From mboxrd@z Thu Jan 1 00:00:00 1970 From: compudj@krystal.dyndns.org (Mathieu Desnoyers) Date: Mon, 23 Feb 2009 13:15:31 -0500 Subject: [ltt-dev] [PATCH take2 06/13] introduce ltt_serialize_printf() In-Reply-To: <498A5D94.9050800@cn.fujitsu.com> References: <498A5D94.9050800@cn.fujitsu.com> Message-ID: <20090223181531.GE31815@Krystal> * Lai Jiangshan (laijs at cn.fujitsu.com) wrote: > introduce ltt_serialize_printf() for format binary data which is in > ltt-relay buffer to human readable text string. > > Signed-off-by: Lai Jiangshan > --- > diff --git a/include/linux/ltt-tracer.h b/include/linux/ltt-tracer.h > index 42fc47d..7cb8f14 100644 > --- a/include/linux/ltt-tracer.h > +++ b/include/linux/ltt-tracer.h > @@ -118,6 +118,9 @@ extern void ltt_vtrace(const struct marker *mdata, void *probe_data, > extern void ltt_trace(const struct marker *mdata, void *probe_data, > void *call_data, const char *fmt, ...); > > +size_t ltt_serialize_printf(struct rchan_buf *buf, size_t buf_offset, > + u32 *msg_size, char *output, size_t outlen, const char *fmt); > + > /* > * Unique ID assigned to each registered probe. > */ > diff --git a/ltt/ltt-serialize.c b/ltt/ltt-serialize.c > index 0ca6683..b1e9f7e 100644 > --- a/ltt/ltt-serialize.c > +++ b/ltt/ltt-serialize.c > @@ -227,7 +227,7 @@ parse_end: > * %n not supported. > */ > static inline const char *parse_c_type(const char *fmt, > - char *c_size, enum ltt_type *c_type) > + char *c_size, enum ltt_type *c_type, char *outfmt) > { > int qualifier; /* 'h', 'l', or 'L' for integer fields */ > /* 'z' support added 23/7/1999 S.H. */ > @@ -259,6 +259,13 @@ repeat: > } > } > > + if (outfmt) { > + if (qualifier != -1) > + *outfmt++ = (char)qualifier; > + *outfmt++ = *fmt; > + *outfmt = 0; > + } > + > switch (*fmt) { > case 'c': > *c_type = LTT_TYPE_UNSIGNED_INT; > @@ -502,7 +509,7 @@ notrace size_t ltt_serialize_data(struct rchan_buf *buf, size_t buf_offset, > ++fmt; /* skip first '%' */ > if (*fmt == '%') /* Escaped %% */ > break; > - fmt = parse_c_type(fmt, &c_size, &c_type); > + fmt = parse_c_type(fmt, &c_size, &c_type, NULL); > /* > * Output c types if no trace types has been > * specified. > @@ -573,6 +580,118 @@ static inline uint64_t unserialize_base_type(struct rchan_buf *buf, > return 0; > } > > +static inline int serialize_printf_data(struct rchan_buf *buf, size_t *ppos, > + char trace_size, enum ltt_type trace_type, > + char c_size, enum ltt_type c_type, > + char *output, size_t outlen, const char *outfmt) > +{ > + u64 value; > + outlen = (ssize_t)outlen < 0 ? 0 : outlen; > + > + if (trace_type == LTT_TYPE_STRING) { > + size_t len = ltt_relay_read_cstr(buf, *ppos, output, outlen); > + *ppos += len + 1; > + return len; > + } > + > + value = unserialize_base_type(buf, ppos, trace_size, trace_type); > + > + if (c_size == 8) > + return snprintf(output, outlen, outfmt, value); > + else > + return snprintf(output, outlen, outfmt, (unsigned int)value); > +} > + > +/** > + * ltt_serialize_printf - Format a string and place it in a buffer > + * @buf: The ltt-relay buffer that store binary data > + * @buf_offset: binary data's offset in @buf > + * @msg_size: return message's length > + * @output: The buffer to place the result into > + * @outlen: The size of the buffer, including the trailing null space Maybe this header should describe that outlen can have a negative ssize_t value ? And then what does that mean ? Why are we doing a max_t at the beginning of ltt_serialize_printf ? > + * @fmt: The format string to use > + * > + * The return value is the number of characters which would > + * be generated for the given input, excluding the trailing > + * '\0', as per ISO C99. If the return is greater than or equal to @size, Do you mean @outlen ? > + * the resulting string is truncated. > + */ > +size_t ltt_serialize_printf(struct rchan_buf *buf, size_t buf_offset, > + u32 *msg_size, char *output, size_t outlen, const char *fmt) > +{ > + char trace_size = 0, c_size = 0; /* > + * 0 (unset), 1, 2, 4, 8 bytes. > + */ > + enum ltt_type trace_type = LTT_TYPE_NONE, c_type = LTT_TYPE_NONE; > + unsigned long attributes = 0; > + char outfmt[4] = "%"; > + size_t outpos = 0; > + size_t len; > + size_t msgpos = buf_offset; > + outlen = max_t(ssize_t, 0, outlen); > + > + for (; *fmt ; ++fmt) { > + switch (*fmt) { > + case '#': > + /* tracetypes (#) */ > + ++fmt; /* skip first '#' */ > + if (*fmt == '#') { /* Escaped ## */ > + if (outpos < outlen) > + output[outpos] = '#'; Does outlen contain the final \0 ? Where is this \0 written to the output ? And I worry about off-by-one here. Mathieu > + outpos++; > + break; > + } > + attributes = 0; > + fmt = parse_trace_type(fmt, &trace_size, &trace_type, > + &attributes); > + break; > + case '%': > + /* c types (%) */ > + ++fmt; /* skip first '%' */ > + if (*fmt == '%') { /* Escaped %% */ > + if (outpos < outlen) > + output[outpos] = '%'; > + outpos++; > + break; > + } > + fmt = parse_c_type(fmt, &c_size, &c_type, outfmt + 1); > + /* > + * Output c types if no trace types has been > + * specified. > + */ > + if (!trace_size) > + trace_size = c_size; > + if (trace_type == LTT_TYPE_NONE) > + trace_type = c_type; > + if (c_type == LTT_TYPE_STRING) > + trace_type = LTT_TYPE_STRING; > + > + /* perform trace printf */ > + len = serialize_printf_data(buf, &msgpos, trace_size, > + trace_type, c_size, c_type, > + output + outpos, outlen - outpos, > + outfmt); > + outpos += len; > + trace_size = 0; > + c_size = 0; > + trace_type = LTT_TYPE_NONE; > + c_size = LTT_TYPE_NONE; > + attributes = 0; > + break; > + default: > + if (outpos < outlen) > + output[outpos] = *fmt; > + outpos++; > + break; > + } > + } > + if (msg_size) > + *msg_size = msgpos - buf_offset; > + > + return outpos; > +} > +EXPORT_SYMBOL_GPL(ltt_serialize_printf); > + > /* > * Calculate data size > * Assume that the padding for alignment starts at a sizeof(void *) address. > > > > _______________________________________________ > ltt-dev mailing list > ltt-dev at lists.casi.polymtl.ca > http://lists.casi.polymtl.ca/cgi-bin/mailman/listinfo/ltt-dev > -- Mathieu Desnoyers OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68