+/* Attempt to allocate memory for trampolines in the first 64 KiB of
+ memory to enable smaller jump patches. */
+
+static void
+initialize_fast_tracepoint_trampoline_buffer (void)
+{
+ const CORE_ADDR buffer_end = 64 * 1024;
+ /* Ensure that the buffer will be at least 1 KiB in size, which is
+ enough space for over 200 fast tracepoints. */
+ const int min_buffer_size = 1024;
+ char buf[IPA_BUFSIZ];
+ CORE_ADDR mmap_min_addr = buffer_end + 1;
+ ULONGEST buffer_size;
+ FILE *f = fopen ("/proc/sys/vm/mmap_min_addr", "r");
+
+ if (!f)
+ {
+ snprintf (buf, sizeof (buf), "mmap_min_addr open failed: %s",
+ strerror (errno));
+ set_trampoline_buffer_space (0, 0, buf);
+ return;
+ }
+
+ if (fgets (buf, IPA_BUFSIZ, f))
+ sscanf (buf, "%llu", &mmap_min_addr);
+
+ fclose (f);
+
+ buffer_size = buffer_end - mmap_min_addr;
+
+ if (buffer_size >= min_buffer_size)
+ {
+ if (mmap ((void *) (uintptr_t) mmap_min_addr, buffer_size,
+ PROT_READ | PROT_EXEC | PROT_WRITE,
+ MAP_FIXED | MAP_PRIVATE | MAP_ANONYMOUS,
+ -1, 0)
+ != MAP_FAILED)
+ set_trampoline_buffer_space (mmap_min_addr, buffer_end, NULL);
+ else
+ {
+ snprintf (buf, IPA_BUFSIZ, "low-64K-buffer mmap() failed: %s",
+ strerror (errno));
+ set_trampoline_buffer_space (0, 0, buf);
+ }
+ }
+ else
+ {
+ snprintf (buf, IPA_BUFSIZ, "mmap_min_addr is %d, must be %d or less",
+ (int) mmap_min_addr, (int) buffer_end - min_buffer_size);
+ set_trampoline_buffer_space (0, 0, buf);
+ }
+}
+
+/* Return target_desc to use for IPA, given the tdesc index passed by
+ gdbserver. */
+
+const struct target_desc *
+get_ipa_tdesc (int idx)
+{
+ switch (idx)
+ {
+ case X86_TDESC_MMX:
+ return tdesc_i386_mmx_linux;
+ case X86_TDESC_SSE:
+ return tdesc_i386_linux;
+ case X86_TDESC_AVX:
+ return tdesc_i386_avx_linux;
+ case X86_TDESC_MPX:
+ return tdesc_i386_mpx_linux;
+ case X86_TDESC_AVX_MPX:
+ return tdesc_i386_avx_mpx_linux;
+ case X86_TDESC_AVX512:
+ return tdesc_i386_avx512_linux;
+ default:
+ internal_error (__FILE__, __LINE__,
+ "unknown ipa tdesc index: %d", idx);
+ return tdesc_i386_linux;
+ }
+}
+
+/* Allocate buffer for the jump pads. On i386, we can reach an arbitrary
+ address with a jump instruction, so just allocate normally. */
+
+void *
+alloc_jump_pad_buffer (size_t size)
+{
+ void *res = mmap (NULL, size, PROT_READ | PROT_WRITE | PROT_EXEC,
+ MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+
+ if (res == MAP_FAILED)
+ return NULL;
+
+ return res;
+}
+