Re: sys_kcmp (was: Re: [PATCH 1/2] ARM: add finit_module syscall to ARM)
From: Mark Salter <hidden>
Date: 2012-09-24 18:16:33
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On Mon, 2012-09-24 at 21:42 +0400, Cyrill Gorcunov wrote:
On Mon, Sep 24, 2012 at 08:49:42PM +0400, Cyrill Gorcunov wrote:quoted
quoted
I got past that with:diff --git a/include/linux/security.h b/include/linux/security.h index 01ef030..14e394d 100644 --- a/include/linux/security.h +++ b/include/linux/security.h@@ -118,6 +118,7 @@ void reset_security_ops(void); extern unsigned long mmap_min_addr; extern unsigned long dac_mmap_min_addr; #else +#define mmap_min_addr 0UL #define dac_mmap_min_addr 0UL #endifI think better to add CONFIG_MMU test here.
Well, my patch was just something quick to get the kernel to build, but thinking about it a bit, I still prefer it. The CONFIG_MMU check is in security.h already so I think it is less clutter and better for future code which may use mmap_min_addr. In any case, the compiler will drop any test for "x < 0UL" so the end result is the same.
quoted hunk ↗ jump to hunk
--- From: Cyrill Gorcunov <redacted> Subject: prctl: prctl_set_mm -- Don't test for mmap_min_addr on non-MMU config In case if CONFIG_MMU is not set the @mmap_min_addr is undefined leading to build error. Thus test for it iif CONFIG_MMU is present. Note this code snippet depends on CONFIG_CHECKPOINT_RESTORE=y. Reported-by: Mark Salter <redacted> Signed-off-by: Cyrill Gorcunov <redacted> --- kernel/sys.c | 4 ++++ 1 file changed, 4 insertions(+) Index: linux-2.6.git/kernel/sys.c ===================================================================--- linux-2.6.git.orig/kernel/sys.c +++ linux-2.6.git/kernel/sys.c@@ -1865,7 +1865,11 @@ static int prctl_set_mm(int opt, unsigne if (opt == PR_SET_MM_EXE_FILE) return prctl_set_mm_exe_file(mm, (unsigned int)addr); +#ifdef CONFIG_MMU if (addr >= TASK_SIZE || addr < mmap_min_addr) +#else + if (addr >= TASK_SIZE) +#endif return -EINVAL; error = -EINVAL;