tools/testing/selftests/rseq/rseq-x86-bits.h

Source file repositories/reference/linux-study-clean/tools/testing/selftests/rseq/rseq-x86-bits.h

File Facts

System
Linux kernel
Corpus path
tools/testing/selftests/rseq/rseq-x86-bits.h
Extension
.h
Size
28034 bytes
Lines
994
Domain
Support Tooling And Documentation
Bucket
tools
Inferred role
Support Tooling And Documentation: implementation source
Status
source implementation candidate

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Dependency Surface

Detected Declarations

Annotated Snippet

#include "rseq-bits-template.h"

#ifdef __x86_64__

#if defined(RSEQ_TEMPLATE_MO_RELAXED) && \
	(defined(RSEQ_TEMPLATE_CPU_ID) || defined(RSEQ_TEMPLATE_MM_CID))

static inline __attribute__((always_inline))
int RSEQ_TEMPLATE_IDENTIFIER(rseq_cmpeqv_storev)(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
{
	RSEQ_INJECT_C(9)

	__asm__ __volatile__ goto (
		RSEQ_ASM_DEFINE_TABLE(3, 1f, 2f, 4f) /* start, commit, abort */
		RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
#ifdef RSEQ_COMPARE_TWICE
		RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
		RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error2])
#endif
		/* Start rseq by storing table entry pointer into rseq_cs. */
		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_ASM_TP_SEGMENT:RSEQ_CS_OFFSET(%[rseq_offset]))
		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_TEMPLATE_CPU_ID_OFFSET(%[rseq_offset]), 4f)
		RSEQ_INJECT_ASM(3)
		"cmpq %[v], %[expect]\n\t"
		"jnz %l[cmpfail]\n\t"
		RSEQ_INJECT_ASM(4)
#ifdef RSEQ_COMPARE_TWICE
		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_TEMPLATE_CPU_ID_OFFSET(%[rseq_offset]), %l[error1])
		"cmpq %[v], %[expect]\n\t"
		"jnz %l[error2]\n\t"
#endif
		/* final store */
		"movq %[newv], %[v]\n\t"
		"2:\n\t"
		RSEQ_INJECT_ASM(5)
		RSEQ_ASM_DEFINE_ABORT(4, "", abort)
		: /* gcc asm goto does not allow outputs */
		: [cpu_id]		"r" (cpu),
		  [rseq_offset]		"r" (rseq_offset),
		  [v]			"m" (*v),
		  [expect]		"r" (expect),
		  [newv]		"r" (newv)
		: "memory", "cc", "rax"
		  RSEQ_INJECT_CLOBBER
		: abort, cmpfail
#ifdef RSEQ_COMPARE_TWICE
		  , error1, error2
#endif
	);
	rseq_after_asm_goto();
	return 0;
abort:
	rseq_after_asm_goto();
	RSEQ_INJECT_FAILED
	return -1;
cmpfail:
	rseq_after_asm_goto();
	return 1;
#ifdef RSEQ_COMPARE_TWICE
error1:
	rseq_after_asm_goto();
	rseq_bug("cpu_id comparison failed");
error2:
	rseq_after_asm_goto();
	rseq_bug("expected value comparison failed");
#endif
}

/*
 * Compare @v against @expectnot. When it does _not_ match, load @v
 * into @load, and store the content of *@v + voffp into @v.
 */
static inline __attribute__((always_inline))
int RSEQ_TEMPLATE_IDENTIFIER(rseq_cmpnev_storeoffp_load)(intptr_t *v, intptr_t expectnot,
			       long voffp, intptr_t *load, int cpu)
{
	RSEQ_INJECT_C(9)

	__asm__ __volatile__ goto (
		RSEQ_ASM_DEFINE_TABLE(3, 1f, 2f, 4f) /* start, commit, abort */
		RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
#ifdef RSEQ_COMPARE_TWICE
		RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
		RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error2])
#endif
		/* Start rseq by storing table entry pointer into rseq_cs. */
		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_ASM_TP_SEGMENT:RSEQ_CS_OFFSET(%[rseq_offset]))
		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_TEMPLATE_CPU_ID_OFFSET(%[rseq_offset]), 4f)
		RSEQ_INJECT_ASM(3)
		"movq %[v], %%rbx\n\t"

Annotation

Implementation Notes