FAILED: patch "[PATCH] rust: compile libcore with edition 2024 for 1.87+" failed to apply to 6.12-stable tree

FAILED: patch "[PATCH] rust: compile libcore with edition 2024 for 1.87+" failed to apply to 6.12-stable tree

[gregkh]

The patch below does not apply to the 6.12-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.12.y
git checkout FETCH_HEAD
git cherry-pick -x f4daa80d6be7d3c55ca72a8e560afc4e21f886aa
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2025061734-shale-reliably-8969@gregkh' --subject-prefix 'PATCH 6.12.y' HEAD^..

Possible dependencies:



thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From f4daa80d6be7d3c55ca72a8e560afc4e21f886aa Mon Sep 17 00:00:00 2001
From: Gary Guo <gary@garyguo.net>
Date: Sat, 17 May 2025 09:55:59 +0100
Subject: [PATCH] rust: compile libcore with edition 2024 for 1.87+

Rust 1.87 (released on 2025-05-15) compiles core library with edition
2024 instead of 2021 [1]. Ensure that the edition matches libcore's
expectation to avoid potential breakage.

[ J3m3 reported in Zulip [2] that the `rust-analyzer` target was
  broken after this patch -- indeed, we need to avoid `core-cfgs`
  since those are passed to the `rust-analyzer` target.

  So, instead, I tweaked the patch to create a new `core-edition`
  variable and explicitly mention the `--edition` flag instead of
  reusing `core-cfg`s.

  In addition, pass a new argument using this new variable to
  `generate_rust_analyzer.py` so that we set the right edition there.

  By the way, for future reference: the `filter-out` change is needed
  for Rust < 1.87, since otherwise we would skip the `--edition=2021`
  we just added, ending up with no edition flag, and thus the compiler
  would default to the 2015 one.

  [2] https://rust-for-linux.zulipchat.com/#narrow/channel/291565/topic/x/near/520206547

    - Miguel ]

Cc: stable@vger.kernel.org # Needed in 6.12.y and later (Rust is pinned in older LTSs).
Link: https://github.com/rust-lang/rust/pull/138162 [1]
Reported-by: est31 <est31@protonmail.com>
Closes: https://github.com/Rust-for-Linux/linux/issues/1163
Signed-off-by: Gary Guo <gary@garyguo.net>
Link: https://lore.kernel.org/r/20250517085600.2857460-1-gary@garyguo.net
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

diff --git a/rust/Makefile b/rust/Makefile
index f207ba0ed466..d62b58d0a55c 100644
--- a/rust/Makefile
+++ b/rust/Makefile
@@ -60,6 +60,8 @@ endif
 core-cfgs = \
     --cfg no_fp_fmt_parse
 
+core-edition := $(if $(call rustc-min-version,108700),2024,2021)
+
 # `rustc` recognizes `--remap-path-prefix` since 1.26.0, but `rustdoc` only
 # since Rust 1.81.0. Moreover, `rustdoc` ICEs on out-of-tree builds since Rust
 # 1.82.0 (https://github.com/rust-lang/rust/issues/138520). Thus workaround both
@@ -106,8 +108,8 @@ rustdoc-macros: $(src)/macros/lib.rs FORCE
 
 # Starting with Rust 1.82.0, skipping `-Wrustdoc::unescaped_backticks` should
 # not be needed -- see https://github.com/rust-lang/rust/pull/128307.
-rustdoc-core: private skip_flags = -Wrustdoc::unescaped_backticks
-rustdoc-core: private rustc_target_flags = $(core-cfgs)
+rustdoc-core: private skip_flags = --edition=2021 -Wrustdoc::unescaped_backticks
+rustdoc-core: private rustc_target_flags = --edition=$(core-edition) $(core-cfgs)
 rustdoc-core: $(RUST_LIB_SRC)/core/src/lib.rs FORCE
 	+$(call if_changed,rustdoc)
 
@@ -416,7 +418,7 @@ quiet_cmd_rustc_library = $(if $(skip_clippy),RUSTC,$(RUSTC_OR_CLIPPY_QUIET)) L
       cmd_rustc_library = \
 	OBJTREE=$(abspath $(objtree)) \
 	$(if $(skip_clippy),$(RUSTC),$(RUSTC_OR_CLIPPY)) \
-		$(filter-out $(skip_flags),$(rust_flags) $(rustc_target_flags)) \
+		$(filter-out $(skip_flags),$(rust_flags)) $(rustc_target_flags) \
 		--emit=dep-info=$(depfile) --emit=obj=$@ \
 		--emit=metadata=$(dir $@)$(patsubst %.o,lib%.rmeta,$(notdir $@)) \
 		--crate-type rlib -L$(objtree)/$(obj) \
@@ -427,7 +429,7 @@ quiet_cmd_rustc_library = $(if $(skip_clippy),RUSTC,$(RUSTC_OR_CLIPPY_QUIET)) L
 
 rust-analyzer:
 	$(Q)MAKEFLAGS= $(srctree)/scripts/generate_rust_analyzer.py \
-		--cfgs='core=$(core-cfgs)' \
+		--cfgs='core=$(core-cfgs)' $(core-edition) \
 		$(realpath $(srctree)) $(realpath $(objtree)) \
 		$(rustc_sysroot) $(RUST_LIB_SRC) $(if $(KBUILD_EXTMOD),$(srcroot)) \
 		> rust-project.json
@@ -483,9 +485,9 @@ $(obj)/helpers/helpers.o: $(src)/helpers/helpers.c $(recordmcount_source) FORCE
 $(obj)/exports.o: private skip_gendwarfksyms = 1
 
 $(obj)/core.o: private skip_clippy = 1
-$(obj)/core.o: private skip_flags = -Wunreachable_pub
+$(obj)/core.o: private skip_flags = --edition=2021 -Wunreachable_pub
 $(obj)/core.o: private rustc_objcopy = $(foreach sym,$(redirect-intrinsics),--redefine-sym $(sym)=__rust$(sym))
-$(obj)/core.o: private rustc_target_flags = $(core-cfgs)
+$(obj)/core.o: private rustc_target_flags = --edition=$(core-edition) $(core-cfgs)
 $(obj)/core.o: $(RUST_LIB_SRC)/core/src/lib.rs \
     $(wildcard $(objtree)/include/config/RUSTC_VERSION_TEXT) FORCE
 	+$(call if_changed_rule,rustc_library)
diff --git a/scripts/generate_rust_analyzer.py b/scripts/generate_rust_analyzer.py
index fe663dd0c43b..7c3ea2b55041 100755
--- a/scripts/generate_rust_analyzer.py
+++ b/scripts/generate_rust_analyzer.py
@@ -19,7 +19,7 @@ def args_crates_cfgs(cfgs):
 
     return crates_cfgs
 
-def generate_crates(srctree, objtree, sysroot_src, external_src, cfgs):
+def generate_crates(srctree, objtree, sysroot_src, external_src, cfgs, core_edition):
     # Generate the configuration list.
     cfg = []
     with open(objtree / "include" / "generated" / "rustc_cfg") as fd:
@@ -35,7 +35,7 @@ def generate_crates(srctree, objtree, sysroot_src, external_src, cfgs):
     crates_indexes = {}
     crates_cfgs = args_crates_cfgs(cfgs)
 
-    def append_crate(display_name, root_module, deps, cfg=[], is_workspace_member=True, is_proc_macro=False):
+    def append_crate(display_name, root_module, deps, cfg=[], is_workspace_member=True, is_proc_macro=False, edition="2021"):
         crate = {
             "display_name": display_name,
             "root_module": str(root_module),
@@ -43,7 +43,7 @@ def generate_crates(srctree, objtree, sysroot_src, external_src, cfgs):
             "is_proc_macro": is_proc_macro,
             "deps": [{"crate": crates_indexes[dep], "name": dep} for dep in deps],
             "cfg": cfg,
-            "edition": "2021",
+            "edition": edition,
             "env": {
                 "RUST_MODFILE": "This is only for rust-analyzer"
             }
@@ -61,6 +61,7 @@ def generate_crates(srctree, objtree, sysroot_src, external_src, cfgs):
         display_name,
         deps,
         cfg=[],
+        edition="2021",
     ):
         append_crate(
             display_name,
@@ -68,12 +69,13 @@ def generate_crates(srctree, objtree, sysroot_src, external_src, cfgs):
             deps,
             cfg,
             is_workspace_member=False,
+            edition=edition,
         )
 
     # NB: sysroot crates reexport items from one another so setting up our transitive dependencies
     # here is important for ensuring that rust-analyzer can resolve symbols. The sources of truth
     # for this dependency graph are `(sysroot_src / crate / "Cargo.toml" for crate in crates)`.
-    append_sysroot_crate("core", [], cfg=crates_cfgs.get("core", []))
+    append_sysroot_crate("core", [], cfg=crates_cfgs.get("core", []), edition=core_edition)
     append_sysroot_crate("alloc", ["core"])
     append_sysroot_crate("std", ["alloc", "core"])
     append_sysroot_crate("proc_macro", ["core", "std"])
@@ -177,6 +179,7 @@ def main():
     parser = argparse.ArgumentParser()
     parser.add_argument('--verbose', '-v', action='store_true')
     parser.add_argument('--cfgs', action='append', default=[])
+    parser.add_argument("core_edition")
     parser.add_argument("srctree", type=pathlib.Path)
     parser.add_argument("objtree", type=pathlib.Path)
     parser.add_argument("sysroot", type=pathlib.Path)
@@ -193,7 +196,7 @@ def main():
     assert args.sysroot in args.sysroot_src.parents
 
     rust_project = {
-        "crates": generate_crates(args.srctree, args.objtree, args.sysroot_src, args.exttree, args.cfgs),
+        "crates": generate_crates(args.srctree, args.objtree, args.sysroot_src, args.exttree, args.cfgs, args.core_edition),
         "sysroot": str(args.sysroot),
     }
 

Re: FAILED: patch "[PATCH] rust: compile libcore with edition 2024 for 1.87+" failed to apply to 6.12-stable tree

[Miguel Ojeda]

On Tue, Jun 17, 2025 at 1:23 PM <gregkh@linuxfoundation.org> wrote:
>
> The patch below does not apply to the 6.12-stable tree.

This will require an extra patch for 6.12.y -- the ones that
introduces `rustc-min-version`
(ac954145e1ee3f72033161cbe4ac0b16b5354ae7).

That one cherry-picks cleanly, but I am replying with both as patches.

Cheers,
Miguel

[PATCH 6.12.y 1/2] kbuild: rust: add rustc-min-version support function

[Miguel Ojeda]

commit ac954145e1ee3f72033161cbe4ac0b16b5354ae7 upstream.

Introduce `rustc-min-version` support function that mimics
`{gcc,clang}-min-version` ones, following commit 88b61e3bff93
("Makefile.compiler: replace cc-ifversion with compiler-specific macros").

In addition, use it in the first use case we have in the kernel (which
was done independently to minimize the changes needed for the fix).

Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Reviewed-by: Fiona Behrens <me@Kloenk.dev>
Reviewed-by: Nicolas Schier <n.schier@avm.de>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 Documentation/kbuild/makefiles.rst | 14 ++++++++++++++
 arch/arm64/Makefile                |  2 +-
 scripts/Makefile.compiler          |  4 ++++
 3 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/Documentation/kbuild/makefiles.rst b/Documentation/kbuild/makefiles.rst
index 7964e0c245ae..81607ce40759 100644
--- a/Documentation/kbuild/makefiles.rst
+++ b/Documentation/kbuild/makefiles.rst
@@ -656,6 +656,20 @@ cc-cross-prefix
             endif
     endif
 
+$(RUSTC) support functions
+--------------------------
+
+rustc-min-version
+  rustc-min-version tests if the value of $(CONFIG_RUSTC_VERSION) is greater
+  than or equal to the provided value and evaluates to y if so.
+
+  Example::
+
+    rustflags-$(call rustc-min-version, 108500) := -Cfoo
+
+  In this example, rustflags-y will be assigned the value -Cfoo if
+  $(CONFIG_RUSTC_VERSION) is >= 1.85.0.
+
 $(LD) support functions
 -----------------------
 
diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile
index 19a4988621ac..88029d38b3c6 100644
--- a/arch/arm64/Makefile
+++ b/arch/arm64/Makefile
@@ -48,7 +48,7 @@ KBUILD_CFLAGS	+= $(CC_FLAGS_NO_FPU) \
 KBUILD_CFLAGS	+= $(call cc-disable-warning, psabi)
 KBUILD_AFLAGS	+= $(compat_vdso)
 
-ifeq ($(call test-ge, $(CONFIG_RUSTC_VERSION), 108500),y)
+ifeq ($(call rustc-min-version, 108500),y)
 KBUILD_RUSTFLAGS += --target=aarch64-unknown-none-softfloat
 else
 KBUILD_RUSTFLAGS += --target=aarch64-unknown-none -Ctarget-feature="-neon"
diff --git a/scripts/Makefile.compiler b/scripts/Makefile.compiler
index c6cd729b65cb..68fdebb657ae 100644
--- a/scripts/Makefile.compiler
+++ b/scripts/Makefile.compiler
@@ -67,6 +67,10 @@ gcc-min-version = $(call test-ge, $(CONFIG_GCC_VERSION), $1)
 # Usage: cflags-$(call clang-min-version, 110000) += -foo
 clang-min-version = $(call test-ge, $(CONFIG_CLANG_VERSION), $1)
 
+# rustc-min-version
+# Usage: rustc-$(call rustc-min-version, 108500) += -Cfoo
+rustc-min-version = $(call test-ge, $(CONFIG_RUSTC_VERSION), $1)
+
 # ld-option
 # Usage: KBUILD_LDFLAGS += $(call ld-option, -X, -Y)
 ld-option = $(call try-run, $(LD) $(KBUILD_LDFLAGS) $(1) -v,$(1),$(2),$(3))
-- 
2.50.0

[PATCH 6.12.y 2/2] rust: compile libcore with edition 2024 for 1.87+

[Miguel Ojeda]

From: Gary Guo <gary@garyguo.net>

commit f4daa80d6be7d3c55ca72a8e560afc4e21f886aa upstream.

Rust 1.87 (released on 2025-05-15) compiles core library with edition
2024 instead of 2021 [1]. Ensure that the edition matches libcore's
expectation to avoid potential breakage.

[ J3m3 reported in Zulip [2] that the `rust-analyzer` target was
  broken after this patch -- indeed, we need to avoid `core-cfgs`
  since those are passed to the `rust-analyzer` target.

  So, instead, I tweaked the patch to create a new `core-edition`
  variable and explicitly mention the `--edition` flag instead of
  reusing `core-cfg`s.

  In addition, pass a new argument using this new variable to
  `generate_rust_analyzer.py` so that we set the right edition there.

  By the way, for future reference: the `filter-out` change is needed
  for Rust < 1.87, since otherwise we would skip the `--edition=2021`
  we just added, ending up with no edition flag, and thus the compiler
  would default to the 2015 one.

  [2] https://rust-for-linux.zulipchat.com/#narrow/channel/291565/topic/x/near/520206547

    - Miguel ]

Cc: stable@vger.kernel.org # Needed in 6.12.y and later (Rust is pinned in older LTSs).
Link: https://github.com/rust-lang/rust/pull/138162 [1]
Reported-by: est31 <est31@protonmail.com>
Closes: https://github.com/Rust-for-Linux/linux/issues/1163
Signed-off-by: Gary Guo <gary@garyguo.net>
Link: https://lore.kernel.org/r/20250517085600.2857460-1-gary@garyguo.net
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
[ Solved conflicts for 6.12.y backport. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 rust/Makefile                     | 14 ++++++++------
 scripts/generate_rust_analyzer.py | 13 ++++++++-----
 2 files changed, 16 insertions(+), 11 deletions(-)

diff --git a/rust/Makefile b/rust/Makefile
index 1b00e16951ee..93650b2ee7d5 100644
--- a/rust/Makefile
+++ b/rust/Makefile
@@ -53,6 +53,8 @@ endif
 core-cfgs = \
     --cfg no_fp_fmt_parse
 
+core-edition := $(if $(call rustc-min-version,108700),2024,2021)
+
 quiet_cmd_rustdoc = RUSTDOC $(if $(rustdoc_host),H, ) $<
       cmd_rustdoc = \
 	OBJTREE=$(abspath $(objtree)) \
@@ -95,8 +97,8 @@ rustdoc-macros: $(src)/macros/lib.rs FORCE
 
 # Starting with Rust 1.82.0, skipping `-Wrustdoc::unescaped_backticks` should
 # not be needed -- see https://github.com/rust-lang/rust/pull/128307.
-rustdoc-core: private skip_flags = -Wrustdoc::unescaped_backticks
-rustdoc-core: private rustc_target_flags = $(core-cfgs)
+rustdoc-core: private skip_flags = --edition=2021 -Wrustdoc::unescaped_backticks
+rustdoc-core: private rustc_target_flags = --edition=$(core-edition) $(core-cfgs)
 rustdoc-core: $(RUST_LIB_SRC)/core/src/lib.rs FORCE
 	+$(call if_changed,rustdoc)
 
@@ -372,7 +374,7 @@ quiet_cmd_rustc_library = $(if $(skip_clippy),RUSTC,$(RUSTC_OR_CLIPPY_QUIET)) L
       cmd_rustc_library = \
 	OBJTREE=$(abspath $(objtree)) \
 	$(if $(skip_clippy),$(RUSTC),$(RUSTC_OR_CLIPPY)) \
-		$(filter-out $(skip_flags),$(rust_flags) $(rustc_target_flags)) \
+		$(filter-out $(skip_flags),$(rust_flags)) $(rustc_target_flags) \
 		--emit=dep-info=$(depfile) --emit=obj=$@ \
 		--emit=metadata=$(dir $@)$(patsubst %.o,lib%.rmeta,$(notdir $@)) \
 		--crate-type rlib -L$(objtree)/$(obj) \
@@ -383,7 +385,7 @@ quiet_cmd_rustc_library = $(if $(skip_clippy),RUSTC,$(RUSTC_OR_CLIPPY_QUIET)) L
 
 rust-analyzer:
 	$(Q)$(srctree)/scripts/generate_rust_analyzer.py \
-		--cfgs='core=$(core-cfgs)' \
+		--cfgs='core=$(core-cfgs)' $(core-edition) \
 		$(realpath $(srctree)) $(realpath $(objtree)) \
 		$(rustc_sysroot) $(RUST_LIB_SRC) $(KBUILD_EXTMOD) > \
 		$(if $(KBUILD_EXTMOD),$(extmod_prefix),$(objtree))/rust-project.json
@@ -407,9 +409,9 @@ define rule_rustc_library
 endef
 
 $(obj)/core.o: private skip_clippy = 1
-$(obj)/core.o: private skip_flags = -Wunreachable_pub
+$(obj)/core.o: private skip_flags = --edition=2021 -Wunreachable_pub
 $(obj)/core.o: private rustc_objcopy = $(foreach sym,$(redirect-intrinsics),--redefine-sym $(sym)=__rust$(sym))
-$(obj)/core.o: private rustc_target_flags = $(core-cfgs)
+$(obj)/core.o: private rustc_target_flags = --edition=$(core-edition) $(core-cfgs)
 $(obj)/core.o: $(RUST_LIB_SRC)/core/src/lib.rs \
     $(wildcard $(objtree)/include/config/RUSTC_VERSION_TEXT) FORCE
 	+$(call if_changed_rule,rustc_library)
diff --git a/scripts/generate_rust_analyzer.py b/scripts/generate_rust_analyzer.py
index 690f9830f064..f9c9a2117632 100755
--- a/scripts/generate_rust_analyzer.py
+++ b/scripts/generate_rust_analyzer.py
@@ -18,7 +18,7 @@ def args_crates_cfgs(cfgs):
 
     return crates_cfgs
 
-def generate_crates(srctree, objtree, sysroot_src, external_src, cfgs):
+def generate_crates(srctree, objtree, sysroot_src, external_src, cfgs, core_edition):
     # Generate the configuration list.
     cfg = []
     with open(objtree / "include" / "generated" / "rustc_cfg") as fd:
@@ -34,7 +34,7 @@ def generate_crates(srctree, objtree, sysroot_src, external_src, cfgs):
     crates_indexes = {}
     crates_cfgs = args_crates_cfgs(cfgs)
 
-    def append_crate(display_name, root_module, deps, cfg=[], is_workspace_member=True, is_proc_macro=False):
+    def append_crate(display_name, root_module, deps, cfg=[], is_workspace_member=True, is_proc_macro=False, edition="2021"):
         crates_indexes[display_name] = len(crates)
         crates.append({
             "display_name": display_name,
@@ -43,7 +43,7 @@ def generate_crates(srctree, objtree, sysroot_src, external_src, cfgs):
             "is_proc_macro": is_proc_macro,
             "deps": [{"crate": crates_indexes[dep], "name": dep} for dep in deps],
             "cfg": cfg,
-            "edition": "2021",
+            "edition": edition,
             "env": {
                 "RUST_MODFILE": "This is only for rust-analyzer"
             }
@@ -53,6 +53,7 @@ def generate_crates(srctree, objtree, sysroot_src, external_src, cfgs):
         display_name,
         deps,
         cfg=[],
+        edition="2021",
     ):
         append_crate(
             display_name,
@@ -60,12 +61,13 @@ def generate_crates(srctree, objtree, sysroot_src, external_src, cfgs):
             deps,
             cfg,
             is_workspace_member=False,
+            edition=edition,
         )
 
     # NB: sysroot crates reexport items from one another so setting up our transitive dependencies
     # here is important for ensuring that rust-analyzer can resolve symbols. The sources of truth
     # for this dependency graph are `(sysroot_src / crate / "Cargo.toml" for crate in crates)`.
-    append_sysroot_crate("core", [], cfg=crates_cfgs.get("core", []))
+    append_sysroot_crate("core", [], cfg=crates_cfgs.get("core", []), edition=core_edition)
     append_sysroot_crate("alloc", ["core"])
     append_sysroot_crate("std", ["alloc", "core"])
     append_sysroot_crate("proc_macro", ["core", "std"])
@@ -155,6 +157,7 @@ def main():
     parser = argparse.ArgumentParser()
     parser.add_argument('--verbose', '-v', action='store_true')
     parser.add_argument('--cfgs', action='append', default=[])
+    parser.add_argument("core_edition")
     parser.add_argument("srctree", type=pathlib.Path)
     parser.add_argument("objtree", type=pathlib.Path)
     parser.add_argument("sysroot", type=pathlib.Path)
@@ -171,7 +174,7 @@ def main():
     assert args.sysroot in args.sysroot_src.parents
 
     rust_project = {
-        "crates": generate_crates(args.srctree, args.objtree, args.sysroot_src, args.exttree, args.cfgs),
+        "crates": generate_crates(args.srctree, args.objtree, args.sysroot_src, args.exttree, args.cfgs, args.core_edition),
         "sysroot": str(args.sysroot),
     }
 
-- 
2.50.0