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riscv/mm/fault: Move vmalloc fault handling to vmalloc_fault()

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This patch moves the vmalloc fault handling in do_page_fault() to
vmalloc_fault() function and converts gotos to calls to the new
function.

Signed-off-by: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
This commit is contained in:
Pekka Enberg 2020-08-25 18:54:26 +03:00 committed by Palmer Dabbelt
parent a51271d99c
commit ac416a724f
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GPG Key ID: 2E1319F35FBB1889
1 changed files with 82 additions and 82 deletions
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164
arch/riscv/mm/fault.c
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@ -53,6 +53,84 @@ static inline void bad_area(struct pt_regs *regs, struct mm_struct *mm, int code
no_context(regs, addr);
}
static void inline vmalloc_fault(struct pt_regs *regs, int code, unsigned long addr)
{
pgd_t *pgd, *pgd_k;
pud_t *pud, *pud_k;
p4d_t *p4d, *p4d_k;
pmd_t *pmd, *pmd_k;
pte_t *pte_k;
int index;
/* User mode accesses just cause a SIGSEGV */
if (user_mode(regs))
return do_trap(regs, SIGSEGV, code, addr);
/*
* Synchronize this task's top level page-table
* with the 'reference' page table.
*
* Do _not_ use "tsk->active_mm->pgd" here.
* We might be inside an interrupt in the middle
* of a task switch.
*/
index = pgd_index(addr);
pgd = (pgd_t *)pfn_to_virt(csr_read(CSR_SATP)) + index;
pgd_k = init_mm.pgd + index;
if (!pgd_present(*pgd_k)) {
no_context(regs, addr);
return;
}
set_pgd(pgd, *pgd_k);
p4d = p4d_offset(pgd, addr);
p4d_k = p4d_offset(pgd_k, addr);
if (!p4d_present(*p4d_k)) {
no_context(regs, addr);
return;
}
pud = pud_offset(p4d, addr);
pud_k = pud_offset(p4d_k, addr);
if (!pud_present(*pud_k)) {
no_context(regs, addr);
return;
}
/*
* Since the vmalloc area is global, it is unnecessary
* to copy individual PTEs
*/
pmd = pmd_offset(pud, addr);
pmd_k = pmd_offset(pud_k, addr);
if (!pmd_present(*pmd_k)) {
no_context(regs, addr);
return;
}
set_pmd(pmd, *pmd_k);
/*
* Make sure the actual PTE exists as well to
* catch kernel vmalloc-area accesses to non-mapped
* addresses. If we don't do this, this will just
* silently loop forever.
*/
pte_k = pte_offset_kernel(pmd_k, addr);
if (!pte_present(*pte_k)) {
no_context(regs, addr);
return;
}
/*
* The kernel assumes that TLBs don't cache invalid
* entries, but in RISC-V, SFENCE.VMA specifies an
* ordering constraint, not a cache flush; it is
* necessary even after writing invalid entries.
*/
local_flush_tlb_page(addr);
}
/*
* This routine handles page faults. It determines the address and the
* problem, and then passes it off to one of the appropriate routines.
@ -82,8 +160,10 @@ asmlinkage void do_page_fault(struct pt_regs *regs)
* only copy the information from the master page table,
* nothing more.
*/
if (unlikely((addr >= VMALLOC_START) && (addr <= VMALLOC_END)))
goto vmalloc_fault;
if (unlikely((addr >= VMALLOC_START) && (addr <= VMALLOC_END))) {
vmalloc_fault(regs, code, addr);
return;
}
/* Enable interrupts if they were enabled in the parent context. */
if (likely(regs->status & SR_PIE))
@ -211,84 +291,4 @@ asmlinkage void do_page_fault(struct pt_regs *regs)
}
do_trap(regs, SIGBUS, BUS_ADRERR, addr);
return;
vmalloc_fault:
{
pgd_t *pgd, *pgd_k;
pud_t *pud, *pud_k;
p4d_t *p4d, *p4d_k;
pmd_t *pmd, *pmd_k;
pte_t *pte_k;
int index;
/* User mode accesses just cause a SIGSEGV */
if (user_mode(regs))
return do_trap(regs, SIGSEGV, code, addr);
/*
* Synchronize this task's top level page-table
* with the 'reference' page table.
*
* Do _not_ use "tsk->active_mm->pgd" here.
* We might be inside an interrupt in the middle
* of a task switch.
*/
index = pgd_index(addr);
pgd = (pgd_t *)pfn_to_virt(csr_read(CSR_SATP)) + index;
pgd_k = init_mm.pgd + index;
if (!pgd_present(*pgd_k)) {
no_context(regs, addr);
return;
}
set_pgd(pgd, *pgd_k);
p4d = p4d_offset(pgd, addr);
p4d_k = p4d_offset(pgd_k, addr);
if (!p4d_present(*p4d_k)) {
no_context(regs, addr);
return;
}
pud = pud_offset(p4d, addr);
pud_k = pud_offset(p4d_k, addr);
if (!pud_present(*pud_k)) {
no_context(regs, addr);
return;
}
/*
* Since the vmalloc area is global, it is unnecessary
* to copy individual PTEs
*/
pmd = pmd_offset(pud, addr);
pmd_k = pmd_offset(pud_k, addr);
if (!pmd_present(*pmd_k)) {
no_context(regs, addr);
return;
}
set_pmd(pmd, *pmd_k);
/*
* Make sure the actual PTE exists as well to
* catch kernel vmalloc-area accesses to non-mapped
* addresses. If we don't do this, this will just
* silently loop forever.
*/
pte_k = pte_offset_kernel(pmd_k, addr);
if (!pte_present(*pte_k)) {
no_context(regs, addr);
return;
}
/*
* The kernel assumes that TLBs don't cache invalid
* entries, but in RISC-V, SFENCE.VMA specifies an
* ordering constraint, not a cache flush; it is
* necessary even after writing invalid entries.
*/
local_flush_tlb_page(addr);
return;
}
}