Subject: [PATCH v12 13/22] selftests/vm: powerpc implementation for generic abstraction

From: Ram Pai <[email-masked]>
Date: Wed, 21 Feb 2018 17:55:32 -0800

Introduce powerpc implementation for the various
abstractions.

cc: Dave Hansen <[email-masked]>
cc: Florian Weimer <[email-masked]>
Signed-off-by: Ram Pai <[email-masked]>
---
 tools/testing/selftests/vm/pkey-helpers.h    |  128 ++++++++++++++++++++++----
 tools/testing/selftests/vm/protection_keys.c |   42 +++++---
 2 files changed, 136 insertions(+), 34 deletions(-)

diff --git a/tools/testing/selftests/vm/pkey-helpers.h b/tools/testing/selftests/vm/pkey-helpers.h
index c8f5739..c47aead 100644
--- a/tools/testing/selftests/vm/pkey-helpers.h
+++ b/tools/testing/selftests/vm/pkey-helpers.h
@@ -18,27 +18,51 @@
 #define u16 uint16_t
 #define u32 uint32_t
 #define u64 uint64_t
-#define pkey_reg_t u32
 
-#ifdef __i386__
+#if defined(__i386__) || defined(__x86_64__) /* arch */
+
+#ifdef __i386__ /* arch */
 #define SYS_mprotect_key 380
-#define SYS_pkey_alloc	 381
-#define SYS_pkey_free	 382
+#define SYS_pkey_alloc   381
+#define SYS_pkey_free    382
 #define REG_IP_IDX REG_EIP
-#define si_pkey_offset 0x14
-#else
+#elif __x86_64__
 #define SYS_mprotect_key 329
-#define SYS_pkey_alloc	 330
-#define SYS_pkey_free	 331
+#define SYS_pkey_alloc   330
+#define SYS_pkey_free    331
 #define REG_IP_IDX REG_RIP
-#define si_pkey_offset 0x20
-#endif
+#endif /* __x86_64__ */
+
+#define NR_PKEYS		16
+#define NR_RESERVED_PKEYS	1
+#define PKEY_BITS_PER_PKEY	2
+#define PKEY_DISABLE_ACCESS	0x1
+#define PKEY_DISABLE_WRITE	0x2
+#define HPAGE_SIZE		(1UL<<21)
+#define pkey_reg_t u32
 
-#define NR_PKEYS 16
-#define PKEY_BITS_PER_PKEY 2
-#define PKEY_DISABLE_ACCESS    0x1
-#define PKEY_DISABLE_WRITE     0x2
-#define HPAGE_SIZE	(1UL<<21)
+#elif __powerpc64__ /* arch */
+
+#define SYS_mprotect_key 386
+#define SYS_pkey_alloc	 384
+#define SYS_pkey_free	 385
+#define REG_IP_IDX PT_NIP
+#define REG_TRAPNO PT_TRAP
+#define gregs gp_regs
+#define fpregs fp_regs
+
+#define NR_PKEYS		32
+#define NR_RESERVED_PKEYS_4K	26
+#define NR_RESERVED_PKEYS_64K	3
+#define PKEY_BITS_PER_PKEY	2
+#define PKEY_DISABLE_ACCESS	0x3  /* disable read and write */
+#define PKEY_DISABLE_WRITE	0x2
+#define HPAGE_SIZE		(1UL<<24)
+#define pkey_reg_t u64
+
+#else /* arch */
+	NOT SUPPORTED
+#endif /* arch */
 
 #ifndef DEBUG_LEVEL
 #define DEBUG_LEVEL 0
@@ -47,7 +71,11 @@
 
 static inline u32 pkey_to_shift(int pkey)
 {
+#if defined(__i386__) || defined(__x86_64__) /* arch */
 	return pkey * PKEY_BITS_PER_PKEY;
+#elif __powerpc64__ /* arch */
+	return (NR_PKEYS - pkey - 1) * PKEY_BITS_PER_PKEY;
+#endif /* arch */
 }
 
 static inline pkey_reg_t reset_bits(int pkey, pkey_reg_t bits)
@@ -111,6 +139,7 @@ static inline void sigsafe_printf(const char *format, ...)
 extern pkey_reg_t shadow_pkey_reg;
 static inline pkey_reg_t __rdpkey_reg(void)
 {
+#if defined(__i386__) || defined(__x86_64__) /* arch */
 	unsigned int eax, edx;
 	unsigned int ecx = 0;
 	pkey_reg_t pkey_reg;
@@ -118,7 +147,13 @@ static inline pkey_reg_t __rdpkey_reg(void)
 	asm volatile(".byte 0x0f,0x01,0xee\n\t"
 		     : "=a" (eax), "=d" (edx)
 		     : "c" (ecx));
-	pkey_reg = eax;
+#elif __powerpc64__ /* arch */
+	pkey_reg_t eax;
+	pkey_reg_t pkey_reg;
+
+	asm volatile("mfspr %0, 0xd" : "=r" ((pkey_reg_t)(eax)));
+#endif /* arch */
+	pkey_reg = (pkey_reg_t)eax;
 	return pkey_reg;
 }
 
@@ -138,6 +173,7 @@ static inline pkey_reg_t _rdpkey_reg(int line)
 static inline void __wrpkey_reg(pkey_reg_t pkey_reg)
 {
 	pkey_reg_t eax = pkey_reg;
+#if defined(__i386__) || defined(__x86_64__) /* arch */
 	pkey_reg_t ecx = 0;
 	pkey_reg_t edx = 0;
 
@@ -146,6 +182,14 @@ static inline void __wrpkey_reg(pkey_reg_t pkey_reg)
 	asm volatile(".byte 0x0f,0x01,0xef\n\t"
 		     : : "a" (eax), "c" (ecx), "d" (edx));
 	assert(pkey_reg == __rdpkey_reg());
+
+#elif __powerpc64__ /* arch */
+	dprintf4("%s() changing %llx to %llx\n",
+			 __func__, __rdpkey_reg(), pkey_reg);
+	asm volatile("mtspr 0xd, %0" : : "r" ((unsigned long)(eax)) : "memory");
+#endif /* arch */
+	dprintf4("%s() pkey register after changing %016lx to %016lx\n",
+			 __func__, __rdpkey_reg(), pkey_reg);
 }
 
 static inline void wrpkey_reg(pkey_reg_t pkey_reg)
@@ -192,6 +236,8 @@ static inline void __pkey_write_allow(int pkey, int do_allow_write)
 	dprintf4("pkey_reg now: %08x\n", rdpkey_reg());
 }
 
+#if defined(__i386__) || defined(__x86_64__) /* arch */
+
 #define PAGE_SIZE 4096
 #define MB	(1<<20)
 
@@ -274,8 +320,18 @@ static inline void __page_o_noops(void)
 	/* 8-bytes of instruction * 512 bytes = 1 page */
 	asm(".rept 512 ; nopl 0x7eeeeeee(%eax) ; .endr");
 }
+#elif __powerpc64__ /* arch */
 
-#endif /* _PKEYS_HELPER_H */
+#define PAGE_SIZE (0x1UL << 16)
+static inline int cpu_has_pku(void)
+{
+	return 1;
+}
+
+/* 8-bytes of instruction * 16384bytes = 1 page */
+#define __page_o_noops() asm(".rept 16384 ; nop; .endr")
+
+#endif /* arch */
 
 #define ARRAY_SIZE(x) (sizeof(x) / sizeof(*(x)))
 #define ALIGN_UP(x, align_to)	(((x) + ((align_to)-1)) & ~((align_to)-1))
@@ -307,11 +363,47 @@ static inline void __page_o_noops(void)
 
 static inline int open_hugepage_file(int flag)
 {
-	return open("/sys/kernel/mm/hugepages/hugepages-2048kB/nr_hugepages",
+	int fd;
+
+#if defined(__i386__) || defined(__x86_64__) /* arch */
+	fd = open("/sys/kernel/mm/hugepages/hugepages-2048kB/nr_hugepages",
 		 O_RDONLY);
+#elif __powerpc64__ /* arch */
+	fd = open("/sys/kernel/mm/hugepages/hugepages-16384kB/nr_hugepages",
+		O_RDONLY);
+#else /* arch */
+	NOT SUPPORTED
+#endif /* arch */
+	return fd;
 }
 
 static inline int get_start_key(void)
 {
+#if defined(__i386__) || defined(__x86_64__) /* arch */
 	return 1;
+#elif __powerpc64__ /* arch */
+	return 0;
+#else /* arch */
+	NOT SUPPORTED
+#endif /* arch */
+}
+
+static inline u32 *siginfo_get_pkey_ptr(siginfo_t *si)
+{
+#ifdef si_pkey
+	return &si->si_pkey;
+#else
+
+#ifdef __i386__ /* arch */
+#define si_pkey_offset 0x14
+#elif __x86_64__ /*arch */
+#define si_pkey_offset 0x1C
+#elif __powerpc64__ /*arch */
+#define si_pkey_offset 0x1C
+#endif /*arch */
+
+	return (u32 *)(((u8 *)si) + si_pkey_offset);
+#endif
 }
+
+#endif /* _PKEYS_HELPER_H */
diff --git a/tools/testing/selftests/vm/protection_keys.c b/tools/testing/selftests/vm/protection_keys.c
index 6fdd8f5..c4c73e6 100644
--- a/tools/testing/selftests/vm/protection_keys.c
+++ b/tools/testing/selftests/vm/protection_keys.c
@@ -186,17 +186,18 @@ 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");
@@ -206,12 +207,14 @@ 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
@@ -219,22 +222,23 @@ 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__) */
 
-	si_pkey_ptr = (u32 *)(((u8 *)si) + si_pkey_offset);
+	dprintf1("siginfo: %p\n", si);
+	dprintf1(" fpregs: %p\n", fpregs);
+
+	si_pkey_ptr = siginfo_get_pkey_ptr(si);
 	dprintf1("si_pkey_ptr: %p\n", si_pkey_ptr);
 	dump_mem(si_pkey_ptr - 8, 24);
 	siginfo_pkey = *si_pkey_ptr;
@@ -248,19 +252,25 @@ void signal_handler(int signum, siginfo_t *si, void *vucontext)
 		exit(4);
 	}
 
-	dprintf1("signal pkey_reg from xsave: %016lx\n", *pkey_reg_ptr);
 	/*
 	 * need __rdpkey_reg() version so we do not do shadow_pkey_reg
 	 * checking
 	 */
 	dprintf1("signal pkey_reg from  pkey_reg: %016lx\n", __rdpkey_reg());
-	dprintf1("pkey from siginfo: %jx\n", siginfo_pkey);
-	*(u64 *)pkey_reg_ptr = 0x00000000;
+	dprintf1("pkey from siginfo: %lx\n", siginfo_pkey);
+#if defined(__i386__) || defined(__x86_64__) /* arch */
+	dprintf1("signal pkey_reg from xsave: %016lx\n", *pkey_reg_ptr);
+	*(u64 *)pkey_reg_ptr &= reset_bits(siginfo_pkey,
+			PKEY_DISABLE_ACCESS | PKEY_DISABLE_WRITE);
+#elif __powerpc64__
+	pkey_access_allow(siginfo_pkey);
+#endif
+	shadow_pkey_reg &= reset_bits(siginfo_pkey,
+			PKEY_DISABLE_ACCESS | PKEY_DISABLE_WRITE);
 	dprintf1("WARNING: set PKEY_REG=0 to allow faulting instruction "
 			"to continue\n");
 	pkey_faults++;
 	dprintf1("<<<<==================================================\n");
-	return;
 }
 
 int wait_all_children(void)
-- 
1.7.1