[PATCH v1 45/48] perf symbol: Silence -Wshorten-64-to-32 warnings
From: Ian Rogers
Date: Tue Apr 01 2025 - 14:35:45 EST
The clang warning -Wshorten-64-to-32 can be useful to catch
inadvertent truncation. In some instances this truncation can lead to
changing the sign of a result, for example, truncation to return an
int to fit a sort routine. Silence the warning by making the implicit
truncation explicit.
Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
---
tools/perf/util/symbol-elf.c | 33 +++++++++++++++++----------------
tools/perf/util/symbol.c | 10 +++++-----
2 files changed, 22 insertions(+), 21 deletions(-)
diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c
index fbf6d0f73af9..9de6e963ca79 100644
--- a/tools/perf/util/symbol-elf.c
+++ b/tools/perf/util/symbol-elf.c
@@ -261,7 +261,7 @@ static int elf_read_program_header(Elf *elf, u64 vaddr, GElf_Phdr *phdr)
return -1;
for (i = 0; i < phdrnum; i++) {
- if (gelf_getphdr(elf, i, phdr) == NULL)
+ if (gelf_getphdr(elf, (int)i, phdr) == NULL)
return -1;
if (phdr->p_type != PT_LOAD)
@@ -550,7 +550,7 @@ static void get_rela_dyn_info(Elf *elf, GElf_Ehdr *ehdr, struct rela_dyn_info *d
if (!scn || !rela_dyn_shdr.sh_link || !rela_dyn_shdr.sh_entsize)
return;
- di->nr_entries = rela_dyn_shdr.sh_size / rela_dyn_shdr.sh_entsize;
+ di->nr_entries = (u32)(rela_dyn_shdr.sh_size / rela_dyn_shdr.sh_entsize);
di->rela_dyn_data = elf_getdata(scn, NULL);
scn = elf_getscn(elf, rela_dyn_shdr.sh_link);
@@ -789,7 +789,7 @@ int dso__synthesize_plt_symbols(struct dso *dso, struct symsrc *ss)
if (symstrs->d_size == 0)
goto out_elf_end;
- ri.nr_entries = shdr_rel_plt.sh_size / shdr_rel_plt.sh_entsize;
+ ri.nr_entries = (u32)(shdr_rel_plt.sh_size / shdr_rel_plt.sh_entsize);
ri.is_rela = shdr_rel_plt.sh_type == SHT_RELA;
@@ -925,7 +925,7 @@ static int elf_read_build_id(Elf *elf, void *bf, size_t size)
size_t sz = min(size, descsz);
memcpy(bf, ptr, sz);
memset(bf + sz, 0, size - sz);
- err = sz;
+ err = (int)sz;
break;
}
}
@@ -1066,14 +1066,14 @@ int sysfs__read_build_id(const char *filename, struct build_id *bid)
} else if (read(fd, bf, descsz) != (ssize_t)descsz)
break;
} else {
- int n = namesz + descsz;
+ size_t n = namesz + descsz;
- if (n > (int)sizeof(bf)) {
+ if (n > sizeof(bf)) {
n = sizeof(bf);
pr_debug("%s: truncating reading of build id in sysfs file %s: n_namesz=%u, n_descsz=%u.\n",
__func__, filename, nhdr.n_namesz, nhdr.n_descsz);
}
- if (read(fd, bf, n) != n)
+ if (read(fd, bf, n) != (ssize_t)n)
break;
}
}
@@ -1426,7 +1426,7 @@ static u64 max_text_section(Elf *elf, GElf_Ehdr *ehdr)
if (!gelf_getshdr(sec, &shdr))
break;
- if (!is_exe_text(shdr.sh_flags))
+ if (!is_exe_text((int)shdr.sh_flags))
continue;
/* .init and .exit sections are not placed with .text */
@@ -1546,7 +1546,7 @@ static int dso__process_kernel_symbol(struct dso *dso, struct map *map,
* perf does not record module section addresses except for .text, but
* some sections can use the same mapping as .text.
*/
- if (kmodule && adjust_kernel_syms && is_exe_text(shdr->sh_flags) &&
+ if (kmodule && adjust_kernel_syms && is_exe_text((int)shdr->sh_flags) &&
shdr->sh_offset <= max_text_sh_offset) {
dso__put(*curr_dsop);
*curr_dsop = dso__get(dso);
@@ -1672,7 +1672,7 @@ dso__load_sym_internal(struct dso *dso, struct map *map, struct symsrc *syms_ss,
if (secstrs_sym == NULL)
goto out_elf_end;
- nr_syms = shdr.sh_size / shdr.sh_entsize;
+ nr_syms = (uint32_t)(shdr.sh_size / shdr.sh_entsize);
memset(&sym, 0, sizeof(sym));
@@ -1734,7 +1734,7 @@ dso__load_sym_internal(struct dso *dso, struct map *map, struct symsrc *syms_ss,
}
if (runtime_ss->opdsec && sym.st_shndx == runtime_ss->opdidx) {
- u32 offset = sym.st_value - syms_ss->opdshdr.sh_addr;
+ u32 offset = (u32)(sym.st_value - syms_ss->opdshdr.sh_addr);
u64 *opd = opddata->d_buf + offset;
sym.st_value = DSO__SWAP(dso, u64, *opd);
sym.st_shndx = elf_addr_to_index(runtime_ss->elf,
@@ -1946,7 +1946,7 @@ static int elf_read_maps(Elf *elf, bool exe, mapfn_t mapfn, void *data)
return -1;
for (i = 0; i < phdrnum; i++) {
- if (gelf_getphdr(elf, i, &phdr) == NULL)
+ if (gelf_getphdr(elf, (int)i, &phdr) == NULL)
return -1;
if (phdr.p_type != PT_LOAD)
continue;
@@ -2767,14 +2767,15 @@ static void sdt_adjust_loc(struct sdt_note *tmp, GElf_Addr base_off)
if (!base_off)
return;
- if (tmp->bit32)
+ if (tmp->bit32) {
tmp->addr.a32[SDT_NOTE_IDX_LOC] =
- tmp->addr.a32[SDT_NOTE_IDX_LOC] + base_off -
- tmp->addr.a32[SDT_NOTE_IDX_BASE];
- else
+ (Elf32_Addr)(tmp->addr.a32[SDT_NOTE_IDX_LOC] + base_off -
+ tmp->addr.a32[SDT_NOTE_IDX_BASE]);
+ } else {
tmp->addr.a64[SDT_NOTE_IDX_LOC] =
tmp->addr.a64[SDT_NOTE_IDX_LOC] + base_off -
tmp->addr.a64[SDT_NOTE_IDX_BASE];
+ }
}
static void sdt_adjust_refctr(struct sdt_note *tmp, GElf_Addr base_addr,
diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 11540219481b..7eceb6679ed5 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -111,7 +111,7 @@ static int prefix_underscores_count(const char *str)
while (*tail == '_')
tail++;
- return tail - str;
+ return (int)(tail - str);
}
const char * __weak arch__normalize_symbol_name(const char *name)
@@ -481,10 +481,10 @@ int symbol__match_symbol_name(const char *name, const char *str,
if (includes == SYMBOL_TAG_INCLUDE__DEFAULT_ONLY &&
(versioning = strstr(name, "@@"))) {
- int len = strlen(str);
+ int len = (int)strlen(str);
if (len < versioning - name)
- len = versioning - name;
+ len = (int)(versioning - name);
return arch__compare_symbol_names_n(name, str, len);
} else
@@ -638,7 +638,7 @@ void dso__sort_by_name(struct dso *dso)
* While we find nice hex chars, build a long_val.
* Return number of chars processed.
*/
-static int hex2u64(const char *ptr, u64 *long_val)
+static size_t hex2u64(const char *ptr, u64 *long_val)
{
char *p;
@@ -1532,7 +1532,7 @@ static int dso__load_perf_map(const char *map_path, struct dso *dso)
while (!feof(file)) {
u64 start, size;
struct symbol *sym;
- int line_len, len;
+ size_t line_len, len;
line_len = getline(&line, &n, file);
if (line_len < 0)
--
2.49.0.504.g3bcea36a83-goog