On Tue, Jun 26, 2018 at 10:05 PM, Ingo Molnar <[email protected]> wrote: > > * Dmitry Vyukov <[email protected]> wrote: > >> From: Dmitry Vyukov <[email protected]> >> >> KERN_CONT leads to split lines in kernel output >> and complicates useful changes to printk like >> printing context before each line. >> >> Only acceptable use of continuations is basically >> boot-time testing. >> >> Get rid of it. >> >> Also tidy up code around as asked by reviewers. >> >> Signed-off-by: Dmitry Vyukov <[email protected]> >> Reviewed-by: Sergey Senozhatsky <[email protected]> >> >> --- >> >> Changes since v1: >> - use pr_alert() instead of printk(KERN_ALERT) >> >> Changes since v2: >> - drop unnecessary parenthesis >> - remove once used nx_warning and smep_warning >> --- >> arch/x86/mm/fault.c | 21 +++++++-------------- >> 1 file changed, 7 insertions(+), 14 deletions(-) >> >> diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c >> index 9a84a0d08727..a73575cacfd9 100644 >> --- a/arch/x86/mm/fault.c >> +++ b/arch/x86/mm/fault.c >> @@ -641,11 +641,6 @@ static int is_f00f_bug(struct pt_regs *regs, unsigned >> long address) >> return 0; >> } >> >> -static const char nx_warning[] = KERN_CRIT >> -"kernel tried to execute NX-protected page - exploit attempt? (uid: %d)\n"; >> -static const char smep_warning[] = KERN_CRIT >> -"unable to execute userspace code (SMEP?) (uid: %d)\n"; >> - >> static void >> show_fault_oops(struct pt_regs *regs, unsigned long error_code, >> unsigned long address) >> @@ -664,20 +659,18 @@ show_fault_oops(struct pt_regs *regs, unsigned long >> error_code, >> pte = lookup_address_in_pgd(pgd, address, &level); >> >> if (pte && pte_present(*pte) && !pte_exec(*pte)) >> - printk(nx_warning, from_kuid(&init_user_ns, >> current_uid())); >> + pr_crit("kernel tried to execute NX-protected page - >> exploit attempt? (uid: %d)\n", >> + from_kuid(&init_user_ns, current_uid())); >> if (pte && pte_present(*pte) && pte_exec(*pte) && >> (pgd_flags(*pgd) & _PAGE_USER) && >> (__read_cr4() & X86_CR4_SMEP)) >> - printk(smep_warning, from_kuid(&init_user_ns, >> current_uid())); >> + pr_crit("unable to execute userspace code (SMEP?) >> (uid: %d)\n", >> + from_kuid(&init_user_ns, current_uid())); >> } >> >> - printk(KERN_ALERT "BUG: unable to handle kernel "); >> - if (address < PAGE_SIZE) >> - printk(KERN_CONT "NULL pointer dereference"); >> - else >> - printk(KERN_CONT "paging request"); >> - >> - printk(KERN_CONT " at %px\n", (void *) address); >> + pr_alert("BUG: unable to handle kernel %s at %px\n", >> + address < PAGE_SIZE ? "NULL pointer dereference" : >> + "paging request", (void *) address); > > I already applied the last hunk in a bit different way - could you send the > rest > as a separate clean-up patch please?
Just mailed "arch/x86: cleanup show_fault_oops()".
