mirror of
https://github.com/torvalds/linux
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36903abedf
The __range_not_ok() helper is an x86 (and sparc64) specific interface that does roughly the same thing as __access_ok(), but with different calling conventions. Change this to use the normal interface in order for consistency as we clean up all access_ok() implementations. This changes the limit from TASK_SIZE to TASK_SIZE_MAX, which Al points out is the right thing do do here anyway. The callers have to use __access_ok() instead of the normal access_ok() though, because on x86 that contains a WARN_ON_IN_IRQ() check that cannot be used inside of NMI context while tracing. The check in copy_code() is not needed any more, because this one is already done by copy_from_user_nmi(). Suggested-by: Al Viro <viro@zeniv.linux.org.uk> Suggested-by: Christoph Hellwig <hch@infradead.org> Link: https://lore.kernel.org/lkml/YgsUKcXGR7r4nINj@zeniv-ca.linux.org.uk/ Signed-off-by: Arnd Bergmann <arnd@arndb.de>
131 lines
2.9 KiB
C
131 lines
2.9 KiB
C
/*
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* Stack trace management functions
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*
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* Copyright (C) 2006-2009 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
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*/
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#include <linux/sched.h>
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#include <linux/sched/debug.h>
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#include <linux/sched/task_stack.h>
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#include <linux/stacktrace.h>
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#include <linux/export.h>
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#include <linux/uaccess.h>
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#include <asm/stacktrace.h>
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#include <asm/unwind.h>
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void arch_stack_walk(stack_trace_consume_fn consume_entry, void *cookie,
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struct task_struct *task, struct pt_regs *regs)
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{
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struct unwind_state state;
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unsigned long addr;
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if (regs && !consume_entry(cookie, regs->ip))
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return;
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for (unwind_start(&state, task, regs, NULL); !unwind_done(&state);
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unwind_next_frame(&state)) {
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addr = unwind_get_return_address(&state);
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if (!addr || !consume_entry(cookie, addr))
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break;
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}
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}
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int arch_stack_walk_reliable(stack_trace_consume_fn consume_entry,
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void *cookie, struct task_struct *task)
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{
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struct unwind_state state;
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struct pt_regs *regs;
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unsigned long addr;
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for (unwind_start(&state, task, NULL, NULL);
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!unwind_done(&state) && !unwind_error(&state);
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unwind_next_frame(&state)) {
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regs = unwind_get_entry_regs(&state, NULL);
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if (regs) {
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/* Success path for user tasks */
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if (user_mode(regs))
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return 0;
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/*
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* Kernel mode registers on the stack indicate an
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* in-kernel interrupt or exception (e.g., preemption
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* or a page fault), which can make frame pointers
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* unreliable.
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*/
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if (IS_ENABLED(CONFIG_FRAME_POINTER))
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return -EINVAL;
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}
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addr = unwind_get_return_address(&state);
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/*
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* A NULL or invalid return address probably means there's some
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* generated code which __kernel_text_address() doesn't know
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* about.
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*/
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if (!addr)
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return -EINVAL;
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if (!consume_entry(cookie, addr))
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return -EINVAL;
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}
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/* Check for stack corruption */
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if (unwind_error(&state))
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return -EINVAL;
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return 0;
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}
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/* Userspace stacktrace - based on kernel/trace/trace_sysprof.c */
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struct stack_frame_user {
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const void __user *next_fp;
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unsigned long ret_addr;
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};
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static int
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copy_stack_frame(const struct stack_frame_user __user *fp,
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struct stack_frame_user *frame)
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{
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int ret;
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if (!__access_ok(fp, sizeof(*frame)))
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return 0;
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ret = 1;
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pagefault_disable();
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if (__get_user(frame->next_fp, &fp->next_fp) ||
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__get_user(frame->ret_addr, &fp->ret_addr))
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ret = 0;
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pagefault_enable();
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return ret;
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}
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void arch_stack_walk_user(stack_trace_consume_fn consume_entry, void *cookie,
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const struct pt_regs *regs)
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{
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const void __user *fp = (const void __user *)regs->bp;
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if (!consume_entry(cookie, regs->ip))
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return;
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while (1) {
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struct stack_frame_user frame;
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frame.next_fp = NULL;
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frame.ret_addr = 0;
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if (!copy_stack_frame(fp, &frame))
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break;
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if ((unsigned long)fp < regs->sp)
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break;
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if (!frame.ret_addr)
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break;
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if (!consume_entry(cookie, frame.ret_addr))
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break;
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fp = frame.next_fp;
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}
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}
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