Merge branch 'arm64/ftrace-with-regs' of git://git.kernel.org/pub/scm/linux/kernel/git/mark/linux into for-next/core
FTRACE_WITH_REGS support for arm64. * 'arm64/ftrace-with-regs' of git://git.kernel.org/pub/scm/linux/kernel/git/mark/linux: arm64: ftrace: minimize ifdeffery arm64: implement ftrace with regs arm64: asm-offsets: add S_FP arm64: insn: add encoder for MOV (register) arm64: module/ftrace: intialize PLT at load time arm64: module: rework special section handling module/ftrace: handle patchable-function-entry ftrace: add ftrace_init_nop()
This commit is contained in:
Catalin Marinas
Коммит
c1c9ea6371
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@ -143,6 +143,8 @@ config ARM64
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select HAVE_DEBUG_KMEMLEAK
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select HAVE_DMA_CONTIGUOUS
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select HAVE_DYNAMIC_FTRACE
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select HAVE_DYNAMIC_FTRACE_WITH_REGS \
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if $(cc-option,-fpatchable-function-entry=2)
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select HAVE_EFFICIENT_UNALIGNED_ACCESS
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select HAVE_FAST_GUP
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select HAVE_FTRACE_MCOUNT_RECORD
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@ -95,6 +95,11 @@ ifeq ($(CONFIG_ARM64_MODULE_PLTS),y)
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KBUILD_LDS_MODULE += $(srctree)/arch/arm64/kernel/module.lds
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endif
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ifeq ($(CONFIG_DYNAMIC_FTRACE_WITH_REGS),y)
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KBUILD_CPPFLAGS += -DCC_USING_PATCHABLE_FUNCTION_ENTRY
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CC_FLAGS_FTRACE := -fpatchable-function-entry=2
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endif
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# Default value
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head-y := arch/arm64/kernel/head.o
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@ -11,9 +11,20 @@
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#include <asm/insn.h>
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#define HAVE_FUNCTION_GRAPH_FP_TEST
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#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
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#define ARCH_SUPPORTS_FTRACE_OPS 1
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#else
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#define MCOUNT_ADDR ((unsigned long)_mcount)
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#endif
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/* The BL at the callsite's adjusted rec->ip */
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#define MCOUNT_INSN_SIZE AARCH64_INSN_SIZE
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#define FTRACE_PLT_IDX 0
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#define FTRACE_REGS_PLT_IDX 1
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#define NR_FTRACE_PLTS 2
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/*
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* Currently, gcc tends to save the link register after the local variables
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* on the stack. This causes the max stack tracer to report the function
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@ -43,6 +54,12 @@ extern void return_to_handler(void);
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static inline unsigned long ftrace_call_adjust(unsigned long addr)
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{
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/*
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* Adjust addr to point at the BL in the callsite.
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* See ftrace_init_nop() for the callsite sequence.
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*/
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if (IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_REGS))
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return addr + AARCH64_INSN_SIZE;
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/*
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* addr is the address of the mcount call instruction.
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* recordmcount does the necessary offset calculation.
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@ -50,6 +67,12 @@ static inline unsigned long ftrace_call_adjust(unsigned long addr)
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return addr;
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}
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#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
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struct dyn_ftrace;
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int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec);
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#define ftrace_init_nop ftrace_init_nop
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#endif
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#define ftrace_return_address(n) return_address(n)
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/*
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@ -440,6 +440,9 @@ u32 aarch64_insn_gen_logical_shifted_reg(enum aarch64_insn_register dst,
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int shift,
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enum aarch64_insn_variant variant,
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enum aarch64_insn_logic_type type);
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u32 aarch64_insn_gen_move_reg(enum aarch64_insn_register dst,
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enum aarch64_insn_register src,
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enum aarch64_insn_variant variant);
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u32 aarch64_insn_gen_logical_immediate(enum aarch64_insn_logic_type type,
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enum aarch64_insn_variant variant,
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enum aarch64_insn_register Rn,
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@ -21,7 +21,7 @@ struct mod_arch_specific {
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struct mod_plt_sec init;
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/* for CONFIG_DYNAMIC_FTRACE */
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struct plt_entry *ftrace_trampoline;
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struct plt_entry *ftrace_trampolines;
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};
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#endif
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@ -56,6 +56,7 @@ int main(void)
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DEFINE(S_X24, offsetof(struct pt_regs, regs[24]));
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DEFINE(S_X26, offsetof(struct pt_regs, regs[26]));
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DEFINE(S_X28, offsetof(struct pt_regs, regs[28]));
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DEFINE(S_FP, offsetof(struct pt_regs, regs[29]));
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DEFINE(S_LR, offsetof(struct pt_regs, regs[30]));
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DEFINE(S_SP, offsetof(struct pt_regs, sp));
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DEFINE(S_PSTATE, offsetof(struct pt_regs, pstate));
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@ -7,10 +7,137 @@
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*/
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#include <linux/linkage.h>
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#include <asm/asm-offsets.h>
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#include <asm/assembler.h>
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#include <asm/ftrace.h>
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#include <asm/insn.h>
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#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
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/*
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* Due to -fpatchable-function-entry=2, the compiler has placed two NOPs before
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* the regular function prologue. For an enabled callsite, ftrace_init_nop() and
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* ftrace_make_call() have patched those NOPs to:
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*
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* MOV X9, LR
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* BL <entry>
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*
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* ... where <entry> is either ftrace_caller or ftrace_regs_caller.
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*
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* Each instrumented function follows the AAPCS, so here x0-x8 and x19-x30 are
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* live, and x9-x18 are safe to clobber.
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*
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* We save the callsite's context into a pt_regs before invoking any ftrace
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* callbacks. So that we can get a sensible backtrace, we create a stack record
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* for the callsite and the ftrace entry assembly. This is not sufficient for
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* reliable stacktrace: until we create the callsite stack record, its caller
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* is missing from the LR and existing chain of frame records.
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*/
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.macro ftrace_regs_entry, allregs=0
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/* Make room for pt_regs, plus a callee frame */
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sub sp, sp, #(S_FRAME_SIZE + 16)
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/* Save function arguments (and x9 for simplicity) */
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stp x0, x1, [sp, #S_X0]
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stp x2, x3, [sp, #S_X2]
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stp x4, x5, [sp, #S_X4]
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stp x6, x7, [sp, #S_X6]
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stp x8, x9, [sp, #S_X8]
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/* Optionally save the callee-saved registers, always save the FP */
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.if \allregs == 1
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stp x10, x11, [sp, #S_X10]
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stp x12, x13, [sp, #S_X12]
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stp x14, x15, [sp, #S_X14]
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stp x16, x17, [sp, #S_X16]
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stp x18, x19, [sp, #S_X18]
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stp x20, x21, [sp, #S_X20]
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stp x22, x23, [sp, #S_X22]
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stp x24, x25, [sp, #S_X24]
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stp x26, x27, [sp, #S_X26]
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stp x28, x29, [sp, #S_X28]
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.else
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str x29, [sp, #S_FP]
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.endif
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/* Save the callsite's SP and LR */
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add x10, sp, #(S_FRAME_SIZE + 16)
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stp x9, x10, [sp, #S_LR]
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/* Save the PC after the ftrace callsite */
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str x30, [sp, #S_PC]
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/* Create a frame record for the callsite above pt_regs */
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stp x29, x9, [sp, #S_FRAME_SIZE]
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add x29, sp, #S_FRAME_SIZE
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/* Create our frame record within pt_regs. */
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stp x29, x30, [sp, #S_STACKFRAME]
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add x29, sp, #S_STACKFRAME
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.endm
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ENTRY(ftrace_regs_caller)
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ftrace_regs_entry 1
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b ftrace_common
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ENDPROC(ftrace_regs_caller)
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ENTRY(ftrace_caller)
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ftrace_regs_entry 0
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b ftrace_common
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ENDPROC(ftrace_caller)
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ENTRY(ftrace_common)
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sub x0, x30, #AARCH64_INSN_SIZE // ip (callsite's BL insn)
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mov x1, x9 // parent_ip (callsite's LR)
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ldr_l x2, function_trace_op // op
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mov x3, sp // regs
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GLOBAL(ftrace_call)
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bl ftrace_stub
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#ifdef CONFIG_FUNCTION_GRAPH_TRACER
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GLOBAL(ftrace_graph_call) // ftrace_graph_caller();
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nop // If enabled, this will be replaced
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// "b ftrace_graph_caller"
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#endif
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/*
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* At the callsite x0-x8 and x19-x30 were live. Any C code will have preserved
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* x19-x29 per the AAPCS, and we created frame records upon entry, so we need
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* to restore x0-x8, x29, and x30.
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*/
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ftrace_common_return:
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/* Restore function arguments */
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ldp x0, x1, [sp]
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ldp x2, x3, [sp, #S_X2]
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ldp x4, x5, [sp, #S_X4]
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ldp x6, x7, [sp, #S_X6]
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ldr x8, [sp, #S_X8]
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/* Restore the callsite's FP, LR, PC */
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ldr x29, [sp, #S_FP]
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ldr x30, [sp, #S_LR]
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ldr x9, [sp, #S_PC]
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/* Restore the callsite's SP */
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add sp, sp, #S_FRAME_SIZE + 16
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ret x9
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ENDPROC(ftrace_common)
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#ifdef CONFIG_FUNCTION_GRAPH_TRACER
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ENTRY(ftrace_graph_caller)
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ldr x0, [sp, #S_PC]
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sub x0, x0, #AARCH64_INSN_SIZE // ip (callsite's BL insn)
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add x1, sp, #S_LR // parent_ip (callsite's LR)
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ldr x2, [sp, #S_FRAME_SIZE] // parent fp (callsite's FP)
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bl prepare_ftrace_return
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b ftrace_common_return
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ENDPROC(ftrace_graph_caller)
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#else
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#endif
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#else /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */
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/*
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* Gcc with -pg will put the following code in the beginning of each function:
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* mov x0, x30
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@ -160,11 +287,6 @@ GLOBAL(ftrace_graph_call) // ftrace_graph_caller();
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mcount_exit
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ENDPROC(ftrace_caller)
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#endif /* CONFIG_DYNAMIC_FTRACE */
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ENTRY(ftrace_stub)
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ret
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ENDPROC(ftrace_stub)
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#ifdef CONFIG_FUNCTION_GRAPH_TRACER
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/*
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@ -184,7 +306,15 @@ ENTRY(ftrace_graph_caller)
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mcount_exit
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ENDPROC(ftrace_graph_caller)
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#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
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#endif /* CONFIG_DYNAMIC_FTRACE */
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#endif /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */
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ENTRY(ftrace_stub)
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ret
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ENDPROC(ftrace_stub)
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#ifdef CONFIG_FUNCTION_GRAPH_TRACER
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/*
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* void return_to_handler(void)
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*
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@ -62,6 +62,19 @@ int ftrace_update_ftrace_func(ftrace_func_t func)
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return ftrace_modify_code(pc, 0, new, false);
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}
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static struct plt_entry *get_ftrace_plt(struct module *mod, unsigned long addr)
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{
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#ifdef CONFIG_ARM64_MODULE_PLTS
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struct plt_entry *plt = mod->arch.ftrace_trampolines;
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if (addr == FTRACE_ADDR)
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return &plt[FTRACE_PLT_IDX];
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if (addr == FTRACE_REGS_ADDR && IS_ENABLED(CONFIG_FTRACE_WITH_REGS))
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return &plt[FTRACE_REGS_PLT_IDX];
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#endif
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return NULL;
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}
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/*
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* Turn on the call to ftrace_caller() in instrumented function
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*/
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@ -72,9 +85,11 @@ int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
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long offset = (long)pc - (long)addr;
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if (offset < -SZ_128M || offset >= SZ_128M) {
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#ifdef CONFIG_ARM64_MODULE_PLTS
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struct plt_entry trampoline, *dst;
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struct module *mod;
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struct plt_entry *plt;
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if (!IS_ENABLED(CONFIG_ARM64_MODULE_PLTS))
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return -EINVAL;
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/*
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* On kernels that support module PLTs, the offset between the
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@ -93,49 +108,13 @@ int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
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if (WARN_ON(!mod))
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return -EINVAL;
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/*
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* There is only one ftrace trampoline per module. For now,
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* this is not a problem since on arm64, all dynamic ftrace
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* invocations are routed via ftrace_caller(). This will need
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* to be revisited if support for multiple ftrace entry points
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* is added in the future, but for now, the pr_err() below
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* deals with a theoretical issue only.
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*
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* Note that PLTs are place relative, and plt_entries_equal()
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* checks whether they point to the same target. Here, we need
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* to check if the actual opcodes are in fact identical,
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* regardless of the offset in memory so use memcmp() instead.
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*/
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dst = mod->arch.ftrace_trampoline;
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trampoline = get_plt_entry(addr, dst);
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if (memcmp(dst, &trampoline, sizeof(trampoline))) {
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if (plt_entry_is_initialized(dst)) {
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pr_err("ftrace: far branches to multiple entry points unsupported inside a single module\n");
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return -EINVAL;
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}
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/* point the trampoline to our ftrace entry point */
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module_disable_ro(mod);
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*dst = trampoline;
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module_enable_ro(mod, true);
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/*
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* Ensure updated trampoline is visible to instruction
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* fetch before we patch in the branch. Although the
|
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* architecture doesn't require an IPI in this case,
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* Neoverse-N1 erratum #1542419 does require one
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* if the TLB maintenance in module_enable_ro() is
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* skipped due to rodata_enabled. It doesn't seem worth
|
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* it to make it conditional given that this is
|
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* certainly not a fast-path.
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*/
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flush_icache_range((unsigned long)&dst[0],
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(unsigned long)&dst[1]);
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plt = get_ftrace_plt(mod, addr);
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if (!plt) {
|
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pr_err("ftrace: no module PLT for %ps\n", (void *)addr);
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return -EINVAL;
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}
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addr = (unsigned long)dst;
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#else /* CONFIG_ARM64_MODULE_PLTS */
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return -EINVAL;
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#endif /* CONFIG_ARM64_MODULE_PLTS */
|
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|
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addr = (unsigned long)plt;
|
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}
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old = aarch64_insn_gen_nop();
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|
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@ -144,6 +123,55 @@ int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
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return ftrace_modify_code(pc, old, new, true);
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}
|
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|
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#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
|
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int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
|
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unsigned long addr)
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{
|
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unsigned long pc = rec->ip;
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u32 old, new;
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|
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old = aarch64_insn_gen_branch_imm(pc, old_addr,
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AARCH64_INSN_BRANCH_LINK);
|
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new = aarch64_insn_gen_branch_imm(pc, addr, AARCH64_INSN_BRANCH_LINK);
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return ftrace_modify_code(pc, old, new, true);
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}
|
||||
|
||||
/*
|
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* The compiler has inserted two NOPs before the regular function prologue.
|
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* All instrumented functions follow the AAPCS, so x0-x8 and x19-x30 are live,
|
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* and x9-x18 are free for our use.
|
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*
|
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* At runtime we want to be able to swing a single NOP <-> BL to enable or
|
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* disable the ftrace call. The BL requires us to save the original LR value,
|
||||
* so here we insert a <MOV X9, LR> over the first NOP so the instructions
|
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* before the regular prologue are:
|
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*
|
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* | Compiled | Disabled | Enabled |
|
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* +----------+------------+------------+
|
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* | NOP | MOV X9, LR | MOV X9, LR |
|
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* | NOP | NOP | BL <entry> |
|
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*
|
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* The LR value will be recovered by ftrace_regs_entry, and restored into LR
|
||||
* before returning to the regular function prologue. When a function is not
|
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* being traced, the MOV is not harmful given x9 is not live per the AAPCS.
|
||||
*
|
||||
* Note: ftrace_process_locs() has pre-adjusted rec->ip to be the address of
|
||||
* the BL.
|
||||
*/
|
||||
int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec)
|
||||
{
|
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unsigned long pc = rec->ip - AARCH64_INSN_SIZE;
|
||||
u32 old, new;
|
||||
|
||||
old = aarch64_insn_gen_nop();
|
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new = aarch64_insn_gen_move_reg(AARCH64_INSN_REG_9,
|
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AARCH64_INSN_REG_LR,
|
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AARCH64_INSN_VARIANT_64BIT);
|
||||
return ftrace_modify_code(pc, old, new, true);
|
||||
}
|
||||
#endif
|
||||
|
||||
/*
|
||||
* Turn off the call to ftrace_caller() in instrumented function
|
||||
*/
|
||||
|
|
@ -156,9 +184,11 @@ int ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec,
|
|||
long offset = (long)pc - (long)addr;
|
||||
|
||||
if (offset < -SZ_128M || offset >= SZ_128M) {
|
||||
#ifdef CONFIG_ARM64_MODULE_PLTS
|
||||
u32 replaced;
|
||||
|
||||
if (!IS_ENABLED(CONFIG_ARM64_MODULE_PLTS))
|
||||
return -EINVAL;
|
||||
|
||||
/*
|
||||
* 'mod' is only set at module load time, but if we end up
|
||||
* dealing with an out-of-range condition, we can assume it
|
||||
|
|
@ -189,9 +219,6 @@ int ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec,
|
|||
return -EINVAL;
|
||||
|
||||
validate = false;
|
||||
#else /* CONFIG_ARM64_MODULE_PLTS */
|
||||
return -EINVAL;
|
||||
#endif /* CONFIG_ARM64_MODULE_PLTS */
|
||||
} else {
|
||||
old = aarch64_insn_gen_branch_imm(pc, addr,
|
||||
AARCH64_INSN_BRANCH_LINK);
|
||||
|
|
|
|||
|
|
@ -1268,6 +1268,19 @@ u32 aarch64_insn_gen_logical_shifted_reg(enum aarch64_insn_register dst,
|
|||
return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_6, insn, shift);
|
||||
}
|
||||
|
||||
/*
|
||||
* MOV (register) is architecturally an alias of ORR (shifted register) where
|
||||
* MOV <*d>, <*m> is equivalent to ORR <*d>, <*ZR>, <*m>
|
||||
*/
|
||||
u32 aarch64_insn_gen_move_reg(enum aarch64_insn_register dst,
|
||||
enum aarch64_insn_register src,
|
||||
enum aarch64_insn_variant variant)
|
||||
{
|
||||
return aarch64_insn_gen_logical_shifted_reg(dst, AARCH64_INSN_REG_ZR,
|
||||
src, 0, variant,
|
||||
AARCH64_INSN_LOGIC_ORR);
|
||||
}
|
||||
|
||||
u32 aarch64_insn_gen_adr(unsigned long pc, unsigned long addr,
|
||||
enum aarch64_insn_register reg,
|
||||
enum aarch64_insn_adr_type type)
|
||||
|
|
|
|||
|
|
@ -4,6 +4,7 @@
|
|||
*/
|
||||
|
||||
#include <linux/elf.h>
|
||||
#include <linux/ftrace.h>
|
||||
#include <linux/kernel.h>
|
||||
#include <linux/module.h>
|
||||
#include <linux/sort.h>
|
||||
|
|
@ -330,7 +331,7 @@ int module_frob_arch_sections(Elf_Ehdr *ehdr, Elf_Shdr *sechdrs,
|
|||
tramp->sh_type = SHT_NOBITS;
|
||||
tramp->sh_flags = SHF_EXECINSTR | SHF_ALLOC;
|
||||
tramp->sh_addralign = __alignof__(struct plt_entry);
|
||||
tramp->sh_size = sizeof(struct plt_entry);
|
||||
tramp->sh_size = NR_FTRACE_PLTS * sizeof(struct plt_entry);
|
||||
}
|
||||
|
||||
return 0;
|
||||
|
|
|
|||
|
|
@ -9,6 +9,7 @@
|
|||
|
||||
#include <linux/bitops.h>
|
||||
#include <linux/elf.h>
|
||||
#include <linux/ftrace.h>
|
||||
#include <linux/gfp.h>
|
||||
#include <linux/kasan.h>
|
||||
#include <linux/kernel.h>
|
||||
|
|
@ -470,22 +471,58 @@ overflow:
|
|||
return -ENOEXEC;
|
||||
}
|
||||
|
||||
int module_finalize(const Elf_Ehdr *hdr,
|
||||
const Elf_Shdr *sechdrs,
|
||||
struct module *me)
|
||||
static const Elf_Shdr *find_section(const Elf_Ehdr *hdr,
|
||||
const Elf_Shdr *sechdrs,
|
||||
const char *name)
|
||||
{
|
||||
const Elf_Shdr *s, *se;
|
||||
const char *secstrs = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
|
||||
|
||||
for (s = sechdrs, se = sechdrs + hdr->e_shnum; s < se; s++) {
|
||||
if (strcmp(".altinstructions", secstrs + s->sh_name) == 0)
|
||||
apply_alternatives_module((void *)s->sh_addr, s->sh_size);
|
||||
#ifdef CONFIG_ARM64_MODULE_PLTS
|
||||
if (IS_ENABLED(CONFIG_DYNAMIC_FTRACE) &&
|
||||
!strcmp(".text.ftrace_trampoline", secstrs + s->sh_name))
|
||||
me->arch.ftrace_trampoline = (void *)s->sh_addr;
|
||||
#endif
|
||||
if (strcmp(name, secstrs + s->sh_name) == 0)
|
||||
return s;
|
||||
}
|
||||
|
||||
return NULL;
|
||||
}
|
||||
|
||||
static inline void __init_plt(struct plt_entry *plt, unsigned long addr)
|
||||
{
|
||||
*plt = get_plt_entry(addr, plt);
|
||||
}
|
||||
|
||||
static int module_init_ftrace_plt(const Elf_Ehdr *hdr,
|
||||
const Elf_Shdr *sechdrs,
|
||||
struct module *mod)
|
||||
{
|
||||
#if defined(CONFIG_ARM64_MODULE_PLTS) && defined(CONFIG_DYNAMIC_FTRACE)
|
||||
const Elf_Shdr *s;
|
||||
struct plt_entry *plts;
|
||||
|
||||
s = find_section(hdr, sechdrs, ".text.ftrace_trampoline");
|
||||
if (!s)
|
||||
return -ENOEXEC;
|
||||
|
||||
plts = (void *)s->sh_addr;
|
||||
|
||||
__init_plt(&plts[FTRACE_PLT_IDX], FTRACE_ADDR);
|
||||
|
||||
if (IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_REGS))
|
||||
__init_plt(&plts[FTRACE_REGS_PLT_IDX], FTRACE_REGS_ADDR);
|
||||
|
||||
mod->arch.ftrace_trampolines = plts;
|
||||
#endif
|
||||
return 0;
|
||||
}
|
||||
|
||||
int module_finalize(const Elf_Ehdr *hdr,
|
||||
const Elf_Shdr *sechdrs,
|
||||
struct module *me)
|
||||
{
|
||||
const Elf_Shdr *s;
|
||||
s = find_section(hdr, sechdrs, ".altinstructions");
|
||||
if (s)
|
||||
apply_alternatives_module((void *)s->sh_addr, s->sh_size);
|
||||
|
||||
return module_init_ftrace_plt(hdr, sechdrs, me);
|
||||
}
|
||||
|
|
|
|||
|
|
@ -60,7 +60,6 @@ KBUILD_CFLAGS += -DCC_USING_PATCHABLE_FUNCTION_ENTRY=1 \
|
|||
-DFTRACE_PATCHABLE_FUNCTION_SIZE=$(NOP_COUNT)
|
||||
|
||||
CC_FLAGS_FTRACE := -fpatchable-function-entry=$(NOP_COUNT),$(shell echo $$(($(NOP_COUNT)-1)))
|
||||
KBUILD_LDS_MODULE += $(srctree)/arch/parisc/kernel/module.lds
|
||||
endif
|
||||
|
||||
OBJCOPY_FLAGS =-O binary -R .note -R .comment -S
|
||||
|
|
|
|||
|
|
@ -43,6 +43,7 @@
|
|||
#include <linux/elf.h>
|
||||
#include <linux/vmalloc.h>
|
||||
#include <linux/fs.h>
|
||||
#include <linux/ftrace.h>
|
||||
#include <linux/string.h>
|
||||
#include <linux/kernel.h>
|
||||
#include <linux/bug.h>
|
||||
|
|
@ -862,7 +863,7 @@ int module_finalize(const Elf_Ehdr *hdr,
|
|||
const char *strtab = NULL;
|
||||
const Elf_Shdr *s;
|
||||
char *secstrings;
|
||||
int err, symindex = -1;
|
||||
int symindex = -1;
|
||||
Elf_Sym *newptr, *oldptr;
|
||||
Elf_Shdr *symhdr = NULL;
|
||||
#ifdef DEBUG
|
||||
|
|
@ -946,11 +947,13 @@ int module_finalize(const Elf_Ehdr *hdr,
|
|||
/* patch .altinstructions */
|
||||
apply_alternatives(aseg, aseg + s->sh_size, me->name);
|
||||
|
||||
#ifdef CONFIG_DYNAMIC_FTRACE
|
||||
/* For 32 bit kernels we're compiling modules with
|
||||
* -ffunction-sections so we must relocate the addresses in the
|
||||
*__mcount_loc section.
|
||||
* ftrace callsite section.
|
||||
*/
|
||||
if (symindex != -1 && !strcmp(secname, "__mcount_loc")) {
|
||||
if (symindex != -1 && !strcmp(secname, FTRACE_CALLSITE_SECTION)) {
|
||||
int err;
|
||||
if (s->sh_type == SHT_REL)
|
||||
err = apply_relocate((Elf_Shdr *)sechdrs,
|
||||
strtab, symindex,
|
||||
|
|
@ -962,6 +965,7 @@ int module_finalize(const Elf_Ehdr *hdr,
|
|||
if (err)
|
||||
return err;
|
||||
}
|
||||
#endif
|
||||
}
|
||||
return 0;
|
||||
}
|
||||
|
|
|
|||
|
|
@ -1,7 +0,0 @@
|
|||
/* SPDX-License-Identifier: GPL-2.0 */
|
||||
|
||||
SECTIONS {
|
||||
__mcount_loc : {
|
||||
*(__patchable_function_entries)
|
||||
}
|
||||
}
|
||||
|
|
@ -110,17 +110,17 @@
|
|||
#endif
|
||||
|
||||
#ifdef CONFIG_FTRACE_MCOUNT_RECORD
|
||||
#ifdef CC_USING_PATCHABLE_FUNCTION_ENTRY
|
||||
#define MCOUNT_REC() . = ALIGN(8); \
|
||||
__start_mcount_loc = .; \
|
||||
KEEP(*(__patchable_function_entries)) \
|
||||
__stop_mcount_loc = .;
|
||||
#else
|
||||
/*
|
||||
* The ftrace call sites are logged to a section whose name depends on the
|
||||
* compiler option used. A given kernel image will only use one, AKA
|
||||
* FTRACE_CALLSITE_SECTION. We capture all of them here to avoid header
|
||||
* dependencies for FTRACE_CALLSITE_SECTION's definition.
|
||||
*/
|
||||
#define MCOUNT_REC() . = ALIGN(8); \
|
||||
__start_mcount_loc = .; \
|
||||
KEEP(*(__mcount_loc)) \
|
||||
KEEP(*(__patchable_function_entries)) \
|
||||
__stop_mcount_loc = .;
|
||||
#endif
|
||||
#else
|
||||
#define MCOUNT_REC()
|
||||
#endif
|
||||
|
|
|
|||
|
|
@ -499,7 +499,7 @@ static inline int ftrace_disable_ftrace_graph_caller(void) { return 0; }
|
|||
/**
|
||||
* ftrace_make_nop - convert code into nop
|
||||
* @mod: module structure if called by module load initialization
|
||||
* @rec: the mcount call site record
|
||||
* @rec: the call site record (e.g. mcount/fentry)
|
||||
* @addr: the address that the call site should be calling
|
||||
*
|
||||
* This is a very sensitive operation and great care needs
|
||||
|
|
@ -520,9 +520,38 @@ static inline int ftrace_disable_ftrace_graph_caller(void) { return 0; }
|
|||
extern int ftrace_make_nop(struct module *mod,
|
||||
struct dyn_ftrace *rec, unsigned long addr);
|
||||
|
||||
|
||||
/**
|
||||
* ftrace_init_nop - initialize a nop call site
|
||||
* @mod: module structure if called by module load initialization
|
||||
* @rec: the call site record (e.g. mcount/fentry)
|
||||
*
|
||||
* This is a very sensitive operation and great care needs
|
||||
* to be taken by the arch. The operation should carefully
|
||||
* read the location, check to see if what is read is indeed
|
||||
* what we expect it to be, and then on success of the compare,
|
||||
* it should write to the location.
|
||||
*
|
||||
* The code segment at @rec->ip should contain the contents created by
|
||||
* the compiler
|
||||
*
|
||||
* Return must be:
|
||||
* 0 on success
|
||||
* -EFAULT on error reading the location
|
||||
* -EINVAL on a failed compare of the contents
|
||||
* -EPERM on error writing to the location
|
||||
* Any other value will be considered a failure.
|
||||
*/
|
||||
#ifndef ftrace_init_nop
|
||||
static inline int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec)
|
||||
{
|
||||
return ftrace_make_nop(mod, rec, MCOUNT_ADDR);
|
||||
}
|
||||
#endif
|
||||
|
||||
/**
|
||||
* ftrace_make_call - convert a nop call site into a call to addr
|
||||
* @rec: the mcount call site record
|
||||
* @rec: the call site record (e.g. mcount/fentry)
|
||||
* @addr: the address that the call site should call
|
||||
*
|
||||
* This is a very sensitive operation and great care needs
|
||||
|
|
@ -545,7 +574,7 @@ extern int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr);
|
|||
#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
|
||||
/**
|
||||
* ftrace_modify_call - convert from one addr to another (no nop)
|
||||
* @rec: the mcount call site record
|
||||
* @rec: the call site record (e.g. mcount/fentry)
|
||||
* @old_addr: the address expected to be currently called to
|
||||
* @addr: the address to change to
|
||||
*
|
||||
|
|
@ -709,6 +738,11 @@ static inline unsigned long get_lock_parent_ip(void)
|
|||
|
||||
#ifdef CONFIG_FTRACE_MCOUNT_RECORD
|
||||
extern void ftrace_init(void);
|
||||
#ifdef CC_USING_PATCHABLE_FUNCTION_ENTRY
|
||||
#define FTRACE_CALLSITE_SECTION "__patchable_function_entries"
|
||||
#else
|
||||
#define FTRACE_CALLSITE_SECTION "__mcount_loc"
|
||||
#endif
|
||||
#else
|
||||
static inline void ftrace_init(void) { }
|
||||
#endif
|
||||
|
|
|
|||
|
|
@ -3222,7 +3222,7 @@ static int find_module_sections(struct module *mod, struct load_info *info)
|
|||
#endif
|
||||
#ifdef CONFIG_FTRACE_MCOUNT_RECORD
|
||||
/* sechdrs[0].sh_size is always zero */
|
||||
mod->ftrace_callsites = section_objs(info, "__mcount_loc",
|
||||
mod->ftrace_callsites = section_objs(info, FTRACE_CALLSITE_SECTION,
|
||||
sizeof(*mod->ftrace_callsites),
|
||||
&mod->num_ftrace_callsites);
|
||||
#endif
|
||||
|
|
|
|||
|
|
@ -2494,14 +2494,14 @@ struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter)
|
|||
}
|
||||
|
||||
static int
|
||||
ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec)
|
||||
ftrace_nop_initialize(struct module *mod, struct dyn_ftrace *rec)
|
||||
{
|
||||
int ret;
|
||||
|
||||
if (unlikely(ftrace_disabled))
|
||||
return 0;
|
||||
|
||||
ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR);
|
||||
ret = ftrace_init_nop(mod, rec);
|
||||
if (ret) {
|
||||
ftrace_bug_type = FTRACE_BUG_INIT;
|
||||
ftrace_bug(ret, rec);
|
||||
|
|
@ -2943,7 +2943,7 @@ static int ftrace_update_code(struct module *mod, struct ftrace_page *new_pgs)
|
|||
* to the NOP instructions.
|
||||
*/
|
||||
if (!__is_defined(CC_USING_NOP_MCOUNT) &&
|
||||
!ftrace_code_disable(mod, p))
|
||||
!ftrace_nop_initialize(mod, p))
|
||||
break;
|
||||
|
||||
update_cnt++;
|
||||
|
|
|
|||
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