From f17d9474776e50ae47aa71c52211ea6e21adf5d5 Mon Sep 17 00:00:00 2001 From: Yao Qi Date: Fri, 8 Dec 2017 17:27:03 +0000 Subject: [PATCH] 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/ChangeLog | 5 +++++ gdb/breakpoint.c | 2 +- gdb/testsuite/ChangeLog | 5 +++++ gdb/testsuite/gdb.arch/aarch64-tagged-pointer.c | 1 + gdb/testsuite/gdb.arch/aarch64-tagged-pointer.exp | 14 ++++++++++++++ 5 files changed, 26 insertions(+), 1 deletion(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 134f7b4c6de..7d061c807cb 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,8 @@ +2017-12-08 Yao Qi + + * breakpoint.c (update_watchpoint): Call + address_significant. + 2017-12-08 Yao Qi * breakpoint.c (adjust_breakpoint_address): Call diff --git a/gdb/breakpoint.c b/gdb/breakpoint.c index 1cee730cc6f..b68718d2505 100644 --- a/gdb/breakpoint.c +++ b/gdb/breakpoint.c @@ -1864,7 +1864,7 @@ update_watchpoint (struct watchpoint *b, int reparse) loc->gdbarch = get_type_arch (value_type (v)); loc->pspace = frame_pspace; - loc->address = addr; + loc->address = address_significant (loc->gdbarch, addr); if (bitsize != 0) { diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog index 17fbe4f939f..53a2ca4727f 100644 --- a/gdb/testsuite/ChangeLog +++ b/gdb/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2017-12-08 Yao Qi + + * gdb.arch/aarch64-tagged-pointer.c (main): Update. + * gdb.arch/aarch64-tagged-pointer.exp: Add tests for watchpoint. + 2017-12-08 Yao Qi * gdb.arch/aarch64-tagged-pointer.c (main): Update. diff --git a/gdb/testsuite/gdb.arch/aarch64-tagged-pointer.c b/gdb/testsuite/gdb.arch/aarch64-tagged-pointer.c index 9bfe41e1298..5754785f3c0 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 fcab1b76d94..c08993ea8d5 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" -- 2.30.2