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, 66 insertions, 0 deletions

diff --git a/Documentation/usb/linux.inf b/Documentation/usb/linux.inf
new file mode 100644
index 000000000..c569ac6be
--- /dev/null
+++ b/Documentation/usb/linux.inf
@@ -0,0 +1,66 @@
+; Based on template INF file found at
+;    <https://msdn.microsoft.com/en-us/library/ff570620.aspx>
+; which was:
+;    Copyright (c) Microsoft Corporation
+; and released under the MLPL as found at:
+;    <http://msdn.microsoft.com/en-us/cc300389.aspx#MLPL>.
+; For use only on Windows operating systems.
+
+[Version]
+Signature           = "$Windows NT$"
+Class               = Net
+ClassGUID           = {4d36e972-e325-11ce-bfc1-08002be10318}
+Provider            = %Linux%
+DriverVer           = 06/21/2006,6.0.6000.16384
+
+[Manufacturer]
+%Linux%             = LinuxDevices,NTx86,NTamd64,NTia64
+
+; Decoration for x86 architecture
+[LinuxDevices.NTx86]
+%LinuxDevice%       = RNDIS.NT.5.1, USB\VID_0525&PID_a4a2, USB\VID_1d6b&PID_0104&MI_00
+
+; Decoration for x64 architecture
+[LinuxDevices.NTamd64]
+%LinuxDevice%       = RNDIS.NT.5.1, USB\VID_0525&PID_a4a2, USB\VID_1d6b&PID_0104&MI_00
+
+; Decoration for ia64 architecture
+[LinuxDevices.NTia64]
+%LinuxDevice%       = RNDIS.NT.5.1, USB\VID_0525&PID_a4a2, USB\VID_1d6b&PID_0104&MI_00
+
+;@@@ This is the common setting for setup
+[ControlFlags]
+ExcludeFromSelect=*
+
+; DDInstall section
+; References the in-build Netrndis.inf
+[RNDIS.NT.5.1]
+Characteristics     = 0x84   ; NCF_PHYSICAL + NCF_HAS_UI
+BusType             = 15
+; NEVER REMOVE THE FOLLOWING REFERENCE FOR NETRNDIS.INF
+include             = netrndis.inf
+needs               = Usb_Rndis.ndi
+AddReg              = Rndis_AddReg_Vista
+
+; DDInstal.Services section
+[RNDIS.NT.5.1.Services]
+include             = netrndis.inf
+needs               = Usb_Rndis.ndi.Services
+
+; Optional registry settings. You can modify as needed.
+[RNDIS_AddReg_Vista]
+HKR, NDI\params\VistaProperty, ParamDesc,  0, %Vista_Property%
+HKR, NDI\params\VistaProperty, type,       0, "edit"
+HKR, NDI\params\VistaProperty, LimitText,  0, "12"
+HKR, NDI\params\VistaProperty, UpperCase,  0, "1"
+HKR, NDI\params\VistaProperty, default,    0, " "
+HKR, NDI\params\VistaProperty, optional,   0, "1"
+
+; No sys copyfiles - the sys files are already in-build
+; (part of the operating system).
+; We do not support XP SP1-, 2003 SP1-, ME, 9x.
+
+[Strings]
+Linux                 = "Linux Developer Community"
+LinuxDevice           = "Linux USB Ethernet/RNDIS Gadget"
+Vista_Property        = "Optional Vista Property"