https://github.com/mbucko created
https://github.com/llvm/llvm-project/pull/93688
Summary:
Moving CommandObjectMemoryFind::FastSearch() to Process::FindInMemory(). Plan
to expose FindInMemory as public API in SBProcess.
Test Plan:
ninja check-lldb
Reviewers: clayborg
Subscribers:
Tasks:
lldb
Tags:
>From b6ac1147a441d774c8a5ea4c2de620b72be151e2 Mon Sep 17 00:00:00 2001
From: Miro Bucko <mbu...@meta.com>
Date: Wed, 29 May 2024 06:38:22 -0700
Subject: [PATCH] [nfc][lldb] Move FastSearch from CommandObjectMemoryFind to
Process
Summary:
Moving CommandObjectMemoryFind::FastSearch() to Process::FindInMemory().
Plan to expose FindInMemory as public API in SBProcess.
Test Plan:
ninja check-lldb
Reviewers:
Subscribers:
Tasks:
lldb
Tags:
---
lldb/include/lldb/Target/Process.h | 22 +++++++
lldb/source/Commands/CommandObjectMemory.cpp | 61 +-------------------
lldb/source/Target/Process.cpp | 55 ++++++++++++++++++
3 files changed, 79 insertions(+), 59 deletions(-)
diff --git a/lldb/include/lldb/Target/Process.h
b/lldb/include/lldb/Target/Process.h
index 637d34c29715c1..f293d1e78494f7 100644
--- a/lldb/include/lldb/Target/Process.h
+++ b/lldb/include/lldb/Target/Process.h
@@ -2663,6 +2663,28 @@ void PruneThreadPlans();
return m_source_file_cache;
}
+ /// Find a pattern within a memory region.
+ ///
+ /// This function searches for a pattern represented by the provided buffer
+ /// within the memory range specified by the low and high addresses. It uses
+ /// a bad character heuristic to optimize the search process.
+ ///
+ /// \param[in] low The starting address of the memory region to be searched.
+ /// (inclusive)
+ ///
+ /// \param[in] high The ending address of the memory region to be searched.
+ /// (exclusive)
+ ///
+ /// \param[in] buf A pointer to the buffer containing the pattern to be
+ /// searched.
+ ///
+ /// \param[in] buffer_size The size of the buffer in bytes.
+ ///
+ /// \return The address where the pattern was found or LLDB_INVALID_ADDRESS
if
+ /// not found.
+ lldb::addr_t FindInMemory(lldb::addr_t low, lldb::addr_t high,
+ const uint8_t *buf, size_t size);
+
protected:
friend class Trace;
diff --git a/lldb/source/Commands/CommandObjectMemory.cpp
b/lldb/source/Commands/CommandObjectMemory.cpp
index b78a0492cca558..1c13484dede648 100644
--- a/lldb/source/Commands/CommandObjectMemory.cpp
+++ b/lldb/source/Commands/CommandObjectMemory.cpp
@@ -977,35 +977,6 @@ class CommandObjectMemoryFind : public CommandObjectParsed
{
Options *GetOptions() override { return &m_option_group; }
protected:
- class ProcessMemoryIterator {
- public:
- ProcessMemoryIterator(ProcessSP process_sp, lldb::addr_t base)
- : m_process_sp(process_sp), m_base_addr(base) {
- lldbassert(process_sp.get() != nullptr);
- }
-
- bool IsValid() { return m_is_valid; }
-
- uint8_t operator[](lldb::addr_t offset) {
- if (!IsValid())
- return 0;
-
- uint8_t retval = 0;
- Status error;
- if (0 ==
- m_process_sp->ReadMemory(m_base_addr + offset, &retval, 1, error)) {
- m_is_valid = false;
- return 0;
- }
-
- return retval;
- }
-
- private:
- ProcessSP m_process_sp;
- lldb::addr_t m_base_addr;
- bool m_is_valid = true;
- };
void DoExecute(Args &command, CommandReturnObject &result) override {
// No need to check "process" for validity as eCommandRequiresProcess
// ensures it is valid
@@ -1106,8 +1077,8 @@ class CommandObjectMemoryFind : public
CommandObjectParsed {
found_location = low_addr;
bool ever_found = false;
while (count) {
- found_location = FastSearch(found_location, high_addr, buffer.GetBytes(),
- buffer.GetByteSize());
+ found_location = process->FindInMemory(
+ found_location, high_addr, buffer.GetBytes(), buffer.GetByteSize());
if (found_location == LLDB_INVALID_ADDRESS) {
if (!ever_found) {
result.AppendMessage("data not found within the range.\n");
@@ -1144,34 +1115,6 @@ class CommandObjectMemoryFind : public
CommandObjectParsed {
result.SetStatus(lldb::eReturnStatusSuccessFinishResult);
}
- lldb::addr_t FastSearch(lldb::addr_t low, lldb::addr_t high, uint8_t *buffer,
- size_t buffer_size) {
- const size_t region_size = high - low;
-
- if (region_size < buffer_size)
- return LLDB_INVALID_ADDRESS;
-
- std::vector<size_t> bad_char_heuristic(256, buffer_size);
- ProcessSP process_sp = m_exe_ctx.GetProcessSP();
- ProcessMemoryIterator iterator(process_sp, low);
-
- for (size_t idx = 0; idx < buffer_size - 1; idx++) {
- decltype(bad_char_heuristic)::size_type bcu_idx = buffer[idx];
- bad_char_heuristic[bcu_idx] = buffer_size - idx - 1;
- }
- for (size_t s = 0; s <= (region_size - buffer_size);) {
- int64_t j = buffer_size - 1;
- while (j >= 0 && buffer[j] == iterator[s + j])
- j--;
- if (j < 0)
- return low + s;
- else
- s += bad_char_heuristic[iterator[s + buffer_size - 1]];
- }
-
- return LLDB_INVALID_ADDRESS;
- }
-
OptionGroupOptions m_option_group;
OptionGroupFindMemory m_memory_options;
OptionGroupMemoryTag m_memory_tag_options;
diff --git a/lldb/source/Target/Process.cpp b/lldb/source/Target/Process.cpp
index 216d2f21abfef0..2e0a96b07b3d55 100644
--- a/lldb/source/Target/Process.cpp
+++ b/lldb/source/Target/Process.cpp
@@ -112,6 +112,34 @@ class ProcessOptionValueProperties
}
};
+class ProcessMemoryIterator {
+public:
+ ProcessMemoryIterator(Process &process, lldb::addr_t base)
+ : m_process(process), m_base_addr(base) { }
+
+ bool IsValid() { return m_is_valid; }
+
+ uint8_t operator[](lldb::addr_t offset) {
+ if (!IsValid())
+ return 0;
+
+ uint8_t retval = 0;
+ Status error;
+ if (0 ==
+ m_process.ReadMemory(m_base_addr + offset, &retval, 1, error)) {
+ m_is_valid = false;
+ return 0;
+ }
+
+ return retval;
+ }
+
+ private:
+ Process &m_process;
+ const lldb::addr_t m_base_addr;
+ bool m_is_valid = true;
+};
+
static constexpr OptionEnumValueElement g_follow_fork_mode_values[] = {
{
eFollowParent,
@@ -3191,6 +3219,33 @@ Status Process::Halt(bool clear_thread_plans, bool
use_run_lock) {
return Status();
}
+lldb::addr_t Process::FindInMemory(lldb::addr_t low, lldb::addr_t high,
+ const uint8_t *buf, size_t size) {
+ const size_t region_size = high - low;
+
+ if (region_size < size)
+ return LLDB_INVALID_ADDRESS;
+
+ std::vector<size_t> bad_char_heuristic(256, size);
+ ProcessMemoryIterator iterator(*this, low);
+
+ for (size_t idx = 0; idx < size - 1; idx++) {
+ decltype(bad_char_heuristic)::size_type bcu_idx = buf[idx];
+ bad_char_heuristic[bcu_idx] = size - idx - 1;
+ }
+ for (size_t s = 0; s <= (region_size - size);) {
+ int64_t j = size - 1;
+ while (j >= 0 && buf[j] == iterator[s + j])
+ j--;
+ if (j < 0)
+ return low + s;
+ else
+ s += bad_char_heuristic[iterator[s + size - 1]];
+ }
+
+ return LLDB_INVALID_ADDRESS;
+}
+
Status Process::StopForDestroyOrDetach(lldb::EventSP &exit_event_sp) {
Status error;
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