diff options
Diffstat (limited to 'Documentation/core-api')
| -rw-r--r-- | Documentation/core-api/printk-formats.rst | 46 |
1 files changed, 36 insertions, 10 deletions
diff --git a/Documentation/core-api/printk-formats.rst b/Documentation/core-api/printk-formats.rst index 8a0f49cd158b..8ebe46b1af39 100644 --- a/Documentation/core-api/printk-formats.rst +++ b/Documentation/core-api/printk-formats.rst @@ -79,6 +79,18 @@ has the added benefit of providing a unique identifier. On 64-bit machines 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. +Error Pointers +-------------- + +:: + + %pe -ENOSPC + +For printing error pointers (i.e. a pointer for which IS_ERR() is true) +as a symbolic error name. Error values for which no symbolic name is +known are printed in decimal, while a non-ERR_PTR passed as the +argument to %pe gets treated as ordinary %p. + Symbols/Function Pointers ------------------------- @@ -86,8 +98,6 @@ Symbols/Function Pointers %pS versatile_init+0x0/0x110 %ps versatile_init - %pF versatile_init+0x0/0x110 - %pf versatile_init %pSR versatile_init+0x9/0x110 (with __builtin_extract_return_addr() translation) %pB prev_fn_of_versatile_init+0x88/0x88 @@ -97,14 +107,6 @@ The ``S`` and ``s`` specifiers are used for printing a pointer in symbolic format. They result in the symbol name with (S) or without (s) offsets. If KALLSYMS are disabled then the symbol address is printed instead. -Note, that the ``F`` and ``f`` specifiers are identical to ``S`` (``s``) -and thus deprecated. We have ``F`` and ``f`` because on ia64, ppc64 and -parisc64 function pointers are indirect and, in fact, are function -descriptors, which require additional dereferencing before we can lookup -the symbol. As of now, ``S`` and ``s`` perform dereferencing on those -platforms (when needed), so ``F`` and ``f`` exist for compatibility -reasons only. - The ``B`` specifier results in the symbol name with offsets and should be used when printing stack backtraces. The specifier takes into consideration the effect of compiler optimisations which may occur @@ -442,6 +444,30 @@ Examples:: Passed by reference. +Fwnode handles +-------------- + +:: + + %pfw[fP] + +For printing information on fwnode handles. The default is to print the full +node name, including the path. The modifiers are functionally equivalent to +%pOF above. + + - f - full name of the node, including the path + - P - the name of the node including an address (if there is one) + +Examples (ACPI):: + + %pfwf \_SB.PCI0.CIO2.port@1.endpoint@0 - Full node name + %pfwP endpoint@0 - Node name + +Examples (OF):: + + %pfwf /ocp@68000000/i2c@48072000/camera@10/port/endpoint - Full name + %pfwP endpoint - Node name + Time and date (struct rtc_time) ------------------------------- |