From 01c62426eee721c6faf63bba95d69453e0ce1822 Mon Sep 17 00:00:00 2001 From: Andrew Cooper Date: Wed, 1 Oct 2014 11:32:56 +0200 Subject: [PATCH] vsprintf: introduce %*ph extended format specifier for hex buffers This behaves in the same way as Linux. The 64 byte limit is arbitrary but long enough for practical purposes. Signed-off-by: Andrew Cooper Release-acked-by: Konrad Rzeszutek Wilk Re-structured code. Signed-off-by: Jan Beulich --- docs/misc/printk-formats.txt | 7 +++++++ xen/common/vsprintf.c | 28 ++++++++++++++++++++++++++++ 2 files changed, 35 insertions(+) diff --git a/docs/misc/printk-formats.txt b/docs/misc/printk-formats.txt index 3b4323a64a..dee0f3e8f7 100644 --- a/docs/misc/printk-formats.txt +++ b/docs/misc/printk-formats.txt @@ -3,6 +3,11 @@ Xen custom %p format options. A subset, borrowed from Linux. All parameters to a %p option should be compatible with void*. Regular pointers are fine. Numbers should make use of the _p() macro. +Raw buffer as hex string: + + %*ph Up to 64 characters, printed as "00 01 02 ... ff". Buffer length + expected via the field_width paramter. i.e. printk("%*ph", 8, buffer); + Symbol/Function pointers: %ps Symbol name with condition offset and size (iff offset != 0) @@ -16,5 +21,7 @@ Symbol/Function pointers: In the case that an appropriate symbol name can't be found, %p[sS] will fall back to '%p' and print the address in hex. +Domain and vCPU information: + %pv Domain and vCPU ID from a 'struct vcpu *' (printed as "dv") diff --git a/xen/common/vsprintf.c b/xen/common/vsprintf.c index e68886a1c2..065cc42525 100644 --- a/xen/common/vsprintf.c +++ b/xen/common/vsprintf.c @@ -272,6 +272,34 @@ static char *pointer(char *str, char *end, const char **fmt_ptr, /* Custom %p suffixes. See XEN_ROOT/docs/misc/printk-formats.txt */ switch ( fmt[1] ) { + case 'h': /* Raw buffer as hex string. */ + { + const uint8_t *hex_buffer = arg; + unsigned int i; + + /* Consumed 'h' from the format string. */ + ++*fmt_ptr; + + /* Bound user count from %* to between 0 and 64 bytes. */ + if ( field_width <= 0 ) + return str; + if ( field_width > 64 ) + field_width = 64; + + for ( i = 0; ; ) + { + /* Each byte: 2 chars, 0-padded, base 16, no hex prefix. */ + str = number(str, end, hex_buffer[i], 16, 2, -1, ZEROPAD); + + if ( ++i == field_width ) + return str; + + if ( str < end ) + *str = ' '; + ++str; + } + } + case 's': /* Symbol name with offset and size (iff offset != 0) */ case 'S': /* Symbol name unconditionally with offset and size */ { -- 2.30.2