diff options
| author | Linus Torvalds <torvalds@linux-foundation.org> | 2018-04-02 20:20:12 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-04-02 20:20:12 -0700 |
| commit | f5a8eb632b562bd9c16c389f5db3a5260fba4157 (patch) | |
| tree | 82687234d772ff8f72a31e598fe16553885c56c9 /arch/tile/kernel/stack.c | |
| parent | c9297d284126b80c9cfd72c690e0da531c99fc48 (diff) | |
| parent | dd3b8c329aa270027fba61a02a12600972dc3983 (diff) | |
Merge tag 'arch-removal' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic
Pul removal of obsolete architecture ports from Arnd Bergmann:
"This removes the entire architecture code for blackfin, cris, frv,
m32r, metag, mn10300, score, and tile, including the associated device
drivers.
I have been working with the (former) maintainers for each one to
ensure that my interpretation was right and the code is definitely
unused in mainline kernels. Many had fond memories of working on the
respective ports to start with and getting them included in upstream,
but also saw no point in keeping the port alive without any users.
In the end, it seems that while the eight architectures are extremely
different, they all suffered the same fate: There was one company in
charge of an SoC line, a CPU microarchitecture and a software
ecosystem, which was more costly than licensing newer off-the-shelf
CPU cores from a third party (typically ARM, MIPS, or RISC-V). It
seems that all the SoC product lines are still around, but have not
used the custom CPU architectures for several years at this point. In
contrast, CPU instruction sets that remain popular and have actively
maintained kernel ports tend to all be used across multiple licensees.
[ See the new nds32 port merged in the previous commit for the next
generation of "one company in charge of an SoC line, a CPU
microarchitecture and a software ecosystem" - Linus ]
The removal came out of a discussion that is now documented at
https://lwn.net/Articles/748074/. Unlike the original plans, I'm not
marking any ports as deprecated but remove them all at once after I
made sure that they are all unused. Some architectures (notably tile,
mn10300, and blackfin) are still being shipped in products with old
kernels, but those products will never be updated to newer kernel
releases.
After this series, we still have a few architectures without mainline
gcc support:
- unicore32 and hexagon both have very outdated gcc releases, but the
maintainers promised to work on providing something newer. At least
in case of hexagon, this will only be llvm, not gcc.
- openrisc, risc-v and nds32 are still in the process of finishing
their support or getting it added to mainline gcc in the first
place. They all have patched gcc-7.3 ports that work to some
degree, but complete upstream support won't happen before gcc-8.1.
Csky posted their first kernel patch set last week, their situation
will be similar
[ Palmer Dabbelt points out that RISC-V support is in mainline gcc
since gcc-7, although gcc-7.3.0 is the recommended minimum - Linus ]"
This really says it all:
2498 files changed, 95 insertions(+), 467668 deletions(-)
* tag 'arch-removal' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic: (74 commits)
MAINTAINERS: UNICORE32: Change email account
staging: iio: remove iio-trig-bfin-timer driver
tty: hvc: remove tile driver
tty: remove bfin_jtag_comm and hvc_bfin_jtag drivers
serial: remove tile uart driver
serial: remove m32r_sio driver
serial: remove blackfin drivers
serial: remove cris/etrax uart drivers
usb: Remove Blackfin references in USB support
usb: isp1362: remove blackfin arch glue
usb: musb: remove blackfin port
usb: host: remove tilegx platform glue
pwm: remove pwm-bfin driver
i2c: remove bfin-twi driver
spi: remove blackfin related host drivers
watchdog: remove bfin_wdt driver
can: remove bfin_can driver
mmc: remove bfin_sdh driver
input: misc: remove blackfin rotary driver
input: keyboard: remove bf54x driver
...
Diffstat (limited to 'arch/tile/kernel/stack.c')
| -rw-r--r-- | arch/tile/kernel/stack.c | 539 |
1 files changed, 0 insertions, 539 deletions
diff --git a/arch/tile/kernel/stack.c b/arch/tile/kernel/stack.c deleted file mode 100644 index 94ecbc6676e5..000000000000 --- a/arch/tile/kernel/stack.c +++ /dev/null @@ -1,539 +0,0 @@ -/* - * 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. - */ - -#include <linux/sched.h> -#include <linux/sched/debug.h> -#include <linux/sched/task_stack.h> -#include <linux/kernel.h> -#include <linux/kprobes.h> -#include <linux/module.h> -#include <linux/pfn.h> -#include <linux/kallsyms.h> -#include <linux/stacktrace.h> -#include <linux/uaccess.h> -#include <linux/mmzone.h> -#include <linux/dcache.h> -#include <linux/fs.h> -#include <linux/hardirq.h> -#include <linux/string.h> -#include <asm/backtrace.h> -#include <asm/page.h> -#include <asm/ucontext.h> -#include <asm/switch_to.h> -#include <asm/sigframe.h> -#include <asm/stack.h> -#include <asm/vdso.h> -#include <arch/abi.h> -#include <arch/interrupts.h> - -#define KBT_ONGOING 0 /* Backtrace still ongoing */ -#define KBT_DONE 1 /* Backtrace cleanly completed */ -#define KBT_RUNNING 2 /* Can't run backtrace on a running task */ -#define KBT_LOOP 3 /* Backtrace entered a loop */ - -/* Is address on the specified kernel stack? */ -static int in_kernel_stack(struct KBacktraceIterator *kbt, unsigned long sp) -{ - ulong kstack_base = (ulong) kbt->task->stack; - if (kstack_base == 0) /* corrupt task pointer; just follow stack... */ - return sp >= PAGE_OFFSET && sp < (unsigned long)high_memory; - return sp >= kstack_base && sp < kstack_base + THREAD_SIZE; -} - -/* 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 (!kbt->is_current) { - return 0; /* can't read from other user address spaces */ - } - pagefault_disable(); - retval = __copy_from_user_inatomic(result, - (void __user __force *)address, - size); - pagefault_enable(); - return (retval == 0); -} - -/* Return a pt_regs pointer for a valid fault handler frame */ -static struct pt_regs *valid_fault_handler(struct KBacktraceIterator* kbt) -{ - char fault[64]; - 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)) - return NULL; - p = (struct pt_regs *)(sp + C_ABI_SAVE_AREA_SIZE); - if (kbt->verbose) { /* else we aren't going to use it */ - if (p->faultnum == INT_SWINT_1 || - p->faultnum == INT_SWINT_1_SIGRETURN) - snprintf(fault, sizeof(fault), - "syscall %ld", p->regs[TREG_SYSCALL_NR]); - else - snprintf(fault, sizeof(fault), - "interrupt %ld", p->faultnum); - } - if (EX1_PL(p->ex1) == KERNEL_PL && - __kernel_text_address(p->pc) && - in_kernel_stack(kbt, p->sp) && - p->sp >= sp) { - if (kbt->verbose) - pr_err(" <%s while in kernel mode>\n", fault); - } else if (user_mode(p) && - p->sp < PAGE_OFFSET && p->sp != 0) { - if (kbt->verbose) - pr_err(" <%s while in user mode>\n", fault); - } else { - if (kbt->verbose && (p->pc != 0 || p->sp != 0 || p->ex1 != 0)) - pr_err(" (odd fault: pc %#lx, sp %#lx, ex1 %#lx?)\n", - p->pc, p->sp, p->ex1); - return NULL; - } - if (kbt->profile && ((1ULL << p->faultnum) & QUEUED_INTERRUPTS) != 0) - return NULL; - return p; -} - -/* Is the iterator pointing to a sigreturn trampoline? */ -static int is_sigreturn(struct KBacktraceIterator *kbt) -{ - return kbt->task->mm && - (kbt->it.pc == ((ulong)kbt->task->mm->context.vdso_base + - (ulong)&__vdso_rt_sigreturn)); -} - -/* Return a pt_regs pointer for a valid signal handler frame */ -static struct pt_regs *valid_sigframe(struct KBacktraceIterator* kbt, - struct rt_sigframe* kframe) -{ - BacktraceIterator *b = &kbt->it; - - if (is_sigreturn(kbt) && 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; - if (kbt->verbose) { - pr_err(" <received signal %d>\n", - kframe->info.si_signo); - } - return (struct pt_regs *)&kframe->uc.uc_mcontext; - } - return NULL; -} - -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, &kframe); - if (p == NULL) - return 0; - backtrace_init(&kbt->it, read_memory_func, kbt, - p->pc, p->lr, p->sp, p->regs[52]); - kbt->new_context = 1; - return 1; -} - -/* Find a frame that isn't a sigreturn, if there is one. */ -static int KBacktraceIterator_next_item_inclusive( - struct KBacktraceIterator *kbt) -{ - for (;;) { - do { - if (!is_sigreturn(kbt)) - return KBT_ONGOING; - } while (backtrace_next(&kbt->it)); - - if (!KBacktraceIterator_restart(kbt)) - return KBT_DONE; - } -} - -/* - * If the current sp is on a page different than what we recorded - * as the top-of-kernel-stack last time we context switched, we have - * probably blown the stack, and nothing is going to work out well. - * If we can at least get out a warning, that may help the debug, - * though we probably won't be able to backtrace into the code that - * actually did the recursive damage. - */ -static void validate_stack(struct pt_regs *regs) -{ - int cpu = raw_smp_processor_id(); - unsigned long ksp0 = get_current_ksp0(); - unsigned long ksp0_base = ksp0 & -THREAD_SIZE; - unsigned long sp = stack_pointer; - - if (EX1_PL(regs->ex1) == KERNEL_PL && regs->sp >= ksp0) { - pr_err("WARNING: cpu %d: kernel stack %#lx..%#lx underrun!\n" - " sp %#lx (%#lx in caller), caller pc %#lx, lr %#lx\n", - cpu, ksp0_base, ksp0, sp, regs->sp, regs->pc, regs->lr); - } - - else if (sp < ksp0_base + sizeof(struct thread_info)) { - pr_err("WARNING: cpu %d: kernel stack %#lx..%#lx overrun!\n" - " sp %#lx (%#lx in caller), caller pc %#lx, lr %#lx\n", - cpu, ksp0_base, ksp0, sp, regs->sp, regs->pc, regs->lr); - } -} - -void KBacktraceIterator_init(struct KBacktraceIterator *kbt, - struct task_struct *t, struct pt_regs *regs) -{ - unsigned long pc, lr, sp, r52; - int is_current; - - /* - * Set up callback information. We grab the kernel stack base - * so we will allow reads of that address range. - */ - is_current = (t == NULL || t == current); - kbt->is_current = is_current; - if (is_current) - t = validate_current(); - kbt->task = t; - kbt->verbose = 0; /* override in caller if desired */ - kbt->profile = 0; /* override in caller if desired */ - kbt->end = KBT_ONGOING; - kbt->new_context = 1; - if (is_current) - validate_stack(regs); - - if (regs == NULL) { - if (is_current || t->state == TASK_RUNNING) { - /* Can't do this; we need registers */ - kbt->end = KBT_RUNNING; - return; - } - pc = get_switch_to_pc(); - lr = t->thread.pc; - sp = t->thread.ksp; - r52 = 0; - } else { - pc = regs->pc; - lr = regs->lr; - sp = regs->sp; - r52 = regs->regs[52]; - } - - backtrace_init(&kbt->it, read_memory_func, kbt, pc, lr, sp, r52); - kbt->end = KBacktraceIterator_next_item_inclusive(kbt); -} -EXPORT_SYMBOL(KBacktraceIterator_init); - -int KBacktraceIterator_end(struct KBacktraceIterator *kbt) -{ - return kbt->end != KBT_ONGOING; -} -EXPORT_SYMBOL(KBacktraceIterator_end); - -void KBacktraceIterator_next(struct KBacktraceIterator *kbt) -{ - unsigned long old_pc = kbt->it.pc, old_sp = kbt->it.sp; - kbt->new_context = 0; - if (!backtrace_next(&kbt->it) && !KBacktraceIterator_restart(kbt)) { - kbt->end = KBT_DONE; - return; - } - kbt->end = KBacktraceIterator_next_item_inclusive(kbt); - if (old_pc == kbt->it.pc && old_sp == kbt->it.sp) { - /* Trapped in a loop; give up. */ - kbt->end = KBT_LOOP; - } -} -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) { - p = file_path(vma->vm_file, buf, bufsize); - if (IS_ERR(p)) - p = "?"; - name = kbasename(p); - } else { - name = "anon"; - } - - /* Generate a string description of the vma info. */ - namelen = strlen(name); - remaining = (bufsize - 1) - namelen; - memmove(buf, name, namelen); - snprintf(buf + namelen, remaining, "[%lx+%lx] ", - vma->vm_start, vma->vm_end - vma->vm_start); -} - -/* - * Avoid possible crash recursion during backtrace. If it happens, it - * makes it easy to lose the actual root cause of the failure, so we - * put a simple guard on all the backtrace loops. - */ -static bool start_backtrace(void) -{ - if (current_thread_info()->in_backtrace) { - pr_err("Backtrace requested while in backtrace!\n"); - return false; - } - current_thread_info()->in_backtrace = true; - return true; -} - -static void end_backtrace(void) -{ - current_thread_info()->in_backtrace = false; -} - -/* - * This method wraps the backtracer's more generic support. - * It is only invoked from the architecture-specific code; show_stack() - * and dump_stack() are architecture-independent entry points. - */ -void tile_show_stack(struct KBacktraceIterator *kbt) -{ - int i; - int have_mmap_sem = 0; - - if (!start_backtrace()) - return; - kbt->verbose = 1; - i = 0; - for (; !KBacktraceIterator_end(kbt); KBacktraceIterator_next(kbt)) { - char namebuf[KSYM_NAME_LEN+100]; - unsigned long address = kbt->it.pc; - - /* - * Try to acquire the mmap_sem as we pass into userspace. - * If we're in an interrupt context, don't even try, since - * it's not safe to call e.g. d_path() from an interrupt, - * since it uses spin locks without disabling interrupts. - * Note we test "kbt->task == current", not "kbt->is_current", - * since we're checking that "current" will work in d_path(). - */ - if (kbt->task == current && address < PAGE_OFFSET && - !have_mmap_sem && kbt->task->mm && !in_interrupt()) { - 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)); - - if (i >= 100) { - pr_err("Stack dump truncated (%d frames)\n", i); - break; - } - } - if (kbt->end == KBT_LOOP) - pr_err("Stack dump stopped; next frame identical to this one\n"); - if (have_mmap_sem) - up_read(&kbt->task->mm->mmap_sem); - end_backtrace(); -} -EXPORT_SYMBOL(tile_show_stack); - -static struct pt_regs *regs_to_pt_regs(struct pt_regs *regs, - ulong pc, ulong lr, ulong sp, ulong r52) -{ - memset(regs, 0, sizeof(struct pt_regs)); - regs->pc = pc; - regs->lr = lr; - regs->sp = sp; - regs->regs[52] = r52; - return regs; -} - -/* Deprecated function currently only used by kernel_double_fault(). */ -void _dump_stack(int dummy, ulong pc, ulong lr, ulong sp, ulong r52) -{ - struct KBacktraceIterator kbt; - struct pt_regs regs; - - regs_to_pt_regs(®s, pc, lr, sp, r52); - KBacktraceIterator_init(&kbt, NULL, ®s); - tile_show_stack(&kbt); -} - -/* This is called from KBacktraceIterator_init_current() */ -void _KBacktraceIterator_init_current(struct KBacktraceIterator *kbt, ulong pc, - ulong lr, ulong sp, ulong r52) -{ - struct pt_regs regs; - KBacktraceIterator_init(kbt, NULL, - regs_to_pt_regs(®s, pc, lr, sp, r52)); -} - -/* - * Called from sched_show_task() with task != NULL, or dump_stack() - * with task == NULL. The esp argument is always NULL. - */ -void show_stack(struct task_struct *task, unsigned long *esp) -{ - struct KBacktraceIterator kbt; - if (task == NULL || task == current) { - KBacktraceIterator_init_current(&kbt); - KBacktraceIterator_next(&kbt); /* don't show first frame */ - } else { - KBacktraceIterator_init(&kbt, task, NULL); - } - tile_show_stack(&kbt); -} - -#ifdef CONFIG_STACKTRACE - -/* Support generic Linux stack API too */ - -static void save_stack_trace_common(struct task_struct *task, - struct pt_regs *regs, - bool user, - struct stack_trace *trace) -{ - struct KBacktraceIterator kbt; - int skip = trace->skip; - int i = 0; - - if (!start_backtrace()) - goto done; - if (regs != NULL) { - KBacktraceIterator_init(&kbt, NULL, regs); - } else if (task == NULL || task == current) { - KBacktraceIterator_init_current(&kbt); - skip++; /* don't show KBacktraceIterator_init_current */ - } else { - KBacktraceIterator_init(&kbt, task, NULL); - } - for (; !KBacktraceIterator_end(&kbt); KBacktraceIterator_next(&kbt)) { - if (skip) { - --skip; - continue; - } - if (i >= trace->max_entries || - (!user && kbt.it.pc < PAGE_OFFSET)) - break; - trace->entries[i++] = kbt.it.pc; - } - end_backtrace(); -done: - if (i < trace->max_entries) - trace->entries[i++] = ULONG_MAX; - trace->nr_entries = i; -} - -void save_stack_trace_tsk(struct task_struct *task, struct stack_trace *trace) -{ - save_stack_trace_common(task, NULL, false, trace); -} -EXPORT_SYMBOL(save_stack_trace_tsk); - -void save_stack_trace(struct stack_trace *trace) -{ - save_stack_trace_common(NULL, NULL, false, trace); -} -EXPORT_SYMBOL_GPL(save_stack_trace); - -void save_stack_trace_regs(struct pt_regs *regs, struct stack_trace *trace) -{ - save_stack_trace_common(NULL, regs, false, trace); -} - -void save_stack_trace_user(struct stack_trace *trace) -{ - /* Trace user stack if we are not a kernel thread. */ - if (current->mm) - save_stack_trace_common(NULL, task_pt_regs(current), - true, trace); - else if (trace->nr_entries < trace->max_entries) - trace->entries[trace->nr_entries++] = ULONG_MAX; -} -#endif - -/* In entry.S */ -EXPORT_SYMBOL(KBacktraceIterator_init_current); |
