| Message ID | 20180322052336.1001-1-joel@jms.id.au |
|---|---|
| State | Accepted |
| Commit | 156383b190cd1b240a4c8636c9ce7a2a42938b24 |
| Headers | show |
| Series | Documentation: Mention why %p prints ptrval | expand |
On Thu, Mar 22, 2018 at 03:53:36PM +1030, Joel Stanley wrote: > When debugging recent kernels, people will see '(ptrval)' but there > isn't much information as to what that means. Briefly describe why it's > there. > > Signed-off-by: Joel Stanley <joel@jms.id.au> > --- > Documentation/core-api/printk-formats.rst | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/Documentation/core-api/printk-formats.rst b/Documentation/core-api/printk-formats.rst > index 934559b3c130..eb30efdd2e78 100644 > --- a/Documentation/core-api/printk-formats.rst > +++ b/Documentation/core-api/printk-formats.rst > @@ -60,8 +60,8 @@ Plain Pointers > Pointers printed without a specifier extension (i.e unadorned %p) are > hashed to prevent leaking information about the kernel memory layout. This > has the added benefit of providing a unique identifier. On 64-bit machines > -the first 32 bits are zeroed. If you *really* want the address see %px > -below. > +the first 32 bits are zeroed. The kernel will print ``(ptrval)`` until it > +gathers enough entropy. If you *really* want the address see %px below. Acked-by: Tobin C. Harding <me@tobin.cc> thanks, Tobin.
On Thu, 22 Mar 2018 15:53:36 +1030 Joel Stanley <joel@jms.id.au> wrote: > When debugging recent kernels, people will see '(ptrval)' but there > isn't much information as to what that means. Briefly describe why it's > there. Applied, thanks. jon
diff --git a/Documentation/core-api/printk-formats.rst b/Documentation/core-api/printk-formats.rst index 934559b3c130..eb30efdd2e78 100644 --- a/Documentation/core-api/printk-formats.rst +++ b/Documentation/core-api/printk-formats.rst @@ -60,8 +60,8 @@ Plain Pointers Pointers printed without a specifier extension (i.e unadorned %p) are hashed to prevent leaking information about the kernel memory layout. This has the added benefit of providing a unique identifier. On 64-bit machines -the first 32 bits are zeroed. If you *really* want the address see %px -below. +the first 32 bits are zeroed. The kernel will print ``(ptrval)`` until it +gathers enough entropy. If you *really* want the address see %px below. Symbols/Function Pointers -------------------------
When debugging recent kernels, people will see '(ptrval)' but there isn't much information as to what that means. Briefly describe why it's there. Signed-off-by: Joel Stanley <joel@jms.id.au> --- Documentation/core-api/printk-formats.rst | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) -- 2.15.1