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authorLinus Torvalds <torvalds@linux-foundation.org>2019-05-15 16:05:47 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2019-05-15 16:05:47 -0700
commitd2d8b146043ae7e250aef1fb312971f6f479d487 (patch)
tree22db8758a5aa0bc850ba8f83fe57b1f679924d0a /arch
parent2bbacd1a92788ee334c7e92b765ea16ebab68dfe (diff)
parent693713cbdb3a4bda5a8a678c31f06560bbb14657 (diff)
downloadlinux-d2d8b146043ae7e250aef1fb312971f6f479d487.tar.bz2
Merge tag 'trace-v5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing updates from Steven Rostedt: "The major changes in this tracing update includes: - Removal of non-DYNAMIC_FTRACE from 32bit x86 - Removal of mcount support from x86 - Emulating a call from int3 on x86_64, fixes live kernel patching - Consolidated Tracing Error logs file Minor updates: - Removal of klp_check_compiler_support() - kdb ftrace dumping output changes - Accessing and creating ftrace instances from inside the kernel - Clean up of #define if macro - Introduction of TRACE_EVENT_NOP() to disable trace events based on config options And other minor fixes and clean ups" * tag 'trace-v5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (44 commits) x86: Hide the int3_emulate_call/jmp functions from UML livepatch: Remove klp_check_compiler_support() ftrace/x86: Remove mcount support ftrace/x86_32: Remove support for non DYNAMIC_FTRACE tracing: Simplify "if" macro code tracing: Fix documentation about disabling options using trace_options tracing: Replace kzalloc with kcalloc tracing: Fix partial reading of trace event's id file tracing: Allow RCU to run between postponed startup tests tracing: Fix white space issues in parse_pred() function tracing: Eliminate const char[] auto variables ring-buffer: Fix mispelling of Calculate tracing: probeevent: Fix to make the type of $comm string tracing: probeevent: Do not accumulate on ret variable tracing: uprobes: Re-enable $comm support for uprobe events ftrace/x86_64: Emulate call function while updating in breakpoint handler x86_64: Allow breakpoints to emulate call instructions x86_64: Add gap to int3 to allow for call emulation tracing: kdb: Allow ftdump to skip all but the last few entries tracing: Add trace_total_entries() / trace_total_entries_cpu() ...
Diffstat (limited to 'arch')
-rw-r--r--arch/nds32/kernel/ftrace.c1
-rw-r--r--arch/parisc/kernel/ftrace.c1
-rw-r--r--arch/powerpc/include/asm/livepatch.h5
-rw-r--r--arch/s390/include/asm/livepatch.h5
-rw-r--r--arch/x86/Kconfig11
-rw-r--r--arch/x86/entry/entry_64.S18
-rw-r--r--arch/x86/include/asm/ftrace.h8
-rw-r--r--arch/x86/include/asm/livepatch.h8
-rw-r--r--arch/x86/include/asm/text-patching.h30
-rw-r--r--arch/x86/kernel/ftrace.c32
-rw-r--r--arch/x86/kernel/ftrace_32.S75
-rw-r--r--arch/x86/kernel/ftrace_64.S28
12 files changed, 93 insertions, 129 deletions
diff --git a/arch/nds32/kernel/ftrace.c b/arch/nds32/kernel/ftrace.c
index 8a41372551ff..fd2a54b8cd57 100644
--- a/arch/nds32/kernel/ftrace.c
+++ b/arch/nds32/kernel/ftrace.c
@@ -7,7 +7,6 @@
#ifndef CONFIG_DYNAMIC_FTRACE
extern void (*ftrace_trace_function)(unsigned long, unsigned long,
struct ftrace_ops*, struct pt_regs*);
-extern int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace);
extern void ftrace_graph_caller(void);
noinline void __naked ftrace_stub(unsigned long ip, unsigned long parent_ip,
diff --git a/arch/parisc/kernel/ftrace.c b/arch/parisc/kernel/ftrace.c
index e46a4157a894..a28f915993b1 100644
--- a/arch/parisc/kernel/ftrace.c
+++ b/arch/parisc/kernel/ftrace.c
@@ -51,7 +51,6 @@ void notrace __hot ftrace_function_trampoline(unsigned long parent,
unsigned long org_sp_gr3)
{
extern ftrace_func_t ftrace_trace_function; /* depends on CONFIG_DYNAMIC_FTRACE */
- extern int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace);
if (ftrace_trace_function != ftrace_stub) {
/* struct ftrace_ops *op, struct pt_regs *regs); */
diff --git a/arch/powerpc/include/asm/livepatch.h b/arch/powerpc/include/asm/livepatch.h
index 5070df19d463..c005aee5ea43 100644
--- a/arch/powerpc/include/asm/livepatch.h
+++ b/arch/powerpc/include/asm/livepatch.h
@@ -24,11 +24,6 @@
#include <linux/sched/task_stack.h>
#ifdef CONFIG_LIVEPATCH
-static inline int klp_check_compiler_support(void)
-{
- return 0;
-}
-
static inline void klp_arch_set_pc(struct pt_regs *regs, unsigned long ip)
{
regs->nip = ip;
diff --git a/arch/s390/include/asm/livepatch.h b/arch/s390/include/asm/livepatch.h
index 672f95b12d40..818612b784cd 100644
--- a/arch/s390/include/asm/livepatch.h
+++ b/arch/s390/include/asm/livepatch.h
@@ -13,11 +13,6 @@
#include <asm/ptrace.h>
-static inline int klp_check_compiler_support(void)
-{
- return 0;
-}
-
static inline void klp_arch_set_pc(struct pt_regs *regs, unsigned long ip)
{
regs->psw.addr = ip;
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 326b2d5bab9d..21e9f2fac04b 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -31,6 +31,17 @@ config X86_64
select SWIOTLB
select ARCH_HAS_SYSCALL_WRAPPER
+config FORCE_DYNAMIC_FTRACE
+ def_bool y
+ depends on X86_32
+ depends on FUNCTION_TRACER
+ select DYNAMIC_FTRACE
+ help
+ We keep the static function tracing (!DYNAMIC_FTRACE) around
+ in order to test the non static function tracing in the
+ generic code, as other architectures still use it. But we
+ only need to keep it around for x86_64. No need to keep it
+ for x86_32. For x86_32, force DYNAMIC_FTRACE.
#
# Arch settings
#
diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index 20e45d9b4e15..11aa3b2afa4d 100644
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -878,7 +878,7 @@ apicinterrupt IRQ_WORK_VECTOR irq_work_interrupt smp_irq_work_interrupt
* @paranoid == 2 is special: the stub will never switch stacks. This is for
* #DF: if the thread stack is somehow unusable, we'll still get a useful OOPS.
*/
-.macro idtentry sym do_sym has_error_code:req paranoid=0 shift_ist=-1 ist_offset=0
+.macro idtentry sym do_sym has_error_code:req paranoid=0 shift_ist=-1 ist_offset=0 create_gap=0
ENTRY(\sym)
UNWIND_HINT_IRET_REGS offset=\has_error_code*8
@@ -898,6 +898,20 @@ ENTRY(\sym)
jnz .Lfrom_usermode_switch_stack_\@
.endif
+ .if \create_gap == 1
+ /*
+ * If coming from kernel space, create a 6-word gap to allow the
+ * int3 handler to emulate a call instruction.
+ */
+ testb $3, CS-ORIG_RAX(%rsp)
+ jnz .Lfrom_usermode_no_gap_\@
+ .rept 6
+ pushq 5*8(%rsp)
+ .endr
+ UNWIND_HINT_IRET_REGS offset=8
+.Lfrom_usermode_no_gap_\@:
+ .endif
+
.if \paranoid
call paranoid_entry
.else
@@ -1129,7 +1143,7 @@ apicinterrupt3 HYPERV_STIMER0_VECTOR \
#endif /* CONFIG_HYPERV */
idtentry debug do_debug has_error_code=0 paranoid=1 shift_ist=IST_INDEX_DB ist_offset=DB_STACK_OFFSET
-idtentry int3 do_int3 has_error_code=0
+idtentry int3 do_int3 has_error_code=0 create_gap=1
idtentry stack_segment do_stack_segment has_error_code=1
#ifdef CONFIG_XEN_PV
diff --git a/arch/x86/include/asm/ftrace.h b/arch/x86/include/asm/ftrace.h
index cf350639e76d..287f1f7b2e52 100644
--- a/arch/x86/include/asm/ftrace.h
+++ b/arch/x86/include/asm/ftrace.h
@@ -3,12 +3,10 @@
#define _ASM_X86_FTRACE_H
#ifdef CONFIG_FUNCTION_TRACER
-#ifdef CC_USING_FENTRY
-# define MCOUNT_ADDR ((unsigned long)(__fentry__))
-#else
-# define MCOUNT_ADDR ((unsigned long)(mcount))
-# define HAVE_FUNCTION_GRAPH_FP_TEST
+#ifndef CC_USING_FENTRY
+# error Compiler does not support fentry?
#endif
+# define MCOUNT_ADDR ((unsigned long)(__fentry__))
#define MCOUNT_INSN_SIZE 5 /* sizeof mcount call */
#ifdef CONFIG_DYNAMIC_FTRACE
diff --git a/arch/x86/include/asm/livepatch.h b/arch/x86/include/asm/livepatch.h
index ed80003ce3e2..a66f6706c2de 100644
--- a/arch/x86/include/asm/livepatch.h
+++ b/arch/x86/include/asm/livepatch.h
@@ -24,14 +24,6 @@
#include <asm/setup.h>
#include <linux/ftrace.h>
-static inline int klp_check_compiler_support(void)
-{
-#ifndef CC_USING_FENTRY
- return 1;
-#endif
- return 0;
-}
-
static inline void klp_arch_set_pc(struct pt_regs *regs, unsigned long ip)
{
regs->ip = ip;
diff --git a/arch/x86/include/asm/text-patching.h b/arch/x86/include/asm/text-patching.h
index c90678fd391a..880b5515b1d6 100644
--- a/arch/x86/include/asm/text-patching.h
+++ b/arch/x86/include/asm/text-patching.h
@@ -42,4 +42,34 @@ extern int after_bootmem;
extern __ro_after_init struct mm_struct *poking_mm;
extern __ro_after_init unsigned long poking_addr;
+#ifndef CONFIG_UML_X86
+static inline void int3_emulate_jmp(struct pt_regs *regs, unsigned long ip)
+{
+ regs->ip = ip;
+}
+
+#define INT3_INSN_SIZE 1
+#define CALL_INSN_SIZE 5
+
+#ifdef CONFIG_X86_64
+static inline void int3_emulate_push(struct pt_regs *regs, unsigned long val)
+{
+ /*
+ * The int3 handler in entry_64.S adds a gap between the
+ * stack where the break point happened, and the saving of
+ * pt_regs. We can extend the original stack because of
+ * this gap. See the idtentry macro's create_gap option.
+ */
+ regs->sp -= sizeof(unsigned long);
+ *(unsigned long *)regs->sp = val;
+}
+
+static inline void int3_emulate_call(struct pt_regs *regs, unsigned long func)
+{
+ int3_emulate_push(regs, regs->ip - INT3_INSN_SIZE + CALL_INSN_SIZE);
+ int3_emulate_jmp(regs, func);
+}
+#endif /* CONFIG_X86_64 */
+#endif /* !CONFIG_UML_X86 */
+
#endif /* _ASM_X86_TEXT_PATCHING_H */
diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c
index 0caf8122d680..0927bb158ffc 100644
--- a/arch/x86/kernel/ftrace.c
+++ b/arch/x86/kernel/ftrace.c
@@ -29,6 +29,7 @@
#include <asm/kprobes.h>
#include <asm/ftrace.h>
#include <asm/nops.h>
+#include <asm/text-patching.h>
#ifdef CONFIG_DYNAMIC_FTRACE
@@ -231,6 +232,7 @@ int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
}
static unsigned long ftrace_update_func;
+static unsigned long ftrace_update_func_call;
static int update_ftrace_func(unsigned long ip, void *new)
{
@@ -259,6 +261,8 @@ int ftrace_update_ftrace_func(ftrace_func_t func)
unsigned char *new;
int ret;
+ ftrace_update_func_call = (unsigned long)func;
+
new = ftrace_call_replace(ip, (unsigned long)func);
ret = update_ftrace_func(ip, new);
@@ -294,13 +298,28 @@ int ftrace_int3_handler(struct pt_regs *regs)
if (WARN_ON_ONCE(!regs))
return 0;
- ip = regs->ip - 1;
- if (!ftrace_location(ip) && !is_ftrace_caller(ip))
- return 0;
+ ip = regs->ip - INT3_INSN_SIZE;
- regs->ip += MCOUNT_INSN_SIZE - 1;
+#ifdef CONFIG_X86_64
+ if (ftrace_location(ip)) {
+ int3_emulate_call(regs, (unsigned long)ftrace_regs_caller);
+ return 1;
+ } else if (is_ftrace_caller(ip)) {
+ if (!ftrace_update_func_call) {
+ int3_emulate_jmp(regs, ip + CALL_INSN_SIZE);
+ return 1;
+ }
+ int3_emulate_call(regs, ftrace_update_func_call);
+ return 1;
+ }
+#else
+ if (ftrace_location(ip) || is_ftrace_caller(ip)) {
+ int3_emulate_jmp(regs, ip + CALL_INSN_SIZE);
+ return 1;
+ }
+#endif
- return 1;
+ return 0;
}
NOKPROBE_SYMBOL(ftrace_int3_handler);
@@ -865,6 +884,8 @@ void arch_ftrace_update_trampoline(struct ftrace_ops *ops)
func = ftrace_ops_get_func(ops);
+ ftrace_update_func_call = (unsigned long)func;
+
/* Do a safe modify in case the trampoline is executing */
new = ftrace_call_replace(ip, (unsigned long)func);
ret = update_ftrace_func(ip, new);
@@ -966,6 +987,7 @@ static int ftrace_mod_jmp(unsigned long ip, void *func)
{
unsigned char *new;
+ ftrace_update_func_call = 0UL;
new = ftrace_jmp_replace(ip, (unsigned long)func);
return update_ftrace_func(ip, new);
diff --git a/arch/x86/kernel/ftrace_32.S b/arch/x86/kernel/ftrace_32.S
index 4c8440de3355..2ba914a34b06 100644
--- a/arch/x86/kernel/ftrace_32.S
+++ b/arch/x86/kernel/ftrace_32.S
@@ -10,22 +10,10 @@
#include <asm/ftrace.h>
#include <asm/nospec-branch.h>
-#ifdef CC_USING_FENTRY
# define function_hook __fentry__
EXPORT_SYMBOL(__fentry__)
-#else
-# define function_hook mcount
-EXPORT_SYMBOL(mcount)
-#endif
-
-#ifdef CONFIG_DYNAMIC_FTRACE
-
-/* mcount uses a frame pointer even if CONFIG_FRAME_POINTER is not set */
-#if !defined(CC_USING_FENTRY) || defined(CONFIG_FRAME_POINTER)
-# define USING_FRAME_POINTER
-#endif
-#ifdef USING_FRAME_POINTER
+#ifdef CONFIG_FRAME_POINTER
# define MCOUNT_FRAME 1 /* using frame = true */
#else
# define MCOUNT_FRAME 0 /* using frame = false */
@@ -37,8 +25,7 @@ END(function_hook)
ENTRY(ftrace_caller)
-#ifdef USING_FRAME_POINTER
-# ifdef CC_USING_FENTRY
+#ifdef CONFIG_FRAME_POINTER
/*
* Frame pointers are of ip followed by bp.
* Since fentry is an immediate jump, we are left with
@@ -49,7 +36,7 @@ ENTRY(ftrace_caller)
pushl %ebp
movl %esp, %ebp
pushl 2*4(%esp) /* function ip */
-# endif
+
/* For mcount, the function ip is directly above */
pushl %ebp
movl %esp, %ebp
@@ -59,7 +46,7 @@ ENTRY(ftrace_caller)
pushl %edx
pushl $0 /* Pass NULL as regs pointer */
-#ifdef USING_FRAME_POINTER
+#ifdef CONFIG_FRAME_POINTER
/* Load parent ebp into edx */
movl 4*4(%esp), %edx
#else
@@ -82,13 +69,11 @@ ftrace_call:
popl %edx
popl %ecx
popl %eax
-#ifdef USING_FRAME_POINTER
+#ifdef CONFIG_FRAME_POINTER
popl %ebp
-# ifdef CC_USING_FENTRY
addl $4,%esp /* skip function ip */
popl %ebp /* this is the orig bp */
addl $4, %esp /* skip parent ip */
-# endif
#endif
.Lftrace_ret:
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
@@ -133,11 +118,7 @@ ENTRY(ftrace_regs_caller)
movl 12*4(%esp), %eax /* Load ip (1st parameter) */
subl $MCOUNT_INSN_SIZE, %eax /* Adjust ip */
-#ifdef CC_USING_FENTRY
movl 15*4(%esp), %edx /* Load parent ip (2nd parameter) */
-#else
- movl 0x4(%ebp), %edx /* Load parent ip (2nd parameter) */
-#endif
movl function_trace_op, %ecx /* Save ftrace_pos in 3rd parameter */
pushl %esp /* Save pt_regs as 4th parameter */
@@ -170,43 +151,6 @@ GLOBAL(ftrace_regs_call)
lea 3*4(%esp), %esp /* Skip orig_ax, ip and cs */
jmp .Lftrace_ret
-#else /* ! CONFIG_DYNAMIC_FTRACE */
-
-ENTRY(function_hook)
- cmpl $__PAGE_OFFSET, %esp
- jb ftrace_stub /* Paging not enabled yet? */
-
- cmpl $ftrace_stub, ftrace_trace_function
- jnz .Ltrace
-#ifdef CONFIG_FUNCTION_GRAPH_TRACER
- cmpl $ftrace_stub, ftrace_graph_return
- jnz ftrace_graph_caller
-
- cmpl $ftrace_graph_entry_stub, ftrace_graph_entry
- jnz ftrace_graph_caller
-#endif
-.globl ftrace_stub
-ftrace_stub:
- ret
-
- /* taken from glibc */
-.Ltrace:
- pushl %eax
- pushl %ecx
- pushl %edx
- movl 0xc(%esp), %eax
- movl 0x4(%ebp), %edx
- subl $MCOUNT_INSN_SIZE, %eax
-
- movl ftrace_trace_function, %ecx
- CALL_NOSPEC %ecx
-
- popl %edx
- popl %ecx
- popl %eax
- jmp ftrace_stub
-END(function_hook)
-#endif /* CONFIG_DYNAMIC_FTRACE */
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
ENTRY(ftrace_graph_caller)
@@ -215,13 +159,8 @@ ENTRY(ftrace_graph_caller)
pushl %edx
movl 3*4(%esp), %eax
/* Even with frame pointers, fentry doesn't have one here */
-#ifdef CC_USING_FENTRY
lea 4*4(%esp), %edx
movl $0, %ecx
-#else
- lea 0x4(%ebp), %edx
- movl (%ebp), %ecx
-#endif
subl $MCOUNT_INSN_SIZE, %eax
call prepare_ftrace_return
popl %edx
@@ -234,11 +173,7 @@ END(ftrace_graph_caller)
return_to_handler:
pushl %eax
pushl %edx
-#ifdef CC_USING_FENTRY
movl $0, %eax
-#else
- movl %ebp, %eax
-#endif
call ftrace_return_to_handler
movl %eax, %ecx
popl %edx
diff --git a/arch/x86/kernel/ftrace_64.S b/arch/x86/kernel/ftrace_64.S
index 75f2b36b41a6..10eb2760ef2c 100644
--- a/arch/x86/kernel/ftrace_64.S
+++ b/arch/x86/kernel/ftrace_64.S
@@ -13,22 +13,12 @@
.code64
.section .entry.text, "ax"
-#ifdef CC_USING_FENTRY
# define function_hook __fentry__
EXPORT_SYMBOL(__fentry__)
-#else
-# define function_hook mcount
-EXPORT_SYMBOL(mcount)
-#endif
#ifdef CONFIG_FRAME_POINTER
-# ifdef CC_USING_FENTRY
/* Save parent and function stack frames (rip and rbp) */
# define MCOUNT_FRAME_SIZE (8+16*2)
-# else
-/* Save just function stack frame (rip and rbp) */
-# define MCOUNT_FRAME_SIZE (8+16)
-# endif
#else
/* No need to save a stack frame */
# define MCOUNT_FRAME_SIZE 0
@@ -75,17 +65,13 @@ EXPORT_SYMBOL(mcount)
* fentry is called before the stack frame is set up, where as mcount
* is called afterward.
*/
-#ifdef CC_USING_FENTRY
+
/* Save the parent pointer (skip orig rbp and our return address) */
pushq \added+8*2(%rsp)
pushq %rbp
movq %rsp, %rbp
/* Save the return address (now skip orig rbp, rbp and parent) */
pushq \added+8*3(%rsp)
-#else
- /* Can't assume that rip is before this (unless added was zero) */
- pushq \added+8(%rsp)
-#endif
pushq %rbp
movq %rsp, %rbp
#endif /* CONFIG_FRAME_POINTER */
@@ -113,12 +99,7 @@ EXPORT_SYMBOL(mcount)
movq %rdx, RBP(%rsp)
/* Copy the parent address into %rsi (second parameter) */
-#ifdef CC_USING_FENTRY
movq MCOUNT_REG_SIZE+8+\added(%rsp), %rsi
-#else
- /* %rdx contains original %rbp */
- movq 8(%rdx), %rsi
-#endif
/* Move RIP to its proper location */
movq MCOUNT_REG_SIZE+\added(%rsp), %rdi
@@ -303,15 +284,8 @@ ENTRY(ftrace_graph_caller)
/* Saves rbp into %rdx and fills first parameter */
save_mcount_regs
-#ifdef CC_USING_FENTRY
leaq MCOUNT_REG_SIZE+8(%rsp), %rsi
movq $0, %rdx /* No framepointers needed */
-#else
- /* Save address of the return address of traced function */
- leaq 8(%rdx), %rsi
- /* ftrace does sanity checks against frame pointers */
- movq (%rdx), %rdx
-#endif
call prepare_ftrace_return
restore_mcount_regs