0a196848ca
The arch_perf_output_copy_user() default of
__copy_from_user_inatomic() returns bytes not copied, while all other
argument functions given DEFINE_OUTPUT_COPY() return bytes copied.
Since copy_from_user_nmi() is the odd duck out by returning bytes
copied where all other *copy_{to,from}* functions return bytes not
copied, change it over and ammend DEFINE_OUTPUT_COPY() to expect bytes
not copied.
Oddly enough DEFINE_OUTPUT_COPY() already returned bytes not copied
while expecting its worker functions to return bytes copied.
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: will.deacon@arm.com
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/20131030201622.GR16117@laptop.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
127 lines
2.7 KiB
C
127 lines
2.7 KiB
C
/**
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* @file backtrace.c
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*
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* @remark Copyright 2002 OProfile authors
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* @remark Read the file COPYING
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*
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* @author John Levon
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* @author David Smith
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*/
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#include <linux/oprofile.h>
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#include <linux/sched.h>
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#include <linux/mm.h>
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#include <linux/compat.h>
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#include <linux/uaccess.h>
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#include <asm/ptrace.h>
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#include <asm/stacktrace.h>
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static int backtrace_stack(void *data, char *name)
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{
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/* Yes, we want all stacks */
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return 0;
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}
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static void backtrace_address(void *data, unsigned long addr, int reliable)
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{
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unsigned int *depth = data;
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if ((*depth)--)
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oprofile_add_trace(addr);
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}
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static struct stacktrace_ops backtrace_ops = {
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.stack = backtrace_stack,
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.address = backtrace_address,
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.walk_stack = print_context_stack,
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};
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#ifdef CONFIG_COMPAT
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static struct stack_frame_ia32 *
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dump_user_backtrace_32(struct stack_frame_ia32 *head)
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{
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/* Also check accessibility of one struct frame_head beyond: */
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struct stack_frame_ia32 bufhead[2];
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struct stack_frame_ia32 *fp;
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unsigned long bytes;
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bytes = copy_from_user_nmi(bufhead, head, sizeof(bufhead));
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if (bytes != 0)
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return NULL;
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fp = (struct stack_frame_ia32 *) compat_ptr(bufhead[0].next_frame);
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oprofile_add_trace(bufhead[0].return_address);
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/* frame pointers should strictly progress back up the stack
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* (towards higher addresses) */
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if (head >= fp)
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return NULL;
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return fp;
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}
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static inline int
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x86_backtrace_32(struct pt_regs * const regs, unsigned int depth)
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{
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struct stack_frame_ia32 *head;
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/* User process is IA32 */
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if (!current || !test_thread_flag(TIF_IA32))
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return 0;
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head = (struct stack_frame_ia32 *) regs->bp;
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while (depth-- && head)
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head = dump_user_backtrace_32(head);
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return 1;
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}
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#else
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static inline int
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x86_backtrace_32(struct pt_regs * const regs, unsigned int depth)
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{
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return 0;
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}
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#endif /* CONFIG_COMPAT */
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static struct stack_frame *dump_user_backtrace(struct stack_frame *head)
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{
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/* Also check accessibility of one struct frame_head beyond: */
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struct stack_frame bufhead[2];
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unsigned long bytes;
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bytes = copy_from_user_nmi(bufhead, head, sizeof(bufhead));
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if (bytes != 0)
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return NULL;
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oprofile_add_trace(bufhead[0].return_address);
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/* frame pointers should strictly progress back up the stack
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* (towards higher addresses) */
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if (head >= bufhead[0].next_frame)
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return NULL;
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return bufhead[0].next_frame;
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}
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void
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x86_backtrace(struct pt_regs * const regs, unsigned int depth)
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{
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struct stack_frame *head = (struct stack_frame *)frame_pointer(regs);
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if (!user_mode_vm(regs)) {
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unsigned long stack = kernel_stack_pointer(regs);
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if (depth)
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dump_trace(NULL, regs, (unsigned long *)stack, 0,
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&backtrace_ops, &depth);
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return;
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}
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if (x86_backtrace_32(regs, depth))
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return;
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while (depth-- && head)
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head = dump_user_backtrace(head);
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}
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