Async safe number to string conversion

[DariaKunoichi]

No description provided.

[GLinnik21]

What about places like

KSCrash/Sources/KSCrashRecording/KSCrashReportC.c

Lines 923 to 941 in 19c1fb6

	static void writeBasicRegisters(const KSCrashReportWriter *const writer, const char *const key,
	const struct KSMachineContext *const machineContext)
	{
	char registerNameBuff[30];
	const char *registerName;
	writer->beginObject(writer, key);
	{
	const int numRegisters = kscpu_numRegisters();
	for (int reg = 0; reg < numRegisters; reg++) {
	registerName = kscpu_registerName(reg);
	if (registerName == NULL) {
	snprintf(registerNameBuff, sizeof(registerNameBuff), "r%d", reg);
	registerName = registerNameBuff;
	}
	writer->addUIntegerElement(writer, registerName, kscpu_registerValue(machineContext, reg));
	}
	}
	writer->endContainer(writer);
	}

writeBasicRegisters can also be called from a signal handler and it still uses snprintf.

[GLinnik21]

Can we use sizeeof to make it more error-proof?

Suggested change

	memcpy(nameBuffer, "stack@0x", 8);
	char *addressStart = nameBuffer + 8;
	static const char prefix[] = "stack@0x";
	memcpy(nameBuffer, prefix, sizeof(prefix) - 1);
	char *addressStart = nameBuffer + sizeof(prefix) - 1;

[Copilot]

Pull Request Overview

This PR introduces async-safe number to string conversion functions to replace unsafe system calls like sprintf in crash reporting contexts. The implementation adds custom hex and UUID string conversion functions that avoid potential deadlocks during crash handling.

• Adds KSStringConversion module with async-safe uint64_to_hex and uuid_to_string functions
• Replaces sprintf call in crash reporting with the new async-safe hex conversion
• Includes comprehensive unit tests and integration tests for the new functionality

Reviewed Changes

Copilot reviewed 8 out of 8 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
Sources/KSCrashRecordingCore/include/KSStringConversion.h	Header defining async-safe string conversion functions
Sources/KSCrashRecordingCore/KSStringConversion.c	Implementation of hex and UUID string conversion utilities
Sources/KSCrashRecording/KSCrashReportC.c	Updates crash reporting to use async-safe hex conversion instead of sprintf
Tests/KSCrashRecordingCoreTests/KSStringConversion_Tests.m	Unit tests for the new string conversion functions
Sources/KSCrashCore/include/KSCrashNamespace.h	Namespace registration for new functions
Samples/Tests/IntegrationTests.swift	Integration test validating memory introspection with new formatting
Samples/Tests/Core/PartialCrashReport.swift	Test model updates to support notable addresses validation
Samples/Common/Sources/IntegrationTestsHelper/InstallConfig.swift	Test configuration support for memory introspection

[Copilot]

The function kssc_uuid_to_string does not null-terminate the output string. The destination buffer should have a null terminator added after the UUID string is written.

Suggested change

	}
	}
	*currentDst = '\0';

[Copilot]

The output from kssc_uint64_to_hex is not null-terminated in the destination buffer. Since nameBuffer is used as a string, it needs proper null termination after the hex conversion.

Suggested change

	kssc_uint64_to_hex((uintptr_t)address, addressStart, 1, false);
	int hexLen = kssc_uint64_to_hex((uintptr_t)address, addressStart, 1, false);
	nameBuffer[8 + hexLen] = '\0';

[Copilot]

Using memcpy to copy a single character is unnecessary. A simple assignment *currentDst++ = '-'; would be more efficient and clearer.

Suggested change

	memcpy(currentDst++, "-", 1);
	*currentDst++ = '-';