[Lldb-commits] [lldb] 8901f8b - AArch64 SVE restore SVE registers after expression
Muhammad Omair Javaid via lldb-commits
lldb-commits at lists.llvm.org
Thu Sep 9 04:07:09 PDT 2021
Author: Muhammad Omair Javaid
Date: 2021-09-09T16:06:48+05:00
New Revision: 8901f8beea3a70f92be8c0b80313260502f03727
URL: https://github.com/llvm/llvm-project/commit/8901f8beea3a70f92be8c0b80313260502f03727
DIFF: https://github.com/llvm/llvm-project/commit/8901f8beea3a70f92be8c0b80313260502f03727.diff
LOG: AArch64 SVE restore SVE registers after expression
This patch fixes register save/restore on expression call to also include SVE registers.
This will fix expression calls like:
re re p1
<Register Value P1 before expression>
p <var-name or function call>
re re p1
<Register Value P1 after expression>
In above example register P1 should remain the same before and after the expression evaluation.
Reviewed By: DavidSpickett
Differential Revision: https://reviews.llvm.org/D108739
Added:
Modified:
lldb/source/Plugins/Process/Linux/NativeRegisterContextLinux_arm64.cpp
lldb/source/Plugins/Process/Linux/NativeRegisterContextLinux_arm64.h
lldb/source/Plugins/Process/Utility/RegisterInfoPOSIX_arm64.h
lldb/test/API/commands/register/register/aarch64_sve_registers/rw_access_static_config/TestSVERegisters.py
lldb/test/API/commands/register/register/aarch64_sve_registers/rw_access_static_config/main.c
Removed:
################################################################################
diff --git a/lldb/source/Plugins/Process/Linux/NativeRegisterContextLinux_arm64.cpp b/lldb/source/Plugins/Process/Linux/NativeRegisterContextLinux_arm64.cpp
index ebde0a499acf7..f28bddcb9a99b 100644
--- a/lldb/source/Plugins/Process/Linux/NativeRegisterContextLinux_arm64.cpp
+++ b/lldb/source/Plugins/Process/Linux/NativeRegisterContextLinux_arm64.cpp
@@ -46,8 +46,6 @@
#define HWCAP_PACA (1 << 30)
#define HWCAP2_MTE (1 << 18)
-#define REG_CONTEXT_SIZE (GetGPRSize() + GetFPRSize())
-
using namespace lldb;
using namespace lldb_private;
using namespace lldb_private::process_linux;
@@ -452,30 +450,73 @@ Status NativeRegisterContextLinux_arm64::WriteRegister(
Status NativeRegisterContextLinux_arm64::ReadAllRegisterValues(
lldb::DataBufferSP &data_sp) {
- Status error;
+ // AArch64 register data must contain GPRs, either FPR or SVE registers
+ // and optional MTE register. Pointer Authentication (PAC) registers are
+ // read-only and will be skiped.
- data_sp.reset(new DataBufferHeap(REG_CONTEXT_SIZE, 0));
+ // In order to create register data checkpoint we first read all register
+ // values if not done already and calculate total size of register set data.
+ // We store all register values in data_sp by copying full PTrace data that
+ // corresponds to register sets enabled by current register context.
+ Status error;
+ uint32_t reg_data_byte_size = GetGPRBufferSize();
error = ReadGPR();
if (error.Fail())
return error;
- error = ReadFPR();
+ // If SVE is enabled we need not copy FPR separately.
+ if (GetRegisterInfo().IsSVEEnabled()) {
+ reg_data_byte_size += GetSVEBufferSize();
+ error = ReadAllSVE();
+ } else {
+ reg_data_byte_size += GetFPRSize();
+ error = ReadFPR();
+ }
if (error.Fail())
return error;
+ if (GetRegisterInfo().IsMTEEnabled()) {
+ reg_data_byte_size += GetMTEControlSize();
+ error = ReadMTEControl();
+ if (error.Fail())
+ return error;
+ }
+
+ data_sp.reset(new DataBufferHeap(reg_data_byte_size, 0));
uint8_t *dst = data_sp->GetBytes();
- ::memcpy(dst, GetGPRBuffer(), GetGPRSize());
- dst += GetGPRSize();
- ::memcpy(dst, GetFPRBuffer(), GetFPRSize());
+
+ ::memcpy(dst, GetGPRBuffer(), GetGPRBufferSize());
+ dst += GetGPRBufferSize();
+
+ if (GetRegisterInfo().IsSVEEnabled()) {
+ ::memcpy(dst, GetSVEBuffer(), GetSVEBufferSize());
+ dst += GetSVEBufferSize();
+ } else {
+ ::memcpy(dst, GetFPRBuffer(), GetFPRSize());
+ dst += GetFPRSize();
+ }
+
+ if (GetRegisterInfo().IsMTEEnabled())
+ ::memcpy(dst, GetMTEControl(), GetMTEControlSize());
return error;
}
Status NativeRegisterContextLinux_arm64::WriteAllRegisterValues(
const lldb::DataBufferSP &data_sp) {
- Status error;
+ // AArch64 register data must contain GPRs, either FPR or SVE registers
+ // and optional MTE register. Pointer Authentication (PAC) registers are
+ // read-only and will be skiped.
+
+ // We store all register values in data_sp by copying full PTrace data that
+ // corresponds to register sets enabled by current register context. In order
+ // to restore from register data checkpoint we will first restore GPRs, based
+ // on size of remaining register data either SVE or FPRs should be restored
+ // next. SVE is not enabled if we have register data size less than or equal
+ // to size of GPR + FPR + MTE.
+ Status error;
if (!data_sp) {
error.SetErrorStringWithFormat(
"NativeRegisterContextLinux_arm64::%s invalid data_sp provided",
@@ -483,14 +524,6 @@ Status NativeRegisterContextLinux_arm64::WriteAllRegisterValues(
return error;
}
- if (data_sp->GetByteSize() != REG_CONTEXT_SIZE) {
- error.SetErrorStringWithFormat(
- "NativeRegisterContextLinux_arm64::%s data_sp contained mismatched "
- "data size, expected %" PRIu64 ", actual %" PRIu64,
- __FUNCTION__, REG_CONTEXT_SIZE, data_sp->GetByteSize());
- return error;
- }
-
uint8_t *src = data_sp->GetBytes();
if (src == nullptr) {
error.SetErrorStringWithFormat("NativeRegisterContextLinux_arm64::%s "
@@ -499,19 +532,79 @@ Status NativeRegisterContextLinux_arm64::WriteAllRegisterValues(
__FUNCTION__);
return error;
}
- ::memcpy(GetGPRBuffer(), src, GetRegisterInfoInterface().GetGPRSize());
+
+ uint64_t reg_data_min_size = GetGPRBufferSize() + GetFPRSize();
+ if (data_sp->GetByteSize() < reg_data_min_size) {
+ error.SetErrorStringWithFormat(
+ "NativeRegisterContextLinux_arm64::%s data_sp contained insufficient "
+ "register data bytes, expected at least %" PRIu64 ", actual %" PRIu64,
+ __FUNCTION__, reg_data_min_size, data_sp->GetByteSize());
+ return error;
+ }
+
+ // Register data starts with GPRs
+ ::memcpy(GetGPRBuffer(), src, GetGPRBufferSize());
+ m_gpr_is_valid = true;
error = WriteGPR();
if (error.Fail())
return error;
- src += GetRegisterInfoInterface().GetGPRSize();
- ::memcpy(GetFPRBuffer(), src, GetFPRSize());
+ src += GetGPRBufferSize();
+
+ // Verify if register data may contain SVE register values.
+ bool contains_sve_reg_data =
+ (data_sp->GetByteSize() > (reg_data_min_size + GetSVEHeaderSize()));
+
+ if (contains_sve_reg_data) {
+ // We have SVE register data first write SVE header.
+ ::memcpy(GetSVEHeader(), src, GetSVEHeaderSize());
+ if (!sve_vl_valid(m_sve_header.vl)) {
+ m_sve_header_is_valid = false;
+ error.SetErrorStringWithFormat("NativeRegisterContextLinux_arm64::%s "
+ "Invalid SVE header in data_sp",
+ __FUNCTION__);
+ return error;
+ }
+ m_sve_header_is_valid = true;
+ error = WriteSVEHeader();
+ if (error.Fail())
+ return error;
+
+ // SVE header has been written configure SVE vector length if needed.
+ ConfigureRegisterContext();
+
+ // Make sure data_sp contains sufficient data to write all SVE registers.
+ reg_data_min_size = GetGPRBufferSize() + GetSVEBufferSize();
+ if (data_sp->GetByteSize() < reg_data_min_size) {
+ error.SetErrorStringWithFormat(
+ "NativeRegisterContextLinux_arm64::%s data_sp contained insufficient "
+ "register data bytes, expected %" PRIu64 ", actual %" PRIu64,
+ __FUNCTION__, reg_data_min_size, data_sp->GetByteSize());
+ return error;
+ }
+
+ ::memcpy(GetSVEBuffer(), src, GetSVEBufferSize());
+ m_sve_buffer_is_valid = true;
+ error = WriteAllSVE();
+ src += GetSVEBufferSize();
+ } else {
+ ::memcpy(GetFPRBuffer(), src, GetFPRSize());
+ m_fpu_is_valid = true;
+ error = WriteFPR();
+ src += GetFPRSize();
+ }
- error = WriteFPR();
if (error.Fail())
return error;
+ if (GetRegisterInfo().IsMTEEnabled() &&
+ data_sp->GetByteSize() > reg_data_min_size) {
+ ::memcpy(GetMTEControl(), src, GetMTEControlSize());
+ m_mte_ctrl_is_valid = true;
+ error = WriteMTEControl();
+ }
+
return error;
}
@@ -864,13 +957,6 @@ uint32_t NativeRegisterContextLinux_arm64::CalculateSVEOffset(
return sve_reg_offset;
}
-void *NativeRegisterContextLinux_arm64::GetSVEBuffer() {
- if (m_sve_state == SVEState::FPSIMD)
- return m_sve_ptrace_payload.data() + sve::ptrace_fpsimd_offset;
-
- return m_sve_ptrace_payload.data();
-}
-
std::vector<uint32_t> NativeRegisterContextLinux_arm64::GetExpeditedRegisters(
ExpeditedRegs expType) const {
std::vector<uint32_t> expedited_reg_nums =
diff --git a/lldb/source/Plugins/Process/Linux/NativeRegisterContextLinux_arm64.h b/lldb/source/Plugins/Process/Linux/NativeRegisterContextLinux_arm64.h
index 4dfc78b5b2827..2f8a4a601181e 100644
--- a/lldb/source/Plugins/Process/Linux/NativeRegisterContextLinux_arm64.h
+++ b/lldb/source/Plugins/Process/Linux/NativeRegisterContextLinux_arm64.h
@@ -139,7 +139,7 @@ class NativeRegisterContextLinux_arm64
void *GetMTEControl() { return &m_mte_ctrl_reg; }
- void *GetSVEBuffer();
+ void *GetSVEBuffer() { return m_sve_ptrace_payload.data(); };
size_t GetSVEHeaderSize() { return sizeof(m_sve_header); }
diff --git a/lldb/source/Plugins/Process/Utility/RegisterInfoPOSIX_arm64.h b/lldb/source/Plugins/Process/Utility/RegisterInfoPOSIX_arm64.h
index ba873ba4436ba..96cab49d5ac85 100644
--- a/lldb/source/Plugins/Process/Utility/RegisterInfoPOSIX_arm64.h
+++ b/lldb/source/Plugins/Process/Utility/RegisterInfoPOSIX_arm64.h
@@ -110,6 +110,7 @@ class RegisterInfoPOSIX_arm64
bool IsSVEEnabled() const { return m_opt_regsets.AnySet(eRegsetMaskSVE); }
bool IsPAuthEnabled() const { return m_opt_regsets.AnySet(eRegsetMaskPAuth); }
+ bool IsMTEEnabled() const { return m_opt_regsets.AnySet(eRegsetMaskMTE); }
bool IsSVEReg(unsigned reg) const;
bool IsSVEZReg(unsigned reg) const;
diff --git a/lldb/test/API/commands/register/register/aarch64_sve_registers/rw_access_static_config/TestSVERegisters.py b/lldb/test/API/commands/register/register/aarch64_sve_registers/rw_access_static_config/TestSVERegisters.py
index b243a6692d852..dd2277b922739 100644
--- a/lldb/test/API/commands/register/register/aarch64_sve_registers/rw_access_static_config/TestSVERegisters.py
+++ b/lldb/test/API/commands/register/register/aarch64_sve_registers/rw_access_static_config/TestSVERegisters.py
@@ -17,6 +17,51 @@ def check_sve_register_size(self, set, name, expected):
self.assertEqual(reg_value.GetByteSize(), expected,
'Verify "%s" == %i' % (name, expected))
+ def check_sve_regs_read(self, z_reg_size):
+ p_reg_size = int(z_reg_size / 8)
+
+ for i in range(32):
+ z_regs_value = '{' + \
+ ' '.join('0x{:02x}'.format(i + 1)
+ for _ in range(z_reg_size)) + '}'
+ self.expect("register read " + 'z%i' %
+ (i), substrs=[z_regs_value])
+
+ p_value_bytes = ['0xff', '0x55', '0x11', '0x01', '0x00']
+ for i in range(16):
+ p_regs_value = '{' + \
+ ' '.join(p_value_bytes[i % 5] for _ in range(p_reg_size)) + '}'
+ self.expect("register read " + 'p%i' % (i), substrs=[p_regs_value])
+
+ self.expect("register read ffr", substrs=[p_regs_value])
+
+ def check_sve_regs_read_after_write(self, z_reg_size):
+ p_reg_size = int(z_reg_size / 8)
+
+ z_regs_value = '{' + \
+ ' '.join(('0x9d' for _ in range(z_reg_size))) + '}'
+
+ p_regs_value = '{' + \
+ ' '.join(('0xee' for _ in range(p_reg_size))) + '}'
+
+ for i in range(32):
+ self.runCmd('register write ' + 'z%i' %
+ (i) + " '" + z_regs_value + "'")
+
+ for i in range(32):
+ self.expect("register read " + 'z%i' % (i), substrs=[z_regs_value])
+
+ for i in range(16):
+ self.runCmd('register write ' + 'p%i' %
+ (i) + " '" + p_regs_value + "'")
+
+ for i in range(16):
+ self.expect("register read " + 'p%i' % (i), substrs=[p_regs_value])
+
+ self.runCmd('register write ' + 'ffr ' + "'" + p_regs_value + "'")
+
+ self.expect("register read " + 'ffr', substrs=[p_regs_value])
+
mydir = TestBase.compute_mydir(__file__)
@no_debug_info_test
@@ -117,43 +162,17 @@ def test_sve_registers_read_write(self):
z_reg_size = vg_reg_value * 8
- p_reg_size = int(z_reg_size / 8)
-
- for i in range(32):
- z_regs_value = '{' + \
- ' '.join('0x{:02x}'.format(i + 1)
- for _ in range(z_reg_size)) + '}'
- self.expect("register read " + 'z%i' %
- (i), substrs=[z_regs_value])
+ self.check_sve_regs_read(z_reg_size)
- p_value_bytes = ['0xff', '0x55', '0x11', '0x01', '0x00']
- for i in range(16):
- p_regs_value = '{' + \
- ' '.join(p_value_bytes[i % 5] for _ in range(p_reg_size)) + '}'
- self.expect("register read " + 'p%i' % (i), substrs=[p_regs_value])
+ # Evaluate simple expression and print function expr_eval_func address.
+ self.expect("p expr_eval_func", substrs=["= 0x"])
- self.expect("register read ffr", substrs=[p_regs_value])
+ # Evaluate expression call function expr_eval_func.
+ self.expect_expr("expr_eval_func()",
+ result_type="int", result_value="1")
- z_regs_value = '{' + \
- ' '.join(('0x9d' for _ in range(z_reg_size))) + '}'
+ # We called a jitted function above which must not have changed SVE
+ # vector length or register values.
+ self.check_sve_regs_read(z_reg_size)
- p_regs_value = '{' + \
- ' '.join(('0xee' for _ in range(p_reg_size))) + '}'
-
- for i in range(32):
- self.runCmd('register write ' + 'z%i' %
- (i) + " '" + z_regs_value + "'")
-
- for i in range(32):
- self.expect("register read " + 'z%i' % (i), substrs=[z_regs_value])
-
- for i in range(16):
- self.runCmd('register write ' + 'p%i' %
- (i) + " '" + p_regs_value + "'")
-
- for i in range(16):
- self.expect("register read " + 'p%i' % (i), substrs=[p_regs_value])
-
- self.runCmd('register write ' + 'ffr ' + "'" + p_regs_value + "'")
-
- self.expect("register read " + 'ffr', substrs=[p_regs_value])
+ self.check_sve_regs_read_after_write(z_reg_size)
diff --git a/lldb/test/API/commands/register/register/aarch64_sve_registers/rw_access_static_config/main.c b/lldb/test/API/commands/register/register/aarch64_sve_registers/rw_access_static_config/main.c
index 0c2573864eeb7..79ff587ab7326 100644
--- a/lldb/test/API/commands/register/register/aarch64_sve_registers/rw_access_static_config/main.c
+++ b/lldb/test/API/commands/register/register/aarch64_sve_registers/rw_access_static_config/main.c
@@ -1,4 +1,6 @@
-int main() {
+#include <sys/prctl.h>
+
+void write_sve_regs() {
asm volatile("setffr\n\t");
asm volatile("ptrue p0.b\n\t");
asm volatile("ptrue p1.h\n\t");
@@ -49,5 +51,20 @@ int main() {
asm volatile("cpy z29.b, p5/z, #30\n\t");
asm volatile("cpy z30.b, p10/z, #31\n\t");
asm volatile("cpy z31.b, p15/z, #32\n\t");
+}
+
+// This function will be called using jitted expression call. We change vector
+// length and write SVE registers. Our program context should restore to
+// orignal vector length and register values after expression evaluation.
+int expr_eval_func() {
+ prctl(PR_SVE_SET_VL, 8 * 2);
+ write_sve_regs();
+ prctl(PR_SVE_SET_VL, 8 * 4);
+ write_sve_regs();
+ return 1;
+}
+
+int main() {
+ write_sve_regs();
return 0; // Set a break point here.
}
More information about the lldb-commits
mailing list