Fix build with latest GCC 9.0 tree

A recent patch [1] to fix a GCC PR [2] actually broke the GDB build.
To fix, remove the stack pointer clobber. GCC will ignore the clobber
marker, and will not save or restore the stack pointer.

I ran "make check-gdb" on x86_64 to ensure there are no regressions.

gdb/ChangeLog:

2018-12-17  Dimitar Dimitrov  <dimitar@dinux.eu>

	* nat/linux-ptrace.c (linux_ptrace_test_ret_to_nx): Remove sp clobbers.

[1] https://gcc.gnu.org/ml/gcc-patches/2018-12/msg00532.html
[2] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=52813

Signed-off-by: Dimitar Dimitrov <dimitar@dinux.eu>

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 08c7c6c..4283cbb 100644 (file)
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,8 @@
+2018-12-19  Dimitar Dimitrov  <dimitar@dinux.eu>
+
+       * nat/linux-ptrace.c (linux_ptrace_test_ret_to_nx): Remove
+       sp clobbers.
+
 2018-12-17  Andrew Burgess  <andrew.burgess@embecosm.com>
 
        * dwarf2read.c (struct dwarf2_cu): Convert the fields 'mark',

diff --git a/gdb/nat/linux-ptrace.c b/gdb/nat/linux-ptrace.c
index d4c1b8f..187cfeb 100644 (file)
--- a/gdb/nat/linux-ptrace.c
+++ b/gdb/nat/linux-ptrace.c
@@ -161,14 +161,14 @@ linux_ptrace_test_ret_to_nx (void)
                        ".globl linux_ptrace_test_ret_to_nx_instr;"
                        "linux_ptrace_test_ret_to_nx_instr:"
                        "ret"
-                       : : "r" (return_address) : "%esp", "memory");
+                       : : "r" (return_address) : "memory");
 #elif defined __x86_64__
          asm volatile ("pushq %0;"
                        ".globl linux_ptrace_test_ret_to_nx_instr;"
                        "linux_ptrace_test_ret_to_nx_instr:"
                        "ret"
                        : : "r" ((uint64_t) (uintptr_t) return_address)
-                       : "%rsp", "memory");
+                       : "memory");
 #else
 # error "!__i386__ && !__x86_64__"
 #endif