Commit ef714f15 authored by Benjamin Berg's avatar Benjamin Berg Committed by Johannes Berg
Browse files

um: remove force_flush_all from fork_handler 



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: default avatarBenjamin Berg <benjamin.berg@intel.com>
Link: https://patch.msgid.link/20240703134536.1161108-11-benjamin@sipsolutions.net


Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
parent 5168f6b4

arch/um/include/asm/mmu_context.h

+0 −2
Original line number Diff line number Diff line
@@ -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)

{

arch/um/kernel/process.c

+0 −2
Original line number Diff line number Diff line
@@ -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);



	/*

arch/um/kernel/tlb.c

+15 −29
Original line number Diff line number Diff line
@@ -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);

}