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um: remove force_flush_all from fork_handler

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There should be no need for this. It may be that this used to work
around another issue where after a clone the MM was in a bad state.

Signed-off-by: Benjamin Berg <benjamin.berg@intel.com>
Link: https://patch.msgid.link/20240703134536.1161108-11-benjamin@sipsolutions.net
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
This commit is contained in:
Benjamin Berg 2024-07-03 15:45:34 +02:00 committed by Johannes Berg
parent 5168f6b4a4
commit ef714f1502
3 changed files with 15 additions and 33 deletions
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2
arch/um/include/asm/mmu_context.h
View File

@ -13,8 +13,6 @@
#include <asm/mm_hooks.h>
#include <asm/mmu.h>
extern void force_flush_all(void);
#define activate_mm activate_mm
static inline void activate_mm(struct mm_struct *old, struct mm_struct *new)
{

2
arch/um/kernel/process.c
View File

@ -122,8 +122,6 @@ void new_thread_handler(void)
/* Called magically, see new_thread_handler above */
static void fork_handler(void)
{
force_flush_all();
schedule_tail(current->thread.prev_sched);
/*

44
arch/um/kernel/tlb.c
View File

@ -41,17 +41,15 @@ struct host_vm_change {
int index;
struct mm_struct *mm;
void *data;
int force;
};
#define INIT_HVC(mm, force, userspace) \
#define INIT_HVC(mm, userspace) \
((struct host_vm_change) \
{ .ops = { { .type = NONE } }, \
.mm = mm, \
.data = NULL, \
.userspace = userspace, \
.index = 0, \
.force = force })
.index = 0 })
void report_enomem(void)
{
@ -235,7 +233,7 @@ static inline int update_pte_range(pmd_t *pmd, unsigned long addr,
prot = ((r ? UM_PROT_READ : 0) | (w ? UM_PROT_WRITE : 0) |
(x ? UM_PROT_EXEC : 0));
if (hvc->force || pte_newpage(*pte)) {
if (pte_newpage(*pte)) {
if (pte_present(*pte)) {
if (pte_newpage(*pte))
ret = add_mmap(addr, pte_val(*pte) & PAGE_MASK,
@ -261,7 +259,7 @@ static inline int update_pmd_range(pud_t *pud, unsigned long addr,
do {
next = pmd_addr_end(addr, end);
if (!pmd_present(*pmd)) {
if (hvc->force || pmd_newpage(*pmd)) {
if (pmd_newpage(*pmd)) {
ret = add_munmap(addr, next - addr, hvc);
pmd_mkuptodate(*pmd);
}
@ -283,7 +281,7 @@ static inline int update_pud_range(p4d_t *p4d, unsigned long addr,
do {
next = pud_addr_end(addr, end);
if (!pud_present(*pud)) {
if (hvc->force || pud_newpage(*pud)) {
if (pud_newpage(*pud)) {
ret = add_munmap(addr, next - addr, hvc);
pud_mkuptodate(*pud);
}
@ -305,7 +303,7 @@ static inline int update_p4d_range(pgd_t *pgd, unsigned long addr,
do {
next = p4d_addr_end(addr, end);
if (!p4d_present(*p4d)) {
if (hvc->force || p4d_newpage(*p4d)) {
if (p4d_newpage(*p4d)) {
ret = add_munmap(addr, next - addr, hvc);
p4d_mkuptodate(*p4d);
}
@ -316,19 +314,19 @@ static inline int update_p4d_range(pgd_t *pgd, unsigned long addr,
}
static void fix_range_common(struct mm_struct *mm, unsigned long start_addr,
unsigned long end_addr, int force)
unsigned long end_addr)
{
pgd_t *pgd;
struct host_vm_change hvc;
unsigned long addr = start_addr, next;
int ret = 0, userspace = 1;
hvc = INIT_HVC(mm, force, userspace);
hvc = INIT_HVC(mm, userspace);
pgd = pgd_offset(mm, addr);
do {
next = pgd_addr_end(addr, end_addr);
if (!pgd_present(*pgd)) {
if (force || pgd_newpage(*pgd)) {
if (pgd_newpage(*pgd)) {
ret = add_munmap(addr, next - addr, &hvc);
pgd_mkuptodate(*pgd);
}
@ -349,11 +347,11 @@ static int flush_tlb_kernel_range_common(unsigned long start, unsigned long end)
pmd_t *pmd;
pte_t *pte;
unsigned long addr, last;
int updated = 0, err = 0, force = 0, userspace = 0;
int updated = 0, err = 0, userspace = 0;
struct host_vm_change hvc;
mm = &init_mm;
hvc = INIT_HVC(mm, force, userspace);
hvc = INIT_HVC(mm, userspace);
for (addr = start; addr < end;) {
pgd = pgd_offset(mm, addr);
if (!pgd_present(*pgd)) {
@ -537,7 +535,7 @@ void __flush_tlb_one(unsigned long addr)
}
static void fix_range(struct mm_struct *mm, unsigned long start_addr,
unsigned long end_addr, int force)
unsigned long end_addr)
{
/*
* Don't bother flushing if this address space is about to be
@ -546,7 +544,7 @@ static void fix_range(struct mm_struct *mm, unsigned long start_addr,
if (atomic_read(&mm->mm_users) == 0)
return;
fix_range_common(mm, start_addr, end_addr, force);
fix_range_common(mm, start_addr, end_addr);
}
void flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
@ -554,7 +552,7 @@ void flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
{
if (vma->vm_mm == NULL)
flush_tlb_kernel_range_common(start, end);
else fix_range(vma->vm_mm, start, end, 0);
else fix_range(vma->vm_mm, start, end);
}
EXPORT_SYMBOL(flush_tlb_range);
@ -564,17 +562,5 @@ void flush_tlb_mm(struct mm_struct *mm)
VMA_ITERATOR(vmi, mm, 0);
for_each_vma(vmi, vma)
fix_range(mm, vma->vm_start, vma->vm_end, 0);
}
void force_flush_all(void)
{
struct mm_struct *mm = current->mm;
struct vm_area_struct *vma;
VMA_ITERATOR(vmi, mm, 0);
mmap_read_lock(mm);
for_each_vma(vmi, vma)
fix_range(mm, vma->vm_start, vma->vm_end, 1);
mmap_read_unlock(mm);
fix_range(mm, vma->vm_start, vma->vm_end);
}