x86-64: use %fs segment selector for accessing rseq thread area

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 %fs segment selector, the constant offset
of the field in struct rseq, and the rseq_offset value (in a register).

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: Ia0c93d32b9b36ee1ef6a737a8a5321498fc8c3bc

diff --git a/include/rseq/rseq-x86.h b/include/rseq/rseq-x86.h
index 0bd472d5edee6d3c6fdade486901fd127715479d..d39f9c03cfec8ec5c3d4092060f63bb324c8dbb8 100644 (file)
--- a/include/rseq/rseq-x86.h
+++ b/include/rseq/rseq-x86.h
@@ -29,6 +29,8 @@
 
 #ifdef __x86_64__
 
+#define RSEQ_ASM_TP_SEGMENT    %%fs
+
 #define rseq_smp_mb()  \
        __asm__ __volatile__ ("lock; addl $0,-128(%%rsp)" ::: "memory", "cc")
 #define rseq_smp_rmb() rseq_barrier()
@@ -124,14 +126,14 @@ 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)
                "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_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])
                "cmpq %[v], %[expect]\n\t"
                "jnz %l[error2]\n\t"
 #endif
@@ -142,7 +144,7 @@ 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" ((long)rseq_offset),
                  [v]                   "m" (*v),
                  [expect]              "r" (expect),
                  [newv]                "r" (newv)
@@ -190,15 +192,15 @@ 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)
                "movq %[v], %%rbx\n\t"
                "cmpq %%rbx, %[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])
                "movq %[v], %%rbx\n\t"
                "cmpq %%rbx, %[expectnot]\n\t"
                "je %l[error2]\n\t"
@@ -213,7 +215,7 @@ 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" ((long)rseq_offset),
                  /* final store input */
                  [v]                   "m" (*v),
                  [expectnot]           "r" (expectnot),
@@ -256,11 +258,11 @@ 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 */
                "addq %[count], %[v]\n\t"
@@ -269,7 +271,7 @@ 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" ((long)rseq_offset),
                  /* final store input */
                  [v]                   "m" (*v),
                  [count]               "er" (count)
@@ -310,11 +312,11 @@ int rseq_offset_deref_addv(intptr_t *ptr, long off, intptr_t inc, 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
                /* get p+v */
                "movq %[ptr], %%rbx\n\t"
@@ -328,7 +330,7 @@ int rseq_offset_deref_addv(intptr_t *ptr, long off, intptr_t inc, 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" ((long)rseq_offset),
                  /* final store input */
                  [ptr]                 "m" (*ptr),
                  [off]                 "er" (off),
@@ -368,14 +370,14 @@ 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)
                "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_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])
                "cmpq %[v], %[expect]\n\t"
                "jnz %l[error2]\n\t"
 #endif
@@ -389,7 +391,7 @@ 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" ((long)rseq_offset),
                  /* try store input */
                  [v2]                  "m" (*v2),
                  [newv2]               "r" (newv2),
@@ -448,8 +450,8 @@ 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)
                "cmpq %[v], %[expect]\n\t"
                "jnz %l[cmpfail]\n\t"
@@ -458,7 +460,7 @@ 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])
                "cmpq %[v], %[expect]\n\t"
                "jnz %l[error2]\n\t"
                "cmpq %[v2], %[expect2]\n\t"
@@ -471,7 +473,7 @@ 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" ((long)rseq_offset),
                  /* cmp2 input */
                  [v2]                  "m" (*v2),
                  [expect2]             "r" (expect2),
@@ -528,14 +530,14 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect,
                "movq %[dst], %[rseq_scratch1]\n\t"
                "movq %[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)
                "cmpq %[v], %[expect]\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)
                "cmpq %[v], %[expect]\n\t"
                "jnz 7f\n\t"
 #endif
@@ -583,7 +585,7 @@ 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" ((long)rseq_offset),
                  /* final store input */
                  [v]                   "m" (*v),
                  [expect]              "r" (expect),
@@ -646,13 +648,13 @@ int rseq_deref_loadoffp(intptr_t *p, long voffp, intptr_t *load, 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)
                "movq %[p], %%rbx\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])
 #endif
                "addq %[voffp], %%rbx\n\t"
                "movq (%%rbx), %%rbx\n\t"
@@ -662,7 +664,7 @@ int rseq_deref_loadoffp(intptr_t *p, long voffp, intptr_t *load, 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" ((long)rseq_offset),
                  /* final store input */
                  [p]                   "m" (*p),
                  [voffp]               "er" (voffp),