[PATCH -fixes] riscv: Fix RISCV_ALTERNATIVE_EARLY
Alexandre Ghiti
alexghiti at rivosinc.com
Mon Aug 26 03:57:37 PDT 2024
RISCV_ALTERNATIVE_EARLY will issue sbi_ecall() very early in the boot
process, before the first memory mapping is setup so we can't have any
instrumentation happening here.
In addition, when the kernel is relocatable, we must also not issue any
relocation this early since they would have been patched virtually only.
So, instead of disabling instrumentation for the whole kernel/sbi.c file
and compiling it with -fno-pie, simply move __sbi_ecall() and
__sbi_base_ecall() into their own file where this is fixed.
Fixes: 1745cfafebdf ("riscv: don't use global static vars to store alternative data")
Signed-off-by: Alexandre Ghiti <alexghiti at rivosinc.com>
---
arch/riscv/include/asm/sbi.h | 2 ++
arch/riscv/kernel/Makefile | 6 ++++-
arch/riscv/kernel/sbi.c | 44 --------------------------------
arch/riscv/kernel/sbi_ecall.c | 48 +++++++++++++++++++++++++++++++++++
4 files changed, 55 insertions(+), 45 deletions(-)
create mode 100644 arch/riscv/kernel/sbi_ecall.c
diff --git a/arch/riscv/include/asm/sbi.h b/arch/riscv/include/asm/sbi.h
index 7cffd4ffecd0..5843a10b380e 100644
--- a/arch/riscv/include/asm/sbi.h
+++ b/arch/riscv/include/asm/sbi.h
@@ -9,6 +9,7 @@
#include <linux/types.h>
#include <linux/cpumask.h>
+#include <linux/jump_label.h>
#ifdef CONFIG_RISCV_SBI
enum sbi_ext_id {
@@ -304,6 +305,7 @@ struct sbiret {
};
void sbi_init(void);
+long __sbi_base_ecall(int fid);
struct sbiret __sbi_ecall(unsigned long arg0, unsigned long arg1,
unsigned long arg2, unsigned long arg3,
unsigned long arg4, unsigned long arg5,
diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile
index 06d407f1b30b..7f88cc4931f5 100644
--- a/arch/riscv/kernel/Makefile
+++ b/arch/riscv/kernel/Makefile
@@ -20,17 +20,21 @@ endif
ifdef CONFIG_RISCV_ALTERNATIVE_EARLY
CFLAGS_alternative.o := -mcmodel=medany
CFLAGS_cpufeature.o := -mcmodel=medany
+CFLAGS_sbi_ecall.o := -mcmodel=medany
ifdef CONFIG_FTRACE
CFLAGS_REMOVE_alternative.o = $(CC_FLAGS_FTRACE)
CFLAGS_REMOVE_cpufeature.o = $(CC_FLAGS_FTRACE)
+CFLAGS_REMOVE_sbi_ecall.o = $(CC_FLAGS_FTRACE)
endif
ifdef CONFIG_RELOCATABLE
CFLAGS_alternative.o += -fno-pie
CFLAGS_cpufeature.o += -fno-pie
+CFLAGS_sbi_ecall.o += -fno-pie
endif
ifdef CONFIG_KASAN
KASAN_SANITIZE_alternative.o := n
KASAN_SANITIZE_cpufeature.o := n
+KASAN_SANITIZE_sbi_ecall.o := n
endif
endif
@@ -88,7 +92,7 @@ obj-$(CONFIG_DYNAMIC_FTRACE) += mcount-dyn.o
obj-$(CONFIG_PERF_EVENTS) += perf_callchain.o
obj-$(CONFIG_HAVE_PERF_REGS) += perf_regs.o
-obj-$(CONFIG_RISCV_SBI) += sbi.o
+obj-$(CONFIG_RISCV_SBI) += sbi.o sbi_ecall.o
ifeq ($(CONFIG_RISCV_SBI), y)
obj-$(CONFIG_SMP) += sbi-ipi.o
obj-$(CONFIG_SMP) += cpu_ops_sbi.o
diff --git a/arch/riscv/kernel/sbi.c b/arch/riscv/kernel/sbi.c
index 837bdab2601b..ace9e2f59c41 100644
--- a/arch/riscv/kernel/sbi.c
+++ b/arch/riscv/kernel/sbi.c
@@ -14,9 +14,6 @@
#include <asm/smp.h>
#include <asm/tlbflush.h>
-#define CREATE_TRACE_POINTS
-#include <asm/trace.h>
-
/* default SBI version is 0.1 */
unsigned long sbi_spec_version __ro_after_init = SBI_SPEC_VERSION_DEFAULT;
EXPORT_SYMBOL(sbi_spec_version);
@@ -27,36 +24,6 @@ static int (*__sbi_rfence)(int fid, const struct cpumask *cpu_mask,
unsigned long start, unsigned long size,
unsigned long arg4, unsigned long arg5) __ro_after_init;
-struct sbiret __sbi_ecall(unsigned long arg0, unsigned long arg1,
- unsigned long arg2, unsigned long arg3,
- unsigned long arg4, unsigned long arg5,
- int fid, int ext)
-{
- struct sbiret ret;
-
- trace_sbi_call(ext, fid);
-
- register uintptr_t a0 asm ("a0") = (uintptr_t)(arg0);
- register uintptr_t a1 asm ("a1") = (uintptr_t)(arg1);
- register uintptr_t a2 asm ("a2") = (uintptr_t)(arg2);
- register uintptr_t a3 asm ("a3") = (uintptr_t)(arg3);
- register uintptr_t a4 asm ("a4") = (uintptr_t)(arg4);
- register uintptr_t a5 asm ("a5") = (uintptr_t)(arg5);
- register uintptr_t a6 asm ("a6") = (uintptr_t)(fid);
- register uintptr_t a7 asm ("a7") = (uintptr_t)(ext);
- asm volatile ("ecall"
- : "+r" (a0), "+r" (a1)
- : "r" (a2), "r" (a3), "r" (a4), "r" (a5), "r" (a6), "r" (a7)
- : "memory");
- ret.error = a0;
- ret.value = a1;
-
- trace_sbi_return(ext, ret.error, ret.value);
-
- return ret;
-}
-EXPORT_SYMBOL(__sbi_ecall);
-
int sbi_err_map_linux_errno(int err)
{
switch (err) {
@@ -535,17 +502,6 @@ long sbi_probe_extension(int extid)
}
EXPORT_SYMBOL(sbi_probe_extension);
-static long __sbi_base_ecall(int fid)
-{
- struct sbiret ret;
-
- ret = sbi_ecall(SBI_EXT_BASE, fid, 0, 0, 0, 0, 0, 0);
- if (!ret.error)
- return ret.value;
- else
- return sbi_err_map_linux_errno(ret.error);
-}
-
static inline long sbi_get_spec_version(void)
{
return __sbi_base_ecall(SBI_EXT_BASE_GET_SPEC_VERSION);
diff --git a/arch/riscv/kernel/sbi_ecall.c b/arch/riscv/kernel/sbi_ecall.c
new file mode 100644
index 000000000000..24aabb4fbde3
--- /dev/null
+++ b/arch/riscv/kernel/sbi_ecall.c
@@ -0,0 +1,48 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2024 Rivos Inc. */
+
+#include <asm/sbi.h>
+#define CREATE_TRACE_POINTS
+#include <asm/trace.h>
+
+long __sbi_base_ecall(int fid)
+{
+ struct sbiret ret;
+
+ ret = sbi_ecall(SBI_EXT_BASE, fid, 0, 0, 0, 0, 0, 0);
+ if (!ret.error)
+ return ret.value;
+ else
+ return sbi_err_map_linux_errno(ret.error);
+}
+EXPORT_SYMBOL(__sbi_base_ecall);
+
+struct sbiret __sbi_ecall(unsigned long arg0, unsigned long arg1,
+ unsigned long arg2, unsigned long arg3,
+ unsigned long arg4, unsigned long arg5,
+ int fid, int ext)
+{
+ struct sbiret ret;
+
+ trace_sbi_call(ext, fid);
+
+ register uintptr_t a0 asm ("a0") = (uintptr_t)(arg0);
+ register uintptr_t a1 asm ("a1") = (uintptr_t)(arg1);
+ register uintptr_t a2 asm ("a2") = (uintptr_t)(arg2);
+ register uintptr_t a3 asm ("a3") = (uintptr_t)(arg3);
+ register uintptr_t a4 asm ("a4") = (uintptr_t)(arg4);
+ register uintptr_t a5 asm ("a5") = (uintptr_t)(arg5);
+ register uintptr_t a6 asm ("a6") = (uintptr_t)(fid);
+ register uintptr_t a7 asm ("a7") = (uintptr_t)(ext);
+ asm volatile ("ecall"
+ : "+r" (a0), "+r" (a1)
+ : "r" (a2), "r" (a3), "r" (a4), "r" (a5), "r" (a6), "r" (a7)
+ : "memory");
+ ret.error = a0;
+ ret.value = a1;
+
+ trace_sbi_return(ext, ret.error, ret.value);
+
+ return ret;
+}
+EXPORT_SYMBOL(__sbi_ecall);
--
2.39.2
More information about the linux-riscv
mailing list