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, 107 insertions, 0 deletions

diff --git a/drivers/phy/amlogic/Kconfig b/drivers/phy/amlogic/Kconfig
new file mode 100644
index 000000000..ce7ba3eb2
--- /dev/null
+++ b/drivers/phy/amlogic/Kconfig
@@ -0,0 +1,107 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Phy drivers for Amlogic platforms
+#
+config PHY_MESON8_HDMI_TX
+	tristate "Meson8, Meson8b and Meson8m2 HDMI TX PHY driver"
+	depends on (ARCH_MESON && ARM) || COMPILE_TEST
+	depends on OF
+	select MFD_SYSCON
+	help
+	  Enable this to support the HDMI TX PHYs found in Meson8,
+	  Meson8b and Meson8m2 SoCs.
+	  If unsure, say N.
+
+config PHY_MESON8B_USB2
+	tristate "Meson8, Meson8b, Meson8m2 and GXBB USB2 PHY driver"
+	default ARCH_MESON
+	depends on OF && (ARCH_MESON || COMPILE_TEST)
+	depends on USB_SUPPORT
+	select USB_COMMON
+	select GENERIC_PHY
+	select REGMAP_MMIO
+	help
+	  Enable this to support the Meson USB2 PHYs found in Meson8,
+	  Meson8b and GXBB SoCs.
+	  If unsure, say N.
+
+config PHY_MESON_GXL_USB2
+	tristate "Meson GXL and GXM USB2 PHY drivers"
+	default ARCH_MESON
+	depends on OF && (ARCH_MESON || COMPILE_TEST)
+	depends on USB_SUPPORT
+	select GENERIC_PHY
+	select REGMAP_MMIO
+	help
+	  Enable this to support the Meson USB2 PHYs found in Meson
+	  GXL and GXM SoCs.
+	  If unsure, say N.
+
+config PHY_MESON_G12A_MIPI_DPHY_ANALOG
+	tristate "Meson G12A MIPI Analog DPHY driver"
+	default ARCH_MESON
+	depends on OF && (ARCH_MESON || COMPILE_TEST)
+	select GENERIC_PHY
+	select MFD_SYSCON
+	select GENERIC_PHY_MIPI_DPHY
+	help
+	  Enable this to support the Meson MIPI Analog DPHY found in Meson G12A
+	  SoCs.
+	  If unsure, say N.
+
+config PHY_MESON_G12A_USB2
+	tristate "Meson G12A USB2 PHY driver"
+	default ARCH_MESON
+	depends on OF && (ARCH_MESON || COMPILE_TEST)
+	select GENERIC_PHY
+	select REGMAP_MMIO
+	help
+	  Enable this to support the Meson USB2 PHYs found in Meson
+	  G12A SoCs.
+	  If unsure, say N.
+
+config PHY_MESON_G12A_USB3_PCIE
+	tristate "Meson G12A USB3+PCIE Combo PHY driver"
+	default ARCH_MESON
+	depends on OF && (ARCH_MESON || COMPILE_TEST)
+	select GENERIC_PHY
+	select REGMAP_MMIO
+	help
+	  Enable this to support the Meson USB3 + PCIE Combo PHY found
+	  in Meson G12A SoCs.
+	  If unsure, say N.
+
+config PHY_MESON_AXG_PCIE
+	tristate "Meson AXG PCIE PHY driver"
+	default ARCH_MESON
+	depends on OF && (ARCH_MESON || COMPILE_TEST)
+	select GENERIC_PHY
+	select REGMAP_MMIO
+	help
+	  Enable this to support the Meson MIPI + PCIE PHY found
+	  in Meson AXG SoCs.
+	  If unsure, say N.
+
+config PHY_MESON_AXG_MIPI_PCIE_ANALOG
+	tristate "Meson AXG MIPI + PCIE analog PHY driver"
+	default ARCH_MESON
+	depends on OF && (ARCH_MESON || COMPILE_TEST)
+	select GENERIC_PHY
+	select REGMAP_MMIO
+	select GENERIC_PHY_MIPI_DPHY
+	help
+	  Enable this to support the Meson MIPI + PCIE analog PHY
+	  found in Meson AXG SoCs.
+	  If unsure, say N.
+
+config PHY_MESON_AXG_MIPI_DPHY
+	tristate "Meson AXG MIPI DPHY driver"
+	default ARCH_MESON
+	depends on OF && (ARCH_MESON || COMPILE_TEST)
+	select GENERIC_PHY
+	select REGMAP_MMIO
+	select GENERIC_PHY_MIPI_DPHY
+	help
+	  Enable this to support the Meson MIPI DPHY found in Meson AXG
+	  SoCs.
+	  If unsure, say N.