On Tue, Feb 02, 2021 at 09:40:40PM +0000, Mike Leach wrote:
> The current fixed metadata version format (version 0), means that adding
> metadata parameter items renders files from a previous version of perf
> unreadable. Per CPU parameters appear in a fixed order, but there is no
> field to indicate the number of ETM parameters per CPU.
> 
> This patch updates the per CPU parameter blocks to include a NR_PARAMs
> value which indicates the number of parameters in the block.
> 
> The header version is incremented to 1. Fixed ordering is retained,
> new ETM parameters are added to the end of the list.
> 
> The reader code is updated to be able to read current version 0 files,
> For version 1, the reader will read the number of parameters in the
> per CPU block. This allows the reader to process older or newer files
> that may have different numbers of parameters than in use at the
> time perf was built.
> 
> Signed-off-by: Mike Leach <mike.le...@linaro.org>
> Reviewed-by: Leo Yan <leo....@linaro.org>
> Tested-by: Leo Yan <leo....@linaro.org>
>

Reviewed-by: Mathieu Poirier <mathieu.poir...@linaro.org>

Please rebase this patch on 5.12-rc1 when it comes out and resend to Arnaldo.

Thanks,
Mathieu
 
> ---
> 
> Changes since v4
> 1. Syntax fixes suggested by Mathieu.
> 
> Changes since v3
> 1. Fixed index bug (Leo)
> 
> Changes since v2
> 1. Add error path print to improve --dump logging
> 2. Replace some hardcoded values with enum consts (Mathieu).
> 
> Changes since v1 (from Review by Leo):
> 1. Split printing routine into sub functions per version
> 2. Renamed NR_PARAMs to NR_TRC_PARAMs to emphasise use as count of trace
> related parameters, not total block parameter.
> 3. Misc other fixes.
> ---
>  tools/perf/arch/arm/util/cs-etm.c |   7 +-
>  tools/perf/util/cs-etm.c          | 235 ++++++++++++++++++++++++------
>  tools/perf/util/cs-etm.h          |  30 +++-
>  3 files changed, 223 insertions(+), 49 deletions(-)
> 
> diff --git a/tools/perf/arch/arm/util/cs-etm.c 
> b/tools/perf/arch/arm/util/cs-etm.c
> index bd446aba64f7..b0470f2a955a 100644
> --- a/tools/perf/arch/arm/util/cs-etm.c
> +++ b/tools/perf/arch/arm/util/cs-etm.c
> @@ -572,7 +572,7 @@ static void cs_etm_get_metadata(int cpu, u32 *offset,
>                               struct auxtrace_record *itr,
>                               struct perf_record_auxtrace_info *info)
>  {
> -     u32 increment;
> +     u32 increment, nr_trc_params;
>       u64 magic;
>       struct cs_etm_recording *ptr =
>                       container_of(itr, struct cs_etm_recording, itr);
> @@ -607,6 +607,7 @@ static void cs_etm_get_metadata(int cpu, u32 *offset,
>  
>               /* How much space was used */
>               increment = CS_ETMV4_PRIV_MAX;
> +             nr_trc_params = CS_ETMV4_PRIV_MAX - CS_ETMV4_TRCCONFIGR;
>       } else {
>               magic = __perf_cs_etmv3_magic;
>               /* Get configuration register */
> @@ -624,11 +625,13 @@ static void cs_etm_get_metadata(int cpu, u32 *offset,
>  
>               /* How much space was used */
>               increment = CS_ETM_PRIV_MAX;
> +             nr_trc_params = CS_ETM_PRIV_MAX - CS_ETM_ETMCR;
>       }
>  
>       /* Build generic header portion */
>       info->priv[*offset + CS_ETM_MAGIC] = magic;
>       info->priv[*offset + CS_ETM_CPU] = cpu;
> +     info->priv[*offset + CS_ETM_NR_TRC_PARAMS] = nr_trc_params;
>       /* Where the next CPU entry should start from */
>       *offset += increment;
>  }
> @@ -674,7 +677,7 @@ static int cs_etm_info_fill(struct auxtrace_record *itr,
>  
>       /* First fill out the session header */
>       info->type = PERF_AUXTRACE_CS_ETM;
> -     info->priv[CS_HEADER_VERSION_0] = 0;
> +     info->priv[CS_HEADER_VERSION] = CS_HEADER_CURRENT_VERSION;
>       info->priv[CS_PMU_TYPE_CPUS] = type << 32;
>       info->priv[CS_PMU_TYPE_CPUS] |= nr_cpu;
>       info->priv[CS_ETM_SNAPSHOT] = ptr->snapshot_mode;
> diff --git a/tools/perf/util/cs-etm.c b/tools/perf/util/cs-etm.c
> index a2a369e2fbb6..ee32d023e9bd 100644
> --- a/tools/perf/util/cs-etm.c
> +++ b/tools/perf/util/cs-etm.c
> @@ -2435,7 +2435,7 @@ static bool cs_etm__is_timeless_decoding(struct 
> cs_etm_auxtrace *etm)
>  }
>  
>  static const char * const cs_etm_global_header_fmts[] = {
> -     [CS_HEADER_VERSION_0]   = "     Header version                 %llx\n",
> +     [CS_HEADER_VERSION]     = "     Header version                 %llx\n",
>       [CS_PMU_TYPE_CPUS]      = "     PMU type/num cpus              %llx\n",
>       [CS_ETM_SNAPSHOT]       = "     Snapshot                       %llx\n",
>  };
> @@ -2443,6 +2443,7 @@ static const char * const cs_etm_global_header_fmts[] = 
> {
>  static const char * const cs_etm_priv_fmts[] = {
>       [CS_ETM_MAGIC]          = "     Magic number                   %llx\n",
>       [CS_ETM_CPU]            = "     CPU                            %lld\n",
> +     [CS_ETM_NR_TRC_PARAMS]  = "     NR_TRC_PARAMS                  %llx\n",
>       [CS_ETM_ETMCR]          = "     ETMCR                          %llx\n",
>       [CS_ETM_ETMTRACEIDR]    = "     ETMTRACEIDR                    %llx\n",
>       [CS_ETM_ETMCCER]        = "     ETMCCER                        %llx\n",
> @@ -2452,6 +2453,7 @@ static const char * const cs_etm_priv_fmts[] = {
>  static const char * const cs_etmv4_priv_fmts[] = {
>       [CS_ETM_MAGIC]          = "     Magic number                   %llx\n",
>       [CS_ETM_CPU]            = "     CPU                            %lld\n",
> +     [CS_ETM_NR_TRC_PARAMS]  = "     NR_TRC_PARAMS                  %llx\n",
>       [CS_ETMV4_TRCCONFIGR]   = "     TRCCONFIGR                     %llx\n",
>       [CS_ETMV4_TRCTRACEIDR]  = "     TRCTRACEIDR                    %llx\n",
>       [CS_ETMV4_TRCIDR0]      = "     TRCIDR0                        %llx\n",
> @@ -2461,26 +2463,167 @@ static const char * const cs_etmv4_priv_fmts[] = {
>       [CS_ETMV4_TRCAUTHSTATUS] = "    TRCAUTHSTATUS                  %llx\n",
>  };
>  
> -static void cs_etm__print_auxtrace_info(__u64 *val, int num)
> +static const char * const param_unk_fmt =
> +     "       Unknown parameter [%d]         %llx\n";
> +static const char * const magic_unk_fmt =
> +     "       Magic number Unknown           %llx\n";
> +
> +static int cs_etm__print_cpu_metadata_v0(__u64 *val, int *offset)
>  {
> -     int i, j, cpu = 0;
> +     int i = *offset, j, nr_params = 0, fmt_offset;
> +     __u64 magic;
>  
> -     for (i = 0; i < CS_HEADER_VERSION_0_MAX; i++)
> -             fprintf(stdout, cs_etm_global_header_fmts[i], val[i]);
> +     /* check magic value */
> +     magic = val[i + CS_ETM_MAGIC];
> +     if ((magic != __perf_cs_etmv3_magic) &&
> +         (magic != __perf_cs_etmv4_magic)) {
> +             /* failure - note bad magic value */
> +             fprintf(stdout, magic_unk_fmt, magic);
> +             return -EINVAL;
> +     }
> +
> +     /* print common header block */
> +     fprintf(stdout, cs_etm_priv_fmts[CS_ETM_MAGIC], val[i++]);
> +     fprintf(stdout, cs_etm_priv_fmts[CS_ETM_CPU], val[i++]);
> +
> +     if (magic == __perf_cs_etmv3_magic) {
> +             nr_params = CS_ETM_NR_TRC_PARAMS_V0;
> +             fmt_offset = CS_ETM_ETMCR;
> +             /* after common block, offset format index past NR_PARAMS */
> +             for (j = fmt_offset; j < nr_params + fmt_offset; j++, i++)
> +                     fprintf(stdout, cs_etm_priv_fmts[j], val[i]);
> +     } else if (magic == __perf_cs_etmv4_magic) {
> +             nr_params = CS_ETMV4_NR_TRC_PARAMS_V0;
> +             fmt_offset = CS_ETMV4_TRCCONFIGR;
> +             /* after common block, offset format index past NR_PARAMS */
> +             for (j = fmt_offset; j < nr_params + fmt_offset; j++, i++)
> +                     fprintf(stdout, cs_etmv4_priv_fmts[j], val[i]);
> +     }
> +     *offset = i;
> +     return 0;
> +}
> +
> +static int cs_etm__print_cpu_metadata_v1(__u64 *val, int *offset)
> +{
> +     int i = *offset, j, total_params = 0;
> +     __u64 magic;
> +
> +     magic = val[i + CS_ETM_MAGIC];
> +     /* total params to print is NR_PARAMS + common block size for v1 */
> +     total_params = val[i + CS_ETM_NR_TRC_PARAMS] + CS_ETM_COMMON_BLK_MAX_V1;
>  
> -     for (i = CS_HEADER_VERSION_0_MAX; cpu < num; cpu++) {
> -             if (val[i] == __perf_cs_etmv3_magic)
> -                     for (j = 0; j < CS_ETM_PRIV_MAX; j++, i++)
> +     if (magic == __perf_cs_etmv3_magic) {
> +             for (j = 0; j < total_params; j++, i++) {
> +                     /* if newer record - could be excess params */
> +                     if (j >= CS_ETM_PRIV_MAX)
> +                             fprintf(stdout, param_unk_fmt, j, val[i]);
> +                     else
>                               fprintf(stdout, cs_etm_priv_fmts[j], val[i]);
> -             else if (val[i] == __perf_cs_etmv4_magic)
> -                     for (j = 0; j < CS_ETMV4_PRIV_MAX; j++, i++)
> +             }
> +     } else if (magic == __perf_cs_etmv4_magic) {
> +             for (j = 0; j < total_params; j++, i++) {
> +                     /* if newer record - could be excess params */
> +                     if (j >= CS_ETMV4_PRIV_MAX)
> +                             fprintf(stdout, param_unk_fmt, j, val[i]);
> +                     else
>                               fprintf(stdout, cs_etmv4_priv_fmts[j], val[i]);
> -             else
> -                     /* failure.. return */
> +             }
> +     } else {
> +             /* failure - note bad magic value and error out */
> +             fprintf(stdout, magic_unk_fmt, magic);
> +             return -EINVAL;
> +     }
> +     *offset = i;
> +     return 0;
> +}
> +
> +static void cs_etm__print_auxtrace_info(__u64 *val, int num)
> +{
> +     int i, cpu = 0, version, err;
> +
> +     /* bail out early on bad header version */
> +     version = val[0];
> +     if (version > CS_HEADER_CURRENT_VERSION) {
> +             /* failure.. return */
> +             fprintf(stdout, "       Unknown Header Version = %x, ", 
> version);
> +             fprintf(stdout, "Version supported <= %x\n", 
> CS_HEADER_CURRENT_VERSION);
> +             return;
> +     }
> +
> +     for (i = 0; i < CS_HEADER_VERSION_MAX; i++)
> +             fprintf(stdout, cs_etm_global_header_fmts[i], val[i]);
> +
> +     for (i = CS_HEADER_VERSION_MAX; cpu < num; cpu++) {
> +             if (version == 0)
> +                     err = cs_etm__print_cpu_metadata_v0(val, &i);
> +             else if (version == 1)
> +                     err = cs_etm__print_cpu_metadata_v1(val, &i);
> +             if (err)
>                       return;
>       }
>  }
>  
> +/*
> + * Read a single cpu parameter block from the auxtrace_info priv block.
> + *
> + * For version 1 there is a per cpu nr_params entry. If we are handling
> + * version 1 file, then there may be less, the same, or more params
> + * indicated by this value than the compile time number we understand.
> + *
> + * For a version 0 info block, there are a fixed number, and we need to
> + * fill out the nr_param value in the metadata we create.
> + */
> +static u64 *cs_etm__create_meta_blk(u64 *buff_in, int *buff_in_offset,
> +                                 int out_blk_size, int nr_params_v0)
> +{
> +     u64 *metadata = NULL;
> +     int hdr_version;
> +     int nr_in_params, nr_out_params, nr_cmn_params;
> +     int i, k;
> +
> +     metadata = zalloc(sizeof(*metadata) * out_blk_size);
> +     if (!metadata)
> +             return NULL;
> +
> +     /* read block current index & version */
> +     i = *buff_in_offset;
> +     hdr_version = buff_in[CS_HEADER_VERSION];
> +
> +     if (!hdr_version) {
> +     /* read version 0 info block into a version 1 metadata block  */
> +             nr_in_params = nr_params_v0;
> +             metadata[CS_ETM_MAGIC] = buff_in[i + CS_ETM_MAGIC];
> +             metadata[CS_ETM_CPU] = buff_in[i + CS_ETM_CPU];
> +             metadata[CS_ETM_NR_TRC_PARAMS] = nr_in_params;
> +             /* remaining block params at offset +1 from source */
> +             for (k = CS_ETM_COMMON_BLK_MAX_V1 - 1; k < nr_in_params; k++)
> +                     metadata[k + 1] = buff_in[i + k];
> +             /* version 0 has 2 common params */
> +             nr_cmn_params = 2;
> +     } else {
> +     /* read version 1 info block - input and output nr_params may differ */
> +             /* version 1 has 3 common params */
> +             nr_cmn_params = 3;
> +             nr_in_params = buff_in[i + CS_ETM_NR_TRC_PARAMS];
> +
> +             /* if input has more params than output - skip excess */
> +             nr_out_params = nr_in_params + nr_cmn_params;
> +             if (nr_out_params > out_blk_size)
> +                     nr_out_params = out_blk_size;
> +
> +             for (k = CS_ETM_MAGIC; k < nr_out_params; k++)
> +                     metadata[k] = buff_in[i + k];
> +
> +             /* record the actual nr params we copied */
> +             metadata[CS_ETM_NR_TRC_PARAMS] = nr_out_params - nr_cmn_params;
> +     }
> +
> +     /* adjust in offset by number of in params used */
> +     i += nr_in_params + nr_cmn_params;
> +     *buff_in_offset = i;
> +     return metadata;
> +}
> +
>  int cs_etm__process_auxtrace_info(union perf_event *event,
>                                 struct perf_session *session)
>  {
> @@ -2492,11 +2635,12 @@ int cs_etm__process_auxtrace_info(union perf_event 
> *event,
>       int info_header_size;
>       int total_size = auxtrace_info->header.size;
>       int priv_size = 0;
> -     int num_cpu;
> -     int err = 0, idx = -1;
> -     int i, j, k;
> +     int num_cpu, trcidr_idx;
> +     int err = 0;
> +     int i, j;
>       u64 *ptr, *hdr = NULL;
>       u64 **metadata = NULL;
> +     u64 hdr_version;
>  
>       /*
>        * sizeof(auxtrace_info_event::type) +
> @@ -2512,16 +2656,21 @@ int cs_etm__process_auxtrace_info(union perf_event 
> *event,
>       /* First the global part */
>       ptr = (u64 *) auxtrace_info->priv;
>  
> -     /* Look for version '0' of the header */
> -     if (ptr[0] != 0)
> +     /* Look for version of the header */
> +     hdr_version = ptr[0];
> +     if (hdr_version > CS_HEADER_CURRENT_VERSION) {
> +             /* print routine will print an error on bad version */
> +             if (dump_trace)
> +                     cs_etm__print_auxtrace_info(auxtrace_info->priv, 0);
>               return -EINVAL;
> +     }
>  
> -     hdr = zalloc(sizeof(*hdr) * CS_HEADER_VERSION_0_MAX);
> +     hdr = zalloc(sizeof(*hdr) * CS_HEADER_VERSION_MAX);
>       if (!hdr)
>               return -ENOMEM;
>  
>       /* Extract header information - see cs-etm.h for format */
> -     for (i = 0; i < CS_HEADER_VERSION_0_MAX; i++)
> +     for (i = 0; i < CS_HEADER_VERSION_MAX; i++)
>               hdr[i] = ptr[i];
>       num_cpu = hdr[CS_PMU_TYPE_CPUS] & 0xffffffff;
>       pmu_type = (unsigned int) ((hdr[CS_PMU_TYPE_CPUS] >> 32) &
> @@ -2552,35 +2701,31 @@ int cs_etm__process_auxtrace_info(union perf_event 
> *event,
>        */
>       for (j = 0; j < num_cpu; j++) {
>               if (ptr[i] == __perf_cs_etmv3_magic) {
> -                     metadata[j] = zalloc(sizeof(*metadata[j]) *
> -                                          CS_ETM_PRIV_MAX);
> -                     if (!metadata[j]) {
> -                             err = -ENOMEM;
> -                             goto err_free_metadata;
> -                     }
> -                     for (k = 0; k < CS_ETM_PRIV_MAX; k++)
> -                             metadata[j][k] = ptr[i + k];
> +                     metadata[j] =
> +                             cs_etm__create_meta_blk(ptr, &i,
> +                                                     CS_ETM_PRIV_MAX,
> +                                                     
> CS_ETM_NR_TRC_PARAMS_V0);
>  
>                       /* The traceID is our handle */
> -                     idx = metadata[j][CS_ETM_ETMTRACEIDR];
> -                     i += CS_ETM_PRIV_MAX;
> +                     trcidr_idx = CS_ETM_ETMTRACEIDR;
> +
>               } else if (ptr[i] == __perf_cs_etmv4_magic) {
> -                     metadata[j] = zalloc(sizeof(*metadata[j]) *
> -                                          CS_ETMV4_PRIV_MAX);
> -                     if (!metadata[j]) {
> -                             err = -ENOMEM;
> -                             goto err_free_metadata;
> -                     }
> -                     for (k = 0; k < CS_ETMV4_PRIV_MAX; k++)
> -                             metadata[j][k] = ptr[i + k];
> +                     metadata[j] =
> +                             cs_etm__create_meta_blk(ptr, &i,
> +                                                     CS_ETMV4_PRIV_MAX,
> +                                                     
> CS_ETMV4_NR_TRC_PARAMS_V0);
>  
>                       /* The traceID is our handle */
> -                     idx = metadata[j][CS_ETMV4_TRCTRACEIDR];
> -                     i += CS_ETMV4_PRIV_MAX;
> +                     trcidr_idx = CS_ETMV4_TRCTRACEIDR;
> +             }
> +
> +             if (!metadata[j]) {
> +                     err = -ENOMEM;
> +                     goto err_free_metadata;
>               }
>  
>               /* Get an RB node for this CPU */
> -             inode = intlist__findnew(traceid_list, idx);
> +             inode = intlist__findnew(traceid_list, metadata[j][trcidr_idx]);
>  
>               /* Something went wrong, no need to continue */
>               if (!inode) {
> @@ -2601,7 +2746,7 @@ int cs_etm__process_auxtrace_info(union perf_event 
> *event,
>       }
>  
>       /*
> -      * Each of CS_HEADER_VERSION_0_MAX, CS_ETM_PRIV_MAX and
> +      * Each of CS_HEADER_VERSION_MAX, CS_ETM_PRIV_MAX and
>        * CS_ETMV4_PRIV_MAX mark how many double words are in the
>        * global metadata, and each cpu's metadata respectively.
>        * The following tests if the correct number of double words was
> @@ -2703,6 +2848,12 @@ int cs_etm__process_auxtrace_info(union perf_event 
> *event,
>       intlist__delete(traceid_list);
>  err_free_hdr:
>       zfree(&hdr);
> -
> +     /*
> +      * At this point, as a minimum we have valid header. Dump the rest of
> +      * the info section - the print routines will error out on structural
> +      * issues.
> +      */
> +     if (dump_trace)
> +             cs_etm__print_auxtrace_info(auxtrace_info->priv, num_cpu);
>       return err;
>  }
> diff --git a/tools/perf/util/cs-etm.h b/tools/perf/util/cs-etm.h
> index 4ad925d6d799..e153d02df0de 100644
> --- a/tools/perf/util/cs-etm.h
> +++ b/tools/perf/util/cs-etm.h
> @@ -17,23 +17,37 @@ struct perf_session;
>   */
>  enum {
>       /* Starting with 0x0 */
> -     CS_HEADER_VERSION_0,
> +     CS_HEADER_VERSION,
>       /* PMU->type (32 bit), total # of CPUs (32 bit) */
>       CS_PMU_TYPE_CPUS,
>       CS_ETM_SNAPSHOT,
> -     CS_HEADER_VERSION_0_MAX,
> +     CS_HEADER_VERSION_MAX,
>  };
>  
> +/*
> + * Update the version for new format.
> + *
> + * New version 1 format adds a param count to the per cpu metadata.
> + * This allows easy adding of new metadata parameters.
> + * Requires that new params always added after current ones.
> + * Also allows client reader to handle file versions that are different by
> + * checking the number of params in the file vs the number expected.
> + */
> +#define CS_HEADER_CURRENT_VERSION 1
> +
>  /* Beginning of header common to both ETMv3 and V4 */
>  enum {
>       CS_ETM_MAGIC,
>       CS_ETM_CPU,
> +     /* Number of trace config params in following ETM specific block */
> +     CS_ETM_NR_TRC_PARAMS,
> +     CS_ETM_COMMON_BLK_MAX_V1,
>  };
>  
>  /* ETMv3/PTM metadata */
>  enum {
>       /* Dynamic, configurable parameters */
> -     CS_ETM_ETMCR = CS_ETM_CPU + 1,
> +     CS_ETM_ETMCR = CS_ETM_COMMON_BLK_MAX_V1,
>       CS_ETM_ETMTRACEIDR,
>       /* RO, taken from sysFS */
>       CS_ETM_ETMCCER,
> @@ -41,10 +55,13 @@ enum {
>       CS_ETM_PRIV_MAX,
>  };
>  
> +/* define fixed version 0 length - allow new format reader to read old 
> files. */
> +#define CS_ETM_NR_TRC_PARAMS_V0 (CS_ETM_ETMIDR - CS_ETM_ETMCR + 1)
> +
>  /* ETMv4 metadata */
>  enum {
>       /* Dynamic, configurable parameters */
> -     CS_ETMV4_TRCCONFIGR = CS_ETM_CPU + 1,
> +     CS_ETMV4_TRCCONFIGR = CS_ETM_COMMON_BLK_MAX_V1,
>       CS_ETMV4_TRCTRACEIDR,
>       /* RO, taken from sysFS */
>       CS_ETMV4_TRCIDR0,
> @@ -55,6 +72,9 @@ enum {
>       CS_ETMV4_PRIV_MAX,
>  };
>  
> +/* define fixed version 0 length - allow new format reader to read old 
> files. */
> +#define CS_ETMV4_NR_TRC_PARAMS_V0 (CS_ETMV4_TRCAUTHSTATUS - 
> CS_ETMV4_TRCCONFIGR + 1)
> +
>  /*
>   * ETMv3 exception encoding number:
>   * See Embedded Trace Macrocell spcification (ARM IHI 0014Q)
> @@ -162,7 +182,7 @@ struct cs_etm_packet_queue {
>  
>  #define BMVAL(val, lsb, msb) ((val & GENMASK(msb, lsb)) >> lsb)
>  
> -#define CS_ETM_HEADER_SIZE (CS_HEADER_VERSION_0_MAX * sizeof(u64))
> +#define CS_ETM_HEADER_SIZE (CS_HEADER_VERSION_MAX * sizeof(u64))
>  
>  #define __perf_cs_etmv3_magic 0x3030303030303030ULL
>  #define __perf_cs_etmv4_magic 0x4040404040404040ULL
> -- 
> 2.17.1
> 

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