[PATCH 0034/1285] Replace numeric parameter like 0444 with macro

[PATCH 0034/1285] Replace numeric parameter like 0444 with macro

[Baole Ni]

I find that the developers often just specified the numeric value
when calling a macro which is defined with a parameter for access permission.
As we know, these numeric value for access permission have had the corresponding macro,
and that using macro can improve the robustness and readability of the code,
thus, I suggest replacing the numeric parameter with the macro.

Signed-off-by: Chuansheng Liu <chuansheng.liu@intel.com>
Signed-off-by: Baole Ni <baolex.ni@intel.com>
---
 arch/x86/kvm/mmu.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index def97b3..ce4f512 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -65,7 +65,7 @@ enum {
 
 #ifdef MMU_DEBUG
 static bool dbg = 0;
-module_param(dbg, bool, 0644);
+module_param(dbg, bool, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
 
 #define pgprintk(x...) do { if (dbg) printk(x); } while (0)
 #define rmap_printk(x...) do { if (dbg) printk(x); } while (0)
-- 
2.9.2

Re: [PATCH 0034/1285] Replace numeric parameter like 0444 with macro

[Radim Krčmář]

2016-08-02 18:36+0800, Baole Ni:
> I find that the developers often just specified the numeric value
> when calling a macro which is defined with a parameter for access permission.
> As we know, these numeric value for access permission have had the corresponding macro,
> and that using macro can improve the robustness and readability of the code,
> thus, I suggest replacing the numeric parameter with the macro.
> 
> Signed-off-by: Chuansheng Liu <chuansheng.liu@intel.com>
> Signed-off-by: Baole Ni <baolex.ni@intel.com>
> ---
> diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
> @@ -65,7 +65,7 @@ enum {
> -module_param(dbg, bool, 0644);
> +module_param(dbg, bool, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);

Please change to "S_IWUSR | S_IRUGO".
0444 -> S_IRUGO should also be applied to other kvm patches.

The result is still less readable than 0644 for me, because octal
numbers are practically never used outside of well known access
permissions and those macros have to be read painfully carefully, but
macros avoid an arbitrary cutoff from flags that might not be known by
heart by all developers, maybe starting at S_ISVTX.


Btw. the posting could be improved with a cover letter that would link
all patches to it; the series will be easier to handle in mail clients
and there will be a clear place for common discussion about the
patchset.  Optionally merge related patches; one patch per subsystem
would be ideal.

Re: [PATCH 0034/1285] Replace numeric parameter like 0444 with macro

[Jiri Kosina]

On Tue, 2 Aug 2016, Radim Krčmář wrote:

> Btw. the posting could be improved with a cover letter that would link 
> all patches to it; the series will be easier to handle in mail clients 
> and there will be a clear place for common discussion about the 
> patchset.  Optionally merge related patches; one patch per subsystem 
> would be ideal.

If this should be done at all (which I don't think so, the octal 
representation looks actually much more straightforward than the cryptic 
macros), it should be scripted (preferably in coccinelle) and sent out as 
a script to run on the whole tree at higher maintainer levels.

-- 
Jiri Kosina
SUSE Labs