From 5969f0dba74e17c694faf333b120f1e0b95783ed Mon Sep 17 00:00:00 2001 From: Omair Javaid Date: Sat, 26 May 2018 05:58:51 +0500 Subject: Unset gdbarch significant_addr_bit by default 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 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. --- gdb/utils.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'gdb/utils.c') diff --git a/gdb/utils.c b/gdb/utils.c index a2e933b..fe9a674 100644 --- a/gdb/utils.c +++ b/gdb/utils.c @@ -2708,10 +2708,11 @@ address_significant (gdbarch *gdbarch, CORE_ADDR addr) /* 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; -- cgit v1.1