From 34f2c0ac111aaf090c7d2432dab532640870733a Mon Sep 17 00:00:00 2001 From: Paul Gortmaker Date: Sun, 1 Apr 2012 16:38:46 -0400 Subject: tile: fix multiple build failures from system.h dismantle Commit bd119c69239322caafdb64517a806037d0d0c70a "Disintegrate asm/system.h for Tile" created the asm/switch_to.h file, but did not add an include of it to all its users. Also, commit b4816afa3986704d1404fc48e931da5135820472 "Move the asm-generic/system.h xchg() implementation to asm-generic/cmpxchg.h" introduced the concept of asm/cmpxchg.h but the tile arch never got one. Fork the cmpxchg content out of the asm/atomic.h file to create one. Acked-by: David Howells Signed-off-by: Paul Gortmaker Signed-off-by: Chris Metcalf --- arch/tile/include/asm/atomic.h | 50 ++-------------------------- arch/tile/include/asm/cmpxchg.h | 73 +++++++++++++++++++++++++++++++++++++++++ 2 files changed, 75 insertions(+), 48 deletions(-) create mode 100644 arch/tile/include/asm/cmpxchg.h (limited to 'arch/tile/include') diff --git a/arch/tile/include/asm/atomic.h b/arch/tile/include/asm/atomic.h index bb696da5d7c..f2461429a4a 100644 --- a/arch/tile/include/asm/atomic.h +++ b/arch/tile/include/asm/atomic.h @@ -17,6 +17,8 @@ #ifndef _ASM_TILE_ATOMIC_H #define _ASM_TILE_ATOMIC_H +#include + #ifndef __ASSEMBLY__ #include @@ -121,54 +123,6 @@ static inline int atomic_read(const atomic_t *v) */ #define atomic_add_negative(i, v) (atomic_add_return((i), (v)) < 0) -/* Nonexistent functions intended to cause link errors. */ -extern unsigned long __xchg_called_with_bad_pointer(void); -extern unsigned long __cmpxchg_called_with_bad_pointer(void); - -#define xchg(ptr, x) \ - ({ \ - typeof(*(ptr)) __x; \ - switch (sizeof(*(ptr))) { \ - case 4: \ - __x = (typeof(__x))(typeof(__x-__x))atomic_xchg( \ - (atomic_t *)(ptr), \ - (u32)(typeof((x)-(x)))(x)); \ - break; \ - case 8: \ - __x = (typeof(__x))(typeof(__x-__x))atomic64_xchg( \ - (atomic64_t *)(ptr), \ - (u64)(typeof((x)-(x)))(x)); \ - break; \ - default: \ - __xchg_called_with_bad_pointer(); \ - } \ - __x; \ - }) - -#define cmpxchg(ptr, o, n) \ - ({ \ - typeof(*(ptr)) __x; \ - switch (sizeof(*(ptr))) { \ - case 4: \ - __x = (typeof(__x))(typeof(__x-__x))atomic_cmpxchg( \ - (atomic_t *)(ptr), \ - (u32)(typeof((o)-(o)))(o), \ - (u32)(typeof((n)-(n)))(n)); \ - break; \ - case 8: \ - __x = (typeof(__x))(typeof(__x-__x))atomic64_cmpxchg( \ - (atomic64_t *)(ptr), \ - (u64)(typeof((o)-(o)))(o), \ - (u64)(typeof((n)-(n)))(n)); \ - break; \ - default: \ - __cmpxchg_called_with_bad_pointer(); \ - } \ - __x; \ - }) - -#define tas(ptr) (xchg((ptr), 1)) - #endif /* __ASSEMBLY__ */ #ifndef __tilegx__ diff --git a/arch/tile/include/asm/cmpxchg.h b/arch/tile/include/asm/cmpxchg.h new file mode 100644 index 00000000000..276f067e364 --- /dev/null +++ b/arch/tile/include/asm/cmpxchg.h @@ -0,0 +1,73 @@ +/* + * cmpxchg.h -- forked from asm/atomic.h with this copyright: + * + * Copyright 2010 Tilera Corporation. All Rights Reserved. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation, version 2. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or + * NON INFRINGEMENT. See the GNU General Public License for + * more details. + * + */ + +#ifndef _ASM_TILE_CMPXCHG_H +#define _ASM_TILE_CMPXCHG_H + +#ifndef __ASSEMBLY__ + +/* Nonexistent functions intended to cause link errors. */ +extern unsigned long __xchg_called_with_bad_pointer(void); +extern unsigned long __cmpxchg_called_with_bad_pointer(void); + +#define xchg(ptr, x) \ + ({ \ + typeof(*(ptr)) __x; \ + switch (sizeof(*(ptr))) { \ + case 4: \ + __x = (typeof(__x))(typeof(__x-__x))atomic_xchg( \ + (atomic_t *)(ptr), \ + (u32)(typeof((x)-(x)))(x)); \ + break; \ + case 8: \ + __x = (typeof(__x))(typeof(__x-__x))atomic64_xchg( \ + (atomic64_t *)(ptr), \ + (u64)(typeof((x)-(x)))(x)); \ + break; \ + default: \ + __xchg_called_with_bad_pointer(); \ + } \ + __x; \ + }) + +#define cmpxchg(ptr, o, n) \ + ({ \ + typeof(*(ptr)) __x; \ + switch (sizeof(*(ptr))) { \ + case 4: \ + __x = (typeof(__x))(typeof(__x-__x))atomic_cmpxchg( \ + (atomic_t *)(ptr), \ + (u32)(typeof((o)-(o)))(o), \ + (u32)(typeof((n)-(n)))(n)); \ + break; \ + case 8: \ + __x = (typeof(__x))(typeof(__x-__x))atomic64_cmpxchg( \ + (atomic64_t *)(ptr), \ + (u64)(typeof((o)-(o)))(o), \ + (u64)(typeof((n)-(n)))(n)); \ + break; \ + default: \ + __cmpxchg_called_with_bad_pointer(); \ + } \ + __x; \ + }) + +#define tas(ptr) (xchg((ptr), 1)) + +#endif /* __ASSEMBLY__ */ + +#endif /* _ASM_TILE_CMPXCHG_H */ -- cgit v1.2.3-70-g09d2 From 327e8b6b25588ab906856a4e506b28c59422f11b Mon Sep 17 00:00:00 2001 From: Chris Metcalf Date: Tue, 27 Mar 2012 14:04:57 -0400 Subject: arch/tile: fix typo in We aren't yet using this definition in the kernel, but fix it up before someone goes looking for it. Signed-off-by: Chris Metcalf --- arch/tile/include/arch/spr_def.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'arch/tile/include') diff --git a/arch/tile/include/arch/spr_def.h b/arch/tile/include/arch/spr_def.h index f548efeb2de..d6ba449b536 100644 --- a/arch/tile/include/arch/spr_def.h +++ b/arch/tile/include/arch/spr_def.h @@ -60,8 +60,8 @@ _concat4(SPR_IPI_EVENT_, CONFIG_KERNEL_PL,,) #define SPR_IPI_EVENT_RESET_K \ _concat4(SPR_IPI_EVENT_RESET_, CONFIG_KERNEL_PL,,) -#define SPR_IPI_MASK_SET_K \ - _concat4(SPR_IPI_MASK_SET_, CONFIG_KERNEL_PL,,) +#define SPR_IPI_EVENT_SET_K \ + _concat4(SPR_IPI_EVENT_SET_, CONFIG_KERNEL_PL,,) #define INT_IPI_K \ _concat4(INT_IPI_, CONFIG_KERNEL_PL,,) -- cgit v1.2.3-70-g09d2 From 07feea877d18453bbe4ad47fe2a365eebf56a7af Mon Sep 17 00:00:00 2001 From: Chris Metcalf Date: Tue, 27 Mar 2012 14:10:03 -0400 Subject: arch/tile: revert comment for atomic64_add_unless(). It still returns whether @v was not @u, not the old value, unlike __atomic_add_unless(). Signed-off-by: Chris Metcalf Acked-by: Arun Sharma --- arch/tile/include/asm/atomic_32.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/tile/include') diff --git a/arch/tile/include/asm/atomic_32.h b/arch/tile/include/asm/atomic_32.h index 466dc4a39a4..54d1da826f9 100644 --- a/arch/tile/include/asm/atomic_32.h +++ b/arch/tile/include/asm/atomic_32.h @@ -200,7 +200,7 @@ static inline u64 atomic64_add_return(u64 i, atomic64_t *v) * @u: ...unless v is equal to u. * * Atomically adds @a to @v, so long as @v was not already @u. - * Returns the old value of @v. + * Returns non-zero if @v was not @u, and zero otherwise. */ static inline u64 atomic64_add_unless(atomic64_t *v, u64 a, u64 u) { -- cgit v1.2.3-70-g09d2 From 664c100bce0070148131f8d49518015476c03cae Mon Sep 17 00:00:00 2001 From: Chris Metcalf Date: Tue, 27 Mar 2012 14:17:05 -0400 Subject: arch/tile: fix gcc 4.6 warnings in Fix some signedness and variable usage warnings in change_bit() and test_and_change_bit(). Signed-off-by: Chris Metcalf --- arch/tile/include/asm/bitops_64.h | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'arch/tile/include') diff --git a/arch/tile/include/asm/bitops_64.h b/arch/tile/include/asm/bitops_64.h index 58d021a9834..60b87ee54fb 100644 --- a/arch/tile/include/asm/bitops_64.h +++ b/arch/tile/include/asm/bitops_64.h @@ -38,10 +38,10 @@ static inline void clear_bit(unsigned nr, volatile unsigned long *addr) static inline void change_bit(unsigned nr, volatile unsigned long *addr) { - unsigned long old, mask = (1UL << (nr % BITS_PER_LONG)); - long guess, oldval; + unsigned long mask = (1UL << (nr % BITS_PER_LONG)); + unsigned long guess, oldval; addr += nr / BITS_PER_LONG; - old = *addr; + oldval = *addr; do { guess = oldval; oldval = atomic64_cmpxchg((atomic64_t *)addr, @@ -85,7 +85,7 @@ static inline int test_and_change_bit(unsigned nr, volatile unsigned long *addr) { unsigned long mask = (1UL << (nr % BITS_PER_LONG)); - long guess, oldval = *addr; + unsigned long guess, oldval; addr += nr / BITS_PER_LONG; oldval = *addr; do { -- cgit v1.2.3-70-g09d2 From cbe224705e573cead57c4d4bed0c91efb564a344 Mon Sep 17 00:00:00 2001 From: Chris Metcalf Date: Tue, 27 Mar 2012 15:21:00 -0400 Subject: arch/tile: use 0 for IRQ_RESCHEDULE instead of 1 This avoids assigning IRQ 0 to PCI devices, because we've seen that doesn't always work well. Signed-off-by: Chris Metcalf --- arch/tile/include/asm/irq.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/tile/include') diff --git a/arch/tile/include/asm/irq.h b/arch/tile/include/asm/irq.h index f80f8ceabc6..33cff9a3058 100644 --- a/arch/tile/include/asm/irq.h +++ b/arch/tile/include/asm/irq.h @@ -21,7 +21,7 @@ #define NR_IRQS 32 /* IRQ numbers used for linux IPIs. */ -#define IRQ_RESCHEDULE 1 +#define IRQ_RESCHEDULE 0 #define irq_canonicalize(irq) (irq) -- cgit v1.2.3-70-g09d2 From 5f639fdcd8c186c8128c616e94a7e7b159c968ae Mon Sep 17 00:00:00 2001 From: Chris Metcalf Date: Thu, 29 Mar 2012 14:06:14 -0400 Subject: arch/tile: various bugs in stack backtracer Fix a long-standing bug in the stack backtracer where we would print garbage to the console instead of kernel function names, if the kernel wasn't built with symbol support (e.g. mboot). Make sure to tag every line of userspace backtrace output if we actually have the mmap_sem, since that way if there's no tag, we know that it's because we couldn't trylock the semaphore. Stop doing a TLB flush and examining page tables during backtrace. Instead, just trust that __copy_from_user_inatomic() will properly fault and return a failure, which it should do in all cases. Fix a latent bug where the backtracer would directly examine a signal context in user space, rather than copying it safely to kernel memory first. This meant that a race with another thread could potentially have caused a kernel panic. Guard against unaligned sp when trying to restart backtrace at an interrupt or signal handler point in the kernel backtracer. Report kernel symbolic information for the call instruction rather than for the following instruction. We still report the actual numeric address corresponding to the instruction after the call, for the sake of consistency with the normal expectations for stack backtracers. Signed-off-by: Chris Metcalf --- arch/tile/include/asm/stack.h | 1 - arch/tile/kernel/stack.c | 231 ++++++++++++++++++++---------------------- 2 files changed, 112 insertions(+), 120 deletions(-) (limited to 'arch/tile/include') diff --git a/arch/tile/include/asm/stack.h b/arch/tile/include/asm/stack.h index 4d97a2db932..0e9d382a2d4 100644 --- a/arch/tile/include/asm/stack.h +++ b/arch/tile/include/asm/stack.h @@ -25,7 +25,6 @@ struct KBacktraceIterator { BacktraceIterator it; struct task_struct *task; /* task we are backtracing */ - pte_t *pgtable; /* page table for user space access */ int end; /* iteration complete. */ int new_context; /* new context is starting */ int profile; /* profiling, so stop on async intrpt */ diff --git a/arch/tile/kernel/stack.c b/arch/tile/kernel/stack.c index 0be6b0109ce..b2f44c28dda 100644 --- a/arch/tile/kernel/stack.c +++ b/arch/tile/kernel/stack.c @@ -21,9 +21,10 @@ #include #include #include +#include +#include #include #include -#include #include #include #include @@ -45,72 +46,23 @@ static int in_kernel_stack(struct KBacktraceIterator *kbt, unsigned long sp) return sp >= kstack_base && sp < kstack_base + THREAD_SIZE; } -/* Is address valid for reading? */ -static int valid_address(struct KBacktraceIterator *kbt, unsigned long address) -{ - HV_PTE *l1_pgtable = kbt->pgtable; - HV_PTE *l2_pgtable; - unsigned long pfn; - HV_PTE pte; - struct page *page; - - if (l1_pgtable == NULL) - return 0; /* can't read user space in other tasks */ - -#ifdef CONFIG_64BIT - /* Find the real l1_pgtable by looking in the l0_pgtable. */ - pte = l1_pgtable[HV_L0_INDEX(address)]; - if (!hv_pte_get_present(pte)) - return 0; - pfn = hv_pte_get_pfn(pte); - if (pte_huge(pte)) { - if (!pfn_valid(pfn)) { - pr_err("L0 huge page has bad pfn %#lx\n", pfn); - return 0; - } - return hv_pte_get_present(pte) && hv_pte_get_readable(pte); - } - page = pfn_to_page(pfn); - BUG_ON(PageHighMem(page)); /* No HIGHMEM on 64-bit. */ - l1_pgtable = (HV_PTE *)pfn_to_kaddr(pfn); -#endif - pte = l1_pgtable[HV_L1_INDEX(address)]; - if (!hv_pte_get_present(pte)) - return 0; - pfn = hv_pte_get_pfn(pte); - if (pte_huge(pte)) { - if (!pfn_valid(pfn)) { - pr_err("huge page has bad pfn %#lx\n", pfn); - return 0; - } - return hv_pte_get_present(pte) && hv_pte_get_readable(pte); - } - - page = pfn_to_page(pfn); - if (PageHighMem(page)) { - pr_err("L2 page table not in LOWMEM (%#llx)\n", - HV_PFN_TO_CPA(pfn)); - return 0; - } - l2_pgtable = (HV_PTE *)pfn_to_kaddr(pfn); - pte = l2_pgtable[HV_L2_INDEX(address)]; - return hv_pte_get_present(pte) && hv_pte_get_readable(pte); -} - /* Callback for backtracer; basically a glorified memcpy */ static bool read_memory_func(void *result, unsigned long address, unsigned int size, void *vkbt) { int retval; struct KBacktraceIterator *kbt = (struct KBacktraceIterator *)vkbt; + + if (address == 0) + return 0; if (__kernel_text_address(address)) { /* OK to read kernel code. */ } else if (address >= PAGE_OFFSET) { /* We only tolerate kernel-space reads of this task's stack */ if (!in_kernel_stack(kbt, address)) return 0; - } else if (!valid_address(kbt, address)) { - return 0; /* invalid user-space address */ + } else if (!kbt->is_current) { + return 0; /* can't read from other user address spaces */ } pagefault_disable(); retval = __copy_from_user_inatomic(result, @@ -128,6 +80,8 @@ static struct pt_regs *valid_fault_handler(struct KBacktraceIterator* kbt) unsigned long sp = kbt->it.sp; struct pt_regs *p; + if (sp % sizeof(long) != 0) + return NULL; if (!in_kernel_stack(kbt, sp)) return NULL; if (!in_kernel_stack(kbt, sp + C_ABI_SAVE_AREA_SIZE + PTREGS_SIZE-1)) @@ -170,27 +124,27 @@ static int is_sigreturn(unsigned long pc) } /* Return a pt_regs pointer for a valid signal handler frame */ -static struct pt_regs *valid_sigframe(struct KBacktraceIterator* kbt) +static struct pt_regs *valid_sigframe(struct KBacktraceIterator* kbt, + struct rt_sigframe* kframe) { BacktraceIterator *b = &kbt->it; - if (b->pc == VDSO_BASE) { - struct rt_sigframe *frame; - unsigned long sigframe_top = - b->sp + sizeof(struct rt_sigframe) - 1; - if (!valid_address(kbt, b->sp) || - !valid_address(kbt, sigframe_top)) { - if (kbt->verbose) - pr_err(" (odd signal: sp %#lx?)\n", - (unsigned long)(b->sp)); + if (b->pc == VDSO_BASE && b->sp < PAGE_OFFSET && + b->sp % sizeof(long) == 0) { + int retval; + pagefault_disable(); + retval = __copy_from_user_inatomic( + kframe, (void __user __force *)b->sp, + sizeof(*kframe)); + pagefault_enable(); + if (retval != 0 || + (unsigned int)(kframe->info.si_signo) >= _NSIG) return NULL; - } - frame = (struct rt_sigframe *)b->sp; if (kbt->verbose) { pr_err(" \n", - frame->info.si_signo); + kframe->info.si_signo); } - return (struct pt_regs *)&frame->uc.uc_mcontext; + return (struct pt_regs *)&kframe->uc.uc_mcontext; } return NULL; } @@ -203,10 +157,11 @@ static int KBacktraceIterator_is_sigreturn(struct KBacktraceIterator *kbt) static int KBacktraceIterator_restart(struct KBacktraceIterator *kbt) { struct pt_regs *p; + struct rt_sigframe kframe; p = valid_fault_handler(kbt); if (p == NULL) - p = valid_sigframe(kbt); + p = valid_sigframe(kbt, &kframe); if (p == NULL) return 0; backtrace_init(&kbt->it, read_memory_func, kbt, @@ -266,41 +221,19 @@ void KBacktraceIterator_init(struct KBacktraceIterator *kbt, /* * Set up callback information. We grab the kernel stack base - * so we will allow reads of that address range, and if we're - * asking about the current process we grab the page table - * so we can check user accesses before trying to read them. - * We flush the TLB to avoid any weird skew issues. + * so we will allow reads of that address range. */ - is_current = (t == NULL); + is_current = (t == NULL || t == current); kbt->is_current = is_current; if (is_current) t = validate_current(); kbt->task = t; - kbt->pgtable = NULL; kbt->verbose = 0; /* override in caller if desired */ kbt->profile = 0; /* override in caller if desired */ kbt->end = KBT_ONGOING; - kbt->new_context = 0; - if (is_current) { - HV_PhysAddr pgdir_pa = hv_inquire_context().page_table; - if (pgdir_pa == (unsigned long)swapper_pg_dir - PAGE_OFFSET) { - /* - * Not just an optimization: this also allows - * this to work at all before va/pa mappings - * are set up. - */ - kbt->pgtable = swapper_pg_dir; - } else { - struct page *page = pfn_to_page(PFN_DOWN(pgdir_pa)); - if (!PageHighMem(page)) - kbt->pgtable = __va(pgdir_pa); - else - pr_err("page table not in LOWMEM" - " (%#llx)\n", pgdir_pa); - } - local_flush_tlb_all(); + kbt->new_context = 1; + if (is_current) validate_stack(regs); - } if (regs == NULL) { if (is_current || t->state == TASK_RUNNING) { @@ -346,6 +279,78 @@ void KBacktraceIterator_next(struct KBacktraceIterator *kbt) } EXPORT_SYMBOL(KBacktraceIterator_next); +static void describe_addr(struct KBacktraceIterator *kbt, + unsigned long address, + int have_mmap_sem, char *buf, size_t bufsize) +{ + struct vm_area_struct *vma; + size_t namelen, remaining; + unsigned long size, offset, adjust; + char *p, *modname; + const char *name; + int rc; + + /* + * Look one byte back for every caller frame (i.e. those that + * aren't a new context) so we look up symbol data for the + * call itself, not the following instruction, which may be on + * a different line (or in a different function). + */ + adjust = !kbt->new_context; + address -= adjust; + + if (address >= PAGE_OFFSET) { + /* Handle kernel symbols. */ + BUG_ON(bufsize < KSYM_NAME_LEN); + name = kallsyms_lookup(address, &size, &offset, + &modname, buf); + if (name == NULL) { + buf[0] = '\0'; + return; + } + namelen = strlen(buf); + remaining = (bufsize - 1) - namelen; + p = buf + namelen; + rc = snprintf(p, remaining, "+%#lx/%#lx ", + offset + adjust, size); + if (modname && rc < remaining) + snprintf(p + rc, remaining - rc, "[%s] ", modname); + buf[bufsize-1] = '\0'; + return; + } + + /* If we don't have the mmap_sem, we can't show any more info. */ + buf[0] = '\0'; + if (!have_mmap_sem) + return; + + /* Find vma info. */ + vma = find_vma(kbt->task->mm, address); + if (vma == NULL || address < vma->vm_start) { + snprintf(buf, bufsize, "[unmapped address] "); + return; + } + + if (vma->vm_file) { + char *s; + p = d_path(&vma->vm_file->f_path, buf, bufsize); + if (IS_ERR(p)) + p = "?"; + s = strrchr(p, '/'); + if (s) + p = s+1; + } else { + p = "anon"; + } + + /* Generate a string description of the vma info. */ + namelen = strlen(p); + remaining = (bufsize - 1) - namelen; + memmove(buf, p, namelen); + snprintf(buf + namelen, remaining, "[%lx+%lx] ", + vma->vm_start, vma->vm_end - vma->vm_start); +} + /* * This method wraps the backtracer's more generic support. * It is only invoked from the architecture-specific code; show_stack() @@ -354,6 +359,7 @@ EXPORT_SYMBOL(KBacktraceIterator_next); void tile_show_stack(struct KBacktraceIterator *kbt, int headers) { int i; + int have_mmap_sem = 0; if (headers) { /* @@ -370,31 +376,16 @@ void tile_show_stack(struct KBacktraceIterator *kbt, int headers) kbt->verbose = 1; i = 0; for (; !KBacktraceIterator_end(kbt); KBacktraceIterator_next(kbt)) { - char *modname; - const char *name; - unsigned long address = kbt->it.pc; - unsigned long offset, size; char namebuf[KSYM_NAME_LEN+100]; + unsigned long address = kbt->it.pc; - if (address >= PAGE_OFFSET) - name = kallsyms_lookup(address, &size, &offset, - &modname, namebuf); - else - name = NULL; - - if (!name) - namebuf[0] = '\0'; - else { - size_t namelen = strlen(namebuf); - size_t remaining = (sizeof(namebuf) - 1) - namelen; - char *p = namebuf + namelen; - int rc = snprintf(p, remaining, "+%#lx/%#lx ", - offset, size); - if (modname && rc < remaining) - snprintf(p + rc, remaining - rc, - "[%s] ", modname); - namebuf[sizeof(namebuf)-1] = '\0'; - } + /* Try to acquire the mmap_sem as we pass into userspace. */ + if (address < PAGE_OFFSET && !have_mmap_sem && kbt->task->mm) + have_mmap_sem = + down_read_trylock(&kbt->task->mm->mmap_sem); + + describe_addr(kbt, address, have_mmap_sem, + namebuf, sizeof(namebuf)); pr_err(" frame %d: 0x%lx %s(sp 0x%lx)\n", i++, address, namebuf, (unsigned long)(kbt->it.sp)); @@ -409,6 +400,8 @@ void tile_show_stack(struct KBacktraceIterator *kbt, int headers) pr_err("Stack dump stopped; next frame identical to this one\n"); if (headers) pr_err("Stack dump complete\n"); + if (have_mmap_sem) + up_read(&kbt->task->mm->mmap_sem); } EXPORT_SYMBOL(tile_show_stack); -- cgit v1.2.3-70-g09d2 From e17235382dbb05f70146e141e4b780fd069050dc Mon Sep 17 00:00:00 2001 From: Chris Metcalf Date: Thu, 29 Mar 2012 14:52:00 -0400 Subject: arch/tile: work around a hardware issue with the return-address stack In certain circumstances we need to do a bunch of jump-and-link instructions to fill the hardware return-address stack with nonzero values. Signed-off-by: Chris Metcalf --- arch/tile/include/asm/traps.h | 6 +++++- arch/tile/kernel/intvec_64.S | 12 ++++++++++++ arch/tile/kernel/traps.c | 6 +++++- 3 files changed, 22 insertions(+), 2 deletions(-) (limited to 'arch/tile/include') diff --git a/arch/tile/include/asm/traps.h b/arch/tile/include/asm/traps.h index 5f20f920f93..e28c3df4176 100644 --- a/arch/tile/include/asm/traps.h +++ b/arch/tile/include/asm/traps.h @@ -64,7 +64,11 @@ void do_breakpoint(struct pt_regs *, int fault_num); #ifdef __tilegx__ +/* kernel/single_step.c */ void gx_singlestep_handle(struct pt_regs *, int fault_num); + +/* kernel/intvec_64.S */ +void fill_ra_stack(void); #endif -#endif /* _ASM_TILE_SYSCALLS_H */ +#endif /* _ASM_TILE_TRAPS_H */ diff --git a/arch/tile/kernel/intvec_64.S b/arch/tile/kernel/intvec_64.S index 79c93e10ba2..2c181c864ef 100644 --- a/arch/tile/kernel/intvec_64.S +++ b/arch/tile/kernel/intvec_64.S @@ -1156,6 +1156,18 @@ int_unalign: push_extra_callee_saves r0 j do_trap +/* Fill the return address stack with nonzero entries. */ +STD_ENTRY(fill_ra_stack) + { + move r0, lr + jal 1f + } +1: jal 2f +2: jal 3f +3: jal 4f +4: jrp r0 + STD_ENDPROC(fill_ra_stack) + /* Include .intrpt1 array of interrupt vectors */ .section ".intrpt1", "ax" diff --git a/arch/tile/kernel/traps.c b/arch/tile/kernel/traps.c index 2bb6602a1ee..32acfd9e23d 100644 --- a/arch/tile/kernel/traps.c +++ b/arch/tile/kernel/traps.c @@ -289,7 +289,10 @@ void __kprobes do_trap(struct pt_regs *regs, int fault_num, address = regs->pc; break; #ifdef __tilegx__ - case INT_ILL_TRANS: + case INT_ILL_TRANS: { + /* Avoid a hardware erratum with the return address stack. */ + fill_ra_stack(); + signo = SIGSEGV; code = SEGV_MAPERR; if (reason & SPR_ILL_TRANS_REASON__I_STREAM_VA_RMASK) @@ -297,6 +300,7 @@ void __kprobes do_trap(struct pt_regs *regs, int fault_num, else address = 0; /* FIXME: GX: single-step for address */ break; + } #endif default: panic("Unexpected do_trap interrupt number %d", fault_num); -- cgit v1.2.3-70-g09d2 From ab306cae660e524edbeb8889e4e23d3c97717b9c Mon Sep 17 00:00:00 2001 From: Chris Metcalf Date: Fri, 30 Mar 2012 15:46:29 -0400 Subject: arch/tile: use atomic exchange in arch_write_unlock() This idiom is used elsewhere when we do an unlock by writing a zero, but I missed it here. Using an atomic operation avoids waiting on the write buffer for the unlocking write to be sent to the home cache. Signed-off-by: Chris Metcalf --- arch/tile/include/asm/spinlock_64.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/tile/include') diff --git a/arch/tile/include/asm/spinlock_64.h b/arch/tile/include/asm/spinlock_64.h index 72be5904e02..5f8b6a095fd 100644 --- a/arch/tile/include/asm/spinlock_64.h +++ b/arch/tile/include/asm/spinlock_64.h @@ -137,7 +137,7 @@ static inline void arch_read_unlock(arch_rwlock_t *rw) static inline void arch_write_unlock(arch_rwlock_t *rw) { __insn_mf(); - rw->lock = 0; + __insn_exch4(&rw->lock, 0); /* Avoid waiting in the write buffer. */ } static inline int arch_read_trylock(arch_rwlock_t *rw) -- cgit v1.2.3-70-g09d2 From 05ef1b79d46347f94d9a78214cc745046c03e45a Mon Sep 17 00:00:00 2001 From: Chris Metcalf Date: Wed, 25 Apr 2012 12:45:26 -0400 Subject: arch/tile: fix a couple of functions that should be __init They were marked __devinit by mistake, causing some warnings at link time. Signed-off-by: Chris Metcalf --- arch/tile/include/asm/pci.h | 4 ++-- arch/tile/kernel/pci.c | 4 ++-- 2 files changed, 4 insertions(+), 4 deletions(-) (limited to 'arch/tile/include') diff --git a/arch/tile/include/asm/pci.h b/arch/tile/include/asm/pci.h index 5d5a635530b..32e6cbe8dff 100644 --- a/arch/tile/include/asm/pci.h +++ b/arch/tile/include/asm/pci.h @@ -47,8 +47,8 @@ struct pci_controller { */ #define PCI_DMA_BUS_IS_PHYS 1 -int __devinit tile_pci_init(void); -int __devinit pcibios_init(void); +int __init tile_pci_init(void); +int __init pcibios_init(void); static inline void pci_iounmap(struct pci_dev *dev, void __iomem *addr) {} diff --git a/arch/tile/kernel/pci.c b/arch/tile/kernel/pci.c index a1bb59eecc1..b56d12bf590 100644 --- a/arch/tile/kernel/pci.c +++ b/arch/tile/kernel/pci.c @@ -141,7 +141,7 @@ static int __devinit tile_init_irqs(int controller_id, * * Returns the number of controllers discovered. */ -int __devinit tile_pci_init(void) +int __init tile_pci_init(void) { int i; @@ -287,7 +287,7 @@ static void __devinit fixup_read_and_payload_sizes(void) * The controllers have been set up by the time we get here, by a call to * tile_pci_init. */ -int __devinit pcibios_init(void) +int __init pcibios_init(void) { int i; -- cgit v1.2.3-70-g09d2