| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <ZpGfYVc_ewcsQxWL@google.com>
Date: Fri, 12 Jul 2024 16:25:53 -0500
From: Namhyung Kim <namhyung@...nel.org>
To: Athira Rajeev <atrajeev@...ux.vnet.ibm.com>
Cc: acme@...nel.org, jolsa@...nel.org, adrian.hunter@...el.com,
irogers@...gle.com, segher@...nel.crashing.org,
christophe.leroy@...roup.eu, linux-kernel@...r.kernel.org,
linux-perf-users@...r.kernel.org, linuxppc-dev@...ts.ozlabs.org,
akanksha@...ux.ibm.com, maddy@...ux.ibm.com, kjain@...ux.ibm.com,
disgoel@...ux.vnet.ibm.com
Subject: Re: [PATCH V6 17/18] tools/perf: Update data_type_cmp and
sort__typeoff_sort function to include var_name in comparison
On Sun, Jul 07, 2024 at 08:14:18PM +0530, Athira Rajeev wrote:
> Currently data_type_cmp() only compares size and type name.
> But in cases where the type name of two data type entries
> is same, but var_name is different, the comparison can't distinguish
> two different types.
>
> Consider there is a "long unsigned int" with var_name as "X" and there
> is global variable "long unsigned int". Currently since
> data_type_cmp uses only type_name for comparison ( "long unsigned int"),
> it won't distinguish these as separate entries. Update the
I'm still not sure if it's ok. It intentionally merges different
instances of the same type together as it's a data 'type' profile.
> functions "data_type_cmp" as well as "sort__typeoff_sort" to
> compare variable names after type name if it exists.
>
> Also updated "hist_entry__typeoff_snprintf" to print var_name if
> it is set. With the changes,
>
> 11.42% long unsigned int long unsigned int +0 (current_stack_pointer)
> 4.68% struct paca_struct struct paca_struct +2312 (__current)
> 4.57% struct paca_struct struct paca_struct +2354 (irq_soft_mask)
> 2.69% struct paca_struct struct paca_struct +2808 (canary)
> 2.68% struct paca_struct struct paca_struct +8 (paca_index)
> 2.24% struct paca_struct struct paca_struct +48 (data_offset)
> 1.43% long unsigned int long unsigned int +0 (no field)
It seems like an output of `perf report -s type,typeoff`. But I'm
curious how it'd work with -s type only? I guess it'd have two separate
entries for 'long unsigned int'. Ideally we can have a single entry
with two different fields.
For example, `perf report -s type,typeoff -H`:
12.85% long unsigned int
11.42% long unsigned int +0 (current_stack_pointer)
1.43% long unsigned int +0 (no field)
...
>
> Signed-off-by: Athira Rajeev <atrajeev@...ux.vnet.ibm.com>
> ---
> tools/perf/util/annotate-data.c | 24 ++++++++++++++++++++++--
> tools/perf/util/sort.c | 23 +++++++++++++++++++++--
> 2 files changed, 43 insertions(+), 4 deletions(-)
>
> diff --git a/tools/perf/util/annotate-data.c b/tools/perf/util/annotate-data.c
> index 8d05f3dbddf6..759c6a22e719 100644
> --- a/tools/perf/util/annotate-data.c
> +++ b/tools/perf/util/annotate-data.c
> @@ -167,7 +167,7 @@ static void exit_type_state(struct type_state *state)
> }
>
> /*
> - * Compare type name and size to maintain them in a tree.
> + * Compare type name, var_name and size to maintain them in a tree.
> * I'm not sure if DWARF would have information of a single type in many
> * different places (compilation units). If not, it could compare the
> * offset of the type entry in the .debug_info section.
> @@ -176,12 +176,32 @@ static int data_type_cmp(const void *_key, const struct rb_node *node)
> {
> const struct annotated_data_type *key = _key;
> struct annotated_data_type *type;
> + int64_t ret = 0;
>
> type = rb_entry(node, struct annotated_data_type, node);
>
> if (key->self.size != type->self.size)
> return key->self.size - type->self.size;
> - return strcmp(key->self.type_name, type->self.type_name);
> +
> + ret = strcmp(key->self.type_name, type->self.type_name);
> + if (ret) {
> + return ret;
> + }
No need for the parentheses.
> +
> + /*
> + * Compare var_name if it exists for key and type.
> + * If both nodes doesn't have var_name, but one of
> + * them has, return non-zero. This is to indicate nodes
> + * are not the same if one has var_name, but other doesn't.
> + */
> + if (key->self.var_name && type->self.var_name) {
> + ret = strcmp(key->self.var_name, type->self.var_name);
> + if (ret)
> + return ret;
> + } else if (key->self.var_name || type->self.var_name)
> + return 1;
I think you need to compare the order properly like in cmp_null() in
util/sort.c. Please see below.
> +
> + return ret;
> }
>
> static bool data_type_less(struct rb_node *node_a, const struct rb_node *node_b)
> diff --git a/tools/perf/util/sort.c b/tools/perf/util/sort.c
> index cd39ea972193..c6d885060ee7 100644
> --- a/tools/perf/util/sort.c
> +++ b/tools/perf/util/sort.c
> @@ -2267,9 +2267,25 @@ sort__typeoff_sort(struct hist_entry *left, struct hist_entry *right)
> right_type = right->mem_type;
> }
>
> + /*
> + * Compare type_name first. Next, ompare var_name if it exists
> + * for left and right hist_entry. If both entries doesn't have
> + * var_name, but one of them has, return non-zero. This is to
> + * indicate entries are not the same if one has var_name, but the
> + * other doesn't.
> + * If type_name and var_name is same, use mem_type_off field.
> + */
> ret = strcmp(left_type->self.type_name, right_type->self.type_name);
> if (ret)
> return ret;
> +
> + if (left_type->self.var_name && right_type->self.var_name) {
> + ret = strcmp(left_type->self.var_name, right_type->self.var_name);
> + if (ret)
> + return ret;
> + } else if (right_type->self.var_name || left_type->self.var_name)
> + return 1;
} else if (!left_type->self.var_name != !right_type->self.var_name)
return cmp_null(left_type->self.var_name, right_type->self.var_name);
Thanks,
Namhyung
> +
> return left->mem_type_off - right->mem_type_off;
> }
>
> @@ -2305,9 +2321,12 @@ static int hist_entry__typeoff_snprintf(struct hist_entry *he, char *bf,
> char buf[4096];
>
> buf[0] = '\0';
> - if (list_empty(&he_type->self.children))
> + if (list_empty(&he_type->self.children)) {
> snprintf(buf, sizeof(buf), "no field");
> - else
> + if (he_type->self.var_name)
> + strcpy(buf, he_type->self.var_name);
> +
> + } else
> fill_member_name(buf, sizeof(buf), &he_type->self,
> he->mem_type_off, true);
> buf[4095] = '\0';
> --
> 2.43.0
>
Powered by blists - more mailing lists