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diff --git a/doc/man/pt_blk_next.3.md b/doc/man/pt_blk_next.3.md new file mode 100644 index 0000000000000..ff576ef01d3ef --- /dev/null +++ b/doc/man/pt_blk_next.3.md @@ -0,0 +1,285 @@ +% PT_BLK_NEXT(3) + +<!--- + ! Copyright (c) 2016-2019, Intel Corporation + ! + ! Redistribution and use in source and binary forms, with or without + ! modification, are permitted provided that the following conditions are met: + ! + ! * Redistributions of source code must retain the above copyright notice, + ! this list of conditions and the following disclaimer. + ! * Redistributions in binary form must reproduce the above copyright notice, + ! this list of conditions and the following disclaimer in the documentation + ! and/or other materials provided with the distribution. + ! * Neither the name of Intel Corporation nor the names of its contributors + ! may be used to endorse or promote products derived from this software + ! without specific prior written permission. + ! + ! THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + ! AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + ! IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + ! ARE DISCLAIMED. IN NO NEXT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE + ! LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + ! CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + ! SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + ! INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + ! CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + ! ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + ! POSSIBILITY OF SUCH DAMAGE. + !--> + +# NAME + +pt_blk_next, pt_block - iterate over blocks of traced instructions + + +# SYNOPSIS + +| **\#include `<intel-pt.h>`** +| +| **struct pt_block;** +| +| **int pt_blk_next(struct pt_blk_decoder \**decoder*,** +| **struct pt_blk \**blk*, size_t *size*);** +| +| **int pt_blk_next(struct pt_block_decoder \**decoder*,** +| **struct pt_block \**block*, size_t *size*);** + +Link with *-lipt*. + + +# DESCRIPTION + +**pt_blk_next**() provides the next block of instructions in execution order, +which is described by the *pt_block* structure. + +The *size* argument must be set to *sizeof(struct pt_block)*. The function will +provide at most *size* bytes of the *pt_block* structure. A newer decoder +library may truncate an extended *pt_block* object to *size* bytes. + +An older decoder library may provide less *pt_block* fields. Fields that are +not provided will be zero-initialized. For fields where zero is a valid value +(e.g. for bit-fields), check the decoder library version to determine which +fields are valid. See **pt_library_version**(3). + +On success, the next block of instructions is provided in the *pt_block* object +pointed to by the *block* argument. The *pt_block* structure is declared as: + +~~~{.c} +/** A block of instructions. + * + * Instructions in this block are executed sequentially but are not necessarily + * contiguous in memory. Users are expected to follow direct branches. + */ +struct pt_block { + /** The IP of the first instruction in this block. */ + uint64_t ip; + + /** The IP of the last instruction in this block. + * + * This can be used for error-detection. + */ + uint64_t end_ip; + + /** The image section that contains the instructions in this block. + * + * A value of zero means that the section did not have an identifier. + * The section was not added via an image section cache or the memory + * was read via the read memory callback. + */ + int isid; + + /** The execution mode for all instructions in this block. */ + enum pt_exec_mode mode; + + /** The instruction class for the last instruction in this block. + * + * This field may be set to ptic_error to indicate that the instruction + * class is not available. The block decoder may choose to not provide + * the instruction class in some cases for performance reasons. + */ + enum pt_insn_class iclass; + + /** The number of instructions in this block. */ + uint16_t ninsn; + + /** The raw bytes of the last instruction in this block in case the + * instruction does not fit entirely into this block's section. + * + * This field is only valid if \@truncated is set. + */ + uint8_t raw[pt_max_insn_size]; + + /** The size of the last instruction in this block in bytes. + * + * This field is only valid if \@truncated is set. + */ + uint8_t size; + + /** A collection of flags giving additional information about the + * instructions in this block. + * + * - all instructions in this block were executed speculatively. + */ + uint32_t speculative:1; + + /** - the last instruction in this block is truncated. + * + * It starts in this block's section but continues in one or more + * other sections depending on how fragmented the memory image is. + * + * The raw bytes for the last instruction are provided in \@raw and + * its size in \@size in this case. + */ + uint32_t truncated:1; +}; +~~~ + +The fields of the *pt_block* structure are described in more detail below: + +ip +: The virtual address of the first instruction in the block. The address + should be interpreted in the current address space context. + +end_ip +: The virtual address of the last instruction in the block. The address + should be interpreted in the current address space context. + + This can be used for error detection. Reconstruction of the instructions in + a block should end with the last instruction at *end_ip*. + +isid +: The image section identifier of the section from which the block of + instructions originated. This will be zero unless the instructions came + from a section that was added via an image section cache. See + **pt_image_add_cached**(3). + + The image section identifier can be used for reading the memory containing + an instruction in order to decode it and for tracing an instruction back to + its binary file and from there to source code. + +mode +: The execution mode at which the instructions in the block were executed. + The *pt_exec_mode* enumeration is declared as: + +~~~{.c} +/** An execution mode. */ +enum pt_exec_mode { + ptem_unknown, + ptem_16bit, + ptem_32bit, + ptem_64bit +}; +~~~ + +iclass +: A coarse classification of the last instruction in the block. This may be + *ptic_error* to indicate that the classification is not available. + + The block decoder knows the instruction class of the instruction that ended + the block most of the time. If it does, it provides this information to + save the caller the effort of decoding the instruction in some cases. + +ninsn +: The number of instructions contained in this block. + + The instructions are sequential in the sense that no trace is required for + reconstructing them. They are not necessarily contiguous in memory. + + The IP of the first instruction is given in the *ip* field and the IP of + other instructions can be determined by decoding and examining the previous + instruction. + +raw +: If the last instruction of this block can not be read entirely from this + block's section, this field provides the instruction's raw bytes. + + It is only valid if the *truncated* flag is set. + +size +: If the last instruction of this block can not be read entirely from this + block's section, this field provides the instruction's size in bytes. + + It is only valid if the *truncated* flag is set. + +speculative +: A flag giving the speculative execution status of all instructions in the + block. If set, the instructions were executed speculatively. Otherwise, + the instructions were executed normally. + +truncated +: A flag saying whether the last instruction in this block can not be read + entirely from this block's section. Some bytes need to be read from one or + more other sections. This can happen when an image section is partially + overwritten by another image section. + + If set, the last instruction's memory is provided in *raw* and its size in + *size*. + + +# RETURN VALUE + +**pt_blk_next**() returns zero or a positive value on success or a negative +*pt_error_code* enumeration constant in case of an error. + +On success, a bit-vector of *pt_status_flag* enumeration constants is returned. +The *pt_status_flag* enumeration is declared as: + +~~~{.c} +/** Decoder status flags. */ +enum pt_status_flag { + /** There is an event pending. */ + pts_event_pending = 1 << 0, + + /** The address has been suppressed. */ + pts_ip_suppressed = 1 << 1, + + /** There is no more trace data available. */ + pts_eos = 1 << 2 +}; +~~~ + +The *pts_event_pending* flag indicates that one or more events are pending. Use +**pt_blk_event**(3) to process pending events before calling **pt_blk_next**() +again. + +The *pt_eos* flag indicates that the information contained in the Intel PT +stream has been consumed. Further calls to **pt_blk_next**() will continue to +provide blocks for instructions as long as the instruction's addresses can be +determined without further trace. + + +# ERRORS + +pte_invalid +: The *decoder* or *block* argument is NULL or the *size* argument is too + small. + +pte_eos +: Decode reached the end of the trace stream. + +pte_nosync +: The decoder has not been synchronized onto the trace stream. Use + **pt_blk_sync_forward**(3), **pt_blk_sync_backward**(3), or + **pt_blk_sync_set**(3) to synchronize *decoder*. + +pte_bad_opc +: The decoder encountered an unsupported Intel PT packet opcode. + +pte_bad_packet +: The decoder encountered an unsupported Intel PT packet payload. + +pte_bad_query +: Execution flow reconstruction and trace got out of sync. + + This typically means that, on its way to the virtual address of the next + event, the decoder encountered a conditional or indirect branch for which it + did not find guidance in the trace. + + +# SEE ALSO + +**pt_blk_alloc_decoder**(3), **pt_blk_free_decoder**(3), +**pt_blk_sync_forward**(3), **pt_blk_sync_backward**(3), +**pt_blk_sync_set**(3), **pt_blk_time**(3), **pt_blk_core_bus_ratio**(3), +**pt_blk_event**(3) |