1b1061409d
Currently rdmsr and wrmsr commands have own MSR support detection code. This code is the same. So, it is duplicated. Additionally, this code cannot be reused by others. Hence, extract this code to a function and make it public. By the way, improve a code a bit. Additionally, use GRUB_ERR_BAD_DEVICE instead of GRUB_ERR_BUG to signal an error because errors encountered by this new routine are not bugs. Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com> Signed-off-by: Sergii Dmytruk <sergii.dmytruk@3mdeb.com> Reviewed-by: Ross Philipson <ross.philipson@oracle.com> Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
84 lines
2.3 KiB
C
84 lines
2.3 KiB
C
/* wrmsr.c - Write CPU model-specific registers. */
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/*
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* GRUB -- GRand Unified Bootloader
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* Copyright (C) 2019 Free Software Foundation, Inc.
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* Based on gcc/gcc/config/i386/driver-i386.c
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*
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* GRUB is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* GRUB is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with GRUB. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include <grub/dl.h>
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#include <grub/misc.h>
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#include <grub/mm.h>
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#include <grub/env.h>
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#include <grub/command.h>
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#include <grub/extcmd.h>
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#include <grub/lockdown.h>
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#include <grub/i18n.h>
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#include <grub/i386/cpuid.h>
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#include <grub/i386/msr.h>
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GRUB_MOD_LICENSE("GPLv3+");
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static grub_command_t cmd_write;
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static grub_err_t
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grub_cmd_msr_write (grub_command_t cmd __attribute__ ((unused)), int argc, char **argv)
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{
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grub_err_t err;
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grub_uint32_t addr;
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grub_uint64_t value;
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const char *ptr;
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err = grub_cpu_is_msr_supported ();
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if (err != GRUB_ERR_NONE)
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return grub_error (err, N_("WRMSR is unsupported"));
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if (argc != 2)
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return grub_error (GRUB_ERR_BAD_ARGUMENT, N_("two arguments expected"));
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grub_errno = GRUB_ERR_NONE;
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ptr = argv[0];
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addr = grub_strtoul (ptr, &ptr, 0);
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if (grub_errno != GRUB_ERR_NONE)
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return grub_errno;
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if (*ptr != '\0')
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return grub_error (GRUB_ERR_BAD_ARGUMENT, N_("invalid argument"));
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ptr = argv[1];
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value = grub_strtoull (ptr, &ptr, 0);
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if (grub_errno != GRUB_ERR_NONE)
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return grub_errno;
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if (*ptr != '\0')
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return grub_error (GRUB_ERR_BAD_ARGUMENT, N_("invalid argument"));
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grub_wrmsr (addr, value);
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return GRUB_ERR_NONE;
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}
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GRUB_MOD_INIT(wrmsr)
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{
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cmd_write = grub_register_command_lockdown ("wrmsr", grub_cmd_msr_write, N_("ADDR VALUE"),
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N_("Write a value to a CPU model specific register."));
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}
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GRUB_MOD_FINI(wrmsr)
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{
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grub_unregister_command (cmd_write);
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}
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