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authorOmair Javaid <omair.javaid@linaro.org>2018-05-26 05:58:51 +0500
committerOmair Javaid <omair.javaid@linaro.org>2018-05-31 07:31:21 +0500
commit5969f0dba74e17c694faf333b120f1e0b95783ed (patch)
tree5b1969d7d5c41099b6e0ec201fbad028b264b4f3 /gdb/utils.c
parent0034eed03a7428c4902244a33a286763bca65016 (diff)
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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 <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.
Diffstat (limited to 'gdb/utils.c')
-rw-r--r--gdb/utils.c5
1 files changed, 3 insertions, 2 deletions
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;