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-rw-r--r--arch/arm64/include/asm/elf.h4
-rw-r--r--arch/arm64/include/asm/kgdb.h45
-rw-r--r--arch/arm64/include/asm/memory.h3
-rw-r--r--arch/arm64/include/asm/page.h12
-rw-r--r--arch/arm64/include/asm/spinlock.h42
-rw-r--r--arch/arm64/include/asm/uaccess.h13
-rw-r--r--arch/arm64/include/asm/unistd.h2
-rw-r--r--arch/arm64/include/asm/unistd32.h8
8 files changed, 89 insertions, 40 deletions
diff --git a/arch/arm64/include/asm/elf.h b/arch/arm64/include/asm/elf.h
index 7a09c48c0475..579b6e654f2d 100644
--- a/arch/arm64/include/asm/elf.h
+++ b/arch/arm64/include/asm/elf.h
@@ -160,14 +160,14 @@ extern int arch_setup_additional_pages(struct linux_binprm *bprm,
#define STACK_RND_MASK (0x3ffff >> (PAGE_SHIFT - 12))
#endif
-#ifdef CONFIG_COMPAT
-
#ifdef __AARCH64EB__
#define COMPAT_ELF_PLATFORM ("v8b")
#else
#define COMPAT_ELF_PLATFORM ("v8l")
#endif
+#ifdef CONFIG_COMPAT
+
#define COMPAT_ELF_ET_DYN_BASE (2 * TASK_SIZE_32 / 3)
/* AArch32 registers. */
diff --git a/arch/arm64/include/asm/kgdb.h b/arch/arm64/include/asm/kgdb.h
index f69f69c8120c..da84645525b9 100644
--- a/arch/arm64/include/asm/kgdb.h
+++ b/arch/arm64/include/asm/kgdb.h
@@ -38,25 +38,54 @@ extern int kgdb_fault_expected;
#endif /* !__ASSEMBLY__ */
/*
- * gdb is expecting the following registers layout.
+ * gdb remote procotol (well most versions of it) expects the following
+ * register layout.
*
* General purpose regs:
* r0-r30: 64 bit
* sp,pc : 64 bit
- * pstate : 64 bit
- * Total: 34
+ * pstate : 32 bit
+ * Total: 33 + 1
* FPU regs:
* f0-f31: 128 bit
- * Total: 32
- * Extra regs
* fpsr & fpcr: 32 bit
- * Total: 2
+ * Total: 32 + 2
*
+ * To expand a little on the "most versions of it"... when the gdb remote
+ * protocol for AArch64 was developed it depended on a statement in the
+ * Architecture Reference Manual that claimed "SPSR_ELx is a 32-bit register".
+ * and, as a result, allocated only 32-bits for the PSTATE in the remote
+ * protocol. In fact this statement is still present in ARM DDI 0487A.i.
+ *
+ * Unfortunately "is a 32-bit register" has a very special meaning for
+ * system registers. It means that "the upper bits, bits[63:32], are
+ * RES0.". RES0 is heavily used in the ARM architecture documents as a
+ * way to leave space for future architecture changes. So to translate a
+ * little for people who don't spend their spare time reading ARM architecture
+ * manuals, what "is a 32-bit register" actually means in this context is
+ * "is a 64-bit register but one with no meaning allocated to any of the
+ * upper 32-bits... *yet*".
+ *
+ * Perhaps then we should not be surprised that this has led to some
+ * confusion. Specifically a patch, influenced by the above translation,
+ * that extended PSTATE to 64-bit was accepted into gdb-7.7 but the patch
+ * was reverted in gdb-7.8.1 and all later releases, when this was
+ * discovered to be an undocumented protocol change.
+ *
+ * So... it is *not* wrong for us to only allocate 32-bits to PSTATE
+ * here even though the kernel itself allocates 64-bits for the same
+ * state. That is because this bit of code tells the kernel how the gdb
+ * remote protocol (well most versions of it) describes the register state.
+ *
+ * Note that if you are using one of the versions of gdb that supports
+ * the gdb-7.7 version of the protocol you cannot use kgdb directly
+ * without providing a custom register description (gdb can load new
+ * protocol descriptions at runtime).
*/
-#define _GP_REGS 34
+#define _GP_REGS 33
#define _FP_REGS 32
-#define _EXTRA_REGS 2
+#define _EXTRA_REGS 3
/*
* general purpose registers size in bytes.
* pstate is only 4 bytes. subtract 4 bytes
diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h
index 72a3025bb583..31b73227b41f 100644
--- a/arch/arm64/include/asm/memory.h
+++ b/arch/arm64/include/asm/memory.h
@@ -55,8 +55,9 @@
#define VMEMMAP_SIZE (UL(1) << (VA_BITS - PAGE_SHIFT - 1 + STRUCT_PAGE_MAX_SHIFT))
/*
- * PAGE_OFFSET - the virtual address of the start of the kernel image (top
+ * PAGE_OFFSET - the virtual address of the start of the linear map (top
* (VA_BITS - 1))
+ * KIMAGE_VADDR - the virtual address of the start of the kernel image
* VA_BITS - the maximum number of bits for virtual addresses.
* VA_START - the first kernel virtual address.
* TASK_SIZE - the maximum size of a user space task.
diff --git a/arch/arm64/include/asm/page.h b/arch/arm64/include/asm/page.h
index 17b45f7d96d3..8472c6def5ef 100644
--- a/arch/arm64/include/asm/page.h
+++ b/arch/arm64/include/asm/page.h
@@ -23,16 +23,8 @@
/* PAGE_SHIFT determines the page size */
/* CONT_SHIFT determines the number of pages which can be tracked together */
-#ifdef CONFIG_ARM64_64K_PAGES
-#define PAGE_SHIFT 16
-#define CONT_SHIFT 5
-#elif defined(CONFIG_ARM64_16K_PAGES)
-#define PAGE_SHIFT 14
-#define CONT_SHIFT 7
-#else
-#define PAGE_SHIFT 12
-#define CONT_SHIFT 4
-#endif
+#define PAGE_SHIFT CONFIG_ARM64_PAGE_SHIFT
+#define CONT_SHIFT CONFIG_ARM64_CONT_SHIFT
#define PAGE_SIZE (_AC(1, UL) << PAGE_SHIFT)
#define PAGE_MASK (~(PAGE_SIZE-1))
diff --git a/arch/arm64/include/asm/spinlock.h b/arch/arm64/include/asm/spinlock.h
index fc9682bfe002..e875a5a551d7 100644
--- a/arch/arm64/include/asm/spinlock.h
+++ b/arch/arm64/include/asm/spinlock.h
@@ -30,22 +30,53 @@ static inline void arch_spin_unlock_wait(arch_spinlock_t *lock)
{
unsigned int tmp;
arch_spinlock_t lockval;
+ u32 owner;
+
+ /*
+ * Ensure prior spin_lock operations to other locks have completed
+ * on this CPU before we test whether "lock" is locked.
+ */
+ smp_mb();
+ owner = READ_ONCE(lock->owner) << 16;
asm volatile(
" sevl\n"
"1: wfe\n"
"2: ldaxr %w0, %2\n"
+ /* Is the lock free? */
" eor %w1, %w0, %w0, ror #16\n"
-" cbnz %w1, 1b\n"
+" cbz %w1, 3f\n"
+ /* Lock taken -- has there been a subsequent unlock->lock transition? */
+" eor %w1, %w3, %w0, lsl #16\n"
+" cbz %w1, 1b\n"
+ /*
+ * The owner has been updated, so there was an unlock->lock
+ * transition that we missed. That means we can rely on the
+ * store-release of the unlock operation paired with the
+ * load-acquire of the lock operation to publish any of our
+ * previous stores to the new lock owner and therefore don't
+ * need to bother with the writeback below.
+ */
+" b 4f\n"
+"3:\n"
+ /*
+ * Serialise against any concurrent lockers by writing back the
+ * unlocked lock value
+ */
ARM64_LSE_ATOMIC_INSN(
/* LL/SC */
" stxr %w1, %w0, %2\n"
-" cbnz %w1, 2b\n", /* Serialise against any concurrent lockers */
- /* LSE atomics */
" nop\n"
-" nop\n")
+" nop\n",
+ /* LSE atomics */
+" mov %w1, %w0\n"
+" cas %w0, %w0, %2\n"
+" eor %w1, %w1, %w0\n")
+ /* Somebody else wrote to the lock, GOTO 10 and reload the value */
+" cbnz %w1, 2b\n"
+"4:"
: "=&r" (lockval), "=&r" (tmp), "+Q" (*lock)
- :
+ : "r" (owner)
: "memory");
}
@@ -148,6 +179,7 @@ static inline int arch_spin_value_unlocked(arch_spinlock_t lock)
static inline int arch_spin_is_locked(arch_spinlock_t *lock)
{
+ smp_mb(); /* See arch_spin_unlock_wait */
return !arch_spin_value_unlocked(READ_ONCE(*lock));
}
diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h
index 0685d74572af..9e397a542756 100644
--- a/arch/arm64/include/asm/uaccess.h
+++ b/arch/arm64/include/asm/uaccess.h
@@ -81,19 +81,6 @@ static inline void set_fs(mm_segment_t fs)
#define segment_eq(a, b) ((a) == (b))
/*
- * Return 1 if addr < current->addr_limit, 0 otherwise.
- */
-#define __addr_ok(addr) \
-({ \
- unsigned long flag; \
- asm("cmp %1, %0; cset %0, lo" \
- : "=&r" (flag) \
- : "r" (addr), "0" (current_thread_info()->addr_limit) \
- : "cc"); \
- flag; \
-})
-
-/*
* Test whether a block of memory is a valid user space address.
* Returns 1 if the range is valid, 0 otherwise.
*
diff --git a/arch/arm64/include/asm/unistd.h b/arch/arm64/include/asm/unistd.h
index 41e58fe3c041..e78ac26324bd 100644
--- a/arch/arm64/include/asm/unistd.h
+++ b/arch/arm64/include/asm/unistd.h
@@ -44,7 +44,7 @@
#define __ARM_NR_compat_cacheflush (__ARM_NR_COMPAT_BASE+2)
#define __ARM_NR_compat_set_tls (__ARM_NR_COMPAT_BASE+5)
-#define __NR_compat_syscalls 390
+#define __NR_compat_syscalls 394
#endif
#define __ARCH_WANT_SYS_CLONE
diff --git a/arch/arm64/include/asm/unistd32.h b/arch/arm64/include/asm/unistd32.h
index 5b925b761a2a..b7e8ef16ff0d 100644
--- a/arch/arm64/include/asm/unistd32.h
+++ b/arch/arm64/include/asm/unistd32.h
@@ -801,6 +801,14 @@ __SYSCALL(__NR_execveat, compat_sys_execveat)
__SYSCALL(__NR_userfaultfd, sys_userfaultfd)
#define __NR_membarrier 389
__SYSCALL(__NR_membarrier, sys_membarrier)
+#define __NR_mlock2 390
+__SYSCALL(__NR_mlock2, sys_mlock2)
+#define __NR_copy_file_range 391
+__SYSCALL(__NR_copy_file_range, sys_copy_file_range)
+#define __NR_preadv2 392
+__SYSCALL(__NR_preadv2, compat_sys_preadv2)
+#define __NR_pwritev2 393
+__SYSCALL(__NR_pwritev2, compat_sys_pwritev2)
/*
* Please add new compat syscalls above this comment and update