kbuild: rust: keep Rust objects out of Clang LTO with inline helpersgrafted

Under `CONFIG_LTO_CLANG` + `CONFIG_RUST_INLINE_HELPERS`, one may hit
`objtool` errors such as:

    vmlinux.o: error: objtool: _R..._3Gsp4boot+0xd6a:
    can't find jump dest instruction at .text._R..._3Gsp4boot+0x1dfd

The reason is that in such builds, the Clang invocation that compiles
the combined Rust plus helpers bitcode emits LLVM bitcode (again) --
the final code generation happens in the linker's LTO step, which the
`-mllvm` trap options passed to Clang do not reach.

This, in turn, means that unreachable traps are missing, and the
impossible paths do not merely fallthrough to the next symbol, but past
the end of their own section, since LTO builds place each function in
its own section.

Thus filter `CC_FLAGS_LTO` out of the Clang invocation, so that it always
emits machine code directly, with the traps in place.

Assisted-by: LLM
Cc: Gary Guo <gary@garyguo.net>
Cc: Boqun Feng <boqun@kernel.org>
Cc: Alice Ryhl <aliceryhl@google.com>
Cc: Matthew Maurer <mmaurer@google.com>
Cc: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: stable@vger.kernel.org
Fixes: 3a2486cc1da5 ("kbuild: rust: provide an option to inline C helpers into Rust")
Acked-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260816133233.197500-2-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

1 files changed, 256 insertions, 0 deletions

diff --git a/drivers/gpib/Kconfig b/drivers/gpib/Kconfig
new file mode 100644
index 000000000..d43a28c62
--- /dev/null
+++ b/drivers/gpib/Kconfig
@@ -0,0 +1,256 @@
+# SPDX-License-Identifier: GPL-2.0
+menuconfig GPIB
+	tristate "GPIB drivers"
+	help
+	  Enable support for GPIB cards and dongles.  GPIB is the
+	  General Purpose Interface Bus which conforms to the IEEE488
+	  standard.
+
+	  This set of drivers can be used with the corresponding user
+	  space library that can be found on Sourceforge under linux-gpib.
+	  Select the drivers for your hardware from the list.
+
+if GPIB
+
+config GPIB_COMMON
+	tristate "GPIB core"
+	help
+
+	  Core common driver for all GPIB drivers. It provides the
+	  interface for the userland library
+
+	  To compile this driver as a module, choose M here: the module will be
+	  called gpib_common
+
+config GPIB_AGILENT_82350B
+	tristate "Agilent 8235xx PCI(e) adapters"
+	depends on PCI
+	select GPIB_COMMON
+	select GPIB_TMS9914
+	help
+	  Enable support for HP/Agilent/Keysight boards
+	    82350A
+	    82350B
+	    82351A
+
+	  To compile this driver as a module, choose M here: the module will be
+	  called agilent_82350b.
+
+config GPIB_AGILENT_82357A
+	tristate "Agilent 82357a/b USB dongles"
+	select GPIB_COMMON
+	depends on USB
+	help
+	  Enable support for Agilent/Keysight 82357x USB dongles.
+
+	  To compile this driver as a module, choose M here: the module will be
+	  called agilent_82357a.
+
+config GPIB_CEC_PCI
+	tristate "CEC PCI board"
+	depends on PCI
+	depends on HAS_IOPORT
+	select GPIB_COMMON
+	select GPIB_NEC7210
+	help
+	  Enable support for Capital Equipment Corporation PCI-488
+	  and Keithly KPCI-488 boards.
+
+	  To compile this driver as a module, choose M here: the module will be
+	  called cec_gpib.
+
+config GPIB_NI_PCI_ISA
+	tristate "NI PCI/ISA compatible boards"
+	depends on ISA_BUS || PCI || PCMCIA
+	depends on HAS_IOPORT
+	depends on PCMCIA || !PCMCIA
+	depends on HAS_IOPORT_MAP
+	select GPIB_COMMON
+	select GPIB_NEC7210
+	help
+	  Enable support for National Instruments boards based
+	  on TNT4882 chips:
+	     AT-GPIB (with NAT4882 chip)
+	     AT-GPIB (with NEC7210 chip)
+	     AT-GPIB/TNT
+	     PCI-GPIB
+	     PCIe-GPIB
+	     PCI-GPIB+
+	     PCM-GPIB
+	     PXI-GPIB
+	     PCMCIA-GPIB
+	     and Capital Equipment Corporation CEC-488 board.
+
+	  To compile this driver as a module, choose M here: the module will be
+	  called tnt4882.
+
+config GPIB_CB7210
+       tristate "Measurement Computing compatible boards"
+	depends on HAS_IOPORT
+	depends on ISA_BUS || PCI || PCMCIA
+	depends on PCMCIA || !PCMCIA
+       select GPIB_COMMON
+	select GPIB_NEC7210
+       help
+       Enable support for Measurement Computing (Computer Boards):
+       CPCI_GPIB, ISA-GPIB, ISA-GPIB/LC, PCI-GPIB/1M, PCI-GPIB/300K and
+       PCMCIA-GPIB
+       Quancom PCIGPIB-1 with MC cb7210 chip
+
+	  To compile this driver as a module, choose M here: the module will be
+
+config GPIB_NI_USB
+	tristate "NI USB dongles"
+	select GPIB_COMMON
+	depends on USB
+	help
+	  Enable support for National Instruments
+	       GPIB-USB-B
+	       GPIB-USB-HS
+	       GPIB-USB-HS+
+	   Keithly
+	       KUSB-488
+	       KUSB-488A
+	   Measurement Computing (Computer Boards)
+	       USB-488
+
+	  To compile this driver as a module, choose M here: the module will be
+	  called ni_usb.
+
+config GPIB_FLUKE
+       tristate "Fluke"
+	depends on OF
+       select GPIB_COMMON
+       select GPIB_NEC7210
+       depends on HAS_IOMEM
+       help
+         GPIB driver for Fluke based cda devices.
+
+	 To compile this driver as a module, choose M here: the module will be
+	 called fluke_gpib
+
+config GPIB_FMH
+       tristate "FMH FPGA based devices"
+       select GPIB_COMMON
+       select GPIB_NEC7210
+       depends on !PPC
+       depends on OF && PCI
+       help
+         GPIB driver for fmhess FPGA based devices
+
+	 To compile this driver as a module, choose M here: the module will be
+	 called fmh_gpib
+
+config GPIB_GPIO
+       tristate "RPi GPIO bitbang"
+	depends on ARCH_BCM2835 || COMPILE_TEST
+       select GPIB_COMMON
+       help
+         GPIB bitbang driver Raspberry Pi GPIO adapters
+
+	 To compile this driver as a module, choose M here: the module will be
+	 called gpib_bitbang
+
+config GPIB_HP82335
+       tristate "HP82335/HP27209"
+	depends on ISA_BUS
+       select GPIB_COMMON
+       select GPIB_TMS9914
+       help
+         GPIB driver for HP82335 and HP27209 boards
+
+	 To compile this driver as a module, choose M here: the module will be
+	 called hp82335
+
+
+config GPIB_HP82341
+       tristate "HP82341x"
+       select GPIB_COMMON
+       select GPIB_TMS9914
+       depends on ISA_BUS || EISA
+       help
+         GPIB driver for HP82341 A/B/C/D boards
+
+	 To compile this driver as a module, choose M here: the module will be
+	 called hp82341
+
+config GPIB_INES
+       tristate "INES"
+	depends on PCI || ISA_BUS || PCMCIA
+	depends on PCMCIA || !PCMCIA
+	depends on HAS_IOPORT
+       select GPIB_COMMON
+       select GPIB_NEC7210
+       help
+         GPIB driver for Ines compatible boards
+	 Ines
+	    GPIB-HS-NT
+	    GPIB for Compact PCI
+	    GPIB for PCI
+	    GPIB for PCMCIA
+	    GPIB PC/104
+	 Hameg
+	    HO80-2
+	 Quancom
+	    PCIGPIB-1 based on Ines iGPIB 72010 chip
+
+	 To compile this driver as a module, choose M here: the module will be
+	 called ines_gpib
+	  called cb7210.
+
+config GPIB_PCMCIA
+       def_bool y
+       depends on PCMCIA && (GPIB_NI_PCI_ISA || GPIB_CB7210 || GPIB_INES)
+       help
+         Enable PCMCIA/CArdbus support for National Instruments,
+	 measurement computing boards and Ines boards.
+
+config GPIB_LPVO
+       tristate "LPVO DIY USB GPIB"
+       select GPIB_COMMON
+       depends on USB
+       help
+         Enable support for LPVO Self-made usb-gpib adapter
+
+	 To compile this driver as a module, choose M here: the module will be
+	 called lpvo_usb_gpib
+
+config GPIB_PC2
+       tristate "PC2 PC2a"
+	depends on ISA_BUS
+	depends on HAS_IOPORT
+       select GPIB_COMMON
+       select GPIB_NEC7210
+       help
+         Enable support for pc2 and pc2a compatible adapters
+	    Capital Equipment Corporation PC-488
+	    CONTEC GP-IB(PC)
+	    Hameg HO80
+	    Iotech GP488B
+	    Keithly MBC-488
+	    Measurement Computing ISA-GPIB-PCA2
+	    National Instruments PCII, PCIIa and PCII/IIa
+
+	 To compile this driver as a module, choose M here: the module will be
+	 called pc2_gpib
+
+
+config GPIB_TMS9914
+       tristate
+       select GPIB_COMMON
+       help
+         Enable support for TMS 9914 chip.
+
+	 To compile this driver as a module, choose M here: the module will be
+	 called tms9914
+
+config GPIB_NEC7210
+       tristate
+       select GPIB_COMMON
+       help
+         Enable support for NEC 7210 compatible chips.
+
+	 To compile this driver as a module, choose M here: the module will be
+	 called nec7210
+
+endif # GPIB