diff options
| -rw-r--r-- | arch/sparc/kernel/signal32.c | 102 |
1 files changed, 60 insertions, 42 deletions
diff --git a/arch/sparc/kernel/signal32.c b/arch/sparc/kernel/signal32.c index ea22cd373c6..76b67c4c6aa 100644 --- a/arch/sparc/kernel/signal32.c +++ b/arch/sparc/kernel/signal32.c @@ -453,6 +453,64 @@ static int save_fpu_state32(struct pt_regs *regs, __siginfo_fpu_t __user *fpu) return err; } +/* The I-cache flush instruction only works in the primary ASI, which + * right now is the nucleus, aka. kernel space. + * + * Therefore we have to kick the instructions out using the kernel + * side linear mapping of the physical address backing the user + * instructions. + */ +static void flush_signal_insns(unsigned long address) +{ + unsigned long pstate, paddr; + pte_t *ptep, pte; + pgd_t *pgdp; + pud_t *pudp; + pmd_t *pmdp; + + /* Commit all stores of the instructions we are about to flush. */ + wmb(); + + /* Disable cross-call reception. In this way even a very wide + * munmap() on another cpu can't tear down the page table + * hierarchy from underneath us, since that can't complete + * until the IPI tlb flush returns. + */ + + __asm__ __volatile__("rdpr %%pstate, %0" : "=r" (pstate)); + __asm__ __volatile__("wrpr %0, %1, %%pstate" + : : "r" (pstate), "i" (PSTATE_IE)); + + pgdp = pgd_offset(current->mm, address); + if (pgd_none(*pgdp)) + goto out_irqs_on; + pudp = pud_offset(pgdp, address); + if (pud_none(*pudp)) + goto out_irqs_on; + pmdp = pmd_offset(pudp, address); + if (pmd_none(*pmdp)) + goto out_irqs_on; + + ptep = pte_offset_map(pmdp, address); + pte = *ptep; + if (!pte_present(pte)) + goto out_unmap; + + paddr = (unsigned long) page_address(pte_page(pte)); + + __asm__ __volatile__("flush %0 + %1" + : /* no outputs */ + : "r" (paddr), + "r" (address & (PAGE_SIZE - 1)) + : "memory"); + +out_unmap: + pte_unmap(ptep); +out_irqs_on: + __asm__ __volatile__("wrpr %0, 0x0, %%pstate" : : "r" (pstate)); + +} + static void setup_frame32(struct k_sigaction *ka, struct pt_regs *regs, int signo, sigset_t *oldset) { @@ -547,13 +605,7 @@ static void setup_frame32(struct k_sigaction *ka, struct pt_regs *regs, if (ka->ka_restorer) { regs->u_regs[UREG_I7] = (unsigned long)ka->ka_restorer; } else { - /* Flush instruction space. */ unsigned long address = ((unsigned long)&(sf->insns[0])); - pgd_t *pgdp = pgd_offset(current->mm, address); - pud_t *pudp = pud_offset(pgdp, address); - pmd_t *pmdp = pmd_offset(pudp, address); - pte_t *ptep; - pte_t pte; regs->u_regs[UREG_I7] = (unsigned long) (&(sf->insns[0]) - 2); @@ -562,22 +614,7 @@ static void setup_frame32(struct k_sigaction *ka, struct pt_regs *regs, if (err) goto sigsegv; - preempt_disable(); - ptep = pte_offset_map(pmdp, address); - pte = *ptep; - if (pte_present(pte)) { - unsigned long page = (unsigned long) - page_address(pte_page(pte)); - - wmb(); - __asm__ __volatile__("flush %0 + %1" - : /* no outputs */ - : "r" (page), - "r" (address & (PAGE_SIZE - 1)) - : "memory"); - } - pte_unmap(ptep); - preempt_enable(); + flush_signal_insns(address); } return; @@ -687,12 +724,7 @@ static void setup_rt_frame32(struct k_sigaction *ka, struct pt_regs *regs, if (ka->ka_restorer) regs->u_regs[UREG_I7] = (unsigned long)ka->ka_restorer; else { - /* Flush instruction space. */ unsigned long address = ((unsigned long)&(sf->insns[0])); - pgd_t *pgdp = pgd_offset(current->mm, address); - pud_t *pudp = pud_offset(pgdp, address); - pmd_t *pmdp = pmd_offset(pudp, address); - pte_t *ptep; regs->u_regs[UREG_I7] = (unsigned long) (&(sf->insns[0]) - 2); @@ -704,21 +736,7 @@ static void setup_rt_frame32(struct k_sigaction *ka, struct pt_regs *regs, if (err) goto sigsegv; - preempt_disable(); - ptep = pte_offset_map(pmdp, address); - if (pte_present(*ptep)) { - unsigned long page = (unsigned long) - page_address(pte_page(*ptep)); - - wmb(); - __asm__ __volatile__("flush %0 + %1" - : /* no outputs */ - : "r" (page), - "r" (address & (PAGE_SIZE - 1)) - : "memory"); - } - pte_unmap(ptep); - preempt_enable(); + flush_signal_insns(address); } return; |