The patch below does not apply to the v6.6-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.

Thanks, Sasha

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

From afedc3126e11ff1404b32e538657b68022e933ca Mon Sep 17 00:00:00 2001 From: Alexandre Ghiti alexghiti@rivosinc.com Date: Wed, 9 Oct 2024 09:27:49 +0200 Subject: [PATCH] riscv: Do not use fortify in early code

Early code designates the code executed when the MMU is not yet enabled, and this comes with some limitations (see Documentation/arch/riscv/boot.rst, section "Pre-MMU execution").

FORTIFY_SOURCE must be disabled then since it can trigger kernel panics as reported in [1].

Reported-by: Jason Montleon jmontleo@redhat.com Closes: https://lore.kernel.org/linux-riscv/CAJD_bPJes4QhmXY5f63GHV9B9HFkSCoaZjk-qCT... [1] Fixes: a35707c3d850 ("riscv: add memory-type errata for T-Head") Fixes: 26e7aacb83df ("riscv: Allow to downgrade paging mode from the command line") Cc: stable@vger.kernel.org Signed-off-by: Alexandre Ghiti alexghiti@rivosinc.com Link: https://lore.kernel.org/r/20241009072749.45006-1-alexghiti@rivosinc.com Signed-off-by: Palmer Dabbelt palmer@rivosinc.com --- arch/riscv/errata/Makefile | 6 ++++++ arch/riscv/kernel/Makefile | 5 +++++ arch/riscv/kernel/pi/Makefile | 6 +++++- 3 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/arch/riscv/errata/Makefile b/arch/riscv/errata/Makefile index 8a27394851233..f0da9d7b39c37 100644 --- a/arch/riscv/errata/Makefile +++ b/arch/riscv/errata/Makefile @@ -2,6 +2,12 @@ ifdef CONFIG_RELOCATABLE KBUILD_CFLAGS += -fno-pie endif

+ifdef CONFIG_RISCV_ALTERNATIVE_EARLY +ifdef CONFIG_FORTIFY_SOURCE +KBUILD_CFLAGS += -D__NO_FORTIFY +endif +endif + obj-$(CONFIG_ERRATA_ANDES) += andes/ obj-$(CONFIG_ERRATA_SIFIVE) += sifive/ obj-$(CONFIG_ERRATA_THEAD) += thead/ diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile index 7f88cc4931f5c..69dc8aaab3fb3 100644 --- a/arch/riscv/kernel/Makefile +++ b/arch/riscv/kernel/Makefile @@ -36,6 +36,11 @@ KASAN_SANITIZE_alternative.o := n KASAN_SANITIZE_cpufeature.o := n KASAN_SANITIZE_sbi_ecall.o := n endif +ifdef CONFIG_FORTIFY_SOURCE +CFLAGS_alternative.o += -D__NO_FORTIFY +CFLAGS_cpufeature.o += -D__NO_FORTIFY +CFLAGS_sbi_ecall.o += -D__NO_FORTIFY +endif endif

extra-y += vmlinux.lds diff --git a/arch/riscv/kernel/pi/Makefile b/arch/riscv/kernel/pi/Makefile index d5bf1bc7de62e..81d69d45c06c3 100644 --- a/arch/riscv/kernel/pi/Makefile +++ b/arch/riscv/kernel/pi/Makefile @@ -16,8 +16,12 @@ KBUILD_CFLAGS := $(filter-out $(CC_FLAGS_LTO), $(KBUILD_CFLAGS)) KBUILD_CFLAGS += -mcmodel=medany

CFLAGS_cmdline_early.o += -D__NO_FORTIFY -CFLAGS_lib-fdt_ro.o += -D__NO_FORTIFY CFLAGS_fdt_early.o += -D__NO_FORTIFY +# lib/string.c already defines __NO_FORTIFY +CFLAGS_ctype.o += -D__NO_FORTIFY +CFLAGS_lib-fdt.o += -D__NO_FORTIFY +CFLAGS_lib-fdt_ro.o += -D__NO_FORTIFY +CFLAGS_archrandom_early.o += -D__NO_FORTIFY

$(obj)/%.pi.o: OBJCOPYFLAGS := --prefix-symbols=__pi_ \ --remove-section=.note.gnu.property \