Lines Matching +full:sub +full:- +full:function

1 /* SPDX-License-Identifier: GPL-2.0-only */
3  * arch/arm64/kernel/entry-ftrace.S
10 #include <asm/asm-offsets.h>
17  * Due to -fpatchable-function-entry=2, the compiler has placed two NOPs before
18  * the regular function prologue. For an enabled callsite, ftrace_init_nop() and
26  * Each instrumented function follows the AAPCS, so here x0-x8 and x18-x30 are
27  * live (x18 holds the Shadow Call Stack pointer), and x9-x17 are safe to
38 	sub	sp, sp, #(PT_REGS_SIZE + 16)
40 	/* Save function arguments (and x9 for simplicity) */
47 	/* Optionally save the callee-saved registers, always save the FP */
90 	sub	x0, x30, #AARCH64_INSN_SIZE	// ip (callsite's BL insn)
105  * At the callsite x0-x8 and x19-x30 were live. Any C code will have preserved
106  * x19-x29 per the AAPCS, and we created frame records upon entry, so we need
107  * to restore x0-x8, x29, and x30.
110 	/* Restore function arguments */
131 	sub	x0, x0, #AARCH64_INSN_SIZE	// ip (callsite's BL insn)
142  * Gcc with -pg will put the following code in the beginning of each function:
145  *	[function's body ...]
150  * get lr(x30) of instrumented function at any time by winding up call stack
151  * as long as the kernel is compiled without -fomit-frame-pointer.
156  * current sp/fp =>  0:+-----+
157  * in _mcount()        | x29 | -> instrumented function's fp
158  *                     +-----+
159  *                     | x30 | -> _mcount()'s lr (= instrumented function's pc)
160  * old sp       => +16:+-----+
162  * function calls      | ... |
165  * instrumented => +xx:+-----+
166  * function's fp       | x29 | -> parent's fp
167  *                     +-----+
168  *                     | x30 | -> instrumented function's lr (= parent's pc)
169  *                     +-----+
174 	stp	x29, x30, [sp, #-16]!
184 	sub	\rd, \rn, #AARCH64_INSN_SIZE
187 	/* for instrumented function's parent */
193 	/* for instrumented function */
216  * @return_address: return address to instrumented function
218  * This function makes calls, if enabled, to:
219  *     - tracer function to probe instrumented function's entry,
220  *     - ftrace_graph_caller to set up an exit hook
230 	mcount_get_pc	x0		//       function's pc
231 	mcount_get_lr	x1		//       function's lr (= parent's pc)
252  * _mcount() is used to build the kernel with -pg option, but all the branch
255  * NOP when disabled per-function base.
265  * @return_address: return address to instrumented function
267  * This function is a counterpart of _mcount() in 'static' ftrace, and
269  *     - tracer function to probe instrumented function's entry,
270  *     - ftrace_graph_caller to set up an exit hook
275 	mcount_get_pc0	x0		//     function's pc
276 	mcount_get_lr	x1		//     function's lr
298  * This function w/ prepare_ftrace_return() fakes link register's value on
299  * the call stack in order to intercept instrumented function's return path
303 	mcount_get_pc		  x0	//     function's pc
304 	mcount_get_lr_addr	  x1	//     pointer to function's saved lr
326 	sub sp, sp, #64