XIP has a history of being broken for long periods of time. In 2023, it was
broken for 18 months before getting fixed [1]. In 2024 it was 4 months [2].
And now it is broken again since commit a44fb57221 ("riscv: Add runtime
constant support"), 10 months ago.
These are clear signs that XIP feature is not being used.
I occasionally looked after XIP, but mostly because I was bored and had
nothing better to do.
Remove XIP support. Revert is possible if someone shows up complaining.
Link: https://lore.kernel.org/linux-riscv/20231212-customary-hardcover-e19462bf8e75@wendy/ [1]
Link: https://lore.kernel.org/linux-riscv/20240526110104.470429-1-namcao@linutronix.de/ [2]
Signed-off-by: Nam Cao <namcao@linutronix.de>
Cc: Frederik Haxel <haxel@fzi.de>
Cc: Vitaly Wool <vitaly.wool@konsulko.com>
Reviewed-by: Jisheng Zhang <jszhang@kernel.org>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://patch.msgid.link/20260202115403.2119218-1-namcao@linutronix.de
[pjw@kernel.org: updated to apply]
Signed-off-by: Paul Walmsley <pjw@kernel.org>
While the GCC and Clang compilers already define __ASSEMBLER__
automatically when compiling assembly code, __ASSEMBLY__ is a
macro that only gets defined by the Makefiles in the kernel.
This can be very confusing when switching between userspace
and kernelspace coding, or when dealing with uapi headers that
rather should use __ASSEMBLER__ instead. So let's standardize on
the __ASSEMBLER__ macro that is provided by the compilers now.
This originally was a completely mechanical patch (done with a
simple "sed -i" statement), with some manual fixups during
rebasing of the patch later.
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexandre Ghiti <alex@ghiti.fr>
Cc: linux-riscv@lists.infradead.org
Signed-off-by: Thomas Huth <thuth@redhat.com>
Link: https://lore.kernel.org/r/20250606070952.498274-3-thuth@redhat.com
Signed-off-by: Paul Walmsley <pjw@kernel.org>
When both CONFIG_IRQ_STACKS and SCS are enabled, also use a separate
per-CPU shadow call stack.
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/r/20230927224757.1154247-13-samitolvanen@google.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Implement CONFIG_SHADOW_CALL_STACK for RISC-V. When enabled, the
compiler injects instructions to all non-leaf C functions to
store the return address to the shadow stack and unconditionally
load it again before returning, which makes it harder to corrupt
the return address through a stack overflow, for example.
The active shadow call stack pointer is stored in the gp
register, which makes SCS incompatible with gp relaxation. Use
--no-relax-gp to ensure gp relaxation is disabled and disable
global pointer loading. Add SCS pointers to struct thread_info,
implement SCS initialization, and task switching
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/r/20230927224757.1154247-12-samitolvanen@google.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
