mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-21 00:10:09 +00:00
ea24213d80
It is important that UACCESS regions are as small as possible; furthermore the UACCESS state is not scheduled, so doing anything that might directly call into the scheduler will cause random code to be ran with UACCESS enabled. Teach objtool too track UACCESS state and warn about any CALL made while UACCESS is enabled. This very much includes the __fentry__() and __preempt_schedule() calls. Note that exceptions _do_ save/restore the UACCESS state, and therefore they can drive preemption. This also means that all exception handlers must have an otherwise redundant UACCESS disable instruction; therefore ignore this warning for !STT_FUNC code (exception handlers are not normal functions). Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
82 lines
2.2 KiB
C
82 lines
2.2 KiB
C
/*
|
|
* Copyright (C) 2017 Josh Poimboeuf <jpoimboe@redhat.com>
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License
|
|
* as published by the Free Software Foundation; either version 2
|
|
* of the License, or (at your option) any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, see <http://www.gnu.org/licenses/>.
|
|
*/
|
|
|
|
#ifndef _CHECK_H
|
|
#define _CHECK_H
|
|
|
|
#include <stdbool.h>
|
|
#include "elf.h"
|
|
#include "cfi.h"
|
|
#include "arch.h"
|
|
#include "orc.h"
|
|
#include <linux/hashtable.h>
|
|
|
|
struct insn_state {
|
|
struct cfi_reg cfa;
|
|
struct cfi_reg regs[CFI_NUM_REGS];
|
|
int stack_size;
|
|
unsigned char type;
|
|
bool bp_scratch;
|
|
bool drap, end, uaccess;
|
|
unsigned int uaccess_stack;
|
|
int drap_reg, drap_offset;
|
|
struct cfi_reg vals[CFI_NUM_REGS];
|
|
};
|
|
|
|
struct instruction {
|
|
struct list_head list;
|
|
struct hlist_node hash;
|
|
struct section *sec;
|
|
unsigned long offset;
|
|
unsigned int len;
|
|
unsigned char type;
|
|
unsigned long immediate;
|
|
bool alt_group, visited, dead_end, ignore, hint, save, restore, ignore_alts;
|
|
bool retpoline_safe;
|
|
struct symbol *call_dest;
|
|
struct instruction *jump_dest;
|
|
struct instruction *first_jump_src;
|
|
struct list_head alts;
|
|
struct symbol *func;
|
|
struct stack_op stack_op;
|
|
struct insn_state state;
|
|
struct orc_entry orc;
|
|
};
|
|
|
|
struct objtool_file {
|
|
struct elf *elf;
|
|
struct list_head insn_list;
|
|
DECLARE_HASHTABLE(insn_hash, 16);
|
|
bool ignore_unreachables, c_file, hints, rodata;
|
|
};
|
|
|
|
int check(const char *objname, bool orc);
|
|
|
|
struct instruction *find_insn(struct objtool_file *file,
|
|
struct section *sec, unsigned long offset);
|
|
|
|
#define for_each_insn(file, insn) \
|
|
list_for_each_entry(insn, &file->insn_list, list)
|
|
|
|
#define sec_for_each_insn(file, sec, insn) \
|
|
for (insn = find_insn(file, sec, 0); \
|
|
insn && &insn->list != &file->insn_list && \
|
|
insn->sec == sec; \
|
|
insn = list_next_entry(insn, list))
|
|
|
|
|
|
#endif /* _CHECK_H */
|