2008-02-14 15:44:05

by S.Çağlar Onur

[permalink] [raw]
Subject: [PATCH 12/14] fs/binfmt_aout.c: Use time_* macros

The functions time_before, time_before_eq, time_after, and time_after_eq are more robust for comparing jiffies against other values.

So following patch implements usage of the time_after() macro, defined at linux/jiffies.h, which deals with wrapping correctly

Cc: [email protected]
Signed-off-by: S.Çağlar Onur <[email protected]>
---
fs/binfmt_aout.c | 7 ++++---
1 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/fs/binfmt_aout.c b/fs/binfmt_aout.c
index a1bb224..72757fe 100644
--- a/fs/binfmt_aout.c
+++ b/fs/binfmt_aout.c
@@ -6,6 +6,7 @@

#include <linux/module.h>

+#include <linux/jiffies.h>
#include <linux/time.h>
#include <linux/kernel.h>
#include <linux/mm.h>
@@ -374,14 +375,14 @@ static int load_aout_binary(struct linux_binprm * bprm, struct pt_regs * regs)
} else {
static unsigned long error_time, error_time2;
if ((ex.a_text & 0xfff || ex.a_data & 0xfff) &&
- (N_MAGIC(ex) != NMAGIC) && (jiffies-error_time2) > 5*HZ)
+ (N_MAGIC(ex) != NMAGIC) && time_after(jiffies, error_time2 + 5 * HZ))
{
printk(KERN_NOTICE "executable not page aligned\n");
error_time2 = jiffies;
}

if ((fd_offset & ~PAGE_MASK) != 0 &&
- (jiffies-error_time) > 5*HZ)
+ time_after(jiffies, error_time + 5 * HZ))
{
printk(KERN_WARNING
"fd_offset is not page aligned. Please convert program: %s\n",
@@ -498,7 +499,7 @@ static int load_aout_library(struct file *file)
static unsigned long error_time;
loff_t pos = N_TXTOFF(ex);

- if ((jiffies-error_time) > 5*HZ)
+ if (time_after(jiffies ,error_time + 5 * HZ))
{
printk(KERN_WARNING
"N_TXTOFF is not page aligned. Please convert library: %s\n",
--
1.5.3.7


2008-02-14 19:46:26

by Geert Uytterhoeven

[permalink] [raw]
Subject: Re: [PATCH 12/14] fs/binfmt_aout.c: Use time_* macros

On Thu, 14 Feb 2008, S.?~Ga?~_lar Onur wrote:
> The functions time_before, time_before_eq, time_after, and time_after_eq are more robust for comparing jiffies against other values.
>
> So following patch implements usage of the time_after() macro, defined at linux/jiffies.h, which deals with wrapping correctly
>
> Cc: [email protected]
> Signed-off-by: S.Çağlar Onur <[email protected]>
> ---
> fs/binfmt_aout.c | 7 ++++---
> 1 files changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/fs/binfmt_aout.c b/fs/binfmt_aout.c
> index a1bb224..72757fe 100644
> --- a/fs/binfmt_aout.c
> +++ b/fs/binfmt_aout.c
> @@ -6,6 +6,7 @@
>
> #include <linux/module.h>
>
> +#include <linux/jiffies.h>
> #include <linux/time.h>
> #include <linux/kernel.h>
> #include <linux/mm.h>
> @@ -374,14 +375,14 @@ static int load_aout_binary(struct linux_binprm * bprm, struct pt_regs * regs)
> } else {
> static unsigned long error_time, error_time2;
> if ((ex.a_text & 0xfff || ex.a_data & 0xfff) &&
> - (N_MAGIC(ex) != NMAGIC) && (jiffies-error_time2) > 5*HZ)
> + (N_MAGIC(ex) != NMAGIC) && time_after(jiffies, error_time2 + 5 * HZ))
> {
> printk(KERN_NOTICE "executable not page aligned\n");
> error_time2 = jiffies;
> }
>
>
> if ((fd_offset & ~PAGE_MASK) != 0 &&
> - (jiffies-error_time) > 5*HZ)
> + time_after(jiffies, error_time + 5 * HZ))
> {
> printk(KERN_WARNING
> "fd_offset is not page aligned. Please convert program: %s\n",
> @@ -498,7 +499,7 @@ static int load_aout_library(struct file *file)
> static unsigned long error_time;
> loff_t pos = N_TXTOFF(ex);
>
> - if ((jiffies-error_time) > 5*HZ)
> + if (time_after(jiffies ,error_time + 5 * HZ))
> {
> printk(KERN_WARNING
> "N_TXTOFF is not page aligned. Please convert library: %s\n",

To me these constructs look like good candidates for replacement by
printk_ratelimit()?

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- [email protected]

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds

2008-02-15 01:22:08

by S.Çağlar Onur

[permalink] [raw]
Subject: Re: [PATCH 12/14] fs/binfmt_aout.c: Use time_* macros

14 Şub 2008 Per tarihinde, Geert Uytterhoeven şunları yazmıştı:
> To me these constructs look like good candidates for replacement by
> printk_ratelimit()?
>
> Gr{oetje,eeting}s,

What about something like following?


Use printk_ratelimit() instead of jiffies based arithmetic, suggested by Geert Uytterhoeven

Signed-off-by: S.Çağlar Onur <[email protected]>

fs/binfmt_aout.c | 12 +++---------
1 files changed, 3 insertions(+), 9 deletions(-)

diff --git a/fs/binfmt_aout.c b/fs/binfmt_aout.c
index a1bb224..ba4cddb 100644
--- a/fs/binfmt_aout.c
+++ b/fs/binfmt_aout.c
@@ -372,21 +372,17 @@ static int load_aout_binary(struct linux_binprm * bprm, struct pt_regs * regs)

flush_icache_range(text_addr, text_addr+ex.a_text+ex.a_data);
} else {
- static unsigned long error_time, error_time2;
if ((ex.a_text & 0xfff || ex.a_data & 0xfff) &&
- (N_MAGIC(ex) != NMAGIC) && (jiffies-error_time2) > 5*HZ)
+ (N_MAGIC(ex) != NMAGIC) && printk_ratelimit())
{
printk(KERN_NOTICE "executable not page aligned\n");
- error_time2 = jiffies;
}

- if ((fd_offset & ~PAGE_MASK) != 0 &&
- (jiffies-error_time) > 5*HZ)
+ if ((fd_offset & ~PAGE_MASK) != 0 && printk_ratelimit())
{
printk(KERN_WARNING
"fd_offset is not page aligned. Please convert program: %s\n",
bprm->file->f_path.dentry->d_name.name);
- error_time = jiffies;
}

if (!bprm->file->f_op->mmap||((fd_offset & ~PAGE_MASK) != 0)) {
@@ -495,15 +491,13 @@ static int load_aout_library(struct file *file)
start_addr = ex.a_entry & 0xfffff000;

if ((N_TXTOFF(ex) & ~PAGE_MASK) != 0) {
- static unsigned long error_time;
loff_t pos = N_TXTOFF(ex);

- if ((jiffies-error_time) > 5*HZ)
+ if (printk_ratelimit())
{
printk(KERN_WARNING
"N_TXTOFF is not page aligned. Please convert library: %s\n",
file->f_path.dentry->d_name.name);
- error_time = jiffies;
}
down_write(&current->mm->mmap_sem);
do_brk(start_addr, ex.a_text + ex.a_data + ex.a_bss);

Cheers
--
S.Çağlar Onur <[email protected]>
http://cekirdek.pardus.org.tr/~caglar/

Linux is like living in a teepee. No Windows, no Gates and an Apache in house!