I encountered a warning while building the sched-ext for the for-6.11
branch. Below are the details:
# make -j40 -s vmlinux
In file included from ./include/linux/rhashtable-types.h:12,
from ./include/linux/sched/ext.h:15,
from ./include/linux/sched.h:83,
from ./include/linux/sched/signal.h:7,
from ./include/linux/sched/cputime.h:5,
from kernel/sched/build_policy.c:17:
kernel/sched/ext.c: In function ‘alloc_exit_info’:
kernel/sched/ext.c:3815:32: warning: ‘kmalloc_array_noprof’ sizes specified with ‘sizeof’ in the earlier argument and not in the later argument [-Wcalloc-transposed-args]
3815 | ei->bt = kcalloc(sizeof(ei->bt[0]), SCX_EXIT_BT_LEN, GFP_KERNEL);
| ^
./include/linux/alloc_tag.h:206:16: note: in definition of macro ‘alloc_hooks_tag’
206 | typeof(_do_alloc) _res = _do_alloc; \
| ^~~~~~~~~
./include/linux/slab.h:701:49: note: in expansion of macro ‘alloc_hooks’
701 | #define kmalloc_array(...) alloc_hooks(kmalloc_array_noprof(__VA_ARGS__))
| ^~~~~~~~~~~
./include/linux/slab.h:730:41: note: in expansion of macro ‘kmalloc_array’
730 | #define kcalloc(n, size, flags) kmalloc_array(n, size, (flags) | __GFP_ZERO)
| ^~~~~~~~~~~~~
kernel/sched/ext.c:3815:18: note: in expansion of macro ‘kcalloc’
3815 | ei->bt = kcalloc(sizeof(ei->bt[0]), SCX_EXIT_BT_LEN, GFP_KERNEL);
| ^~~~~~~
kernel/sched/ext.c:3815:32: note: earlier argument should specify number of elements, later size of each element
3815 | ei->bt = kcalloc(sizeof(ei->bt[0]), SCX_EXIT_BT_LEN, GFP_KERNEL);
| ^
./include/linux/alloc_tag.h:206:16: note: in definition of macro ‘alloc_hooks_tag’
206 | typeof(_do_alloc) _res = _do_alloc; \
| ^~~~~~~~~
./include/linux/slab.h:701:49: note: in expansion of macro ‘alloc_hooks’
701 | #define kmalloc_array(...) alloc_hooks(kmalloc_array_noprof(__VA_ARGS__))
| ^~~~~~~~~~~
./include/linux/slab.h:730:41: note: in expansion of macro ‘kmalloc_array’
730 | #define kcalloc(n, size, flags) kmalloc_array(n, size, (flags) | __GFP_ZERO)
| ^~~~~~~~~~~~~
kernel/sched/ext.c:3815:18: note: in expansion of macro ‘kcalloc’
3815 | ei->bt = kcalloc(sizeof(ei->bt[0]), SCX_EXIT_BT_LEN, GFP_KERNEL);
| ^~~~~~~
# gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/libexec/gcc/ppc64le-redhat-linux/14/lto-wrapper
OFFLOAD_TARGET_NAMES=nvptx-none
OFFLOAD_TARGET_DEFAULT=1
Target: ppc64le-redhat-linux
Configured with: ../configure --enable-bootstrap
--enable-languages=c,c++,fortran,lto --prefix=/usr
--mandir=/usr/share/man --infodir=/usr/share/info
--with-bugurl=http://bugzilla.redhat.com/bugzilla --enable-shared
--enable-threads=posix --enable-checking=release
--enable-targets=powerpcle-linux --disable-multilib --with-system-zlib
--enable-__cxa_atexit --disable-libunwind-exceptions
--enable-gnu-unique-object --enable-linker-build-id
--with-gcc-major-version-only --enable-libstdcxx-backtrace
--with-libstdcxx-zoneinfo=/usr/share/zoneinfo
--with-linker-hash-style=gnu --enable-plugin --enable-initfini-array
--without-isl --enable-offload-targets=nvptx-none
--enable-offload-defaulted --without-cuda-driver
--enable-gnu-indirect-function --enable-secureplt --with-long-double-128
--with-long-double-format=ieee --with-cpu-32=power9
--with-tune-32=power9 --with-cpu-64=power9 --with-tune-64=power9
--build=ppc64le-redhat-linux --with-build-config=bootstrap-lto
--enable-link-serialization=1 --enable-host-pie --enable-host-bind-now
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 14.1.1 20240507 (Red Hat 14.1.1-2) (GCC)
If this is intentional, (I am not sure why)
// consider changing to
diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c
index f6e25545bfc0..9050f8051918 100644
--- a/kernel/sched/ext.c
+++ b/kernel/sched/ext.c
@@ -3812,7 +3812,7 @@ static struct scx_exit_info *alloc_exit_info(size_t exit_dump_len)
if (!ei)
return NULL;
- ei->bt = kcalloc(sizeof(ei->bt[0]), SCX_EXIT_BT_LEN, GFP_KERNEL);
+ ei->bt = kcalloc(sizeof(ei->bt[0]) * SCX_EXIT_BT_LEN, 1, GFP_KERNEL);
ei->msg = kzalloc(SCX_EXIT_MSG_LEN, GFP_KERNEL);
ei->dump = kzalloc(exit_dump_len, GFP_KERNEL);
else
diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c
index f6e25545bfc0..ae9ec8f542f2 100644
--- a/kernel/sched/ext.c
+++ b/kernel/sched/ext.c
@@ -3812,7 +3812,7 @@ static struct scx_exit_info *alloc_exit_info(size_t exit_dump_len)
if (!ei)
return NULL;
- ei->bt = kcalloc(sizeof(ei->bt[0]), SCX_EXIT_BT_LEN, GFP_KERNEL);
+ ei->bt = kcalloc(SCX_EXIT_BT_LEN, sizeof(ei->bt[0]), GFP_KERNEL);
ei->msg = kzalloc(SCX_EXIT_MSG_LEN, GFP_KERNEL);
ei->dump = kzalloc(exit_dump_len, GFP_KERNEL);
https://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html#index-Wcalloc-transposed-args
From b651d7c39289850b5a0a2c67231dd36117340a2e Mon Sep 17 00:00:00 2001
From: Tejun Heo <tj@kernel.org>
Date: Mon, 1 Jul 2024 08:30:02 -1000
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
alloc_exit_info() calls kcalloc() but puts in the size of the element as the
first argument which triggers the following gcc warning:
kernel/sched/ext.c:3815:32: warning: ‘kmalloc_array_noprof’ sizes
specified with ‘sizeof’ in the earlier argument and not in the later
argument [-Wcalloc-transposed-args]
Fix it by swapping the positions of the first two arguments. No functional
changes.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Vishal Chourasia <vishalc@linux.ibm.com>
Link: http://lkml.kernel.org/r/ZoG6zreEtQhAUr_2@linux.ibm.com
---
Applied to sched_ext/for-6.11.
Thanks.
kernel/sched/ext.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c
index f6e25545bfc0..ae9ec8f542f2 100644
--- a/kernel/sched/ext.c
+++ b/kernel/sched/ext.c
@@ -3812,7 +3812,7 @@ static struct scx_exit_info *alloc_exit_info(size_t exit_dump_len)
if (!ei)
return NULL;
- ei->bt = kcalloc(sizeof(ei->bt[0]), SCX_EXIT_BT_LEN, GFP_KERNEL);
+ ei->bt = kcalloc(SCX_EXIT_BT_LEN, sizeof(ei->bt[0]), GFP_KERNEL);
ei->msg = kzalloc(SCX_EXIT_MSG_LEN, GFP_KERNEL);
ei->dump = kzalloc(exit_dump_len, GFP_KERNEL);
--
2.45.2
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