diff options
Diffstat (limited to 'Documentation/printk-formats.txt')
| -rw-r--r-- | Documentation/printk-formats.txt | 92 |
1 files changed, 83 insertions, 9 deletions
diff --git a/Documentation/printk-formats.txt b/Documentation/printk-formats.txt index 5df176ed59b..b4498218c47 100644 --- a/Documentation/printk-formats.txt +++ b/Documentation/printk-formats.txt @@ -17,6 +17,8 @@ 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 @@ -53,11 +55,38 @@ Struct Resources: For printing struct resources. The 'R' and 'r' specifiers result in a printed resource with ('R') or without ('r') a decoded flags member. +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 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 @@ -67,11 +96,15 @@ MAC/FDDI addresses: 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. + IPv4 addresses: %pI4 1.2.3.4 %pi4 001.002.003.004 - %p[Ii][hnbl] + %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') @@ -95,6 +128,38 @@ IPv6 addresses: print a compressed IPv6 address as described by http://tools.ietf.org/html/rfc5952 +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. + + 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 @@ -110,6 +175,15 @@ UUID/GUID addresses: Where no additional specifiers are used the default little endian order with lower case hex characters will be printed. +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. + struct va_format: %pV @@ -125,18 +199,18 @@ struct va_format: Do not use this feature without some mechanism to verify the correctness of the format string and va_list arguments. -u64 SHOULD be printed with %llu/%llx, (unsigned long long): +u64 SHOULD be printed with %llu/%llx: - printk("%llu", (unsigned long long)u64_var); + printk("%llu", u64_var); -s64 SHOULD be printed with %lld/%llx, (long long): +s64 SHOULD be printed with %lld/%llx: - printk("%lld", (long long)s64_var); + printk("%lld", s64_var); If <type> is dependent on a config option for its size (e.g., sector_t, -blkcnt_t, phys_addr_t, resource_size_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: +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); @@ -146,5 +220,5 @@ Reminder: sizeof() result is of type size_t. Thank you for your cooperation and attention. -By Randy Dunlap <rdunlap@xenotime.net> and +By Randy Dunlap <rdunlap@infradead.org> and Andrew Murray <amurray@mpc-data.co.uk> |