summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2023-02-03 10:18:39 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2023-02-03 10:18:39 -0800
commita30df1ea94ad35c7b42d44199fe1376b4d648862 (patch)
tree5188b188878cd8898bdc14a05be18d50b3941bbe
parentbffede38f82c27cf5e203a2c659fcc9b581dd7b8 (diff)
parent2f394c0e7d1129a35156e492bc8f445fb20f43ac (diff)
Merge tag 'riscv-for-linus-6.2-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux
Pull RISC-V fixes from Palmer Dabbelt: - A build fix to avoid static branches in cpu_relax(), which greatly inflates the jump tables and breaks at least CONFIG_CC_OPTIMIZE_FOR_SIZE=y. - A fix for a kernel panic when probing impossible instruction positions. - A fix to disable unwind tables, which are enabled by default for GCC-13 and result in unhandled relocations in modules. * tag 'riscv-for-linus-6.2-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: riscv: disable generation of unwind tables riscv: kprobe: Fixup kernel panic when probing an illegal position riscv: Fix build with CONFIG_CC_OPTIMIZE_FOR_SIZE=y
-rw-r--r--arch/riscv/Makefile3
-rw-r--r--arch/riscv/include/asm/hwcap.h3
-rw-r--r--arch/riscv/include/asm/vdso/processor.h28
-rw-r--r--arch/riscv/kernel/probes/kprobes.c18
4 files changed, 33 insertions, 19 deletions
diff --git a/arch/riscv/Makefile b/arch/riscv/Makefile
index faf2c2177094..82153960ac00 100644
--- a/arch/riscv/Makefile
+++ b/arch/riscv/Makefile
@@ -80,6 +80,9 @@ ifeq ($(CONFIG_PERF_EVENTS),y)
KBUILD_CFLAGS += -fno-omit-frame-pointer
endif
+# Avoid generating .eh_frame sections.
+KBUILD_CFLAGS += -fno-asynchronous-unwind-tables -fno-unwind-tables
+
KBUILD_CFLAGS_MODULE += $(call cc-option,-mno-relax)
KBUILD_AFLAGS_MODULE += $(call as-option,-Wa$(comma)-mno-relax)
diff --git a/arch/riscv/include/asm/hwcap.h b/arch/riscv/include/asm/hwcap.h
index 86328e3acb02..64ad1937e714 100644
--- a/arch/riscv/include/asm/hwcap.h
+++ b/arch/riscv/include/asm/hwcap.h
@@ -70,7 +70,6 @@ static_assert(RISCV_ISA_EXT_ID_MAX <= RISCV_ISA_EXT_MAX);
*/
enum riscv_isa_ext_key {
RISCV_ISA_EXT_KEY_FPU, /* For 'F' and 'D' */
- RISCV_ISA_EXT_KEY_ZIHINTPAUSE,
RISCV_ISA_EXT_KEY_SVINVAL,
RISCV_ISA_EXT_KEY_MAX,
};
@@ -91,8 +90,6 @@ static __always_inline int riscv_isa_ext2key(int num)
return RISCV_ISA_EXT_KEY_FPU;
case RISCV_ISA_EXT_d:
return RISCV_ISA_EXT_KEY_FPU;
- case RISCV_ISA_EXT_ZIHINTPAUSE:
- return RISCV_ISA_EXT_KEY_ZIHINTPAUSE;
case RISCV_ISA_EXT_SVINVAL:
return RISCV_ISA_EXT_KEY_SVINVAL;
default:
diff --git a/arch/riscv/include/asm/vdso/processor.h b/arch/riscv/include/asm/vdso/processor.h
index fa70cfe507aa..14f5d27783b8 100644
--- a/arch/riscv/include/asm/vdso/processor.h
+++ b/arch/riscv/include/asm/vdso/processor.h
@@ -4,30 +4,26 @@
#ifndef __ASSEMBLY__
-#include <linux/jump_label.h>
#include <asm/barrier.h>
-#include <asm/hwcap.h>
static inline void cpu_relax(void)
{
- if (!static_branch_likely(&riscv_isa_ext_keys[RISCV_ISA_EXT_KEY_ZIHINTPAUSE])) {
#ifdef __riscv_muldiv
- int dummy;
- /* In lieu of a halt instruction, induce a long-latency stall. */
- __asm__ __volatile__ ("div %0, %0, zero" : "=r" (dummy));
+ int dummy;
+ /* In lieu of a halt instruction, induce a long-latency stall. */
+ __asm__ __volatile__ ("div %0, %0, zero" : "=r" (dummy));
#endif
- } else {
- /*
- * Reduce instruction retirement.
- * This assumes the PC changes.
- */
-#ifdef CONFIG_TOOLCHAIN_HAS_ZIHINTPAUSE
- __asm__ __volatile__ ("pause");
+
+#ifdef __riscv_zihintpause
+ /*
+ * Reduce instruction retirement.
+ * This assumes the PC changes.
+ */
+ __asm__ __volatile__ ("pause");
#else
- /* Encoding of the pause instruction */
- __asm__ __volatile__ (".4byte 0x100000F");
+ /* Encoding of the pause instruction */
+ __asm__ __volatile__ (".4byte 0x100000F");
#endif
- }
barrier();
}
diff --git a/arch/riscv/kernel/probes/kprobes.c b/arch/riscv/kernel/probes/kprobes.c
index f21592d20306..41c7481afde3 100644
--- a/arch/riscv/kernel/probes/kprobes.c
+++ b/arch/riscv/kernel/probes/kprobes.c
@@ -48,6 +48,21 @@ static void __kprobes arch_simulate_insn(struct kprobe *p, struct pt_regs *regs)
post_kprobe_handler(p, kcb, regs);
}
+static bool __kprobes arch_check_kprobe(struct kprobe *p)
+{
+ unsigned long tmp = (unsigned long)p->addr - p->offset;
+ unsigned long addr = (unsigned long)p->addr;
+
+ while (tmp <= addr) {
+ if (tmp == addr)
+ return true;
+
+ tmp += GET_INSN_LENGTH(*(u16 *)tmp);
+ }
+
+ return false;
+}
+
int __kprobes arch_prepare_kprobe(struct kprobe *p)
{
unsigned long probe_addr = (unsigned long)p->addr;
@@ -55,6 +70,9 @@ int __kprobes arch_prepare_kprobe(struct kprobe *p)
if (probe_addr & 0x1)
return -EILSEQ;
+ if (!arch_check_kprobe(p))
+ return -EILSEQ;
+
/* copy instruction */
p->opcode = *p->addr;