Re: [PATCH -tip] x86: headers - fix export private data to userspace

From: H. Peter Anvin
Date: Wed Jan 14 2009 - 14:42:54 EST


Cyrill Gorcunov wrote:
Impact: cleanup

'make headers_check' warn us about leaking of kernel private
(mostly compile time vars) data to userspace in headers. Fix it.

More detailed report for easier reviewing:

1) boot.h - neither BOOT_HEAP_SIZE, BOOT_STACK_SIZE refs
was found by searching thru net (ie in user-space area).

2) prctl.h - sys_arch_prctl is completely removed from
header since frankly I don't even understand why we
describe it here. It is described like
__SYSCALL(__NR_arch_prctl, sys_arch_prctl) in unistd_64.h
and implemented in process_64.c. User-mode linux involved?
So this one in fact is suspicious.

3) ptrace-abi.h - ptrace_bts_config struct is wrapped
by __KERNEL__ -- not sure if it was ever proposed for
userland.

4) setup.h - COMMAND_LINE_SIZE saved for userspace, bootloaders
could use it.

5) sigcontext32.h - we really need linux/types.h here
since we use __u... types.

Signed-off-by: Cyrill Gorcunov <gorcunov@xxxxxxxxxx>

Hi Cyrill; in addition to nonexporting COMMAND_LINE_SIZE, could you submit this as a patchset to make post-integration bisect easier?

-hpa
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