diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2020-06-01 13:13:00 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-06-01 13:13:00 -0700 |
commit | 69fc06f70f4569c9969f99fe25bdc9a6bb537b43 (patch) | |
tree | b676e053da23cce02675c1f77c6fb0da23603d4d /arch/x86/kernel | |
parent | 60056060bede58c3073dccb8a5e73a6c40804aa9 (diff) | |
parent | 0decf1f8de919782b152daf9c991967a2bac54f0 (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')
-rw-r--r-- | arch/x86/kernel/ftrace.c | 14 | ||||
-rw-r--r-- | arch/x86/kernel/ftrace_32.S | 2 | ||||
-rw-r--r-- | arch/x86/kernel/ftrace_64.S | 44 |
3 files changed, 33 insertions, 27 deletions
diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c index b0e641793be4..c84d28e90a58 100644 --- a/arch/x86/kernel/ftrace.c +++ b/arch/x86/kernel/ftrace.c @@ -282,7 +282,8 @@ static inline void tramp_free(void *tramp) { } /* Defined as markers to the end of the ftrace default trampolines */ extern void ftrace_regs_caller_end(void); -extern void ftrace_epilogue(void); +extern void ftrace_regs_caller_ret(void); +extern void ftrace_caller_end(void); extern void ftrace_caller_op_ptr(void); extern void ftrace_regs_caller_op_ptr(void); @@ -334,7 +335,7 @@ create_trampoline(struct ftrace_ops *ops, unsigned int *tramp_size) call_offset = (unsigned long)ftrace_regs_call; } else { start_offset = (unsigned long)ftrace_caller; - end_offset = (unsigned long)ftrace_epilogue; + end_offset = (unsigned long)ftrace_caller_end; op_offset = (unsigned long)ftrace_caller_op_ptr; call_offset = (unsigned long)ftrace_call; } @@ -366,6 +367,13 @@ create_trampoline(struct ftrace_ops *ops, unsigned int *tramp_size) if (WARN_ON(ret < 0)) goto fail; + if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) { + ip = trampoline + (ftrace_regs_caller_ret - ftrace_regs_caller); + ret = probe_kernel_read(ip, (void *)retq, RET_SIZE); + if (WARN_ON(ret < 0)) + goto fail; + } + /* * The address of the ftrace_ops that is used for this trampoline * is stored at the end of the trampoline. This will be used to @@ -433,7 +441,7 @@ void set_ftrace_ops_ro(void) end_offset = (unsigned long)ftrace_regs_caller_end; } else { start_offset = (unsigned long)ftrace_caller; - end_offset = (unsigned long)ftrace_epilogue; + end_offset = (unsigned long)ftrace_caller_end; } size = end_offset - start_offset; size = size + RET_SIZE + sizeof(void *); diff --git a/arch/x86/kernel/ftrace_32.S b/arch/x86/kernel/ftrace_32.S index e8a9f8370112..e405fe1a8bf4 100644 --- a/arch/x86/kernel/ftrace_32.S +++ b/arch/x86/kernel/ftrace_32.S @@ -189,5 +189,5 @@ return_to_handler: movl %eax, %ecx popl %edx popl %eax - JMP_NOSPEC %ecx + JMP_NOSPEC ecx #endif 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 |