[Lldb-commits] [lldb] Return high address masks correctly in Process (PR #78379)

[Jason Molenda via lldb-commits]

https://github.com/jasonmolenda created https://github.com/llvm/llvm-project/pull/78379

In https://reviews.llvm.org/D151292 I added the ability to track address masks separately for high and low memory addresses, a capability of AArch64.  I did my testing with manual address mask settings (via target.process.highmem-virtual-addressable-bits) but didn't have a real corefile that included this metadata and required it.

My intention is that when the high address mask isn't specified, by the user (via the setting) or the Process plugin, we fall back to using the low address mask.  The low and high address mask is the same for almost all environments.

But the patch I wrote never uses the Process plugin high address mask if it was set, e.g. from corefile metadata.  This patch corrects that.

I also have an old patch in Phabractor that was approved to add FixAddress methods to SBProcess; I need to pick that patch up and finish it (I wanted to add an enum to specify which mask is being requested iirc), so I can do address masks tests in API tests.

rdar://120926000

>From 6b33e1e288e2c2b0094a7ac783ac7847b491dc91 Mon Sep 17 00:00:00 2001
From: Jason Molenda <jmolenda at apple.com>
Date: Tue, 16 Jan 2024 17:53:11 -0800
Subject: [PATCH] Return high address masks correctly in Process

In https://reviews.llvm.org/D151292 I added the ability to
track address masks separately for high and low memory addresses,
a capability of AArch64.  I did my testing with manual address
mask settings (via target.process.highmem-virtual-addressable-bits)
but didn't have a real corefile that included this metadata and
required it.

My intention is that when the high address mask isn't specified,
by the user (via the setting) or the Process plugin, we fall back
to using the low address mask.  The low and high address mask is
the same for almost all environments.

But the patch I wrote never uses the Process plugin high address
mask if it was set, e.g. from corefile metadata.  This patch
corrects that.

I also have an old patch in Phabractor that was approved to add
FixAddress methods to SBProcess; I need to pick that patch up
and finish it (I wanted to add an enum to specify which mask
is being requested iirc), so I can do address masks tests in
API tests.

rdar://120926000
---
 lldb/source/Target/Process.cpp | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/lldb/source/Target/Process.cpp b/lldb/source/Target/Process.cpp
index aa3b04c43cc5cd..8158bf61258378 100644
--- a/lldb/source/Target/Process.cpp
+++ b/lldb/source/Target/Process.cpp
@@ -5694,12 +5694,16 @@ lldb::addr_t Process::GetDataAddressMask() {
 lldb::addr_t Process::GetHighmemCodeAddressMask() {
   if (uint32_t num_bits_setting = GetHighmemVirtualAddressableBits())
     return ~((1ULL << num_bits_setting) - 1);
+  if (m_highmem_code_address_mask)
+    return m_highmem_code_address_mask;
   return GetCodeAddressMask();
 }
 
 lldb::addr_t Process::GetHighmemDataAddressMask() {
   if (uint32_t num_bits_setting = GetHighmemVirtualAddressableBits())
     return ~((1ULL << num_bits_setting) - 1);
+  if (m_highmem_data_address_mask)
+    return m_highmem_data_address_mask;
   return GetDataAddressMask();
 }