Merge branch 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm

Pull ARM updates from Russell King:

 - add support for ftrace-with-registers, which is needed for kgraft and
   other ftrace tools

 - support for mremap() for the sigpage/vDSO so that checkpoint/restore
   can work

 - add timestamps to each line of the register dump output

 - remove the unused KTHREAD_SIZE from nommu

 - align the ARM bitops APIs with the generic API (using unsigned long
   pointers rather than void pointers)

 - make the configuration of userspace Thumb support an expert option so
   that we can default it on, and avoid some hard to debug userspace
   crashes

* 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm:
  ARM: 8684/1: NOMMU: Remove unused KTHREAD_SIZE definition
  ARM: 8683/1: ARM32: Support mremap() for sigpage/vDSO
  ARM: 8679/1: bitops: Align prototypes to generic API
  ARM: 8678/1: ftrace: Adds support for CONFIG_DYNAMIC_FTRACE_WITH_REGS
  ARM: make configuration of userspace Thumb support an expert option
  ARM: 8673/1: Fix __show_regs output timestamps

11 files changed, 185 insertions, 18 deletions

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 0b731e8ab17e..a208bfe367b5 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -58,6 +58,7 @@ config ARM
         select HAVE_DMA_API_DEBUG
         select HAVE_DMA_CONTIGUOUS if MMU
         select HAVE_DYNAMIC_FTRACE if (!XIP_KERNEL) && !CPU_ENDIAN_BE32 && MMU
+        select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE
         select HAVE_EFFICIENT_UNALIGNED_ACCESS if (CPU_V6 || CPU_V6K || CPU_V7) && MMU
         select HAVE_EXIT_THREAD
         select HAVE_FTRACE_MCOUNT_RECORD if (!XIP_KERNEL)
diff --git a/arch/arm/include/asm/bitops.h b/arch/arm/include/asm/bitops.h
index e943e6cee254..f308c8c40cb9 100644
--- a/arch/arm/include/asm/bitops.h
+++ b/arch/arm/include/asm/bitops.h
@@ -159,16 +159,16 @@ extern int _test_and_change_bit(int nr, volatile unsigned long * p);
 /*
  * Little endian assembly bitops.  nr = 0 -> byte 0 bit 0.
  */
-extern int _find_first_zero_bit_le(const void * p, unsigned size);
-extern int _find_next_zero_bit_le(const void * p, int size, int offset);
+extern int _find_first_zero_bit_le(const unsigned long *p, unsigned size);
+extern int _find_next_zero_bit_le(const unsigned long *p, int size, int offset);
 extern int _find_first_bit_le(const unsigned long *p, unsigned size);
 extern int _find_next_bit_le(const unsigned long *p, int size, int offset);
 
 /*
  * Big endian assembly bitops.  nr = 0 -> byte 3 bit 0.
  */
-extern int _find_first_zero_bit_be(const void * p, unsigned size);
-extern int _find_next_zero_bit_be(const void * p, int size, int offset);
+extern int _find_first_zero_bit_be(const unsigned long *p, unsigned size);
+extern int _find_next_zero_bit_be(const unsigned long *p, int size, int offset);
 extern int _find_first_bit_be(const unsigned long *p, unsigned size);
 extern int _find_next_bit_be(const unsigned long *p, int size, int offset);
 
diff --git a/arch/arm/include/asm/ftrace.h b/arch/arm/include/asm/ftrace.h
index 22b73112b75f..f379881d5cc3 100644
--- a/arch/arm/include/asm/ftrace.h
+++ b/arch/arm/include/asm/ftrace.h
@@ -1,6 +1,10 @@
 #ifndef _ASM_ARM_FTRACE
 #define _ASM_ARM_FTRACE
 
+#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
+#define ARCH_SUPPORTS_FTRACE_OPS 1
+#endif
+
 #ifdef CONFIG_FUNCTION_TRACER
 #define MCOUNT_ADDR             ((unsigned long)(__gnu_mcount_nc))
 #define MCOUNT_INSN_SIZE        4 /* sizeof mcount call */
diff --git a/arch/arm/include/asm/page-nommu.h b/arch/arm/include/asm/page-nommu.h
index 503f488053de..8f2c47bec375 100644
--- a/arch/arm/include/asm/page-nommu.h
+++ b/arch/arm/include/asm/page-nommu.h
@@ -11,12 +11,6 @@
 #ifndef _ASMARM_PAGE_NOMMU_H
 #define _ASMARM_PAGE_NOMMU_H
 
-#if !defined(CONFIG_SMALL_TASKS) && PAGE_SHIFT < 13
-#define KTHREAD_SIZE (8192)
-#else
-#define KTHREAD_SIZE PAGE_SIZE
-#endif
- 
 #define clear_page(page)        memset((page), 0, PAGE_SIZE)
 #define copy_page(to,from)      memcpy((to), (from), PAGE_SIZE)
 
diff --git a/arch/arm/kernel/entry-ftrace.S b/arch/arm/kernel/entry-ftrace.S
index c73c4030ca5d..efcd9f25a14b 100644
--- a/arch/arm/kernel/entry-ftrace.S
+++ b/arch/arm/kernel/entry-ftrace.S
@@ -92,12 +92,95 @@
 2:      mcount_exit
 .endm
 
+#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
+
+.macro __ftrace_regs_caller
+
+        sub     sp, sp, #8      @ space for PC and CPSR OLD_R0,
+                                @ OLD_R0 will overwrite previous LR
+
+        add     ip, sp, #12     @ move in IP the value of SP as it was
+                                @ before the push {lr} of the mcount mechanism
+
+        str     lr, [sp, #0]    @ store LR instead of PC
+
+        ldr     lr, [sp, #8]    @ get previous LR
+
+        str     r0, [sp, #8]    @ write r0 as OLD_R0 over previous LR
+
+        stmdb   sp!, {ip, lr}
+        stmdb   sp!, {r0-r11, lr}
+
+        @ stack content at this point:
+        @ 0  4          48   52       56            60   64    68       72
+        @ R0 | R1 | ... | LR | SP + 4 | previous LR | LR | PSR | OLD_R0 |
+
+        mov r3, sp                              @ struct pt_regs*
+
+        ldr r2, =function_trace_op
+        ldr r2, [r2]                            @ pointer to the current
+                                                @ function tracing op
+
+        ldr     r1, [sp, #S_LR]                 @ lr of instrumented func
+
+        ldr     lr, [sp, #S_PC]                 @ get LR
+
+        mcount_adjust_addr      r0, lr          @ instrumented function
+
+        .globl ftrace_regs_call
+ftrace_regs_call:
+        bl      ftrace_stub
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+        .globl ftrace_graph_regs_call
+ftrace_graph_regs_call:
+        mov     r0, r0
+#endif
+
+        @ pop saved regs
+        ldmia   sp!, {r0-r12}                   @ restore r0 through r12
+        ldr     ip, [sp, #8]                    @ restore PC
+        ldr     lr, [sp, #4]                    @ restore LR
+        ldr     sp, [sp, #0]                    @ restore SP
+        mov     pc, ip                          @ return
+.endm
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+.macro __ftrace_graph_regs_caller
+
+        sub     r0, fp, #4              @ lr of instrumented routine (parent)
+
+        @ called from __ftrace_regs_caller
+        ldr     r1, [sp, #S_PC]         @ instrumented routine (func)
+        mcount_adjust_addr      r1, r1
+
+        mov     r2, fp                  @ frame pointer
+        bl      prepare_ftrace_return
+
+        @ pop registers saved in ftrace_regs_caller
+        ldmia   sp!, {r0-r12}                   @ restore r0 through r12
+        ldr     ip, [sp, #8]                    @ restore PC
+        ldr     lr, [sp, #4]                    @ restore LR
+        ldr     sp, [sp, #0]                    @ restore SP
+        mov     pc, ip                          @ return
+
+.endm
+#endif
+#endif
+
 .macro __ftrace_caller suffix
         mcount_enter
 
         mcount_get_lr   r1                      @ lr of instrumented func
         mcount_adjust_addr      r0, lr          @ instrumented function
 
+#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
+        ldr r2, =function_trace_op
+        ldr r2, [r2]                            @ pointer to the current
+                                                @ function tracing op
+        mov r3, #0                              @ regs is NULL
+#endif
+
         .globl ftrace_call\suffix
 ftrace_call\suffix:
         bl      ftrace_stub
@@ -212,6 +295,15 @@ UNWIND(.fnstart)
         __ftrace_caller
 UNWIND(.fnend)
 ENDPROC(ftrace_caller)
+
+#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
+ENTRY(ftrace_regs_caller)
+UNWIND(.fnstart)
+        __ftrace_regs_caller
+UNWIND(.fnend)
+ENDPROC(ftrace_regs_caller)
+#endif
+
 #endif
 
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
@@ -220,6 +312,14 @@ UNWIND(.fnstart)
         __ftrace_graph_caller
 UNWIND(.fnend)
 ENDPROC(ftrace_graph_caller)
+
+#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
+ENTRY(ftrace_graph_regs_caller)
+UNWIND(.fnstart)
+        __ftrace_graph_regs_caller
+UNWIND(.fnend)
+ENDPROC(ftrace_graph_regs_caller)
+#endif
 #endif
 
 .purgem mcount_enter
diff --git a/arch/arm/kernel/ftrace.c b/arch/arm/kernel/ftrace.c
index 833c991075a1..5617932a83df 100644
--- a/arch/arm/kernel/ftrace.c
+++ b/arch/arm/kernel/ftrace.c
@@ -141,6 +141,15 @@ int ftrace_update_ftrace_func(ftrace_func_t func)
 
         ret = ftrace_modify_code(pc, 0, new, false);
 
+#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
+        if (!ret) {
+                pc = (unsigned long)&ftrace_regs_call;
+                new = ftrace_call_replace(pc, (unsigned long)func);
+
+                ret = ftrace_modify_code(pc, 0, new, false);
+        }
+#endif
+
 #ifdef CONFIG_OLD_MCOUNT
         if (!ret) {
                 pc = (unsigned long)&ftrace_call_old;
@@ -159,11 +168,29 @@ int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
         unsigned long ip = rec->ip;
 
         old = ftrace_nop_replace(rec);
+
+        new = ftrace_call_replace(ip, adjust_address(rec, addr));
+
+        return ftrace_modify_code(rec->ip, old, new, true);
+}
+
+#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
+
+int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
+                                unsigned long addr)
+{
+        unsigned long new, old;
+        unsigned long ip = rec->ip;
+
+        old = ftrace_call_replace(ip, adjust_address(rec, old_addr));
+
         new = ftrace_call_replace(ip, adjust_address(rec, addr));
 
         return ftrace_modify_code(rec->ip, old, new, true);
 }
 
+#endif
+
 int ftrace_make_nop(struct module *mod,
                     struct dyn_ftrace *rec, unsigned long addr)
 {
@@ -231,6 +258,8 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
 extern unsigned long ftrace_graph_call;
 extern unsigned long ftrace_graph_call_old;
 extern void ftrace_graph_caller_old(void);
+extern unsigned long ftrace_graph_regs_call;
+extern void ftrace_graph_regs_caller(void);
 
 static int __ftrace_modify_caller(unsigned long *callsite,
                                   void (*func) (void), bool enable)
@@ -253,6 +282,14 @@ static int ftrace_modify_graph_caller(bool enable)
                                      ftrace_graph_caller,
                                      enable);
 
+#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
+        if (!ret)
+                ret = __ftrace_modify_caller(&ftrace_graph_regs_call,
+                                     ftrace_graph_regs_caller,
+                                     enable);
+#endif
+
+
 #ifdef CONFIG_OLD_MCOUNT
         if (!ret)
                 ret = __ftrace_modify_caller(&ftrace_graph_call_old,
diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
index 939e8b58c59d..d96714e1858c 100644
--- a/arch/arm/kernel/process.c
+++ b/arch/arm/kernel/process.c
@@ -123,10 +123,10 @@ void __show_regs(struct pt_regs *regs)
 
         print_symbol("PC is at %s\n", instruction_pointer(regs));
         print_symbol("LR is at %s\n", regs->ARM_lr);
-        printk("pc : [<%08lx>]    lr : [<%08lx>]    psr: %08lx\n"
-               "sp : %08lx  ip : %08lx  fp : %08lx\n",
-                regs->ARM_pc, regs->ARM_lr, regs->ARM_cpsr,
-                regs->ARM_sp, regs->ARM_ip, regs->ARM_fp);
+        printk("pc : [<%08lx>]    lr : [<%08lx>]    psr: %08lx\n",
+               regs->ARM_pc, regs->ARM_lr, regs->ARM_cpsr);
+        printk("sp : %08lx  ip : %08lx  fp : %08lx\n",
+               regs->ARM_sp, regs->ARM_ip, regs->ARM_fp);
         printk("r10: %08lx  r9 : %08lx  r8 : %08lx\n",
                 regs->ARM_r10, regs->ARM_r9,
                 regs->ARM_r8);
@@ -404,9 +404,17 @@ static unsigned long sigpage_addr(const struct mm_struct *mm,
 static struct page *signal_page;
 extern struct page *get_signal_page(void);
 
+static int sigpage_mremap(const struct vm_special_mapping *sm,
+                struct vm_area_struct *new_vma)
+{
+        current->mm->context.sigpage = new_vma->vm_start;
+        return 0;
+}
+
 static const struct vm_special_mapping sigpage_mapping = {
         .name = "[sigpage]",
         .pages = &signal_page,
+        .mremap = sigpage_mremap,
 };
 
 int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
diff --git a/arch/arm/kernel/vdso.c b/arch/arm/kernel/vdso.c
index 53cf86cf2d1a..a4d6dc0f2427 100644
--- a/arch/arm/kernel/vdso.c
+++ b/arch/arm/kernel/vdso.c
@@ -54,8 +54,26 @@ static const struct vm_special_mapping vdso_data_mapping = {
         .pages = &vdso_data_page,
 };
 
+static int vdso_mremap(const struct vm_special_mapping *sm,
+                struct vm_area_struct *new_vma)
+{
+        unsigned long new_size = new_vma->vm_end - new_vma->vm_start;
+        unsigned long vdso_size;
+
+        /* without VVAR page */
+        vdso_size = (vdso_total_pages - 1) << PAGE_SHIFT;
+
+        if (vdso_size != new_size)
+                return -EINVAL;
+
+        current->mm->context.vdso = new_vma->vm_start;
+
+        return 0;
+}
+
 static struct vm_special_mapping vdso_text_mapping __ro_after_init = {
         .name = "[vdso]",
+        .mremap = vdso_mremap,
 };
 
 struct elfinfo {
diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig
index 877a0e3fd17d..60cdfdc151aa 100644
--- a/arch/arm/mm/Kconfig
+++ b/arch/arm/mm/Kconfig
@@ -679,7 +679,7 @@ config ARCH_DMA_ADDR_T_64BIT
         bool
 
 config ARM_THUMB
-        bool "Support Thumb user binaries" if !CPU_THUMBONLY
+        bool "Support Thumb user binaries" if !CPU_THUMBONLY && EXPERT
         depends on CPU_THUMB_CAPABLE
         default y
         help
@@ -690,6 +690,10 @@ config ARM_THUMB
           instruction set resulting in smaller binaries at the expense of
           slightly less efficient code.
 
+          If this option is disabled, and you run userspace that switches to
+          Thumb mode, signal handling will not work correctly, resulting in
+          segmentation faults or illegal instruction aborts.
+
           If you don't know what this all is, saying Y is a safe choice.
 
 config ARM_THUMBEE
diff --git a/arch/x86/entry/vdso/vma.c b/arch/x86/entry/vdso/vma.c
index 139ad7726e10..726355ce8497 100644
--- a/arch/x86/entry/vdso/vma.c
+++ b/arch/x86/entry/vdso/vma.c
@@ -78,9 +78,6 @@ static int vdso_mremap(const struct vm_special_mapping *sm,
         if (image->size != new_size)
                 return -EINVAL;
 
-        if (WARN_ON_ONCE(current->mm != new_vma->vm_mm))
-                return -EFAULT;
-
         vdso_fix_landing(image, new_vma);
         current->mm->context.vdso = (void __user *)new_vma->vm_start;
 
diff --git a/mm/mmap.c b/mm/mmap.c
index 5a0ba9788cdd..7f8cfe9d9b4d 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -3186,8 +3186,12 @@ static int special_mapping_mremap(struct vm_area_struct *new_vma)
 {
         struct vm_special_mapping *sm = new_vma->vm_private_data;
 
+        if (WARN_ON_ONCE(current->mm != new_vma->vm_mm))
+                return -EFAULT;
+
         if (sm->mremap)
                 return sm->mremap(sm, new_vma);
+
         return 0;
 }