An issue was reported with clang and llvm libc where the noinline
attribute [1] was being expanded due to the #define in
linux/compiler.h (now in compiler_attributes.h). The expansion caused
the __attribute__ to appear twice and break the build. To avoid this
conflict, rename noinline to __noinline which is more consistent with
other compiler attributes.
[1] https://clang.llvm.org/docs/AttributeReference.html#noinline
Reported-by: Christopher Di Bella <cjdb@google.com>
Signed-off-by: Ian Rogers <irogers@google.com>
---
tools/include/linux/compiler_attributes.h | 4 ++--
tools/perf/arch/x86/tests/bp-modify.c | 4 ++--
tools/perf/bench/find-bit-bench.c | 2 +-
tools/perf/tests/bp_account.c | 2 +-
tools/perf/tests/bp_signal.c | 2 +-
tools/perf/tests/bp_signal_overflow.c | 2 +-
tools/perf/tests/dwarf-unwind.c | 12 ++++++------
tools/perf/tests/workloads/leafloop.c | 8 ++++----
tools/perf/tests/workloads/thloop.c | 4 ++--
9 files changed, 20 insertions(+), 20 deletions(-)
diff --git a/tools/include/linux/compiler_attributes.h b/tools/include/linux/compiler_attributes.h
index 9bfaec783e48..1ff3d85f5af3 100644
--- a/tools/include/linux/compiler_attributes.h
+++ b/tools/include/linux/compiler_attributes.h
@@ -267,12 +267,12 @@
# define __flatten __attribute__((flatten))
/*
- * Note the missing underscores.
+ * Note, the kernel version is missing the underscores.
*
* gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-noinline-function-attribute
* clang: mentioned
*/
-#define noinline __attribute__((__noinline__))
+#define __noinline __attribute__((__noinline__))
/*
* Optional: only supported since gcc >= 8
diff --git a/tools/perf/arch/x86/tests/bp-modify.c b/tools/perf/arch/x86/tests/bp-modify.c
index 0924ccd9e36d..65493ff7a76f 100644
--- a/tools/perf/arch/x86/tests/bp-modify.c
+++ b/tools/perf/arch/x86/tests/bp-modify.c
@@ -15,13 +15,13 @@
#include "tests/tests.h"
#include "arch-tests.h"
-static noinline int bp_1(void)
+static __noinline int bp_1(void)
{
pr_debug("in %s\n", __func__);
return 0;
}
-static noinline int bp_2(void)
+static __noinline int bp_2(void)
{
pr_debug("in %s\n", __func__);
return 0;
diff --git a/tools/perf/bench/find-bit-bench.c b/tools/perf/bench/find-bit-bench.c
index 7e25b0e413f6..dd97a51649bc 100644
--- a/tools/perf/bench/find-bit-bench.c
+++ b/tools/perf/bench/find-bit-bench.c
@@ -31,7 +31,7 @@ static const char *const bench_usage[] = {
static unsigned int accumulator;
static unsigned int use_of_val;
-static noinline void workload(int val)
+static __noinline void workload(int val)
{
use_of_val += val;
accumulator++;
diff --git a/tools/perf/tests/bp_account.c b/tools/perf/tests/bp_account.c
index 6f921db33cf9..459f61752a71 100644
--- a/tools/perf/tests/bp_account.c
+++ b/tools/perf/tests/bp_account.c
@@ -34,7 +34,7 @@
static volatile long the_var;
-static noinline int test_function(void)
+static __noinline int test_function(void)
{
return 0;
}
diff --git a/tools/perf/tests/bp_signal.c b/tools/perf/tests/bp_signal.c
index 1f2908f02389..484a7e7f96ee 100644
--- a/tools/perf/tests/bp_signal.c
+++ b/tools/perf/tests/bp_signal.c
@@ -59,7 +59,7 @@ static void __test_function(volatile long *ptr)
}
#endif
-static noinline int test_function(void)
+static __noinline int test_function(void)
{
__test_function(&the_var);
the_var++;
diff --git a/tools/perf/tests/bp_signal_overflow.c b/tools/perf/tests/bp_signal_overflow.c
index 4e897c2cf26b..9436bf2973f8 100644
--- a/tools/perf/tests/bp_signal_overflow.c
+++ b/tools/perf/tests/bp_signal_overflow.c
@@ -30,7 +30,7 @@
static int overflows;
-static noinline int test_function(void)
+static __noinline int test_function(void)
{
return time(NULL);
}
diff --git a/tools/perf/tests/dwarf-unwind.c b/tools/perf/tests/dwarf-unwind.c
index d01aa931fe81..a669c69a9242 100644
--- a/tools/perf/tests/dwarf-unwind.c
+++ b/tools/perf/tests/dwarf-unwind.c
@@ -109,7 +109,7 @@ static int unwind_entry(struct unwind_entry *entry, void *arg)
return strcmp((const char *) symbol, funcs[idx]);
}
-NO_TAIL_CALL_ATTRIBUTE noinline int test_dwarf_unwind__thread(struct thread *thread)
+NO_TAIL_CALL_ATTRIBUTE __noinline int test_dwarf_unwind__thread(struct thread *thread)
{
struct perf_sample sample;
unsigned long cnt = 0;
@@ -140,7 +140,7 @@ NO_TAIL_CALL_ATTRIBUTE noinline int test_dwarf_unwind__thread(struct thread *thr
static int global_unwind_retval = -INT_MAX;
-NO_TAIL_CALL_ATTRIBUTE noinline int test_dwarf_unwind__compare(void *p1, void *p2)
+NO_TAIL_CALL_ATTRIBUTE __noinline int test_dwarf_unwind__compare(void *p1, void *p2)
{
/* Any possible value should be 'thread' */
struct thread *thread = *(struct thread **)p1;
@@ -159,7 +159,7 @@ NO_TAIL_CALL_ATTRIBUTE noinline int test_dwarf_unwind__compare(void *p1, void *p
return p1 - p2;
}
-NO_TAIL_CALL_ATTRIBUTE noinline int test_dwarf_unwind__krava_3(struct thread *thread)
+NO_TAIL_CALL_ATTRIBUTE __noinline int test_dwarf_unwind__krava_3(struct thread *thread)
{
struct thread *array[2] = {thread, thread};
void *fp = &bsearch;
@@ -178,7 +178,7 @@ NO_TAIL_CALL_ATTRIBUTE noinline int test_dwarf_unwind__krava_3(struct thread *th
return global_unwind_retval;
}
-NO_TAIL_CALL_ATTRIBUTE noinline int test_dwarf_unwind__krava_2(struct thread *thread)
+NO_TAIL_CALL_ATTRIBUTE __noinline int test_dwarf_unwind__krava_2(struct thread *thread)
{
int ret;
@@ -187,7 +187,7 @@ NO_TAIL_CALL_ATTRIBUTE noinline int test_dwarf_unwind__krava_2(struct thread *th
return ret;
}
-NO_TAIL_CALL_ATTRIBUTE noinline int test_dwarf_unwind__krava_1(struct thread *thread)
+NO_TAIL_CALL_ATTRIBUTE __noinline int test_dwarf_unwind__krava_1(struct thread *thread)
{
int ret;
@@ -196,7 +196,7 @@ NO_TAIL_CALL_ATTRIBUTE noinline int test_dwarf_unwind__krava_1(struct thread *th
return ret;
}
-noinline int test__dwarf_unwind(struct test_suite *test __maybe_unused,
+__noinline int test__dwarf_unwind(struct test_suite *test __maybe_unused,
int subtest __maybe_unused)
{
struct machine *machine;
diff --git a/tools/perf/tests/workloads/leafloop.c b/tools/perf/tests/workloads/leafloop.c
index 1bf5cc97649b..89d2cec2f461 100644
--- a/tools/perf/tests/workloads/leafloop.c
+++ b/tools/perf/tests/workloads/leafloop.c
@@ -4,18 +4,18 @@
#include "../tests.h"
/* We want to check these symbols in perf script */
-noinline void leaf(volatile int b);
-noinline void parent(volatile int b);
+__noinline void leaf(volatile int b);
+__noinline void parent(volatile int b);
static volatile int a;
-noinline void leaf(volatile int b)
+__noinline void leaf(volatile int b)
{
for (;;)
a += b;
}
-noinline void parent(volatile int b)
+__noinline void parent(volatile int b)
{
leaf(b);
}
diff --git a/tools/perf/tests/workloads/thloop.c b/tools/perf/tests/workloads/thloop.c
index 457b29f91c3e..e252efb76203 100644
--- a/tools/perf/tests/workloads/thloop.c
+++ b/tools/perf/tests/workloads/thloop.c
@@ -9,14 +9,14 @@
static volatile sig_atomic_t done;
/* We want to check this symbol in perf report */
-noinline void test_loop(void);
+__noinline void test_loop(void);
static void sighandler(int sig __maybe_unused)
{
done = 1;
}
-noinline void test_loop(void)
+__noinline void test_loop(void)
{
while (!done);
}
--
2.44.0.278.ge034bb2e1d-googOn Sat, Mar 09, 2024 at 06:05:08PM -0800, Ian Rogers wrote:
> An issue was reported with clang and llvm libc where the noinline
> attribute [1] was being expanded due to the #define in
> linux/compiler.h (now in compiler_attributes.h). The expansion caused
> the __attribute__ to appear twice and break the build. To avoid this
> conflict, rename noinline to __noinline which is more consistent with
> other compiler attributes.
>
> [1] https://clang.llvm.org/docs/AttributeReference.html#noinline
Following this link, I don't see __noinline there - only __noinline__ and
noinline. What's up?
Als, pls add an empty line before tags.
> Reported-by: Christopher Di Bella <cjdb@google.com>
>
> Signed-off-by: Ian Rogers <irogers@google.com>
tags should not have empty lines between them.
> ---
> tools/include/linux/compiler_attributes.h | 4 ++--
> tools/perf/arch/x86/tests/bp-modify.c | 4 ++--
> tools/perf/bench/find-bit-bench.c | 2 +-
> tools/perf/tests/bp_account.c | 2 +-
> tools/perf/tests/bp_signal.c | 2 +-
> tools/perf/tests/bp_signal_overflow.c | 2 +-
> tools/perf/tests/dwarf-unwind.c | 12 ++++++------
> tools/perf/tests/workloads/leafloop.c | 8 ++++----
> tools/perf/tests/workloads/thloop.c | 4 ++--
> 9 files changed, 20 insertions(+), 20 deletions(-)
>
> diff --git a/tools/include/linux/compiler_attributes.h b/tools/include/linux/compiler_attributes.h
> index 9bfaec783e48..1ff3d85f5af3 100644
> --- a/tools/include/linux/compiler_attributes.h
> +++ b/tools/include/linux/compiler_attributes.h
> @@ -267,12 +267,12 @@
> # define __flatten __attribute__((flatten))
>
> /*
> - * Note the missing underscores.
> + * Note, the kernel version is missing the underscores.
> *
> * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-noinline-function-attribute
> * clang: mentioned
> */
> -#define noinline __attribute__((__noinline__))
> +#define __noinline __attribute__((__noinline__))
>
> /*
> * Optional: only supported since gcc >= 8
> diff --git a/tools/perf/arch/x86/tests/bp-modify.c b/tools/perf/arch/x86/tests/bp-modify.c
> index 0924ccd9e36d..65493ff7a76f 100644
> --- a/tools/perf/arch/x86/tests/bp-modify.c
> +++ b/tools/perf/arch/x86/tests/bp-modify.c
> @@ -15,13 +15,13 @@
> #include "tests/tests.h"
> #include "arch-tests.h"
>
> -static noinline int bp_1(void)
> +static __noinline int bp_1(void)
> {
> pr_debug("in %s\n", __func__);
> return 0;
> }
>
> -static noinline int bp_2(void)
> +static __noinline int bp_2(void)
> {
> pr_debug("in %s\n", __func__);
> return 0;
> diff --git a/tools/perf/bench/find-bit-bench.c b/tools/perf/bench/find-bit-bench.c
> index 7e25b0e413f6..dd97a51649bc 100644
> --- a/tools/perf/bench/find-bit-bench.c
> +++ b/tools/perf/bench/find-bit-bench.c
> @@ -31,7 +31,7 @@ static const char *const bench_usage[] = {
> static unsigned int accumulator;
> static unsigned int use_of_val;
>
> -static noinline void workload(int val)
> +static __noinline void workload(int val)
> {
> use_of_val += val;
> accumulator++;
> diff --git a/tools/perf/tests/bp_account.c b/tools/perf/tests/bp_account.c
> index 6f921db33cf9..459f61752a71 100644
> --- a/tools/perf/tests/bp_account.c
> +++ b/tools/perf/tests/bp_account.c
> @@ -34,7 +34,7 @@
>
> static volatile long the_var;
>
> -static noinline int test_function(void)
> +static __noinline int test_function(void)
> {
> return 0;
> }
> diff --git a/tools/perf/tests/bp_signal.c b/tools/perf/tests/bp_signal.c
> index 1f2908f02389..484a7e7f96ee 100644
> --- a/tools/perf/tests/bp_signal.c
> +++ b/tools/perf/tests/bp_signal.c
> @@ -59,7 +59,7 @@ static void __test_function(volatile long *ptr)
> }
> #endif
>
> -static noinline int test_function(void)
> +static __noinline int test_function(void)
> {
> __test_function(&the_var);
> the_var++;
> diff --git a/tools/perf/tests/bp_signal_overflow.c b/tools/perf/tests/bp_signal_overflow.c
> index 4e897c2cf26b..9436bf2973f8 100644
> --- a/tools/perf/tests/bp_signal_overflow.c
> +++ b/tools/perf/tests/bp_signal_overflow.c
> @@ -30,7 +30,7 @@
>
> static int overflows;
>
> -static noinline int test_function(void)
> +static __noinline int test_function(void)
> {
> return time(NULL);
> }
> diff --git a/tools/perf/tests/dwarf-unwind.c b/tools/perf/tests/dwarf-unwind.c
> index d01aa931fe81..a669c69a9242 100644
> --- a/tools/perf/tests/dwarf-unwind.c
> +++ b/tools/perf/tests/dwarf-unwind.c
> @@ -109,7 +109,7 @@ static int unwind_entry(struct unwind_entry *entry, void *arg)
> return strcmp((const char *) symbol, funcs[idx]);
> }
>
> -NO_TAIL_CALL_ATTRIBUTE noinline int test_dwarf_unwind__thread(struct thread *thread)
> +NO_TAIL_CALL_ATTRIBUTE __noinline int test_dwarf_unwind__thread(struct thread *thread)
> {
> struct perf_sample sample;
> unsigned long cnt = 0;
> @@ -140,7 +140,7 @@ NO_TAIL_CALL_ATTRIBUTE noinline int test_dwarf_unwind__thread(struct thread *thr
>
> static int global_unwind_retval = -INT_MAX;
>
> -NO_TAIL_CALL_ATTRIBUTE noinline int test_dwarf_unwind__compare(void *p1, void *p2)
> +NO_TAIL_CALL_ATTRIBUTE __noinline int test_dwarf_unwind__compare(void *p1, void *p2)
> {
> /* Any possible value should be 'thread' */
> struct thread *thread = *(struct thread **)p1;
> @@ -159,7 +159,7 @@ NO_TAIL_CALL_ATTRIBUTE noinline int test_dwarf_unwind__compare(void *p1, void *p
> return p1 - p2;
> }
>
> -NO_TAIL_CALL_ATTRIBUTE noinline int test_dwarf_unwind__krava_3(struct thread *thread)
> +NO_TAIL_CALL_ATTRIBUTE __noinline int test_dwarf_unwind__krava_3(struct thread *thread)
> {
> struct thread *array[2] = {thread, thread};
> void *fp = &bsearch;
> @@ -178,7 +178,7 @@ NO_TAIL_CALL_ATTRIBUTE noinline int test_dwarf_unwind__krava_3(struct thread *th
> return global_unwind_retval;
> }
>
> -NO_TAIL_CALL_ATTRIBUTE noinline int test_dwarf_unwind__krava_2(struct thread *thread)
> +NO_TAIL_CALL_ATTRIBUTE __noinline int test_dwarf_unwind__krava_2(struct thread *thread)
> {
> int ret;
>
> @@ -187,7 +187,7 @@ NO_TAIL_CALL_ATTRIBUTE noinline int test_dwarf_unwind__krava_2(struct thread *th
> return ret;
> }
>
> -NO_TAIL_CALL_ATTRIBUTE noinline int test_dwarf_unwind__krava_1(struct thread *thread)
> +NO_TAIL_CALL_ATTRIBUTE __noinline int test_dwarf_unwind__krava_1(struct thread *thread)
> {
> int ret;
>
> @@ -196,7 +196,7 @@ NO_TAIL_CALL_ATTRIBUTE noinline int test_dwarf_unwind__krava_1(struct thread *th
> return ret;
> }
>
> -noinline int test__dwarf_unwind(struct test_suite *test __maybe_unused,
> +__noinline int test__dwarf_unwind(struct test_suite *test __maybe_unused,
> int subtest __maybe_unused)
> {
> struct machine *machine;
> diff --git a/tools/perf/tests/workloads/leafloop.c b/tools/perf/tests/workloads/leafloop.c
> index 1bf5cc97649b..89d2cec2f461 100644
> --- a/tools/perf/tests/workloads/leafloop.c
> +++ b/tools/perf/tests/workloads/leafloop.c
> @@ -4,18 +4,18 @@
> #include "../tests.h"
>
> /* We want to check these symbols in perf script */
> -noinline void leaf(volatile int b);
> -noinline void parent(volatile int b);
> +__noinline void leaf(volatile int b);
> +__noinline void parent(volatile int b);
>
> static volatile int a;
>
> -noinline void leaf(volatile int b)
> +__noinline void leaf(volatile int b)
> {
> for (;;)
> a += b;
> }
>
> -noinline void parent(volatile int b)
> +__noinline void parent(volatile int b)
> {
> leaf(b);
> }
> diff --git a/tools/perf/tests/workloads/thloop.c b/tools/perf/tests/workloads/thloop.c
> index 457b29f91c3e..e252efb76203 100644
> --- a/tools/perf/tests/workloads/thloop.c
> +++ b/tools/perf/tests/workloads/thloop.c
> @@ -9,14 +9,14 @@
> static volatile sig_atomic_t done;
>
> /* We want to check this symbol in perf report */
> -noinline void test_loop(void);
> +__noinline void test_loop(void);
>
> static void sighandler(int sig __maybe_unused)
> {
> done = 1;
> }
>
> -noinline void test_loop(void)
> +__noinline void test_loop(void)
> {
> while (!done);
> }
> --
> 2.44.0.278.ge034bb2e1d-goog
On Mon, Mar 11, 2024 at 8:44 AM Michael S. Tsirkin <mst@redhat.com> wrote: > > On Sat, Mar 09, 2024 at 06:05:08PM -0800, Ian Rogers wrote: > > An issue was reported with clang and llvm libc where the noinline > > attribute [1] was being expanded due to the #define in > > linux/compiler.h (now in compiler_attributes.h). The expansion caused > > the __attribute__ to appear twice and break the build. To avoid this > > conflict, rename noinline to __noinline which is more consistent with > > other compiler attributes. > > > > [1] https://clang.llvm.org/docs/AttributeReference.html#noinline > > Following this link, I don't see __noinline there - only __noinline__ and > noinline. What's up? __noinline (which is what this patch is changing the preprocessor define to) will not be expanded in the presence of __attribute__((__noinline__)), __attribute__((noinline)), or [[gnu::inline]], unlike the previous macro definition. -- Thanks, ~Nick Desaulniers
On Sun, Mar 10, 2024 at 3:06 AM Ian Rogers <irogers@google.com> wrote: > > [1] https://clang.llvm.org/docs/AttributeReference.html#noinline > Reported-by: Christopher Di Bella <cjdb@google.com> Out of curiosity, was this due to the `[[gnu::noinline]]` or similar in e.g. `src/string/memset_explicit.h`? > -#define noinline __attribute__((__noinline__)) > +#define __noinline __attribute__((__noinline__)) I guess it does not matter since I don't see it used in `tools/`, but should the one inside `__fix_address` be updated too? Or is the idea to keep the diff as minimal as possible? Cheers, Miguel
On Sun, Mar 10, 2024 at 4:25 AM Miguel Ojeda <miguel.ojeda.sandonis@gmail.com> wrote: > > On Sun, Mar 10, 2024 at 3:06 AM Ian Rogers <irogers@google.com> wrote: > > > > [1] https://clang.llvm.org/docs/AttributeReference.html#noinline > > Reported-by: Christopher Di Bella <cjdb@google.com> > > Out of curiosity, was this due to the `[[gnu::noinline]]` or similar > in e.g. `src/string/memset_explicit.h`? Yes, and in src/__support/threads/linux/thread.cpp's definition of start_thread(). Thanks for the patch! Acked-by: Nick Desaulniers <ndesaulniers@google.com> -- Thanks, ~Nick Desaulniers
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