linux/arch/powerpc/lib/feature-fixups.c
Nicholas Miehlbradt 676b2f99b0 powerpc: Add static_key_feature_checks_initialized flag
JUMP_LABEL_FEATURE_CHECK_DEBUG used static_key_intialized to determine
whether {cpu,mmu}_has_feature() is used before static keys were
initialized. However, {cpu,mmu}_has_feature() should not be used before
setup_feature_keys() is called but static_key_initialized is set well
before this by the call to jump_label_init() in early_init_devtree().
This creates a window in which JUMP_LABEL_FEATURE_CHECK_DEBUG will not
detect misuse and report errors. Add a flag specifically to indicate
when {cpu,mmu}_has_feature() is safe to use.

Signed-off-by: Nicholas Miehlbradt <nicholas@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240408052358.5030-1-nicholas@linux.ibm.com
2024-04-15 12:53:39 +10:00

1021 lines
30 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (C) 2001 Ben. Herrenschmidt (benh@kernel.crashing.org)
*
* Modifications for ppc64:
* Copyright (C) 2003 Dave Engebretsen <engebret@us.ibm.com>
*
* Copyright 2008 Michael Ellerman, IBM Corporation.
*/
#include <linux/types.h>
#include <linux/jump_label.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/init.h>
#include <linux/sched/mm.h>
#include <linux/stop_machine.h>
#include <asm/cputable.h>
#include <asm/code-patching.h>
#include <asm/interrupt.h>
#include <asm/page.h>
#include <asm/sections.h>
#include <asm/setup.h>
#include <asm/security_features.h>
#include <asm/firmware.h>
#include <asm/inst.h>
/*
* Used to generate warnings if mmu or cpu feature check functions that
* use static keys before they are initialized.
*/
bool static_key_feature_checks_initialized __read_mostly;
EXPORT_SYMBOL_GPL(static_key_feature_checks_initialized);
struct fixup_entry {
unsigned long mask;
unsigned long value;
long start_off;
long end_off;
long alt_start_off;
long alt_end_off;
};
static u32 *calc_addr(struct fixup_entry *fcur, long offset)
{
/*
* We store the offset to the code as a negative offset from
* the start of the alt_entry, to support the VDSO. This
* routine converts that back into an actual address.
*/
return (u32 *)((unsigned long)fcur + offset);
}
static int patch_alt_instruction(u32 *src, u32 *dest, u32 *alt_start, u32 *alt_end)
{
int err;
ppc_inst_t instr;
instr = ppc_inst_read(src);
if (instr_is_relative_branch(ppc_inst_read(src))) {
u32 *target = (u32 *)branch_target(src);
/* Branch within the section doesn't need translating */
if (target < alt_start || target > alt_end) {
err = translate_branch(&instr, dest, src);
if (err)
return 1;
}
}
raw_patch_instruction(dest, instr);
return 0;
}
static int patch_feature_section_mask(unsigned long value, unsigned long mask,
struct fixup_entry *fcur)
{
u32 *start, *end, *alt_start, *alt_end, *src, *dest;
start = calc_addr(fcur, fcur->start_off);
end = calc_addr(fcur, fcur->end_off);
alt_start = calc_addr(fcur, fcur->alt_start_off);
alt_end = calc_addr(fcur, fcur->alt_end_off);
if ((alt_end - alt_start) > (end - start))
return 1;
if ((value & fcur->mask & mask) == (fcur->value & mask))
return 0;
src = alt_start;
dest = start;
for (; src < alt_end; src = ppc_inst_next(src, src),
dest = ppc_inst_next(dest, dest)) {
if (patch_alt_instruction(src, dest, alt_start, alt_end))
return 1;
}
for (; dest < end; dest++)
raw_patch_instruction(dest, ppc_inst(PPC_RAW_NOP()));
return 0;
}
static void do_feature_fixups_mask(unsigned long value, unsigned long mask,
void *fixup_start, void *fixup_end)
{
struct fixup_entry *fcur, *fend;
fcur = fixup_start;
fend = fixup_end;
for (; fcur < fend; fcur++) {
if (patch_feature_section_mask(value, mask, fcur)) {
WARN_ON(1);
printk("Unable to patch feature section at %p - %p" \
" with %p - %p\n",
calc_addr(fcur, fcur->start_off),
calc_addr(fcur, fcur->end_off),
calc_addr(fcur, fcur->alt_start_off),
calc_addr(fcur, fcur->alt_end_off));
}
}
}
void do_feature_fixups(unsigned long value, void *fixup_start, void *fixup_end)
{
do_feature_fixups_mask(value, ~0, fixup_start, fixup_end);
}
#ifdef CONFIG_PPC_BARRIER_NOSPEC
static bool is_fixup_addr_valid(void *dest, size_t size)
{
return system_state < SYSTEM_FREEING_INITMEM ||
!init_section_contains(dest, size);
}
static int do_patch_fixups(long *start, long *end, unsigned int *instrs, int num)
{
int i;
for (i = 0; start < end; start++, i++) {
int j;
unsigned int *dest = (void *)start + *start;
if (!is_fixup_addr_valid(dest, sizeof(*instrs) * num))
continue;
pr_devel("patching dest %lx\n", (unsigned long)dest);
for (j = 0; j < num; j++)
patch_instruction(dest + j, ppc_inst(instrs[j]));
}
return i;
}
#endif
#ifdef CONFIG_PPC_BOOK3S_64
static int do_patch_entry_fixups(long *start, long *end, unsigned int *instrs,
bool do_fallback, void *fallback)
{
int i;
for (i = 0; start < end; start++, i++) {
unsigned int *dest = (void *)start + *start;
if (!is_fixup_addr_valid(dest, sizeof(*instrs) * 3))
continue;
pr_devel("patching dest %lx\n", (unsigned long)dest);
// See comment in do_entry_flush_fixups() RE order of patching
if (do_fallback) {
patch_instruction(dest, ppc_inst(instrs[0]));
patch_instruction(dest + 2, ppc_inst(instrs[2]));
patch_branch(dest + 1, (unsigned long)fallback, BRANCH_SET_LINK);
} else {
patch_instruction(dest + 1, ppc_inst(instrs[1]));
patch_instruction(dest + 2, ppc_inst(instrs[2]));
patch_instruction(dest, ppc_inst(instrs[0]));
}
}
return i;
}
static void do_stf_entry_barrier_fixups(enum stf_barrier_type types)
{
unsigned int instrs[3];
long *start, *end;
int i;
start = PTRRELOC(&__start___stf_entry_barrier_fixup);
end = PTRRELOC(&__stop___stf_entry_barrier_fixup);
instrs[0] = PPC_RAW_NOP();
instrs[1] = PPC_RAW_NOP();
instrs[2] = PPC_RAW_NOP();
i = 0;
if (types & STF_BARRIER_FALLBACK) {
instrs[i++] = PPC_RAW_MFLR(_R10);
instrs[i++] = PPC_RAW_NOP(); /* branch patched below */
instrs[i++] = PPC_RAW_MTLR(_R10);
} else if (types & STF_BARRIER_EIEIO) {
instrs[i++] = PPC_RAW_EIEIO() | 0x02000000; /* eieio + bit 6 hint */
} else if (types & STF_BARRIER_SYNC_ORI) {
instrs[i++] = PPC_RAW_SYNC();
instrs[i++] = PPC_RAW_LD(_R10, _R13, 0);
instrs[i++] = PPC_RAW_ORI(_R31, _R31, 0); /* speculation barrier */
}
i = do_patch_entry_fixups(start, end, instrs, types & STF_BARRIER_FALLBACK,
&stf_barrier_fallback);
printk(KERN_DEBUG "stf-barrier: patched %d entry locations (%s barrier)\n", i,
(types == STF_BARRIER_NONE) ? "no" :
(types == STF_BARRIER_FALLBACK) ? "fallback" :
(types == STF_BARRIER_EIEIO) ? "eieio" :
(types == (STF_BARRIER_SYNC_ORI)) ? "hwsync"
: "unknown");
}
static void do_stf_exit_barrier_fixups(enum stf_barrier_type types)
{
unsigned int instrs[6];
long *start, *end;
int i;
start = PTRRELOC(&__start___stf_exit_barrier_fixup);
end = PTRRELOC(&__stop___stf_exit_barrier_fixup);
instrs[0] = PPC_RAW_NOP();
instrs[1] = PPC_RAW_NOP();
instrs[2] = PPC_RAW_NOP();
instrs[3] = PPC_RAW_NOP();
instrs[4] = PPC_RAW_NOP();
instrs[5] = PPC_RAW_NOP();
i = 0;
if (types & STF_BARRIER_FALLBACK || types & STF_BARRIER_SYNC_ORI) {
if (cpu_has_feature(CPU_FTR_HVMODE)) {
instrs[i++] = PPC_RAW_MTSPR(SPRN_HSPRG1, _R13);
instrs[i++] = PPC_RAW_MFSPR(_R13, SPRN_HSPRG0);
} else {
instrs[i++] = PPC_RAW_MTSPR(SPRN_SPRG2, _R13);
instrs[i++] = PPC_RAW_MFSPR(_R13, SPRN_SPRG1);
}
instrs[i++] = PPC_RAW_SYNC();
instrs[i++] = PPC_RAW_LD(_R13, _R13, 0);
instrs[i++] = PPC_RAW_ORI(_R31, _R31, 0); /* speculation barrier */
if (cpu_has_feature(CPU_FTR_HVMODE))
instrs[i++] = PPC_RAW_MFSPR(_R13, SPRN_HSPRG1);
else
instrs[i++] = PPC_RAW_MFSPR(_R13, SPRN_SPRG2);
} else if (types & STF_BARRIER_EIEIO) {
instrs[i++] = PPC_RAW_EIEIO() | 0x02000000; /* eieio + bit 6 hint */
}
i = do_patch_fixups(start, end, instrs, ARRAY_SIZE(instrs));
printk(KERN_DEBUG "stf-barrier: patched %d exit locations (%s barrier)\n", i,
(types == STF_BARRIER_NONE) ? "no" :
(types == STF_BARRIER_FALLBACK) ? "fallback" :
(types == STF_BARRIER_EIEIO) ? "eieio" :
(types == (STF_BARRIER_SYNC_ORI)) ? "hwsync"
: "unknown");
}
static bool stf_exit_reentrant = false;
static bool rfi_exit_reentrant = false;
static DEFINE_MUTEX(exit_flush_lock);
static int __do_stf_barrier_fixups(void *data)
{
enum stf_barrier_type *types = data;
do_stf_entry_barrier_fixups(*types);
do_stf_exit_barrier_fixups(*types);
return 0;
}
void do_stf_barrier_fixups(enum stf_barrier_type types)
{
/*
* The call to the fallback entry flush, and the fallback/sync-ori exit
* flush can not be safely patched in/out while other CPUs are
* executing them. So call __do_stf_barrier_fixups() on one CPU while
* all other CPUs spin in the stop machine core with interrupts hard
* disabled.
*
* The branch to mark interrupt exits non-reentrant is enabled first,
* then stop_machine runs which will ensure all CPUs are out of the
* low level interrupt exit code before patching. After the patching,
* if allowed, then flip the branch to allow fast exits.
*/
// Prevent static key update races with do_rfi_flush_fixups()
mutex_lock(&exit_flush_lock);
static_branch_enable(&interrupt_exit_not_reentrant);
stop_machine(__do_stf_barrier_fixups, &types, NULL);
if ((types & STF_BARRIER_FALLBACK) || (types & STF_BARRIER_SYNC_ORI))
stf_exit_reentrant = false;
else
stf_exit_reentrant = true;
if (stf_exit_reentrant && rfi_exit_reentrant)
static_branch_disable(&interrupt_exit_not_reentrant);
mutex_unlock(&exit_flush_lock);
}
void do_uaccess_flush_fixups(enum l1d_flush_type types)
{
unsigned int instrs[4];
long *start, *end;
int i;
start = PTRRELOC(&__start___uaccess_flush_fixup);
end = PTRRELOC(&__stop___uaccess_flush_fixup);
instrs[0] = PPC_RAW_NOP();
instrs[1] = PPC_RAW_NOP();
instrs[2] = PPC_RAW_NOP();
instrs[3] = PPC_RAW_BLR();
i = 0;
if (types == L1D_FLUSH_FALLBACK) {
instrs[3] = PPC_RAW_NOP();
/* fallthrough to fallback flush */
}
if (types & L1D_FLUSH_ORI) {
instrs[i++] = PPC_RAW_ORI(_R31, _R31, 0); /* speculation barrier */
instrs[i++] = PPC_RAW_ORI(_R30, _R30, 0); /* L1d flush */
}
if (types & L1D_FLUSH_MTTRIG)
instrs[i++] = PPC_RAW_MTSPR(SPRN_TRIG2, _R0);
i = do_patch_fixups(start, end, instrs, ARRAY_SIZE(instrs));
printk(KERN_DEBUG "uaccess-flush: patched %d locations (%s flush)\n", i,
(types == L1D_FLUSH_NONE) ? "no" :
(types == L1D_FLUSH_FALLBACK) ? "fallback displacement" :
(types & L1D_FLUSH_ORI) ? (types & L1D_FLUSH_MTTRIG)
? "ori+mttrig type"
: "ori type" :
(types & L1D_FLUSH_MTTRIG) ? "mttrig type"
: "unknown");
}
static int __do_entry_flush_fixups(void *data)
{
enum l1d_flush_type types = *(enum l1d_flush_type *)data;
unsigned int instrs[3];
long *start, *end;
int i;
instrs[0] = PPC_RAW_NOP();
instrs[1] = PPC_RAW_NOP();
instrs[2] = PPC_RAW_NOP();
i = 0;
if (types == L1D_FLUSH_FALLBACK) {
instrs[i++] = PPC_RAW_MFLR(_R10);
instrs[i++] = PPC_RAW_NOP(); /* branch patched below */
instrs[i++] = PPC_RAW_MTLR(_R10);
}
if (types & L1D_FLUSH_ORI) {
instrs[i++] = PPC_RAW_ORI(_R31, _R31, 0); /* speculation barrier */
instrs[i++] = PPC_RAW_ORI(_R30, _R30, 0); /* L1d flush */
}
if (types & L1D_FLUSH_MTTRIG)
instrs[i++] = PPC_RAW_MTSPR(SPRN_TRIG2, _R0);
/*
* If we're patching in or out the fallback flush we need to be careful about the
* order in which we patch instructions. That's because it's possible we could
* take a page fault after patching one instruction, so the sequence of
* instructions must be safe even in a half patched state.
*
* To make that work, when patching in the fallback flush we patch in this order:
* - the mflr (dest)
* - the mtlr (dest + 2)
* - the branch (dest + 1)
*
* That ensures the sequence is safe to execute at any point. In contrast if we
* patch the mtlr last, it's possible we could return from the branch and not
* restore LR, leading to a crash later.
*
* When patching out the fallback flush (either with nops or another flush type),
* we patch in this order:
* - the branch (dest + 1)
* - the mtlr (dest + 2)
* - the mflr (dest)
*
* Note we are protected by stop_machine() from other CPUs executing the code in a
* semi-patched state.
*/
start = PTRRELOC(&__start___entry_flush_fixup);
end = PTRRELOC(&__stop___entry_flush_fixup);
i = do_patch_entry_fixups(start, end, instrs, types == L1D_FLUSH_FALLBACK,
&entry_flush_fallback);
start = PTRRELOC(&__start___scv_entry_flush_fixup);
end = PTRRELOC(&__stop___scv_entry_flush_fixup);
i += do_patch_entry_fixups(start, end, instrs, types == L1D_FLUSH_FALLBACK,
&scv_entry_flush_fallback);
printk(KERN_DEBUG "entry-flush: patched %d locations (%s flush)\n", i,
(types == L1D_FLUSH_NONE) ? "no" :
(types == L1D_FLUSH_FALLBACK) ? "fallback displacement" :
(types & L1D_FLUSH_ORI) ? (types & L1D_FLUSH_MTTRIG)
? "ori+mttrig type"
: "ori type" :
(types & L1D_FLUSH_MTTRIG) ? "mttrig type"
: "unknown");
return 0;
}
void do_entry_flush_fixups(enum l1d_flush_type types)
{
/*
* The call to the fallback flush can not be safely patched in/out while
* other CPUs are executing it. So call __do_entry_flush_fixups() on one
* CPU while all other CPUs spin in the stop machine core with interrupts
* hard disabled.
*/
stop_machine(__do_entry_flush_fixups, &types, NULL);
}
static int __do_rfi_flush_fixups(void *data)
{
enum l1d_flush_type types = *(enum l1d_flush_type *)data;
unsigned int instrs[3];
long *start, *end;
int i;
start = PTRRELOC(&__start___rfi_flush_fixup);
end = PTRRELOC(&__stop___rfi_flush_fixup);
instrs[0] = PPC_RAW_NOP();
instrs[1] = PPC_RAW_NOP();
instrs[2] = PPC_RAW_NOP();
if (types & L1D_FLUSH_FALLBACK)
/* b .+16 to fallback flush */
instrs[0] = PPC_RAW_BRANCH(16);
i = 0;
if (types & L1D_FLUSH_ORI) {
instrs[i++] = PPC_RAW_ORI(_R31, _R31, 0); /* speculation barrier */
instrs[i++] = PPC_RAW_ORI(_R30, _R30, 0); /* L1d flush */
}
if (types & L1D_FLUSH_MTTRIG)
instrs[i++] = PPC_RAW_MTSPR(SPRN_TRIG2, _R0);
i = do_patch_fixups(start, end, instrs, ARRAY_SIZE(instrs));
printk(KERN_DEBUG "rfi-flush: patched %d locations (%s flush)\n", i,
(types == L1D_FLUSH_NONE) ? "no" :
(types == L1D_FLUSH_FALLBACK) ? "fallback displacement" :
(types & L1D_FLUSH_ORI) ? (types & L1D_FLUSH_MTTRIG)
? "ori+mttrig type"
: "ori type" :
(types & L1D_FLUSH_MTTRIG) ? "mttrig type"
: "unknown");
return 0;
}
void do_rfi_flush_fixups(enum l1d_flush_type types)
{
/*
* stop_machine gets all CPUs out of the interrupt exit handler same
* as do_stf_barrier_fixups. do_rfi_flush_fixups patching can run
* without stop_machine, so this could be achieved with a broadcast
* IPI instead, but this matches the stf sequence.
*/
// Prevent static key update races with do_stf_barrier_fixups()
mutex_lock(&exit_flush_lock);
static_branch_enable(&interrupt_exit_not_reentrant);
stop_machine(__do_rfi_flush_fixups, &types, NULL);
if (types & L1D_FLUSH_FALLBACK)
rfi_exit_reentrant = false;
else
rfi_exit_reentrant = true;
if (stf_exit_reentrant && rfi_exit_reentrant)
static_branch_disable(&interrupt_exit_not_reentrant);
mutex_unlock(&exit_flush_lock);
}
void do_barrier_nospec_fixups_range(bool enable, void *fixup_start, void *fixup_end)
{
unsigned int instr;
long *start, *end;
int i;
start = fixup_start;
end = fixup_end;
instr = PPC_RAW_NOP();
if (enable) {
pr_info("barrier-nospec: using ORI speculation barrier\n");
instr = PPC_RAW_ORI(_R31, _R31, 0); /* speculation barrier */
}
i = do_patch_fixups(start, end, &instr, 1);
printk(KERN_DEBUG "barrier-nospec: patched %d locations\n", i);
}
#endif /* CONFIG_PPC_BOOK3S_64 */
#ifdef CONFIG_PPC_BARRIER_NOSPEC
void do_barrier_nospec_fixups(bool enable)
{
void *start, *end;
start = PTRRELOC(&__start___barrier_nospec_fixup);
end = PTRRELOC(&__stop___barrier_nospec_fixup);
do_barrier_nospec_fixups_range(enable, start, end);
}
#endif /* CONFIG_PPC_BARRIER_NOSPEC */
#ifdef CONFIG_PPC_E500
void do_barrier_nospec_fixups_range(bool enable, void *fixup_start, void *fixup_end)
{
unsigned int instr[2];
long *start, *end;
int i;
start = fixup_start;
end = fixup_end;
instr[0] = PPC_RAW_NOP();
instr[1] = PPC_RAW_NOP();
if (enable) {
pr_info("barrier-nospec: using isync; sync as speculation barrier\n");
instr[0] = PPC_RAW_ISYNC();
instr[1] = PPC_RAW_SYNC();
}
i = do_patch_fixups(start, end, instr, ARRAY_SIZE(instr));
printk(KERN_DEBUG "barrier-nospec: patched %d locations\n", i);
}
static void __init patch_btb_flush_section(long *curr)
{
unsigned int *start, *end;
start = (void *)curr + *curr;
end = (void *)curr + *(curr + 1);
for (; start < end; start++) {
pr_devel("patching dest %lx\n", (unsigned long)start);
patch_instruction(start, ppc_inst(PPC_RAW_NOP()));
}
}
void __init do_btb_flush_fixups(void)
{
long *start, *end;
start = PTRRELOC(&__start__btb_flush_fixup);
end = PTRRELOC(&__stop__btb_flush_fixup);
for (; start < end; start += 2)
patch_btb_flush_section(start);
}
#endif /* CONFIG_PPC_E500 */
void do_lwsync_fixups(unsigned long value, void *fixup_start, void *fixup_end)
{
long *start, *end;
u32 *dest;
if (!(value & CPU_FTR_LWSYNC))
return ;
start = fixup_start;
end = fixup_end;
for (; start < end; start++) {
dest = (void *)start + *start;
raw_patch_instruction(dest, ppc_inst(PPC_INST_LWSYNC));
}
}
static void __init do_final_fixups(void)
{
#if defined(CONFIG_PPC64) && defined(CONFIG_RELOCATABLE)
ppc_inst_t inst;
u32 *src, *dest, *end;
if (PHYSICAL_START == 0)
return;
src = (u32 *)(KERNELBASE + PHYSICAL_START);
dest = (u32 *)KERNELBASE;
end = (void *)src + (__end_interrupts - _stext);
while (src < end) {
inst = ppc_inst_read(src);
raw_patch_instruction(dest, inst);
src = ppc_inst_next(src, src);
dest = ppc_inst_next(dest, dest);
}
#endif
}
static unsigned long __initdata saved_cpu_features;
static unsigned int __initdata saved_mmu_features;
#ifdef CONFIG_PPC64
static unsigned long __initdata saved_firmware_features;
#endif
void __init apply_feature_fixups(void)
{
struct cpu_spec *spec = PTRRELOC(*PTRRELOC(&cur_cpu_spec));
*PTRRELOC(&saved_cpu_features) = spec->cpu_features;
*PTRRELOC(&saved_mmu_features) = spec->mmu_features;
/*
* Apply the CPU-specific and firmware specific fixups to kernel text
* (nop out sections not relevant to this CPU or this firmware).
*/
do_feature_fixups(spec->cpu_features,
PTRRELOC(&__start___ftr_fixup),
PTRRELOC(&__stop___ftr_fixup));
do_feature_fixups(spec->mmu_features,
PTRRELOC(&__start___mmu_ftr_fixup),
PTRRELOC(&__stop___mmu_ftr_fixup));
do_lwsync_fixups(spec->cpu_features,
PTRRELOC(&__start___lwsync_fixup),
PTRRELOC(&__stop___lwsync_fixup));
#ifdef CONFIG_PPC64
saved_firmware_features = powerpc_firmware_features;
do_feature_fixups(powerpc_firmware_features,
&__start___fw_ftr_fixup, &__stop___fw_ftr_fixup);
#endif
do_final_fixups();
}
void __init update_mmu_feature_fixups(unsigned long mask)
{
saved_mmu_features &= ~mask;
saved_mmu_features |= cur_cpu_spec->mmu_features & mask;
do_feature_fixups_mask(cur_cpu_spec->mmu_features, mask,
PTRRELOC(&__start___mmu_ftr_fixup),
PTRRELOC(&__stop___mmu_ftr_fixup));
mmu_feature_keys_init();
}
void __init setup_feature_keys(void)
{
/*
* Initialise jump label. This causes all the cpu/mmu_has_feature()
* checks to take on their correct polarity based on the current set of
* CPU/MMU features.
*/
jump_label_init();
cpu_feature_keys_init();
mmu_feature_keys_init();
static_key_feature_checks_initialized = true;
}
static int __init check_features(void)
{
WARN(saved_cpu_features != cur_cpu_spec->cpu_features,
"CPU features changed after feature patching!\n");
WARN(saved_mmu_features != cur_cpu_spec->mmu_features,
"MMU features changed after feature patching!\n");
#ifdef CONFIG_PPC64
WARN(saved_firmware_features != powerpc_firmware_features,
"Firmware features changed after feature patching!\n");
#endif
return 0;
}
late_initcall(check_features);
#ifdef CONFIG_FTR_FIXUP_SELFTEST
#define check(x) \
if (!(x)) printk("feature-fixups: test failed at line %d\n", __LINE__);
static int patch_feature_section(unsigned long value, struct fixup_entry *fcur)
{
return patch_feature_section_mask(value, ~0, fcur);
}
/* This must be after the text it fixes up, vmlinux.lds.S enforces that atm */
static struct fixup_entry fixup;
static long __init calc_offset(struct fixup_entry *entry, unsigned int *p)
{
return (unsigned long)p - (unsigned long)entry;
}
static void __init test_basic_patching(void)
{
extern unsigned int ftr_fixup_test1[];
extern unsigned int end_ftr_fixup_test1[];
extern unsigned int ftr_fixup_test1_orig[];
extern unsigned int ftr_fixup_test1_expected[];
int size = 4 * (end_ftr_fixup_test1 - ftr_fixup_test1);
fixup.value = fixup.mask = 8;
fixup.start_off = calc_offset(&fixup, ftr_fixup_test1 + 1);
fixup.end_off = calc_offset(&fixup, ftr_fixup_test1 + 2);
fixup.alt_start_off = fixup.alt_end_off = 0;
/* Sanity check */
check(memcmp(ftr_fixup_test1, ftr_fixup_test1_orig, size) == 0);
/* Check we don't patch if the value matches */
patch_feature_section(8, &fixup);
check(memcmp(ftr_fixup_test1, ftr_fixup_test1_orig, size) == 0);
/* Check we do patch if the value doesn't match */
patch_feature_section(0, &fixup);
check(memcmp(ftr_fixup_test1, ftr_fixup_test1_expected, size) == 0);
/* Check we do patch if the mask doesn't match */
memcpy(ftr_fixup_test1, ftr_fixup_test1_orig, size);
check(memcmp(ftr_fixup_test1, ftr_fixup_test1_orig, size) == 0);
patch_feature_section(~8, &fixup);
check(memcmp(ftr_fixup_test1, ftr_fixup_test1_expected, size) == 0);
}
static void __init test_alternative_patching(void)
{
extern unsigned int ftr_fixup_test2[];
extern unsigned int end_ftr_fixup_test2[];
extern unsigned int ftr_fixup_test2_orig[];
extern unsigned int ftr_fixup_test2_alt[];
extern unsigned int ftr_fixup_test2_expected[];
int size = 4 * (end_ftr_fixup_test2 - ftr_fixup_test2);
fixup.value = fixup.mask = 0xF;
fixup.start_off = calc_offset(&fixup, ftr_fixup_test2 + 1);
fixup.end_off = calc_offset(&fixup, ftr_fixup_test2 + 2);
fixup.alt_start_off = calc_offset(&fixup, ftr_fixup_test2_alt);
fixup.alt_end_off = calc_offset(&fixup, ftr_fixup_test2_alt + 1);
/* Sanity check */
check(memcmp(ftr_fixup_test2, ftr_fixup_test2_orig, size) == 0);
/* Check we don't patch if the value matches */
patch_feature_section(0xF, &fixup);
check(memcmp(ftr_fixup_test2, ftr_fixup_test2_orig, size) == 0);
/* Check we do patch if the value doesn't match */
patch_feature_section(0, &fixup);
check(memcmp(ftr_fixup_test2, ftr_fixup_test2_expected, size) == 0);
/* Check we do patch if the mask doesn't match */
memcpy(ftr_fixup_test2, ftr_fixup_test2_orig, size);
check(memcmp(ftr_fixup_test2, ftr_fixup_test2_orig, size) == 0);
patch_feature_section(~0xF, &fixup);
check(memcmp(ftr_fixup_test2, ftr_fixup_test2_expected, size) == 0);
}
static void __init test_alternative_case_too_big(void)
{
extern unsigned int ftr_fixup_test3[];
extern unsigned int end_ftr_fixup_test3[];
extern unsigned int ftr_fixup_test3_orig[];
extern unsigned int ftr_fixup_test3_alt[];
int size = 4 * (end_ftr_fixup_test3 - ftr_fixup_test3);
fixup.value = fixup.mask = 0xC;
fixup.start_off = calc_offset(&fixup, ftr_fixup_test3 + 1);
fixup.end_off = calc_offset(&fixup, ftr_fixup_test3 + 2);
fixup.alt_start_off = calc_offset(&fixup, ftr_fixup_test3_alt);
fixup.alt_end_off = calc_offset(&fixup, ftr_fixup_test3_alt + 2);
/* Sanity check */
check(memcmp(ftr_fixup_test3, ftr_fixup_test3_orig, size) == 0);
/* Expect nothing to be patched, and the error returned to us */
check(patch_feature_section(0xF, &fixup) == 1);
check(memcmp(ftr_fixup_test3, ftr_fixup_test3_orig, size) == 0);
check(patch_feature_section(0, &fixup) == 1);
check(memcmp(ftr_fixup_test3, ftr_fixup_test3_orig, size) == 0);
check(patch_feature_section(~0xF, &fixup) == 1);
check(memcmp(ftr_fixup_test3, ftr_fixup_test3_orig, size) == 0);
}
static void __init test_alternative_case_too_small(void)
{
extern unsigned int ftr_fixup_test4[];
extern unsigned int end_ftr_fixup_test4[];
extern unsigned int ftr_fixup_test4_orig[];
extern unsigned int ftr_fixup_test4_alt[];
extern unsigned int ftr_fixup_test4_expected[];
int size = 4 * (end_ftr_fixup_test4 - ftr_fixup_test4);
unsigned long flag;
/* Check a high-bit flag */
flag = 1UL << ((sizeof(unsigned long) - 1) * 8);
fixup.value = fixup.mask = flag;
fixup.start_off = calc_offset(&fixup, ftr_fixup_test4 + 1);
fixup.end_off = calc_offset(&fixup, ftr_fixup_test4 + 5);
fixup.alt_start_off = calc_offset(&fixup, ftr_fixup_test4_alt);
fixup.alt_end_off = calc_offset(&fixup, ftr_fixup_test4_alt + 2);
/* Sanity check */
check(memcmp(ftr_fixup_test4, ftr_fixup_test4_orig, size) == 0);
/* Check we don't patch if the value matches */
patch_feature_section(flag, &fixup);
check(memcmp(ftr_fixup_test4, ftr_fixup_test4_orig, size) == 0);
/* Check we do patch if the value doesn't match */
patch_feature_section(0, &fixup);
check(memcmp(ftr_fixup_test4, ftr_fixup_test4_expected, size) == 0);
/* Check we do patch if the mask doesn't match */
memcpy(ftr_fixup_test4, ftr_fixup_test4_orig, size);
check(memcmp(ftr_fixup_test4, ftr_fixup_test4_orig, size) == 0);
patch_feature_section(~flag, &fixup);
check(memcmp(ftr_fixup_test4, ftr_fixup_test4_expected, size) == 0);
}
static void test_alternative_case_with_branch(void)
{
extern unsigned int ftr_fixup_test5[];
extern unsigned int end_ftr_fixup_test5[];
extern unsigned int ftr_fixup_test5_expected[];
int size = 4 * (end_ftr_fixup_test5 - ftr_fixup_test5);
check(memcmp(ftr_fixup_test5, ftr_fixup_test5_expected, size) == 0);
}
static void __init test_alternative_case_with_external_branch(void)
{
extern unsigned int ftr_fixup_test6[];
extern unsigned int end_ftr_fixup_test6[];
extern unsigned int ftr_fixup_test6_expected[];
int size = 4 * (end_ftr_fixup_test6 - ftr_fixup_test6);
check(memcmp(ftr_fixup_test6, ftr_fixup_test6_expected, size) == 0);
}
static void __init test_alternative_case_with_branch_to_end(void)
{
extern unsigned int ftr_fixup_test7[];
extern unsigned int end_ftr_fixup_test7[];
extern unsigned int ftr_fixup_test7_expected[];
int size = 4 * (end_ftr_fixup_test7 - ftr_fixup_test7);
check(memcmp(ftr_fixup_test7, ftr_fixup_test7_expected, size) == 0);
}
static void __init test_cpu_macros(void)
{
extern u8 ftr_fixup_test_FTR_macros[];
extern u8 ftr_fixup_test_FTR_macros_expected[];
unsigned long size = ftr_fixup_test_FTR_macros_expected -
ftr_fixup_test_FTR_macros;
/* The fixups have already been done for us during boot */
check(memcmp(ftr_fixup_test_FTR_macros,
ftr_fixup_test_FTR_macros_expected, size) == 0);
}
static void __init test_fw_macros(void)
{
#ifdef CONFIG_PPC64
extern u8 ftr_fixup_test_FW_FTR_macros[];
extern u8 ftr_fixup_test_FW_FTR_macros_expected[];
unsigned long size = ftr_fixup_test_FW_FTR_macros_expected -
ftr_fixup_test_FW_FTR_macros;
/* The fixups have already been done for us during boot */
check(memcmp(ftr_fixup_test_FW_FTR_macros,
ftr_fixup_test_FW_FTR_macros_expected, size) == 0);
#endif
}
static void __init test_lwsync_macros(void)
{
extern u8 lwsync_fixup_test[];
extern u8 end_lwsync_fixup_test[];
extern u8 lwsync_fixup_test_expected_LWSYNC[];
extern u8 lwsync_fixup_test_expected_SYNC[];
unsigned long size = end_lwsync_fixup_test -
lwsync_fixup_test;
/* The fixups have already been done for us during boot */
if (cur_cpu_spec->cpu_features & CPU_FTR_LWSYNC) {
check(memcmp(lwsync_fixup_test,
lwsync_fixup_test_expected_LWSYNC, size) == 0);
} else {
check(memcmp(lwsync_fixup_test,
lwsync_fixup_test_expected_SYNC, size) == 0);
}
}
#ifdef CONFIG_PPC64
static void __init test_prefix_patching(void)
{
extern unsigned int ftr_fixup_prefix1[];
extern unsigned int end_ftr_fixup_prefix1[];
extern unsigned int ftr_fixup_prefix1_orig[];
extern unsigned int ftr_fixup_prefix1_expected[];
int size = sizeof(unsigned int) * (end_ftr_fixup_prefix1 - ftr_fixup_prefix1);
fixup.value = fixup.mask = 8;
fixup.start_off = calc_offset(&fixup, ftr_fixup_prefix1 + 1);
fixup.end_off = calc_offset(&fixup, ftr_fixup_prefix1 + 3);
fixup.alt_start_off = fixup.alt_end_off = 0;
/* Sanity check */
check(memcmp(ftr_fixup_prefix1, ftr_fixup_prefix1_orig, size) == 0);
patch_feature_section(0, &fixup);
check(memcmp(ftr_fixup_prefix1, ftr_fixup_prefix1_expected, size) == 0);
check(memcmp(ftr_fixup_prefix1, ftr_fixup_prefix1_orig, size) != 0);
}
static void __init test_prefix_alt_patching(void)
{
extern unsigned int ftr_fixup_prefix2[];
extern unsigned int end_ftr_fixup_prefix2[];
extern unsigned int ftr_fixup_prefix2_orig[];
extern unsigned int ftr_fixup_prefix2_expected[];
extern unsigned int ftr_fixup_prefix2_alt[];
int size = sizeof(unsigned int) * (end_ftr_fixup_prefix2 - ftr_fixup_prefix2);
fixup.value = fixup.mask = 8;
fixup.start_off = calc_offset(&fixup, ftr_fixup_prefix2 + 1);
fixup.end_off = calc_offset(&fixup, ftr_fixup_prefix2 + 3);
fixup.alt_start_off = calc_offset(&fixup, ftr_fixup_prefix2_alt);
fixup.alt_end_off = calc_offset(&fixup, ftr_fixup_prefix2_alt + 2);
/* Sanity check */
check(memcmp(ftr_fixup_prefix2, ftr_fixup_prefix2_orig, size) == 0);
patch_feature_section(0, &fixup);
check(memcmp(ftr_fixup_prefix2, ftr_fixup_prefix2_expected, size) == 0);
check(memcmp(ftr_fixup_prefix2, ftr_fixup_prefix2_orig, size) != 0);
}
static void __init test_prefix_word_alt_patching(void)
{
extern unsigned int ftr_fixup_prefix3[];
extern unsigned int end_ftr_fixup_prefix3[];
extern unsigned int ftr_fixup_prefix3_orig[];
extern unsigned int ftr_fixup_prefix3_expected[];
extern unsigned int ftr_fixup_prefix3_alt[];
int size = sizeof(unsigned int) * (end_ftr_fixup_prefix3 - ftr_fixup_prefix3);
fixup.value = fixup.mask = 8;
fixup.start_off = calc_offset(&fixup, ftr_fixup_prefix3 + 1);
fixup.end_off = calc_offset(&fixup, ftr_fixup_prefix3 + 4);
fixup.alt_start_off = calc_offset(&fixup, ftr_fixup_prefix3_alt);
fixup.alt_end_off = calc_offset(&fixup, ftr_fixup_prefix3_alt + 3);
/* Sanity check */
check(memcmp(ftr_fixup_prefix3, ftr_fixup_prefix3_orig, size) == 0);
patch_feature_section(0, &fixup);
check(memcmp(ftr_fixup_prefix3, ftr_fixup_prefix3_expected, size) == 0);
patch_feature_section(0, &fixup);
check(memcmp(ftr_fixup_prefix3, ftr_fixup_prefix3_orig, size) != 0);
}
#else
static inline void test_prefix_patching(void) {}
static inline void test_prefix_alt_patching(void) {}
static inline void test_prefix_word_alt_patching(void) {}
#endif /* CONFIG_PPC64 */
static int __init test_feature_fixups(void)
{
printk(KERN_DEBUG "Running feature fixup self-tests ...\n");
test_basic_patching();
test_alternative_patching();
test_alternative_case_too_big();
test_alternative_case_too_small();
test_alternative_case_with_branch();
test_alternative_case_with_external_branch();
test_alternative_case_with_branch_to_end();
test_cpu_macros();
test_fw_macros();
test_lwsync_macros();
test_prefix_patching();
test_prefix_alt_patching();
test_prefix_word_alt_patching();
return 0;
}
late_initcall(test_feature_fixups);
#endif /* CONFIG_FTR_FIXUP_SELFTEST */