On Fri, Sep 04, 2020 at 03:10:15PM -0700, Joe Perches wrote:
> Reduce the object size of logging messages by removing the
> separate KERN_LEVEL argument and adding it to the format.
>
> Miscellanea:
>
> o Rename fscypt_msg to fscrypt_printk
>
> x86-64 defconfig with fscrypto:
>
> Original sizes:
> $ size fs/crypto/built-in.a -t
> text data bss dec hex filename
> 3815 300 24 4139 102b fs/crypto/crypto.o (ex fs/crypto/built-in.a)
> 4354 84 0 4438 1156 fs/crypto/fname.o (ex fs/crypto/built-in.a)
> 1484 24 0 1508 5e4 fs/crypto/hkdf.o (ex fs/crypto/built-in.a)
> 2910 68 0 2978 ba2 fs/crypto/hooks.o (ex fs/crypto/built-in.a)
> 7797 664 65 8526 214e fs/crypto/keyring.o (ex fs/crypto/built-in.a)
> 5005 493 0 5498 157a fs/crypto/keysetup.o (ex fs/crypto/built-in.a)
> 2805 0 544 3349 d15 fs/crypto/keysetup_v1.o (ex fs/crypto/built-in.a)
> 6391 90 0 6481 1951 fs/crypto/policy.o (ex fs/crypto/built-in.a)
> 1369 40 0 1409 581 fs/crypto/bio.o (ex fs/crypto/built-in.a)
> 35930 1763 633 38326 95b6 (TOTALS)
>
> New sizes:
> $ size fs/crypto/built-in.a -t
> text data bss dec hex filename
> 3874 300 24 4198 1066 fs/crypto/crypto.o (ex fs/crypto/built-in.a)
> 4347 84 0 4431 114f fs/crypto/fname.o (ex fs/crypto/built-in.a)
> 1476 24 0 1500 5dc fs/crypto/hkdf.o (ex fs/crypto/built-in.a)
> 2902 68 0 2970 b9a fs/crypto/hooks.o (ex fs/crypto/built-in.a)
> 7781 664 65 8510 213e fs/crypto/keyring.o (ex fs/crypto/built-in.a)
> 4961 493 0 5454 154e fs/crypto/keysetup.o (ex fs/crypto/built-in.a)
> 2790 0 544 3334 d06 fs/crypto/keysetup_v1.o (ex fs/crypto/built-in.a)
> 6306 90 0 6396 18fc fs/crypto/policy.o (ex fs/crypto/built-in.a)
> 1369 40 0 1409 581 fs/crypto/bio.o (ex fs/crypto/built-in.a)
> 35806 1763 633 38202 953a (TOTALS)
>
> Signed-off-by: Joe Perches <joe@xxxxxxxxxxx>
> ---
> fs/crypto/crypto.c | 14 ++++++++------
> fs/crypto/fscrypt_private.h | 12 ++++++------
> 2 files changed, 14 insertions(+), 12 deletions(-)
>
> diff --git a/fs/crypto/crypto.c b/fs/crypto/crypto.c
> index 9212325763b0..c82cc3907e43 100644
> --- a/fs/crypto/crypto.c
> +++ b/fs/crypto/crypto.c
> @@ -329,25 +329,27 @@ int fscrypt_initialize(unsigned int cop_flags)
> return err;
> }
>
> -void fscrypt_msg(const struct inode *inode, const char *level,
> - const char *fmt, ...)
> +void fscrypt_printk(const struct inode *inode, const char *fmt, ...)
> {
> static DEFINE_RATELIMIT_STATE(rs, DEFAULT_RATELIMIT_INTERVAL,
> DEFAULT_RATELIMIT_BURST);
> struct va_format vaf;
> va_list args;
> + int level;
>
> if (!__ratelimit(&rs))
> return;
>
> va_start(args, fmt);
> - vaf.fmt = fmt;
> + level = printk_get_level(fmt);
> + vaf.fmt = printk_skip_level(fmt);
> vaf.va = &args;
> if (inode)
> - printk("%sfscrypt (%s, inode %lu): %pV\n",
> - level, inode->i_sb->s_id, inode->i_ino, &vaf);
> + printk("%c%cfscrypt (%s, inode %lu): %pV\n",
> + KERN_SOH_ASCII, level, inode->i_sb->s_id, inode->i_ino,
> + &vaf);
> else
> - printk("%sfscrypt: %pV\n", level, &vaf);
> + printk("%c%cfscrypt: %pV\n", KERN_SOH_ASCII, level, &vaf);
> va_end(args);
The problem with this approach is that if fscrypt_printk() is called without
providing a log level in the format string (which one would assume would work,
since printk() allows it), then the real format string will be truncated to just
KERN_SOH because 'level' will be 0.
Can you find a way to avoid that?
> -#define fscrypt_warn(inode, fmt, ...) \
> - fscrypt_msg((inode), KERN_WARNING, fmt, ##__VA_ARGS__)
> -#define fscrypt_err(inode, fmt, ...) \
> - fscrypt_msg((inode), KERN_ERR, fmt, ##__VA_ARGS__)
> +#define fscrypt_err(inode, fmt, ...) \
> + fscrypt_printk(inode, KERN_ERR fmt, ##__VA_ARGS__)
> +#define fscrypt_warn(inode, fmt, ...) \
> + fscrypt_printk(inode, KERN_WARNING fmt, ##__VA_ARGS__)
It's probably best to keep the parentheses around 'inode'.
- Eric
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