This patch fixes a bug introduced by fix to AArch64 pointer tagging.
In our fix for tagged pointer support our agreed approach was to sign
extend user-space address after clearing tag bits. This is not same
for all architectures and this patch allows sign extension for
addresses on targets which specifically set significant_addr_bit.
More information about patch that caused the issues and discussion
around tagged pointer support can be found in links below:
https://sourceware.org/ml/gdb-patches/2018-05/msg00000.html
https://sourceware.org/ml/gdb-patches/2017-12/msg00159.html
gdb/ChangeLog:
2018-05-31 Omair Javaid <omair.javaid@linaro.org>
PR gdb/23210
* gdbarch.sh (significant_addr_bit): Default to zero when
not set by target architecture.
* gdbarch.c: Re-generated.
* utils.c (address_significant): Update.
+2018-05-31 Omair Javaid <omair.javaid@linaro.org>
+
+ PR gdb/23210
+ * gdbarch.sh (significant_addr_bit): Default to zero when
+ not set by target architecture.
+ * gdbarch.c: Re-generated.
+ * utils.c (address_significant): Update.
+
2018-05-30 Joel Brobecker <brobecker@adacore.com>
* stack.c (func_command): Remove trailing newline in call to error.
/* Skip verify of stabs_argument_has_addr, invalid_p == 0 */
/* Skip verify of convert_from_func_ptr_addr, invalid_p == 0 */
/* Skip verify of addr_bits_remove, invalid_p == 0 */
- if (gdbarch->significant_addr_bit == 0)
- gdbarch->significant_addr_bit = gdbarch_addr_bit (gdbarch);
+ /* Skip verify of significant_addr_bit, invalid_p == 0 */
/* Skip verify of software_single_step, has predicate. */
/* Skip verify of single_step_through_delay, has predicate. */
/* Skip verify of print_insn, invalid_p == 0 */
gdbarch_significant_addr_bit (struct gdbarch *gdbarch)
{
gdb_assert (gdbarch != NULL);
+ /* Skip verify of significant_addr_bit, invalid_p == 0 */
if (gdbarch_debug >= 2)
fprintf_unfiltered (gdb_stdlog, "gdbarch_significant_addr_bit called\n");
return gdbarch->significant_addr_bit;
# For example, on AArch64, the top bits of an address known as the "tag"
# are ignored by the kernel, the hardware, etc. and can be regarded as
# additional data associated with the address.
-v;int;significant_addr_bit;;;;;gdbarch_addr_bit (gdbarch);
+v;int;significant_addr_bit;;;;;;0
# FIXME/cagney/2001-01-18: This should be split in two. A target method that
# indicates if the target needs software single step. An ISA method to
/* Clear insignificant bits of a target address and sign extend resulting
address, avoiding shifts larger or equal than the width of a CORE_ADDR.
The local variable ADDR_BIT stops the compiler reporting a shift overflow
- when it won't occur. */
+ when it won't occur. Skip updating of target address if current target
+ has not set gdbarch significant_addr_bit. */
int addr_bit = gdbarch_significant_addr_bit (gdbarch);
- if (addr_bit < (sizeof (CORE_ADDR) * HOST_CHAR_BIT))
+ if (addr_bit && (addr_bit < (sizeof (CORE_ADDR) * HOST_CHAR_BIT)))
{
CORE_ADDR sign = (CORE_ADDR) 1 << (addr_bit - 1);
addr &= ((CORE_ADDR) 1 << addr_bit) - 1;