (0) +__attribute__((noinline)) int read_ptr(int *ptr); +void expected_pkey_fault(int pkey); + #if defined(__i386__) || defined(__x86_64__) /* arch */ #include "pkey-x86.h" +#elif defined(__powerpc64__) /* arch */ +#include "pkey-powerpc.h" #else /* arch */ #error Architecture not supported #endif /* arch */ @@ -186,7 +191,16 @@ static inline int open_hugepage_file(int flag) static inline int get_start_key(void) { - return 1; + return 0; +} + +static inline u32 *siginfo_get_pkey_ptr(siginfo_t *si) +{ +#ifdef si_pkey + return &si->si_pkey; +#else + return (u32 *)(((u8 *)si) + si_pkey_offset); +#endif } #endif /* _PKEYS_HELPER_H */ diff --git a/tools/testing/selftests/vm/pkey-powerpc.h b/tools/testing/selftests/vm/pkey-powerpc.h new file mode 100644 index 0000000..b0d1abe --- /dev/null +++ b/tools/testing/selftests/vm/pkey-powerpc.h @@ -0,0 +1,93 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef _PKEYS_POWERPC_H +#define _PKEYS_POWERPC_H + +#ifndef SYS_mprotect_key +# define SYS_mprotect_key 386 +#endif +#ifndef SYS_pkey_alloc +# define SYS_pkey_alloc 384 +# define SYS_pkey_free 385 +#endif +#define REG_IP_IDX PT_NIP +#define REG_TRAPNO PT_TRAP +#define gregs gp_regs +#define fpregs fp_regs +#define si_pkey_offset 0x20 + +#ifndef PKEY_DISABLE_ACCESS +# define PKEY_DISABLE_ACCESS 0x3 /* disable read and write */ +#endif + +#ifndef PKEY_DISABLE_WRITE +# define PKEY_DISABLE_WRITE 0x2 +#endif + +#define NR_PKEYS 32 +#define NR_RESERVED_PKEYS_4K 27 /* pkey-0, pkey-1, exec-only-pkey + and 24 other keys that cannot be + represented in the PTE */ +#define NR_RESERVED_PKEYS_64K 3 /* pkey-0, pkey-1 and exec-only-pkey */ +#define PKEY_BITS_PER_PKEY 2 +#define HPAGE_SIZE (1UL << 24) +#define PAGE_SIZE (1UL << 16) +#define pkey_reg_t u64 +#define PKEY_REG_FMT "%016lx" +#define HUGEPAGE_FILE "/sys/kernel/mm/hugepages/hugepages-16384kB/nr_hugepages" + +static inline u32 pkey_bit_position(int pkey) +{ + return (NR_PKEYS - pkey - 1) * PKEY_BITS_PER_PKEY; +} + +static inline pkey_reg_t __read_pkey_reg(void) +{ + pkey_reg_t pkey_reg; + + asm volatile("mfspr %0, 0xd" : "=r" (pkey_reg)); + + return pkey_reg; +} + +static inline void __write_pkey_reg(pkey_reg_t pkey_reg) +{ + pkey_reg_t eax = pkey_reg; + + dprintf4("%s() changing "PKEY_REG_FMT" to "PKEY_REG_FMT"\n", + __func__, __read_pkey_reg(), pkey_reg); + + asm volatile("mtspr 0xd, %0" : : "r" ((unsigned long)(eax)) : "memory"); + + dprintf4("%s() pkey register after changing "PKEY_REG_FMT" to " + PKEY_REG_FMT"\n", __func__, __read_pkey_reg(), + pkey_reg); +} + +static inline int cpu_has_pku(void) +{ + return 1; +} + +static inline int arch_reserved_keys(void) +{ + if (sysconf(_SC_PAGESIZE) == 4096) + return NR_RESERVED_PKEYS_4K; + else + return NR_RESERVED_PKEYS_64K; +} + +void expect_fault_on_read_execonly_key(void *p1, int pkey) +{ + /* powerpc does not allow userspace to change permissions of exec-only + * keys since those keys are not allocated by userspace. The signal + * handler wont be able to reset the permissions, which means the code + * will infinitely continue to segfault here. + */ + return; +} + +/* 8-bytes of instruction * 16384bytes = 1 page */ +#define __page_o_noops() asm(".rept 16384 ; nop; .endr") + +#endif /* _PKEYS_POWERPC_H */ diff --git a/tools/testing/selftests/vm/pkey-x86.h b/tools/testing/selftests/vm/pkey-x86.h index d5fa299..f5d0ff2 100644 --- a/tools/testing/selftests/vm/pkey-x86.h +++ b/tools/testing/selftests/vm/pkey-x86.h @@ -42,6 +42,7 @@ #endif #define NR_PKEYS 16 +#define NR_RESERVED_PKEYS 2 /* pkey-0 and exec-only-pkey */ #define PKEY_BITS_PER_PKEY 2 #define HPAGE_SIZE (1UL<<21) #define PAGE_SIZE 4096 @@ -161,4 +162,18 @@ int pkey_reg_xstate_offset(void) return xstate_offset; } +static inline int arch_reserved_keys(void) +{ + return NR_RESERVED_PKEYS; +} + +void expect_fault_on_read_execonly_key(void *p1, int pkey) +{ + int ptr_contents; + + ptr_contents = read_ptr(p1); + dprintf2("ptr (%p) contents@%d: %x\n", p1, __LINE__, ptr_contents); + expected_pkey_fault(pkey); +} + #endif /* _PKEYS_X86_H */ diff --git a/tools/testing/selftests/vm/protection_keys.c b/tools/testing/selftests/vm/protection_keys.c index 304f74f..18e1bb7 100644 --- a/tools/testing/selftests/vm/protection_keys.c +++ b/tools/testing/selftests/vm/protection_keys.c @@ -197,17 +197,18 @@ void dump_mem(void *dumpme, int len_bytes) int pkey_faults; int last_si_pkey = -1; +void pkey_access_allow(int pkey); void signal_handler(int signum, siginfo_t *si, void *vucontext) { ucontext_t *uctxt = vucontext; int trapno; unsigned long ip; char *fpregs; +#if defined(__i386__) || defined(__x86_64__) /* arch */ pkey_reg_t *pkey_reg_ptr; - u64 siginfo_pkey; +#endif /* defined(__i386__) || defined(__x86_64__) */ + u32 siginfo_pkey; u32 *si_pkey_ptr; - int pkey_reg_offset; - fpregset_t fpregset; dprint_in_signal = 1; dprintf1(">>>>===============SIGSEGV============================\n"); @@ -217,12 +218,14 @@ void signal_handler(int signum, siginfo_t *si, void *vucontext) trapno = uctxt->uc_mcontext.gregs[REG_TRAPNO]; ip = uctxt->uc_mcontext.gregs[REG_IP_IDX]; - fpregset = uctxt->uc_mcontext.fpregs; - fpregs = (void *)fpregset; + fpregs = (char *) uctxt->uc_mcontext.fpregs; dprintf2("%s() trapno: %d ip: 0x%016lx info->si_code: %s/%d\n", __func__, trapno, ip, si_code_str(si->si_code), si->si_code); + +#if defined(__i386__) || defined(__x86_64__) /* arch */ + #ifdef __i386__ /* * 32-bit has some extra padding so that userspace can tell whether @@ -230,20 +233,21 @@ void signal_handler(int signum, siginfo_t *si, void *vucontext) * state. We just assume that it is here. */ fpregs += 0x70; -#endif - pkey_reg_offset = pkey_reg_xstate_offset(); - pkey_reg_ptr = (void *)(&fpregs[pkey_reg_offset]); +#endif /* __i386__ */ - dprintf1("siginfo: %p\n", si); - dprintf1(" fpregs: %p\n", fpregs); + pkey_reg_ptr = (void *)(&fpregs[pkey_reg_xstate_offset()]); /* - * If we got a PKEY fault, we *HAVE* to have at least one bit set in + * If we got a key fault, we *HAVE* to have at least one bit set in * here. */ dprintf1("pkey_reg_xstate_offset: %d\n", pkey_reg_xstate_offset()); if (DEBUG_LEVEL > 4) dump_mem(pkey_reg_ptr - 128, 256); pkey_assert(*pkey_reg_ptr); +#endif /* defined(__i386__) || defined(__x86_64__) */ + + dprintf1("siginfo: %p\n", si); + dprintf1(" fpregs: %p\n", fpregs); if ((si->si_code == SEGV_MAPERR) || (si->si_code == SEGV_ACCERR) || @@ -252,22 +256,28 @@ void signal_handler(int signum, siginfo_t *si, void *vucontext) exit(4); } - si_pkey_ptr = (u32 *)(((u8 *)si) + si_pkey_offset); + si_pkey_ptr = siginfo_get_pkey_ptr(si); dprintf1("si_pkey_ptr: %p\n", si_pkey_ptr); - dump_mem((u8 *)si_pkey_ptr - 8, 24); + dump_mem(si_pkey_ptr - 8, 24); siginfo_pkey = *si_pkey_ptr; pkey_assert(siginfo_pkey < NR_PKEYS); last_si_pkey = siginfo_pkey; - dprintf1("signal pkey_reg from xsave: "PKEY_REG_FMT"\n", *pkey_reg_ptr); /* * need __read_pkey_reg() version so we do not do shadow_pkey_reg * checking */ dprintf1("signal pkey_reg from pkey_reg: "PKEY_REG_FMT"\n", __read_pkey_reg()); - dprintf1("pkey from siginfo: %jx\n", siginfo_pkey); - *(u64 *)pkey_reg_ptr = 0x00000000; +#if defined(__i386__) || defined(__x86_64__) /* arch */ + dprintf1("signal pkey_reg from xsave: "PKEY_REG_FMT"\n", *pkey_reg_ptr); + *(u64 *)pkey_reg_ptr &= clear_pkey_flags(siginfo_pkey, + PKEY_DISABLE_ACCESS | PKEY_DISABLE_WRITE); +#elif __powerpc64__ + pkey_access_allow(siginfo_pkey); +#endif + shadow_pkey_reg &= clear_pkey_flags(siginfo_pkey, + PKEY_DISABLE_ACCESS | PKEY_DISABLE_WRITE); dprintf1("WARNING: set PKEY_REG=0 to allow faulting instruction " "to continue\n"); pkey_faults++; @@ -1328,9 +1338,8 @@ void test_executing_on_unreadable_memory(int *ptr, u16 pkey) madvise(p1, PAGE_SIZE, MADV_DONTNEED); lots_o_noops_around_write(&scratch); do_not_expect_pkey_fault("executing on PROT_EXEC memory"); - ptr_contents = read_ptr(p1); - dprintf2("ptr (%p) contents@%d: %x\n", p1, __LINE__, ptr_contents); - expected_pkey_fault(pkey); + + expect_fault_on_read_execonly_key(p1, pkey); } void test_implicit_mprotect_exec_only_memory(int *ptr, u16 pkey) @@ -1357,9 +1366,8 @@ void test_implicit_mprotect_exec_only_memory(int *ptr, u16 pkey) madvise(p1, PAGE_SIZE, MADV_DONTNEED); lots_o_noops_around_write(&scratch); do_not_expect_pkey_fault("executing on PROT_EXEC memory"); - ptr_contents = read_ptr(p1); - dprintf2("ptr (%p) contents@%d: %x\n", p1, __LINE__, ptr_contents); - expected_pkey_fault(UNKNOWN_PKEY); + + expect_fault_on_read_execonly_key(p1, UNKNOWN_PKEY); /* * Put the memory back to non-PROT_EXEC. Should clear the