Re: [PATCH] tools/build: make in-target rule robust against too long argument error
From: Ian Rogers
Date: Tue Mar 03 2026 - 17:35:28 EST
On Mon, Oct 27, 2025 at 7:16 PM Changqing Li <changqing.li@xxxxxxxxxxxxx> wrote:
>
> Hi, Ian
>
> Kindly ping. Could you reproduce it? Any comments?
Sorry Changqing,
I was reminded by:
https://lore.kernel.org/lkml/20260303211503.165337-1-mmayer@xxxxxxxxxxxx/
that "argument list too long" is a problem for others.
I tried reproducing it, but I think it doesn't fail for me, possibly
because MAX_ARGS is larger on my system:
```
$ xargs --show-limits
Your environment variables take up 6133 bytes
POSIX upper limit on argument length (this system): 2088971
POSIX smallest allowable upper limit on argument length (all systems): 4096
Maximum length of command we could actually use: 2082838
Size of command buffer we are actually using: 131072
Maximum parallelism (--max-procs must be no greater): 2147483647
```
Anyway, the change makes sense to me.
Reviewed-by: Ian Rogers <irogers@xxxxxxxxxx>
Thanks,
Ian
> Regards
>
> Changqing
>
> On 8/19/25 11:01, Changqing Li wrote:
> >
> > On 8/19/25 04:38, Ian Rogers wrote:
> >> CAUTION: This email comes from a non Wind River email account!
> >> Do not click links or open attachments unless you recognize the
> >> sender and know the content is safe.
> >>
> >> On Mon, Jul 28, 2025 at 2:31 AM <changqing.li@xxxxxxxxxxxxx> wrote:
> >>> From: Changqing Li <changqing.li@xxxxxxxxxxxxx>
> >>>
> >>> The command length of in-target scales with the depth of the directory
> >>> times the number of objects in the Makefile. When there are many
> >>> objects, and O=[absolute_path] is set, and the absolute_path is
> >>> relatively long. It is possile that this line "$(call
> >>> if_changed,$(host)ld_multi)" will report error:
> >>> "make[4]: /bin/sh: Argument list too long"
> >>>
> >>> For example, build perf tools with O=/long/output/path
> >>>
> >>> Like built-in.a and *.mod rules in scripts/Makefile.build, add
> >>> $(objpredix)/ by the shell command instead of by Make's builtin
> >>> function.
> >>>
> >>> Signed-off-by: Changqing Li <changqing.li@xxxxxxxxxxxxx>
> >> Thanks Changqing, the change makes sense to me. The printf is pushing
> >> the values into xargs rather than using $^ with ld. I've tried
> >> reproducing the error to test your fix by creating long directory
> >> names in /tmp and then passing them to O=. I've not been able to do
> >> this. Could you send a reproduction for me to test?
> >>
> >> Thanks,
> >> Ian
> >
> > Hi, Ian
> >
> > Thanks. Here is my steps:
> >
> > 1. git clone https://github.com/torvalds/linux.git
> >
> > 2. cd linux/tools/perf/
> >
> > 3. mkdir
> > /tmp/01234567890123456789/0123456789012345678901234567890123456789/0123456789012345678901234567890123456789/012345678901234567890123456789/01234567890123456789/012345678901234567890123456789/01234567890123456789012345678/9012345678901234567890123456789/012345678901234567890123456789/012345678901234567890123456789/01234567890123456789012345678901234567890123456789012345678901234567890123/perf-1.0
> >
> > 4. make NO_LIBTRACEEVENT=1
> > O=/tmp/01234567890123456789/0123456789012345678901234567890123456789/0123456789012345678901234567890123456789/012345678901234567890123456789/01234567890123456789/012345678901234567890123456789/01234567890123456789012345678/9012345678901234567890123456789/012345678901234567890123456789/012345678901234567890123456789/01234567890123456789012345678901234567890123456789012345678901234567890123/perf-1.0
> >
> >
> > 5. Above step failed with error:
> >
> > make[4]: /bin/sh: Argument list too long
> >
> > make[4]: *** [/buildarea2/cli10/tmp/linux/tools/build/Makefile.build
> > <https://urldefense.com/v3/__http://Makefile.build__;!!AjveYdw8EvQ!c2n7zPX4Vrhwd7a9UxsjCXBGO5V8Llmon1egvupz4kHL4869ilesQgRgQZO8nj8AWwQJUlY9DOoWPD688quA73jNugR6IZRxy09Eig$>:148:
> > /tmp/01234567890123456789/0123456789012345678901234567890123456789/0123456789012345678901234567890123456789/012345678901234567890123456789/01234567890123456789/012345678901234567890123456789/01234567890123456789012345678/9012345678901234567890123456789/012345678901234567890123456789/012345678901234567890123456789/01234567890123456789012345678901234567890123456789012345678901234567890123/perf-1.0/util/perf-util-in.o]
> > Error 127
> >
> > make[3]: *** [/buildarea2/cli10/tmp/linux/tools/build/Makefile.build
> > <https://urldefense.com/v3/__http://Makefile.build__;!!AjveYdw8EvQ!c2n7zPX4Vrhwd7a9UxsjCXBGO5V8Llmon1egvupz4kHL4869ilesQgRgQZO8nj8AWwQJUlY9DOoWPD688quA73jNugR6IZRxy09Eig$>:142:
> > util] Error 2
> >
> > make[2]: *** [Makefile.perf:797:
> > /tmp/01234567890123456789/0123456789012345678901234567890123456789/0123456789012345678901234567890123456789/012345678901234567890123456789/01234567890123456789/012345678901234567890123456789/01234567890123456789012345678/9012345678901234567890123456789/012345678901234567890123456789/012345678901234567890123456789/01234567890123456789012345678901234567890123456789012345678901234567890123/perf-1.0/perf-util-in.o]
> > Error 2
> >
> >
> > Regards
> >
> > Changqing
> >>> ---
> >>> tools/build/Makefile.build | 6 ++++--
> >>> 1 file changed, 4 insertions(+), 2 deletions(-)
> >>>
> >>> diff --git a/tools/build/Makefile.build b/tools/build/Makefile.build
> >>> index 3584ff308607..39066a3ef2fc 100644
> >>> --- a/tools/build/Makefile.build
> >>> +++ b/tools/build/Makefile.build
> >>> @@ -70,11 +70,13 @@ quiet_cmd_gen = GEN $@
> >>> # If there's nothing to link, create empty $@ object.
> >>> quiet_cmd_ld_multi = LD $@
> >>> cmd_ld_multi = $(if $(strip $(obj-y)),\
> >>> - $(LD) -r -o $@ $(filter $(obj-y),$^),rm -f
> >>> $@; $(AR) rcs $@)
> >>> + printf "$(objprefix)%s " $(patsubst
> >>> $(objprefix)%,%,$(filter $(obj-y),$^)) | \
> >>> + xargs $(LD) -r -o $@,rm -f $@; $(AR) rcs $@)
> >>>
> >>> quiet_cmd_host_ld_multi = HOSTLD $@
> >>> cmd_host_ld_multi = $(if $(strip $(obj-y)),\
> >>> - $(HOSTLD) -r -o $@ $(filter
> >>> $(obj-y),$^),rm -f $@; $(HOSTAR) rcs $@)
> >>> + printf "$(objprefix)%s " $(patsubst
> >>> $(objprefix)%,%,$(filter $(obj-y),$^)) | \
> >>> + xargs $(HOSTLD) -r -o $@,rm -f $@;
> >>> $(HOSTAR) rcs $@)
> >>>
> >>> ifneq ($(filter $(obj),$(hostprogs)),)
> >>> host = host_
> >>> --
> >>> 2.34.1
> >>>