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: 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>

diff --git a/arch/um/include/asm/mmu_context.h b/arch/um/include/asm/mmu_context.h
index 68e2eb9cfb476a0efe6a10a33d1ead6b402e385f..23dcc914d44e8cd492ed692ce1ab92cdad0ddb25 100644 (file)
--- a/arch/um/include/asm/mmu_context.h
+++ b/arch/um/include/asm/mmu_context.h
@@ -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)
 {

diff --git a/arch/um/kernel/process.c b/arch/um/kernel/process.c
index 79f41f06a98fbb4c6aa0f873c82a8eaf9537afc1..f36b63f53babd4719edd57125799acca6566071e 100644 (file)
--- a/arch/um/kernel/process.c
+++ b/arch/um/kernel/process.c
@@ -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);
 
        /*

diff --git a/arch/um/kernel/tlb.c b/arch/um/kernel/tlb.c
index 1eee7134cba81f7f33c59e1243d8e68a30ed8679..4f482b881adcf641ec6596da7bd7795a213878e5 100644 (file)
--- a/arch/um/kernel/tlb.c
+++ b/arch/um/kernel/tlb.c
@@ -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);
 }