Revert "ANDROID: android: Create debug_symbols driver"

This reverts commit bb732365f7.

Reason for revert: breaks when enabled via config

when building the target `//common-modules/virtual-device:virtual_device_arm_dist`

```
In file included from common/drivers/android/android_debug_symbols.c:12:
common/arch/arm/include/asm/stacktrace.h:41:21: error: call to undeclared function 'in_entry_text'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
                frame->ex_frame = in_entry_text(frame->pc);
                                  ^
In file included from common/drivers/android/android_debug_symbols.c:13:
common/arch/arm/include/asm/sections.h:14:20: error: static declaration of 'in_entry_text' follows non-static declaration
static inline bool in_entry_text(unsigned long addr)
                   ^
common/arch/arm/include/asm/stacktrace.h:41:21: note: previous implicit declaration is here
                frame->ex_frame = in_entry_text(frame->pc);
                                  ^
```

Change-Id: Id31003d4c9c60758f6038a63d40ffd7f8044cc9f
Signed-off-by: Matthias Maennich <maennich@google.com>

drivers/android/Kconfig

@@ -47,17 +47,6 @@ config ANDROID_BINDER_IPC_SELFTEST
 	  exhaustively with combinations of various buffer sizes and
 	  alignments.
 
-config ANDROID_DEBUG_SYMBOLS
-	bool "Android Debug Symbols"
-	help
-	  Enables export of debug symbols that are useful for offline debugging
-	  of a kernel. These symbols would be used in vendor modules to find
-	  addresses of the core kernel symbols for vendor extensions.
-
-	  This driver is statically compiled into kernel and maintains all the
-	  required symbol addresses for vendor modules and provides necessary
-	  interface vendor modules.
-
 config ANDROID_VENDOR_HOOKS
 	bool "Android Vendor Hooks"
 	depends on TRACEPOINTS

drivers/android/Makefile

@@ -4,6 +4,5 @@ ccflags-y += -I$(src)			# needed for trace events
 obj-$(CONFIG_ANDROID_BINDERFS)		+= binderfs.o
 obj-$(CONFIG_ANDROID_BINDER_IPC)	+= binder.o binder_alloc.o
 obj-$(CONFIG_ANDROID_BINDER_IPC_SELFTEST) += binder_alloc_selftest.o
-obj-$(CONFIG_ANDROID_DEBUG_SYMBOLS)	+= android_debug_symbols.o
 obj-$(CONFIG_ANDROID_VENDOR_HOOKS) += vendor_hooks.o
 obj-$(CONFIG_ANDROID_DEBUG_KINFO)	+= debug_kinfo.o

drivers/android/android_debug_symbols.c

@@ -1,96 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-only
-
-/*
- * Copyright (c) 2021, The Linux Foundation. All rights reserved.
- * Copyright (c) 2023, Unisoc (Shanghai) Technologies Co., Ltd
- */
-
-#include <linux/types.h>
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/android_debug_symbols.h>
-#include <asm/stacktrace.h>
-#include <asm/sections.h>
-
-#include <linux/cma.h>
-#include <linux/mm.h>
-#include "../../mm/slab.h"
-#include <linux/security.h>
-
-struct ads_entry {
-	char *name;
-	void *addr;
-};
-
-#define _ADS_ENTRY(index, symbol)			\
-	[index] = { .name = #symbol, .addr = (void *)symbol }
-#define ADS_ENTRY(index, symbol) _ADS_ENTRY(index, symbol)
-
-#define _ADS_PER_CPU_ENTRY(index, symbol)			\
-	[index] = { .name = #symbol, .addr = (void *)&symbol }
-#define ADS_PER_CPU_ENTRY(index, symbol) _ADS_PER_CPU_ENTRY(index, symbol)
-
-/*
- * This module maintains static array of symbol and address information.
- * Add all required core kernel symbols and their addresses into ads_entries[] array,
- * so that vendor modules can query and to find address of non-exported symbol.
- */
-static const struct ads_entry ads_entries[ADS_END] = {
-	ADS_ENTRY(ADS_SDATA, _sdata),
-	ADS_ENTRY(ADS_BSS_END, __bss_stop),
-	ADS_ENTRY(ADS_PER_CPU_START, __per_cpu_start),
-	ADS_ENTRY(ADS_PER_CPU_END, __per_cpu_end),
-	ADS_ENTRY(ADS_TEXT, _text),
-	ADS_ENTRY(ADS_SEND, _end),
-	ADS_ENTRY(ADS_LINUX_BANNER, linux_banner),
-	ADS_ENTRY(ADS_TOTAL_CMA, &totalcma_pages),
-	ADS_ENTRY(ADS_SLAB_CACHES, &slab_caches),
-	ADS_ENTRY(ADS_SLAB_MUTEX, &slab_mutex),
-};
-
-/*
- * ads_per_cpu_entries array contains all the per_cpu variable address information.
- */
-static const struct ads_entry ads_per_cpu_entries[ADS_DEBUG_PER_CPU_END] = {
-#ifdef CONFIG_ARM64
-	ADS_PER_CPU_ENTRY(ADS_IRQ_STACK_PTR, irq_stack_ptr),
-#endif
-#ifdef CONFIG_X86
-	ADS_PER_CPU_ENTRY(ADS_IRQ_STACK_PTR, hardirq_stack_ptr),
-#endif
-};
-
-/*
- * android_debug_symbol - Provide address inforamtion of debug symbol.
- * @symbol: Index of debug symbol array.
- *
- * Return address of core kernel symbol on success and a negative errno will be
- * returned in error cases.
- *
- */
-void *android_debug_symbol(enum android_debug_symbol symbol)
-{
-	if (symbol >= ADS_END)
-		return ERR_PTR(-EINVAL);
-
-	return ads_entries[symbol].addr;
-}
-EXPORT_SYMBOL_NS_GPL(android_debug_symbol, MINIDUMP);
-
-/*
- * android_debug_per_cpu_symbol - Provide address inforamtion of per cpu debug symbol.
- * @symbol: Index of per cpu debug symbol array.
- *
- * Return address of core kernel symbol on success and a negative errno will be
- * returned in error cases.
- *
- */
-void *android_debug_per_cpu_symbol(enum android_debug_per_cpu_symbol symbol)
-{
-	if (symbol >= ADS_DEBUG_PER_CPU_END)
-		return ERR_PTR(-EINVAL);
-
-	return ads_per_cpu_entries[symbol].addr;
-}
-EXPORT_SYMBOL_NS_GPL(android_debug_per_cpu_symbol, MINIDUMP);
-

include/linux/android_debug_symbols.h

@@ -1,47 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0-only */
-/*
- * Copyright (c) 2021, The Linux Foundation. All rights reserved.
- * Copyright (c) 2023, Unisoc (Shanghai) Technologies Co., Ltd
- */
-
-#ifndef _ANDROID_DEBUG_SYMBOLS_H
-#define _ANDROID_DEBUG_SYMBOLS_H
-
-enum android_debug_symbol {
-	ADS_SDATA = 0,
-	ADS_BSS_END,
-	ADS_PER_CPU_START,
-	ADS_PER_CPU_END,
-	ADS_TEXT,
-	ADS_SEND,
-	ADS_LINUX_BANNER,
-	ADS_TOTAL_CMA,
-	ADS_SLAB_CACHES,
-	ADS_SLAB_MUTEX,
-	ADS_END
-};
-
-enum android_debug_per_cpu_symbol {
-	ADS_IRQ_STACK_PTR = 0,
-	ADS_DEBUG_PER_CPU_END
-};
-
-#ifdef CONFIG_ANDROID_DEBUG_SYMBOLS
-
-void *android_debug_symbol(enum android_debug_symbol symbol);
-void *android_debug_per_cpu_symbol(enum android_debug_per_cpu_symbol symbol);
-
-#else /* !CONFIG_ANDROID_DEBUG_SYMBOLS */
-
-static inline void *android_debug_symbol(enum android_debug_symbol symbol)
-{
-	return NULL;
-}
-static inline void *android_debug_per_cpu_symbol(enum android_debug_per_cpu_symbol symbol)
-{
-	return NULL;
-}
-
-#endif /* CONFIG_ANDROID_DEBUG_SYMBOLS */
-
-#endif /* _ANDROID_DEBUG_SYMBOLS_H */