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Commit dc282528 authored by Mathieu Desnoyers's avatar Mathieu Desnoyers Committed by Greg Kroah-Hartman
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selftests/rseq: x86-32: use %gs segment selector for accessing rseq thread area 



commit 127b6429d235ab7c358223bbfd8a8b8d8cc799b6 upstream.

Rather than use rseq_get_abi() and pass its result through a register to
the inline assembler, directly access the per-thread rseq area through a
memory reference combining the %gs segment selector, the constant offset
of the field in struct rseq, and the rseq_offset value (in a register).

Signed-off-by: default avatarMathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20220124171253.22072-16-mathieu.desnoyers@efficios.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent f89d15c9

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

+34 −32
Original line number Diff line number Diff line
@@ -633,6 +633,8 @@ int rseq_cmpeqv_trymemcpy_storev_release(intptr_t *v, intptr_t expect, 


#elif defined(__i386__)



#define RSEQ_ASM_TP_SEGMENT	%%gs



#define rseq_smp_mb()	\

	__asm__ __volatile__ ("lock; addl $0,-128(%%esp)" ::: "memory", "cc")

#define rseq_smp_rmb()	\
@@ -732,14 +734,14 @@ int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu) 
		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_CS_OFFSET(%[rseq_abi]))

		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), 4f)

		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_CPU_ID_OFFSET(%[rseq_offset]), 4f)

		RSEQ_INJECT_ASM(3)

		"cmpl %[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_CPU_ID_OFFSET(%[rseq_abi]), %l[error1])

		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), %l[error1])

		"cmpl %[v], %[expect]\n\t"

		"jnz %l[error2]\n\t"

#endif
@@ -750,7 +752,7 @@ int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu) 
		RSEQ_ASM_DEFINE_ABORT(4, "", abort)

		: /* gcc asm goto does not allow outputs */

		: [cpu_id]		"r" (cpu),

		  [rseq_abi]		"r" (rseq_get_abi()),

		  [rseq_offset]		"r" (rseq_offset),

		  [v]			"m" (*v),

		  [expect]		"r" (expect),

		  [newv]		"r" (newv)
@@ -798,15 +800,15 @@ int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot, 
		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_CS_OFFSET(%[rseq_abi]))

		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), 4f)

		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_CPU_ID_OFFSET(%[rseq_offset]), 4f)

		RSEQ_INJECT_ASM(3)

		"movl %[v], %%ebx\n\t"

		"cmpl %%ebx, %[expectnot]\n\t"

		"je %l[cmpfail]\n\t"

		RSEQ_INJECT_ASM(4)

#ifdef RSEQ_COMPARE_TWICE

		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), %l[error1])

		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), %l[error1])

		"movl %[v], %%ebx\n\t"

		"cmpl %%ebx, %[expectnot]\n\t"

		"je %l[error2]\n\t"
@@ -821,7 +823,7 @@ int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot, 
		RSEQ_ASM_DEFINE_ABORT(4, "", abort)

		: /* gcc asm goto does not allow outputs */

		: [cpu_id]		"r" (cpu),

		  [rseq_abi]		"r" (rseq_get_abi()),

		  [rseq_offset]		"r" (rseq_offset),

		  /* final store input */

		  [v]			"m" (*v),

		  [expectnot]		"r" (expectnot),
@@ -864,11 +866,11 @@ int rseq_addv(intptr_t *v, intptr_t count, int cpu) 
		RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])

#endif

		/* Start rseq by storing table entry pointer into rseq_cs. */

		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_CS_OFFSET(%[rseq_abi]))

		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), 4f)

		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_CPU_ID_OFFSET(%[rseq_offset]), 4f)

		RSEQ_INJECT_ASM(3)

#ifdef RSEQ_COMPARE_TWICE

		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), %l[error1])

		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), %l[error1])

#endif

		/* final store */

		"addl %[count], %[v]\n\t"
@@ -877,7 +879,7 @@ int rseq_addv(intptr_t *v, intptr_t count, int cpu) 
		RSEQ_ASM_DEFINE_ABORT(4, "", abort)

		: /* gcc asm goto does not allow outputs */

		: [cpu_id]		"r" (cpu),

		  [rseq_abi]		"r" (rseq_get_abi()),

		  [rseq_offset]		"r" (rseq_offset),

		  /* final store input */

		  [v]			"m" (*v),

		  [count]		"ir" (count)
@@ -916,14 +918,14 @@ int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect, 
		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_CS_OFFSET(%[rseq_abi]))

		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), 4f)

		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_CPU_ID_OFFSET(%[rseq_offset]), 4f)

		RSEQ_INJECT_ASM(3)

		"cmpl %[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_CPU_ID_OFFSET(%[rseq_abi]), %l[error1])

		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), %l[error1])

		"cmpl %[v], %[expect]\n\t"

		"jnz %l[error2]\n\t"

#endif
@@ -938,7 +940,7 @@ int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect, 
		RSEQ_ASM_DEFINE_ABORT(4, "", abort)

		: /* gcc asm goto does not allow outputs */

		: [cpu_id]		"r" (cpu),

		  [rseq_abi]		"r" (rseq_get_abi()),

		  [rseq_offset]		"r" (rseq_offset),

		  /* try store input */

		  [v2]			"m" (*v2),

		  [newv2]		"m" (newv2),
@@ -987,15 +989,15 @@ int rseq_cmpeqv_trystorev_storev_release(intptr_t *v, intptr_t expect, 
		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_CS_OFFSET(%[rseq_abi]))

		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), 4f)

		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_CPU_ID_OFFSET(%[rseq_offset]), 4f)

		RSEQ_INJECT_ASM(3)

		"movl %[expect], %%eax\n\t"

		"cmpl %[v], %%eax\n\t"

		"jnz %l[cmpfail]\n\t"

		RSEQ_INJECT_ASM(4)

#ifdef RSEQ_COMPARE_TWICE

		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), %l[error1])

		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), %l[error1])

		"movl %[expect], %%eax\n\t"

		"cmpl %[v], %%eax\n\t"

		"jnz %l[error2]\n\t"
@@ -1011,7 +1013,7 @@ int rseq_cmpeqv_trystorev_storev_release(intptr_t *v, intptr_t expect, 
		RSEQ_ASM_DEFINE_ABORT(4, "", abort)

		: /* gcc asm goto does not allow outputs */

		: [cpu_id]		"r" (cpu),

		  [rseq_abi]		"r" (rseq_get_abi()),

		  [rseq_offset]		"r" (rseq_offset),

		  /* try store input */

		  [v2]			"m" (*v2),

		  [newv2]		"r" (newv2),
@@ -1062,8 +1064,8 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect, 
		RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error3])

#endif

		/* Start rseq by storing table entry pointer into rseq_cs. */

		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_CS_OFFSET(%[rseq_abi]))

		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), 4f)

		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_CPU_ID_OFFSET(%[rseq_offset]), 4f)

		RSEQ_INJECT_ASM(3)

		"cmpl %[v], %[expect]\n\t"

		"jnz %l[cmpfail]\n\t"
@@ -1072,7 +1074,7 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect, 
		"jnz %l[cmpfail]\n\t"

		RSEQ_INJECT_ASM(5)

#ifdef RSEQ_COMPARE_TWICE

		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), %l[error1])

		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), %l[error1])

		"cmpl %[v], %[expect]\n\t"

		"jnz %l[error2]\n\t"

		"cmpl %[expect2], %[v2]\n\t"
@@ -1086,7 +1088,7 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect, 
		RSEQ_ASM_DEFINE_ABORT(4, "", abort)

		: /* gcc asm goto does not allow outputs */

		: [cpu_id]		"r" (cpu),

		  [rseq_abi]		"r" (rseq_get_abi()),

		  [rseq_offset]		"r" (rseq_offset),

		  /* cmp2 input */

		  [v2]			"m" (*v2),

		  [expect2]		"r" (expect2),
@@ -1144,15 +1146,15 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect, 
		"movl %[dst], %[rseq_scratch1]\n\t"

		"movl %[len], %[rseq_scratch2]\n\t"

		/* Start rseq by storing table entry pointer into rseq_cs. */

		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_CS_OFFSET(%[rseq_abi]))

		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), 4f)

		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_CPU_ID_OFFSET(%[rseq_offset]), 4f)

		RSEQ_INJECT_ASM(3)

		"movl %[expect], %%eax\n\t"

		"cmpl %%eax, %[v]\n\t"

		"jnz 5f\n\t"

		RSEQ_INJECT_ASM(4)

#ifdef RSEQ_COMPARE_TWICE

		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), 6f)

		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), 6f)

		"movl %[expect], %%eax\n\t"

		"cmpl %%eax, %[v]\n\t"

		"jnz 7f\n\t"
@@ -1202,7 +1204,7 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect, 
#endif

		: /* gcc asm goto does not allow outputs */

		: [cpu_id]		"r" (cpu),

		  [rseq_abi]		"r" (rseq_get_abi()),

		  [rseq_offset]		"r" (rseq_offset),

		  /* final store input */

		  [v]			"m" (*v),

		  [expect]		"m" (expect),
@@ -1261,15 +1263,15 @@ int rseq_cmpeqv_trymemcpy_storev_release(intptr_t *v, intptr_t expect, 
		"movl %[dst], %[rseq_scratch1]\n\t"

		"movl %[len], %[rseq_scratch2]\n\t"

		/* Start rseq by storing table entry pointer into rseq_cs. */

		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_CS_OFFSET(%[rseq_abi]))

		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), 4f)

		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_CPU_ID_OFFSET(%[rseq_offset]), 4f)

		RSEQ_INJECT_ASM(3)

		"movl %[expect], %%eax\n\t"

		"cmpl %%eax, %[v]\n\t"

		"jnz 5f\n\t"

		RSEQ_INJECT_ASM(4)

#ifdef RSEQ_COMPARE_TWICE

		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), 6f)

		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), 6f)

		"movl %[expect], %%eax\n\t"

		"cmpl %%eax, %[v]\n\t"

		"jnz 7f\n\t"
@@ -1320,7 +1322,7 @@ int rseq_cmpeqv_trymemcpy_storev_release(intptr_t *v, intptr_t expect, 
#endif

		: /* gcc asm goto does not allow outputs */

		: [cpu_id]		"r" (cpu),

		  [rseq_abi]		"r" (rseq_get_abi()),

		  [rseq_offset]		"r" (rseq_offset),

		  /* final store input */

		  [v]			"m" (*v),

		  [expect]		"m" (expect),