From 0f8f8030038ae37c32a233186caab2c381396784 Mon Sep 17 00:00:00 2001
From: Alexei Starovoitov <ast@kernel.org>
Date: Mon, 21 Mar 2022 21:40:51 -0700
Subject: [PATCH] Revert "arm64: rethook: Add arm64 rethook implementation"
This reverts commit 83acdce6894908337ca82973149d9709d28204d7.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
---
arch/arm64/Kconfig | 1 -
arch/arm64/include/asm/stacktrace.h | 2 +-
arch/arm64/kernel/probes/Makefile | 1 -
arch/arm64/kernel/probes/rethook.c | 25 ------
arch/arm64/kernel/probes/rethook_trampoline.S | 87 -------------------
arch/arm64/kernel/stacktrace.c | 7 +-
6 files changed, 2 insertions(+), 121 deletions(-)
delete mode 100644 arch/arm64/kernel/probes/rethook.c
delete mode 100644 arch/arm64/kernel/probes/rethook_trampoline.S
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 62cff9d0a5bb..09b885cc4db5 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -201,7 +201,6 @@ config ARM64
select HAVE_SYSCALL_TRACEPOINTS
select HAVE_KPROBES
select HAVE_KRETPROBES
- select HAVE_RETHOOK
select HAVE_GENERIC_VDSO
select IOMMU_DMA if IOMMU_SUPPORT
select IRQ_DOMAIN
diff --git a/arch/arm64/include/asm/stacktrace.h b/arch/arm64/include/asm/stacktrace.h
index bf04107da97c..e77cdef9ca29 100644
--- a/arch/arm64/include/asm/stacktrace.h
+++ b/arch/arm64/include/asm/stacktrace.h
@@ -58,7 +58,7 @@ struct stackframe {
DECLARE_BITMAP(stacks_done, __NR_STACK_TYPES);
unsigned long prev_fp;
enum stack_type prev_type;
-#if defined(CONFIG_KRETPROBES) || defined(CONFIG_RETHOOK)
+#ifdef CONFIG_KRETPROBES
struct llist_node *kr_cur;
#endif
};
diff --git a/arch/arm64/kernel/probes/Makefile b/arch/arm64/kernel/probes/Makefile
index 24e689f44c32..8e4be92e25b1 100644
--- a/arch/arm64/kernel/probes/Makefile
+++ b/arch/arm64/kernel/probes/Makefile
@@ -4,4 +4,3 @@ obj-$(CONFIG_KPROBES) += kprobes.o decode-insn.o \
simulate-insn.o
obj-$(CONFIG_UPROBES) += uprobes.o decode-insn.o \
simulate-insn.o
-obj-$(CONFIG_RETHOOK) += rethook.o rethook_trampoline.o
diff --git a/arch/arm64/kernel/probes/rethook.c b/arch/arm64/kernel/probes/rethook.c
deleted file mode 100644
index edc6b804ad6a..000000000000
--- a/arch/arm64/kernel/probes/rethook.c
+++ /dev/null
@@ -1,25 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * Generic return hook for arm64.
- * Most of the code is copied from arch/arm64/kernel/probes/kprobes.c
- */
-
-#include <linux/kprobes.h>
-#include <linux/rethook.h>
-
-/* This is called from arch_rethook_trampoline() */
-unsigned long __used arch_rethook_trampoline_callback(struct pt_regs *regs)
-{
- return rethook_trampoline_handler(regs, regs->regs[29]);
-}
-NOKPROBE_SYMBOL(arch_rethook_trampoline_callback);
-
-void arch_rethook_prepare(struct rethook_node *rhn, struct pt_regs *regs, bool mcount)
-{
- rhn->ret_addr = regs->regs[30];
- rhn->frame = regs->regs[29];
-
- /* replace return addr (x30) with trampoline */
- regs->regs[30] = (u64)arch_rethook_trampoline;
-}
-NOKPROBE_SYMBOL(arch_rethook_prepare);
diff --git a/arch/arm64/kernel/probes/rethook_trampoline.S b/arch/arm64/kernel/probes/rethook_trampoline.S
deleted file mode 100644
index 610f520ee72b..000000000000
--- a/arch/arm64/kernel/probes/rethook_trampoline.S
+++ /dev/null
@@ -1,87 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-/*
- * trampoline entry and return code for rethook.
- * Copied from arch/arm64/kernel/probes/kprobes_trampoline.S
- */
-
-#include <linux/linkage.h>
-#include <asm/asm-offsets.h>
-#include <asm/assembler.h>
-
- .text
-
- .macro save_all_base_regs
- stp x0, x1, [sp, #S_X0]
- stp x2, x3, [sp, #S_X2]
- stp x4, x5, [sp, #S_X4]
- stp x6, x7, [sp, #S_X6]
- stp x8, x9, [sp, #S_X8]
- stp x10, x11, [sp, #S_X10]
- stp x12, x13, [sp, #S_X12]
- stp x14, x15, [sp, #S_X14]
- stp x16, x17, [sp, #S_X16]
- stp x18, x19, [sp, #S_X18]
- stp x20, x21, [sp, #S_X20]
- stp x22, x23, [sp, #S_X22]
- stp x24, x25, [sp, #S_X24]
- stp x26, x27, [sp, #S_X26]
- stp x28, x29, [sp, #S_X28]
- add x0, sp, #PT_REGS_SIZE
- stp lr, x0, [sp, #S_LR]
- /*
- * Construct a useful saved PSTATE
- */
- mrs x0, nzcv
- mrs x1, daif
- orr x0, x0, x1
- mrs x1, CurrentEL
- orr x0, x0, x1
- mrs x1, SPSel
- orr x0, x0, x1
- stp xzr, x0, [sp, #S_PC]
- .endm
-
- .macro restore_all_base_regs
- ldr x0, [sp, #S_PSTATE]
- and x0, x0, #(PSR_N_BIT | PSR_Z_BIT | PSR_C_BIT | PSR_V_BIT)
- msr nzcv, x0
- ldp x0, x1, [sp, #S_X0]
- ldp x2, x3, [sp, #S_X2]
- ldp x4, x5, [sp, #S_X4]
- ldp x6, x7, [sp, #S_X6]
- ldp x8, x9, [sp, #S_X8]
- ldp x10, x11, [sp, #S_X10]
- ldp x12, x13, [sp, #S_X12]
- ldp x14, x15, [sp, #S_X14]
- ldp x16, x17, [sp, #S_X16]
- ldp x18, x19, [sp, #S_X18]
- ldp x20, x21, [sp, #S_X20]
- ldp x22, x23, [sp, #S_X22]
- ldp x24, x25, [sp, #S_X24]
- ldp x26, x27, [sp, #S_X26]
- ldp x28, x29, [sp, #S_X28]
- .endm
-
-SYM_CODE_START(arch_rethook_trampoline)
- sub sp, sp, #PT_REGS_SIZE
-
- save_all_base_regs
-
- /* Setup a frame pointer. */
- add x29, sp, #S_FP
-
- mov x0, sp
- bl arch_rethook_trampoline_callback
- /*
- * Replace trampoline address in lr with actual orig_ret_addr return
- * address.
- */
- mov lr, x0
-
- /* The frame pointer (x29) is restored with other registers. */
- restore_all_base_regs
-
- add sp, sp, #PT_REGS_SIZE
- ret
-
-SYM_CODE_END(arch_rethook_trampoline)
diff --git a/arch/arm64/kernel/stacktrace.c b/arch/arm64/kernel/stacktrace.c
index efb5b85b57c2..e4103e085681 100644
--- a/arch/arm64/kernel/stacktrace.c
+++ b/arch/arm64/kernel/stacktrace.c
@@ -8,7 +8,6 @@
#include <linux/export.h>
#include <linux/ftrace.h>
#include <linux/kprobes.h>
-#include <linux/rethook.h>
#include <linux/sched.h>
#include <linux/sched/debug.h>
#include <linux/sched/task_stack.h>
@@ -39,7 +38,7 @@ static notrace void start_backtrace(struct stackframe *frame, unsigned long fp,
{
frame->fp = fp;
frame->pc = pc;
-#if defined(CONFIG_KRETPROBES) || defined(CONFIG_RETHOOK)
+#ifdef CONFIG_KRETPROBES
frame->kr_cur = NULL;
#endif
@@ -139,10 +138,6 @@ static int notrace unwind_frame(struct task_struct *tsk,
if (is_kretprobe_trampoline(frame->pc))
frame->pc = kretprobe_find_ret_addr(tsk, (void *)frame->fp, &frame->kr_cur);
#endif
-#ifdef CONFIG_RETHOOK
- if (is_rethook_trampoline(frame->pc))
- frame->pc = rethook_find_ret_addr(tsk, frame->fp, &frame->kr_cur);
-#endif
return 0;
}