X-Git-Url: http://drtracing.org/?a=blobdiff_plain;f=gdb%2Fgdbserver%2Flinux-aarch64-ipa.c;h=50caeae4f3f46d58daffaed948d32757f1802832;hb=a13c46966d308297a1273e35ccc807a3912d573d;hp=00cbf3ee89d3bedc9961077aa039714d961ba687;hpb=0a191de98469e84783025cbee88c86e51f072d78;p=deliverable%2Fbinutils-gdb.git
diff --git a/gdb/gdbserver/linux-aarch64-ipa.c b/gdb/gdbserver/linux-aarch64-ipa.c
index 00cbf3ee89..50caeae4f3 100644
--- a/gdb/gdbserver/linux-aarch64-ipa.c
+++ b/gdb/gdbserver/linux-aarch64-ipa.c
@@ -19,7 +19,11 @@
along with this program. If not, see . */
#include "server.h"
+#include
#include "tracepoint.h"
+#ifdef HAVE_GETAUXVAL
+#include
+#endif
/* Defined in auto-generated file aarch64.c. */
void init_registers_aarch64 (void);
@@ -153,6 +157,52 @@ get_ipa_tdesc (int idx)
return tdesc_aarch64;
}
+/* Allocate buffer for the jump pads. The branch instruction has a reach
+ of +/- 128MiB, and the executable is loaded at 0x400000 (4MiB).
+ To maximize the area of executable that can use tracepoints, try
+ allocating at 0x400000 - size initially, decreasing until we hit
+ a free area. */
+
+void *
+alloc_jump_pad_buffer (size_t size)
+{
+ uintptr_t addr;
+ uintptr_t exec_base = getauxval (AT_PHDR);
+ int pagesize;
+ void *res;
+
+ if (exec_base == 0)
+ exec_base = 0x400000;
+
+ pagesize = sysconf (_SC_PAGE_SIZE);
+ if (pagesize == -1)
+ perror_with_name ("sysconf");
+
+ addr = exec_base - size;
+
+ /* size should already be page-aligned, but this can't hurt. */
+ addr &= ~(pagesize - 1);
+
+ /* Search for a free area. If we hit 0, we're out of luck. */
+ for (; addr; addr -= pagesize)
+ {
+ /* No MAP_FIXED - we don't want to zap someone's mapping. */
+ res = mmap ((void *) addr, size,
+ PROT_READ | PROT_WRITE | PROT_EXEC,
+ MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+
+ /* If we got what we wanted, return. */
+ if ((uintptr_t) res == addr)
+ return res;
+
+ /* If we got a mapping, but at a wrong address, undo it. */
+ if (res != MAP_FAILED)
+ munmap (res, size);
+ }
+
+ return NULL;
+}
+
void
initialize_low_tracepoint (void)
{