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authorLinus Torvalds <torvalds@linux-foundation.org>2020-06-01 13:13:00 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2020-06-01 13:13:00 -0700
commit69fc06f70f4569c9969f99fe25bdc9a6bb537b43 (patch)
treeb676e053da23cce02675c1f77c6fb0da23603d4d /arch/x86/kernel/ftrace_64.S
parent60056060bede58c3073dccb8a5e73a6c40804aa9 (diff)
parent0decf1f8de919782b152daf9c991967a2bac54f0 (diff)
Merge tag 'objtool-core-2020-06-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull objtool updates from Ingo Molnar: "There are a lot of objtool changes in this cycle, all across the map: - Speed up objtool significantly, especially when there are large number of sections - Improve objtool's understanding of special instructions such as IRET, to reduce the number of annotations required - Implement 'noinstr' validation - Do baby steps for non-x86 objtool use - Simplify/fix retpoline decoding - Add vmlinux validation - Improve documentation - Fix various bugs and apply smaller cleanups" * tag 'objtool-core-2020-06-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (54 commits) objtool: Enable compilation of objtool for all architectures objtool: Move struct objtool_file into arch-independent header objtool: Exit successfully when requesting help objtool: Add check_kcov_mode() to the uaccess safelist samples/ftrace: Fix asm function ELF annotations objtool: optimize add_dead_ends for split sections objtool: use gelf_getsymshndx to handle >64k sections objtool: Allow no-op CFI ops in alternatives x86/retpoline: Fix retpoline unwind x86: Change {JMP,CALL}_NOSPEC argument x86: Simplify retpoline declaration x86/speculation: Change FILL_RETURN_BUFFER to work with objtool objtool: Add support for intra-function calls objtool: Move the IRET hack into the arch decoder objtool: Remove INSN_STACK objtool: Make handle_insn_ops() unconditional objtool: Rework allocating stack_ops on decode objtool: UNWIND_HINT_RET_OFFSET should not check registers objtool: is_fentry_call() crashes if call has no destination x86,smap: Fix smap_{save,restore}() alternatives ...
Diffstat (limited to 'arch/x86/kernel/ftrace_64.S')
-rw-r--r--arch/x86/kernel/ftrace_64.S44
1 files changed, 21 insertions, 23 deletions
diff --git a/arch/x86/kernel/ftrace_64.S b/arch/x86/kernel/ftrace_64.S
index 369e61faacfe..aa5d28aeb31e 100644
--- a/arch/x86/kernel/ftrace_64.S
+++ b/arch/x86/kernel/ftrace_64.S
@@ -23,7 +23,7 @@
#endif /* CONFIG_FRAME_POINTER */
/* Size of stack used to save mcount regs in save_mcount_regs */
-#define MCOUNT_REG_SIZE (SS+8 + MCOUNT_FRAME_SIZE)
+#define MCOUNT_REG_SIZE (FRAME_SIZE + MCOUNT_FRAME_SIZE)
/*
* gcc -pg option adds a call to 'mcount' in most functions.
@@ -77,7 +77,7 @@
/*
* We add enough stack to save all regs.
*/
- subq $(MCOUNT_REG_SIZE - MCOUNT_FRAME_SIZE), %rsp
+ subq $(FRAME_SIZE), %rsp
movq %rax, RAX(%rsp)
movq %rcx, RCX(%rsp)
movq %rdx, RDX(%rsp)
@@ -157,8 +157,12 @@ SYM_INNER_LABEL(ftrace_call, SYM_L_GLOBAL)
* think twice before adding any new code or changing the
* layout here.
*/
-SYM_INNER_LABEL(ftrace_epilogue, SYM_L_GLOBAL)
+SYM_INNER_LABEL(ftrace_caller_end, SYM_L_GLOBAL)
+ jmp ftrace_epilogue
+SYM_FUNC_END(ftrace_caller);
+
+SYM_FUNC_START(ftrace_epilogue)
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
SYM_INNER_LABEL(ftrace_graph_call, SYM_L_GLOBAL)
jmp ftrace_stub
@@ -170,14 +174,12 @@ SYM_INNER_LABEL(ftrace_graph_call, SYM_L_GLOBAL)
*/
SYM_INNER_LABEL_ALIGN(ftrace_stub, SYM_L_WEAK)
retq
-SYM_FUNC_END(ftrace_caller)
+SYM_FUNC_END(ftrace_epilogue)
SYM_FUNC_START(ftrace_regs_caller)
/* Save the current flags before any operations that can change them */
pushfq
- UNWIND_HINT_SAVE
-
/* added 8 bytes to save flags */
save_mcount_regs 8
/* save_mcount_regs fills in first two parameters */
@@ -233,10 +235,13 @@ SYM_INNER_LABEL(ftrace_regs_call, SYM_L_GLOBAL)
movq ORIG_RAX(%rsp), %rax
movq %rax, MCOUNT_REG_SIZE-8(%rsp)
- /* If ORIG_RAX is anything but zero, make this a call to that */
+ /*
+ * If ORIG_RAX is anything but zero, make this a call to that.
+ * See arch_ftrace_set_direct_caller().
+ */
movq ORIG_RAX(%rsp), %rax
- cmpq $0, %rax
- je 1f
+ testq %rax, %rax
+ jz 1f
/* Swap the flags with orig_rax */
movq MCOUNT_REG_SIZE(%rsp), %rdi
@@ -244,20 +249,14 @@ SYM_INNER_LABEL(ftrace_regs_call, SYM_L_GLOBAL)
movq %rax, MCOUNT_REG_SIZE(%rsp)
restore_mcount_regs 8
+ /* Restore flags */
+ popfq
- jmp 2f
+SYM_INNER_LABEL(ftrace_regs_caller_ret, SYM_L_GLOBAL);
+ UNWIND_HINT_RET_OFFSET
+ jmp ftrace_epilogue
1: restore_mcount_regs
-
-
-2:
- /*
- * The stack layout is nondetermistic here, depending on which path was
- * taken. This confuses objtool and ORC, rightfully so. For now,
- * pretend the stack always looks like the non-direct case.
- */
- UNWIND_HINT_RESTORE
-
/* Restore flags */
popfq
@@ -268,7 +267,6 @@ SYM_INNER_LABEL(ftrace_regs_call, SYM_L_GLOBAL)
* to the return.
*/
SYM_INNER_LABEL(ftrace_regs_caller_end, SYM_L_GLOBAL)
-
jmp ftrace_epilogue
SYM_FUNC_END(ftrace_regs_caller)
@@ -303,7 +301,7 @@ trace:
* function tracing is enabled.
*/
movq ftrace_trace_function, %r8
- CALL_NOSPEC %r8
+ CALL_NOSPEC r8
restore_mcount_regs
jmp fgraph_trace
@@ -340,6 +338,6 @@ SYM_CODE_START(return_to_handler)
movq 8(%rsp), %rdx
movq (%rsp), %rax
addq $24, %rsp
- JMP_NOSPEC %rdi
+ JMP_NOSPEC rdi
SYM_CODE_END(return_to_handler)
#endif