3fcbb15c1a
Introduce new API to expose symbols useful for debugging the GKI kernel. Symbols exported from this driver would be difficult to maintain via the traditional EXPORT_SYMBOL_GPL. Bug: 160245776 Change-Id: I92053450bd74788889d1b7a569e291a35cd525ea Signed-off-by: Elliot Berman <eberman@codeaurora.org> Signed-off-by: Prasad Sodagudi <psodagud@codeaurora.org>
100 lines
2.7 KiB
C
100 lines
2.7 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Copyright (c) 2021, The Linux Foundation. All rights reserved.
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*/
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#include <linux/types.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/android_debug_symbols.h>
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#include <asm/stacktrace.h>
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#include <asm/sections.h>
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struct ads_entry {
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char *name;
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void *addr;
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};
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#define _ADS_ENTRY(index, symbol) \
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[index] = { .name = #symbol, .addr = (void *)symbol }
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#define ADS_ENTRY(index, symbol) _ADS_ENTRY(index, symbol)
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#define _ADS_PER_CPU_ENTRY(index, symbol) \
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[index] = { .name = #symbol, .addr = (void *)&symbol }
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#define ADS_PER_CPU_ENTRY(index, symbol) _ADS_PER_CPU_ENTRY(index, symbol)
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/*
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* This module maintains static array of symbol and address information.
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* Add all required core kernel symbols and their addresses into ads_entries[] array,
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* so that vendor modules can query and to find address of non-exported symbol.
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*/
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static const struct ads_entry ads_entries[ADS_END] = {
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ADS_ENTRY(ADS_SDATA, _sdata),
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ADS_ENTRY(ADS_BSS_END, __bss_stop),
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ADS_ENTRY(ADS_PER_CPU_START, __per_cpu_start),
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ADS_ENTRY(ADS_PER_CPU_END, __per_cpu_end),
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ADS_ENTRY(ADS_START_RO_AFTER_INIT, __start_ro_after_init),
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ADS_ENTRY(ADS_END_RO_AFTER_INIT, __end_ro_after_init),
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ADS_ENTRY(ADS_LINUX_BANNER, linux_banner),
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};
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/*
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* ads_per_cpu_entries array contains all the per_cpu variable address information.
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*/
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static const struct ads_entry ads_per_cpu_entries[ADS_DEBUG_PER_CPU_END] = {
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#ifdef CONFIG_ARM64
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ADS_PER_CPU_ENTRY(ADS_IRQ_STACK_PTR, irq_stack_ptr),
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#endif
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#ifdef CONFIG_X86
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ADS_PER_CPU_ENTRY(ADS_IRQ_STACK_PTR, hardirq_stack_ptr),
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#endif
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};
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/*
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* android_debug_symbol - Provide address inforamtion of debug symbol.
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* @symbol: Index of debug symbol array.
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*
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* Return address of core kernel symbol on success and a negative errno will be
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* returned in error cases.
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*
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*/
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void *android_debug_symbol(enum android_debug_symbol symbol)
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{
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if (symbol >= ADS_END)
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return ERR_PTR(-EINVAL);
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return ads_entries[symbol].addr;
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}
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EXPORT_SYMBOL_GPL(android_debug_symbol);
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/*
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* android_debug_per_cpu_symbol - Provide address inforamtion of per cpu debug symbol.
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* @symbol: Index of per cpu debug symbol array.
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*
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* Return address of core kernel symbol on success and a negative errno will be
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* returned in error cases.
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*
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*/
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void *android_debug_per_cpu_symbol(enum android_debug_per_cpu_symbol symbol)
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{
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if (symbol >= ADS_DEBUG_PER_CPU_END)
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return ERR_PTR(-EINVAL);
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return ads_per_cpu_entries[symbol].addr;
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}
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EXPORT_SYMBOL_GPL(android_debug_per_cpu_symbol);
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static int __init debug_symbol_init(void)
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{
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return 0;
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}
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module_init(debug_symbol_init);
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static void __exit debug_symbol_exit(void)
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{ }
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module_exit(debug_symbol_exit);
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MODULE_DESCRIPTION("Debug Symbol Driver");
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MODULE_LICENSE("GPL v2");
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