kernel/linux.git/tools/perf/util/expr.c, branch v5.15.209

perf expr: Return -EINVAL for syntax error in expr__find_ids()

2026-06-01T15:35:35+00:00

[ Upstream commit 3a61fd866ef9aaa1d3158b460f852b74a2df07f4 ] expr__find_ids() propagates the parser return value directly. For syntax errors, the parser can return a positive value, but callers treat it as success, e.g., for below case on Arm64 platform: metric expr 100 * (STALL_SLOT_BACKEND / (CPU_CYCLES * #slots) - BR_MIS_PRED * 3 / CPU_CYCLES) for backend_bound parsing metric: 100 * (STALL_SLOT_BACKEND / (CPU_CYCLES * #slots) - BR_MIS_PRED * 3 / CPU_CYCLES) Failure to read '#slots' literal: #slots = nan syntax error Convert positive parser returns in expr__find_ids() to -EINVAL, as a result, the error value will be respected by callers. Before: perf stat -C 5 Failure to read '#slots'Failure to read '#slots'Failure to read '#slots'Failure to read '#slots'Segmentation fault After: perf stat -C 5 Failure to read '#slots'Cannot find metric or group `Default' Fixes: ded80bda8bc9 ("perf expr: Migrate expr ids table to a hashmap") Signed-off-by: Leo Yan Reviewed-by: Ian Rogers Signed-off-by: Namhyung Kim Signed-off-by: Sasha Levin

perf expr: Force encapsulation on expr_id_data

2020-11-16T17:09:18+00:00

This patch resolves some undefined behavior where variables in expr_id_data were accessed (for debugging) without being defined. To better enforce the tagged union behavior, the struct is moved into expr.c and accessors provided. Tag values (kinds) are explicitly identified. Signed-off-by: Ian Rogers Reviewed-By: Kajol Jain Acked-by: Jiri Olsa Link: https://lore.kernel.org/r/20200826153055.2067780-1-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo

perf metric: Add recursion check when processing nested metrics

2020-07-30T10:01:49+00:00

Keeping the stack of nested metrics via 'struct expr_id' objects and checking if we are in recursion via already processed metric. The stack is implemented as static array within the struct egroup with 100 entries, which should be enough nesting depth for any metric we have or plan to have at the moment. Adding test that simulates the recursion and checks we can detect it. Committer notes: Bumped RECURSION_ID_MAX to 1000 as per Jiri's reply to Paul Clark on the patch series e-mail discussion. Fixed these: tests/parse-metric.c:308:7: error: missing field 'val' initializer [-Werror,-Wmissing-field-initializers] { 0 }, ^ util/metricgroup.c:924:28: error: missing field 'parent' initializer [-Werror,-Wmissing-field-initializers] struct expr_ids ids = { 0 }; ^ util/metricgroup.c:924:26: error: suggest braces around initialization of subobject [-Werror,-Wmissing-braces] struct expr_ids ids = { 0 }; ^ {} util/metricgroup.c:924:26: error: suggest braces around initialization of subobject [-Werror,-Wmissing-braces] struct expr_ids ids = { 0 }; ^ {} util/metricgroup.c:924:28: error: missing field 'cnt' initializer [-Werror,-Wmissing-field-initializers] struct expr_ids ids = { 0 }; ^ Signed-off-by: Jiri Olsa Reviewed-by: Kajol Jain Acked-by: Ian Rogers Cc: Alexander Shishkin Cc: Andi Kleen Cc: John Garry Cc: Michael Petlan Cc: Namhyung Kim Cc: Paul Clarke Cc: Peter Zijlstra Cc: Stephane Eranian Link: http://lore.kernel.org/lkml/20200719181320.785305-16-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf metric: Compute referenced metrics

2020-07-30T10:01:49+00:00

Adding computation (expr__parse call) of referenced metric at the point when it needs to be resolved during the parent metric computation. Once the inner metric is computed, the result is stored and used if there's another usage of that metric. Signed-off-by: Jiri Olsa Reviewed-by: Kajol Jain Acked-by: Ian Rogers Cc: Alexander Shishkin Cc: Andi Kleen Cc: John Garry Cc: Michael Petlan Cc: Namhyung Kim Cc: Paul Clarke Cc: Peter Zijlstra Cc: Stephane Eranian Link: http://lore.kernel.org/lkml/20200719181320.785305-12-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf metric: Add referenced metrics to hash data

2020-07-30T10:01:49+00:00

Adding referenced metrics to the parsing context so they can be resolved during the metric processing. Adding expr__add_ref function to store referenced metrics into parse context. Signed-off-by: Jiri Olsa Reviewed-by: Kajol Jain Acked-by: Ian Rogers Cc: Alexander Shishkin Cc: Andi Kleen Cc: John Garry Cc: Michael Petlan Cc: Namhyung Kim Cc: Paul Clarke Cc: Peter Zijlstra Cc: Stephane Eranian Link: http://lore.kernel.org/lkml/20200719181320.785305-11-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf metric: Add expr__del_id function

2020-07-30T10:01:49+00:00

Adding expr__del_id function to remove ID from hashmap. It will save us few lines in following changes. Signed-off-by: Jiri Olsa Reviewed-by: Kajol Jain Acked-by: Ian Rogers Cc: Alexander Shishkin Cc: Andi Kleen Cc: John Garry Cc: Michael Petlan Cc: Namhyung Kim Cc: Paul Clarke Cc: Peter Zijlstra Cc: Stephane Eranian Link: http://lore.kernel.org/lkml/20200719181320.785305-5-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf metric: Change expr__get_id to return struct expr_id_data

2020-07-30T10:01:49+00:00

Changing expr__get_id to use and return struct expr_id_data pointer as value for the ID. This way we can access data other than value for given ID in following changes. Signed-off-by: Jiri Olsa Reviewed-by: Kajol Jain Acked-by: Ian Rogers Cc: Alexander Shishkin Cc: Andi Kleen Cc: John Garry Cc: Michael Petlan Cc: Namhyung Kim Cc: Paul Clarke Cc: Peter Zijlstra Cc: Stephane Eranian Link: http://lore.kernel.org/lkml/20200719181320.785305-4-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf metric: Add expr__add_id function

2020-07-30T10:01:49+00:00

Add the expr__add_id() function to data for ID with zero value, which is used when scanning the expression for IDs. Signed-off-by: Jiri Olsa Reviewed-by: Kajol Jain Acked-by: Ian Rogers Cc: Alexander Shishkin Cc: Andi Kleen Cc: John Garry Cc: Michael Petlan Cc: Namhyung Kim Cc: Paul Clarke Cc: Peter Zijlstra Cc: Stephane Eranian Link: http://lore.kernel.org/lkml/20200719181320.785305-3-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf metric: Fix memory leak in expr__add_id function

2020-07-30T10:01:49+00:00

Arnaldo found that we don't release value data in case the hashmap__set fails. Releasing it in case of an error. Reported-by: Arnaldo Carvalho de Melo Signed-off-by: Jiri Olsa Acked-by: Ian Rogers Cc: Alexander Shishkin Cc: Andi Kleen Cc: John Garry Cc: Kajol Jain Cc: Michael Petlan Cc: Namhyung Kim Cc: Paul Clarke Cc: Peter Zijlstra Cc: Stephane Eranian Link: http://lore.kernel.org/lkml/20200719181320.785305-2-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf metric: Add 'struct expr_id_data' to keep expr value

2020-07-17T12:09:48+00:00

Add 'struct expr_id_data' to keep an expr value instead of just a simple double pointer, so we can store more data for ID in the following changes. Signed-off-by: Jiri Olsa Acked-by: Ian Rogers Cc: Alexander Shishkin Cc: Andi Kleen Cc: John Garry Cc: Kajol Jain Cc: Michael Petlan Cc: Namhyung Kim Cc: Paul Clarke Cc: Peter Zijlstra Cc: Stephane Eranian Link: http://lore.kernel.org/lkml/20200712132634.138901-3-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo