123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292 |
- If variable is of Type, use printk format specifier:
- ---------------------------------------------------------
- int %d or %x
- unsigned int %u or %x
- long %ld or %lx
- unsigned long %lu or %lx
- long long %lld or %llx
- unsigned long long %llu or %llx
- size_t %zu or %zx
- ssize_t %zd or %zx
- s32 %d or %x
- u32 %u or %x
- s64 %lld or %llx
- u64 %llu or %llx
- If <type> is dependent on a config option for its size (e.g., sector_t,
- blkcnt_t) or is architecture-dependent for its size (e.g., tcflag_t), use a
- format specifier of its largest possible type and explicitly cast to it.
- Example:
- printk("test: sector number/total blocks: %llu/%llu\n",
- (unsigned long long)sector, (unsigned long long)blockcount);
- Reminder: sizeof() result is of type size_t.
- Raw pointer value SHOULD be printed with %p. The kernel supports
- the following extended format specifiers for pointer types:
- Symbols/Function Pointers:
- %pF versatile_init+0x0/0x110
- %pf versatile_init
- %pS versatile_init+0x0/0x110
- %pSR versatile_init+0x9/0x110
- (with __builtin_extract_return_addr() translation)
- %ps versatile_init
- %pB prev_fn_of_versatile_init+0x88/0x88
- For printing symbols and function pointers. The 'S' and 's' specifiers
- result in the symbol name with ('S') or without ('s') offsets. Where
- this is used on a kernel without KALLSYMS - the symbol address is
- printed instead.
- 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
- when tail-call's are used and marked with the noreturn GCC attribute.
- On ia64, ppc64 and parisc64 architectures function pointers are
- actually function descriptors which must first be resolved. The 'F' and
- 'f' specifiers perform this resolution and then provide the same
- functionality as the 'S' and 's' specifiers.
- Kernel Pointers:
- %pK 0x01234567 or 0x0123456789abcdef
- For printing kernel pointers which should be hidden from unprivileged
- users. The behaviour of %pK depends on the kptr_restrict sysctl - see
- Documentation/sysctl/kernel.txt for more details.
- Struct Resources:
- %pr [mem 0x60000000-0x6fffffff flags 0x2200] or
- [mem 0x0000000060000000-0x000000006fffffff flags 0x2200]
- %pR [mem 0x60000000-0x6fffffff pref] or
- [mem 0x0000000060000000-0x000000006fffffff pref]
- For printing struct resources. The 'R' and 'r' specifiers result in a
- printed resource with ('R') or without ('r') a decoded flags member.
- Passed by reference.
- Physical addresses types phys_addr_t:
- %pa[p] 0x01234567 or 0x0123456789abcdef
- For printing a phys_addr_t type (and its derivatives, such as
- resource_size_t) which can vary based on build options, regardless of
- the width of the CPU data path. Passed by reference.
- DMA addresses types dma_addr_t:
- %pad 0x01234567 or 0x0123456789abcdef
- For printing a dma_addr_t type which can vary based on build options,
- regardless of the width of the CPU data path. Passed by reference.
- Raw buffer as an escaped string:
- %*pE[achnops]
- For printing raw buffer as an escaped string. For the following buffer
- 1b 62 20 5c 43 07 22 90 0d 5d
- few examples show how the conversion would be done (the result string
- without surrounding quotes):
- %*pE "\eb \C\a"\220\r]"
- %*pEhp "\x1bb \C\x07"\x90\x0d]"
- %*pEa "\e\142\040\\\103\a\042\220\r\135"
- The conversion rules are applied according to an optional combination
- of flags (see string_escape_mem() kernel documentation for the
- details):
- a - ESCAPE_ANY
- c - ESCAPE_SPECIAL
- h - ESCAPE_HEX
- n - ESCAPE_NULL
- o - ESCAPE_OCTAL
- p - ESCAPE_NP
- s - ESCAPE_SPACE
- By default ESCAPE_ANY_NP is used.
- ESCAPE_ANY_NP is the sane choice for many cases, in particularly for
- printing SSIDs.
- If field width is omitted the 1 byte only will be escaped.
- Raw buffer as a hex string:
- %*ph 00 01 02 ... 3f
- %*phC 00:01:02: ... :3f
- %*phD 00-01-02- ... -3f
- %*phN 000102 ... 3f
- For printing a small buffers (up to 64 bytes long) as a hex string with
- certain separator. For the larger buffers consider to use
- print_hex_dump().
- MAC/FDDI addresses:
- %pM 00:01:02:03:04:05
- %pMR 05:04:03:02:01:00
- %pMF 00-01-02-03-04-05
- %pm 000102030405
- %pmR 050403020100
- For printing 6-byte MAC/FDDI addresses in hex notation. The 'M' and 'm'
- specifiers result in a printed address with ('M') or without ('m') byte
- separators. The default byte separator is the colon (':').
- Where FDDI addresses are concerned the 'F' specifier can be used after
- the 'M' specifier to use dash ('-') separators instead of the default
- separator.
- For Bluetooth addresses the 'R' specifier shall be used after the 'M'
- specifier to use reversed byte order suitable for visual interpretation
- of Bluetooth addresses which are in the little endian order.
- Passed by reference.
- IPv4 addresses:
- %pI4 1.2.3.4
- %pi4 001.002.003.004
- %p[Ii]4[hnbl]
- For printing IPv4 dot-separated decimal addresses. The 'I4' and 'i4'
- specifiers result in a printed address with ('i4') or without ('I4')
- leading zeros.
- The additional 'h', 'n', 'b', and 'l' specifiers are used to specify
- host, network, big or little endian order addresses respectively. Where
- no specifier is provided the default network/big endian order is used.
- Passed by reference.
- IPv6 addresses:
- %pI6 0001:0002:0003:0004:0005:0006:0007:0008
- %pi6 00010002000300040005000600070008
- %pI6c 1:2:3:4:5:6:7:8
- For printing IPv6 network-order 16-bit hex addresses. The 'I6' and 'i6'
- specifiers result in a printed address with ('I6') or without ('i6')
- colon-separators. Leading zeros are always used.
- The additional 'c' specifier can be used with the 'I' specifier to
- print a compressed IPv6 address as described by
- http://tools.ietf.org/html/rfc5952
- Passed by reference.
- IPv4/IPv6 addresses (generic, with port, flowinfo, scope):
- %pIS 1.2.3.4 or 0001:0002:0003:0004:0005:0006:0007:0008
- %piS 001.002.003.004 or 00010002000300040005000600070008
- %pISc 1.2.3.4 or 1:2:3:4:5:6:7:8
- %pISpc 1.2.3.4:12345 or [1:2:3:4:5:6:7:8]:12345
- %p[Ii]S[pfschnbl]
- For printing an IP address without the need to distinguish whether it's
- of type AF_INET or AF_INET6, a pointer to a valid 'struct sockaddr',
- specified through 'IS' or 'iS', can be passed to this format specifier.
- The additional 'p', 'f', and 's' specifiers are used to specify port
- (IPv4, IPv6), flowinfo (IPv6) and scope (IPv6). Ports have a ':' prefix,
- flowinfo a '/' and scope a '%', each followed by the actual value.
- In case of an IPv6 address the compressed IPv6 address as described by
- http://tools.ietf.org/html/rfc5952 is being used if the additional
- specifier 'c' is given. The IPv6 address is surrounded by '[', ']' in
- case of additional specifiers 'p', 'f' or 's' as suggested by
- https://tools.ietf.org/html/draft-ietf-6man-text-addr-representation-07
- In case of IPv4 addresses, the additional 'h', 'n', 'b', and 'l'
- specifiers can be used as well and are ignored in case of an IPv6
- address.
- Passed by reference.
- Further examples:
- %pISfc 1.2.3.4 or [1:2:3:4:5:6:7:8]/123456789
- %pISsc 1.2.3.4 or [1:2:3:4:5:6:7:8]%1234567890
- %pISpfc 1.2.3.4:12345 or [1:2:3:4:5:6:7:8]:12345/123456789
- UUID/GUID addresses:
- %pUb 00010203-0405-0607-0809-0a0b0c0d0e0f
- %pUB 00010203-0405-0607-0809-0A0B0C0D0E0F
- %pUl 03020100-0504-0706-0809-0a0b0c0e0e0f
- %pUL 03020100-0504-0706-0809-0A0B0C0E0E0F
- For printing 16-byte UUID/GUIDs addresses. The additional 'l', 'L',
- 'b' and 'B' specifiers are used to specify a little endian order in
- lower ('l') or upper case ('L') hex characters - and big endian order
- in lower ('b') or upper case ('B') hex characters.
- Where no additional specifiers are used the default big endian
- order with lower case hex characters will be printed.
- Passed by reference.
- dentry names:
- %pd{,2,3,4}
- %pD{,2,3,4}
- For printing dentry name; if we race with d_move(), the name might be
- a mix of old and new ones, but it won't oops. %pd dentry is a safer
- equivalent of %s dentry->d_name.name we used to use, %pd<n> prints
- n last components. %pD does the same thing for struct file.
- Passed by reference.
- struct va_format:
- %pV
- For printing struct va_format structures. These contain a format string
- and va_list as follows:
- struct va_format {
- const char *fmt;
- va_list *va;
- };
- Do not use this feature without some mechanism to verify the
- correctness of the format string and va_list arguments.
- Passed by reference.
- struct clk:
- %pC pll1
- %pCn pll1
- %pCr 1560000000
- For printing struct clk structures. '%pC' and '%pCn' print the name
- (Common Clock Framework) or address (legacy clock framework) of the
- structure; '%pCr' prints the current clock rate.
- Passed by reference.
- bitmap and its derivatives such as cpumask and nodemask:
- %*pb 0779
- %*pbl 0,3-6,8-10
- For printing bitmap and its derivatives such as cpumask and nodemask,
- %*pb output the bitmap with field width as the number of bits and %*pbl
- output the bitmap as range list with field width as the number of bits.
- Passed by reference.
- Thank you for your cooperation and attention.
- By Randy Dunlap <rdunlap@infradead.org> and
- Andrew Murray <amurray@mpc-data.co.uk>
|