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arm64 fixes:

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- Restore previous SIGBUS behaviour for unhandled unaligned user accesses
 
 - Revert broken support for the contiguous bit in hugetlb (again...)
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Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 fixes from Will Deacon:
 "We've got a regression fix for the signal raised when userspace makes
  an unsupported unaligned access and a revert of the contiguous
  (hugepte) support for hugetlb, which has once again been found to be
  broken. One day, maybe, we'll get it right.

  Summary:

   - restore previous SIGBUS behaviour for unhandled unaligned user
     accesses

   - revert broken support for the contiguous bit in hugetlb (again...)"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  Revert "Revert "arm64: hugetlb: partial revert of 66b3923a1a0f""
  arm64: mm: unaligned access by user-land should be received as SIGBUS
This commit is contained in:
Linus Torvalds 2017-04-07 10:43:22 -07:00
commit dc25ad3fe1
2 changed files with 24 additions and 32 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

42
arch/arm64/mm/fault.c
View File

@ -42,7 +42,20 @@
#include <asm/pgtable.h>
#include <asm/tlbflush.h>
static const char *fault_name(unsigned int esr);
struct fault_info {
int (*fn)(unsigned long addr, unsigned int esr,
struct pt_regs *regs);
int sig;
int code;
const char *name;
};
static const struct fault_info fault_info[];
static inline const struct fault_info *esr_to_fault_info(unsigned int esr)
{
return fault_info + (esr & 63);
}
#ifdef CONFIG_KPROBES
static inline int notify_page_fault(struct pt_regs *regs, unsigned int esr)
@ -197,10 +210,12 @@ static void __do_user_fault(struct task_struct *tsk, unsigned long addr,
struct pt_regs *regs)
{
struct siginfo si;
const struct fault_info *inf;
if (unhandled_signal(tsk, sig) && show_unhandled_signals_ratelimited()) {
inf = esr_to_fault_info(esr);
pr_info("%s[%d]: unhandled %s (%d) at 0x%08lx, esr 0x%03x\n",
tsk->comm, task_pid_nr(tsk), fault_name(esr), sig,
tsk->comm, task_pid_nr(tsk), inf->name, sig,
addr, esr);
show_pte(tsk->mm, addr);
show_regs(regs);
@ -219,14 +234,16 @@ static void do_bad_area(unsigned long addr, unsigned int esr, struct pt_regs *re
{
struct task_struct *tsk = current;
struct mm_struct *mm = tsk->active_mm;
const struct fault_info *inf;
/*
* If we are in kernel mode at this point, we have no context to
* handle this fault with.
*/
if (user_mode(regs))
__do_user_fault(tsk, addr, esr, SIGSEGV, SEGV_MAPERR, regs);
else
if (user_mode(regs)) {
inf = esr_to_fault_info(esr);
__do_user_fault(tsk, addr, esr, inf->sig, inf->code, regs);
} else
__do_kernel_fault(mm, addr, esr, regs);
}
@ -488,12 +505,7 @@ static int do_bad(unsigned long addr, unsigned int esr, struct pt_regs *regs)
return 1;
}
static const struct fault_info {
int (*fn)(unsigned long addr, unsigned int esr, struct pt_regs *regs);
int sig;
int code;
const char *name;
} fault_info[] = {
static const struct fault_info fault_info[] = {
{ do_bad, SIGBUS, 0, "ttbr address size fault" },
{ do_bad, SIGBUS, 0, "level 1 address size fault" },
{ do_bad, SIGBUS, 0, "level 2 address size fault" },
@ -560,19 +572,13 @@ static const struct fault_info {
{ do_bad, SIGBUS, 0, "unknown 63" },
};
static const char *fault_name(unsigned int esr)
{
const struct fault_info *inf = fault_info + (esr & 63);
return inf->name;
}
/*
* Dispatch a data abort to the relevant handler.
*/
asmlinkage void __exception do_mem_abort(unsigned long addr, unsigned int esr,
struct pt_regs *regs)
{
const struct fault_info *inf = fault_info + (esr & 63);
const struct fault_info *inf = esr_to_fault_info(esr);
struct siginfo info;
if (!inf->fn(addr, esr, regs))

14
arch/arm64/mm/hugetlbpage.c
View File

@ -294,10 +294,6 @@ static __init int setup_hugepagesz(char *opt)
hugetlb_add_hstate(PMD_SHIFT - PAGE_SHIFT);
} else if (ps == PUD_SIZE) {
hugetlb_add_hstate(PUD_SHIFT - PAGE_SHIFT);
} else if (ps == (PAGE_SIZE * CONT_PTES)) {
hugetlb_add_hstate(CONT_PTE_SHIFT);
} else if (ps == (PMD_SIZE * CONT_PMDS)) {
hugetlb_add_hstate((PMD_SHIFT + CONT_PMD_SHIFT) - PAGE_SHIFT);
} else {
hugetlb_bad_size();
pr_err("hugepagesz: Unsupported page size %lu K\n", ps >> 10);
@ -306,13 +302,3 @@ static __init int setup_hugepagesz(char *opt)
return 1;
}
__setup("hugepagesz=", setup_hugepagesz);
#ifdef CONFIG_ARM64_64K_PAGES
static __init int add_default_hugepagesz(void)
{
if (size_to_hstate(CONT_PTES * PAGE_SIZE) == NULL)
hugetlb_add_hstate(CONT_PTE_SHIFT);
return 0;
}
arch_initcall(add_default_hugepagesz);
#endif