mirror of https://github.com/Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
46 lines
1.2 KiB
46 lines
1.2 KiB
// SPDX-License-Identifier: GPL-2.0 |
|
#include <linux/err.h> |
|
#include <linux/mm.h> |
|
#include <asm/current.h> |
|
#include <asm/traps.h> |
|
#include <asm/vdso.h> |
|
|
|
struct vdso_exception_table_entry { |
|
int insn, fixup; |
|
}; |
|
|
|
bool fixup_vdso_exception(struct pt_regs *regs, int trapnr, |
|
unsigned long error_code, unsigned long fault_addr) |
|
{ |
|
const struct vdso_image *image = current->mm->context.vdso_image; |
|
const struct vdso_exception_table_entry *extable; |
|
unsigned int nr_entries, i; |
|
unsigned long base; |
|
|
|
/* |
|
* Do not attempt to fixup #DB or #BP. It's impossible to identify |
|
* whether or not a #DB/#BP originated from within an SGX enclave and |
|
* SGX enclaves are currently the only use case for vDSO fixup. |
|
*/ |
|
if (trapnr == X86_TRAP_DB || trapnr == X86_TRAP_BP) |
|
return false; |
|
|
|
if (!current->mm->context.vdso) |
|
return false; |
|
|
|
base = (unsigned long)current->mm->context.vdso + image->extable_base; |
|
nr_entries = image->extable_len / (sizeof(*extable)); |
|
extable = image->extable; |
|
|
|
for (i = 0; i < nr_entries; i++) { |
|
if (regs->ip == base + extable[i].insn) { |
|
regs->ip = base + extable[i].fixup; |
|
regs->di = trapnr; |
|
regs->si = error_code; |
|
regs->dx = fault_addr; |
|
return true; |
|
} |
|
} |
|
|
|
return false; |
|
}
|
|
|