Commit efeb156e authored Jan 12, 2012 by Stephen Boyd Committed by Linus Torvalds Jan 12, 2012

kprobes: silence DEBUG_STRICT_USER_COPY_CHECKS=y warning



Enabling DEBUG_STRICT_USER_COPY_CHECKS causes the following warning:

  In file included from arch/x86/include/asm/uaccess.h:573,
                   from kernel/kprobes.c:55:
  In function 'copy_from_user',
      inlined from 'write_enabled_file_bool' at
      kernel/kprobes.c:2191:
  arch/x86/include/asm/uaccess_64.h:65:
  warning: call to 'copy_from_user_overflow' declared with attribute warning: copy_from_user() buffer size is not provably correct

presumably due to buf_size being signed causing GCC to fail to see that
buf_size can't become negative.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: David S. Miller <davem@davemloft.net>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent a2ef990a

kernel/kprobes.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -2198,7 +2198,7 @@ static ssize_t write_enabled_file_bool(struct file *file,
		const char __user user_buf, size_t count, loff_t ppos)
		{
		char buf[32];
		int buf_size;
		size_t buf_size;

		buf_size = min(count, (sizeof(buf)-1));
		if (copy_from_user(buf, user_buf, buf_size))

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