Messages in this thread |  | | Subject | Re: [PATCH v2] perf tools: Fix arm64 build error with gcc-11 | From | John Garry <> | Date | Wed, 10 Feb 2021 09:38:27 +0000 |
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On 10/02/2021 03:24, Jianlin Lv wrote: > gcc version: 11.0.0 20210208 (experimental) (GCC) > > Following build error on arm64: > > ....... > In function ‘printf’, > inlined from ‘regs_dump__printf’ at util/session.c:1141:3, > inlined from ‘regs__printf’ at util/session.c:1169:2: > /usr/include/aarch64-linux-gnu/bits/stdio2.h:107:10: \ > error: ‘%-5s’ directive argument is null [-Werror=format-overflow=] > > 107 | return __printf_chk (__USE_FORTIFY_LEVEL - 1, __fmt, \ > __va_arg_pack ()); > > ...... > In function ‘fprintf’, > inlined from ‘perf_sample__fprintf_regs.isra’ at \ > builtin-script.c:622:14: > /usr/include/aarch64-linux-gnu/bits/stdio2.h:100:10: \ > error: ‘%5s’ directive argument is null [-Werror=format-overflow=] > 100 | return __fprintf_chk (__stream, __USE_FORTIFY_LEVEL - 1, __fmt, > 101 | __va_arg_pack ()); > > cc1: all warnings being treated as errors > ....... > > This patch fixes Wformat-overflow warnings. Add ternary operator, > The statement evaluates to "Unknown" if reg_name==NULL is met. > > Signed-off-by: Jianlin Lv <Jianlin.Lv@arm.com> > --- > v2: Add ternary operator to avoid similar errors in other arch. > --- > tools/perf/builtin-script.c | 4 +++- > tools/perf/util/scripting-engines/trace-event-python.c | 4 +++- > tools/perf/util/session.c | 5 +++-- > 3 files changed, 9 insertions(+), 4 deletions(-) > > diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c > index 42dad4a0f8cf..d59da3a063d0 100644 > --- a/tools/perf/builtin-script.c > +++ b/tools/perf/builtin-script.c > @@ -635,6 +635,7 @@ static int perf_sample__fprintf_regs(struct regs_dump *regs, uint64_t mask, > { > unsigned i = 0, r; > int printed = 0; > + const char *reg_name; > > if (!regs || !regs->regs) > return 0; > @@ -643,7 +644,8 @@ static int perf_sample__fprintf_regs(struct regs_dump *regs, uint64_t mask, > > for_each_set_bit(r, (unsigned long *) &mask, sizeof(mask) * 8) { > u64 val = regs->regs[i++]; > - printed += fprintf(fp, "%5s:0x%"PRIx64" ", perf_reg_name(r), val); > + reg_name = perf_reg_name(r); > + printed += fprintf(fp, "%5s:0x%"PRIx64" ", reg_name ?: "Unknown", val);
is it possible not have to do this check for NULL and reassignment everywhere?
> } > > return printed; > diff --git a/tools/perf/util/scripting-engines/trace-event-python.c b/tools/perf/util/scripting-engines/trace-event-python.c > index c83c2c6564e0..e1222cc6a699 100644 > --- a/tools/perf/util/scripting-engines/trace-event-python.c > +++ b/tools/perf/util/scripting-engines/trace-event-python.c > @@ -691,6 +691,7 @@ static int regs_map(struct regs_dump *regs, uint64_t mask, char *bf, int size) > { > unsigned int i = 0, r; > int printed = 0; > + const char *reg_name; > > bf[0] = 0; > > @@ -700,9 +701,10 @@ static int regs_map(struct regs_dump *regs, uint64_t mask, char *bf, int size) > for_each_set_bit(r, (unsigned long *) &mask, sizeof(mask) * 8) {
a good practice is to limit scope of variables as much as possible, so reg_name could be declared here
> u64 val = regs->regs[i++]; > > + reg_name = perf_reg_name(r); > printed += scnprintf(bf + printed, size - printed, > "%5s:0x%" PRIx64 " ", > - perf_reg_name(r), val); > + reg_name ?: "Unknown", val); > } > > return printed; > diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c > index 25adbcce0281..1058d8487e98 100644 > --- a/tools/perf/util/session.c > +++ b/tools/perf/util/session.c > @@ -1135,12 +1135,13 @@ static void branch_stack__printf(struct perf_sample *sample, bool callstack) > static void regs_dump__printf(u64 mask, u64 *regs) > { > unsigned rid, i = 0; > + const char *reg_name; > > for_each_set_bit(rid, (unsigned long *) &mask, sizeof(mask) * 8) { > u64 val = regs[i++]; > - > + reg_name = perf_reg_name(rid); > printf(".... %-5s 0x%016" PRIx64 "\n", > - perf_reg_name(rid), val); > + reg_name ?: "Unknown", val);
super nit: it's "unknown" in util/perf_regs.h::perf_reg_name(), so nice to be consistent
> } > } > >
thanks, John
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