From f17d9474776e50ae47aa71c52211ea6e21adf5d5 Mon Sep 17 00:00:00 2001 From: Yao Qi Date: Fri, 8 Dec 2017 17:27:03 +0000 Subject: Clear non-significant bits of address in watchpoint Nowadays, GDB can't set watchpoint on tagged address on AArch64, (gdb) p p2 $1 = (int *) 0xf000fffffffff474 (gdb) watch *((int *) 0xf000fffffffff474) Hardware watchpoint 2: *((int *) 0xf000fffffffff474) (gdb) c Continuing. main () at binutils-gdb/gdb/testsuite/gdb.arch/aarch64-tagged-pointer.c:45 45 void (*func_ptr) (void) = foo; Unexpected error setting hardware debug registers This patch is about setting watchpoint on a tagged address. Unlike breakpoint, watchpoint record the expression rather than the address, and when a watchpoint is fired, GDB checks the expression value changed instead of matching address, so we can mask the watchpoint address by getting rid of non-significant bits of address. gdb: 2017-12-08 Yao Qi * breakpoint.c (update_watchpoint): Call address_significant. gdb/testsuite: 2017-12-08 Yao Qi * gdb.arch/aarch64-tagged-pointer.c (main): Update. * gdb.arch/aarch64-tagged-pointer.exp: Add tests for watchpoint. --- gdb/testsuite/gdb.arch/aarch64-tagged-pointer.c | 1 + gdb/testsuite/gdb.arch/aarch64-tagged-pointer.exp | 14 ++++++++++++++ 2 files changed, 15 insertions(+) (limited to 'gdb/testsuite/gdb.arch') diff --git a/gdb/testsuite/gdb.arch/aarch64-tagged-pointer.c b/gdb/testsuite/gdb.arch/aarch64-tagged-pointer.c index 9bfe41e..5754785 100644 --- a/gdb/testsuite/gdb.arch/aarch64-tagged-pointer.c +++ b/gdb/testsuite/gdb.arch/aarch64-tagged-pointer.c @@ -53,4 +53,5 @@ main (void) } sp1->i = 8765; + i = 1; } diff --git a/gdb/testsuite/gdb.arch/aarch64-tagged-pointer.exp b/gdb/testsuite/gdb.arch/aarch64-tagged-pointer.exp index fcab1b7..c08993e 100644 --- a/gdb/testsuite/gdb.arch/aarch64-tagged-pointer.exp +++ b/gdb/testsuite/gdb.arch/aarch64-tagged-pointer.exp @@ -89,3 +89,17 @@ foreach_with_prefix bptype {"hbreak" "break"} { gdb_test "up" "\\(\*func_ptr\\) \\(\\).*" "caller is *func_ptr" delete_breakpoints } + +gdb_test "down" +gdb_test "finish" +# Watch on tagged pointer. +gdb_test "watch *sp2" +gdb_test "continue" \ + "Continuing\\..*Hardware watchpoint \[0-9\]+.*" \ + "run until watchpoint on s1" +delete_breakpoints + +gdb_test "watch *p2" +gdb_test "continue" \ + "Continuing\\..*Hardware watchpoint \[0-9\]+.*" \ + "run until watchpoint on i" -- cgit v1.1