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arm64: Unify kernel fault reporting 

In do_page_fault(), we handle some kernel faults early, and simply
die() with a message. For faults handled later, we dump the faulting
address, decode the ESR, walk the page tables, and perform a number of
steps to ensure that this data is reported.

Let's unify the handling of fatal kernel faults with a new
die_kernel_fault() helper, handling all of these details. This is
largely the same as the existing logic in __do_kernel_fault(), except
that addresses are consistently padded to 16 hex characters, as would be
expected for a 64-bit address.

The messages currently logged in do_page_fault are adjusted to fit into
the die_kernel_fault() message template.

Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
This commit is contained in:
Mark Rutland 2018-05-21 14:14:51 +01:00 committed by Catalin Marinas
parent 969e61ba87
commit c870f14ea1
1 changed files with 23 additions and 14 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

37
arch/arm64/mm/fault.c
View File

@ -255,6 +255,22 @@ static inline bool is_el1_permission_fault(unsigned int esr,
return false;
}
static void die_kernel_fault(const char *msg, unsigned long addr,
unsigned int esr, struct pt_regs *regs)
{
bust_spinlocks(1);
pr_alert("Unable to handle kernel %s at virtual address %016lx\n", msg,
addr);
mem_abort_decode(esr);
show_pte(addr);
die("Oops", regs, esr);
bust_spinlocks(0);
do_exit(SIGKILL);
}
static void __do_kernel_fault(unsigned long addr, unsigned int esr,
struct pt_regs *regs)
{
@ -267,8 +283,6 @@ static void __do_kernel_fault(unsigned long addr, unsigned int esr,
if (!is_el1_instruction_abort(esr) && fixup_exception(regs))
return;
bust_spinlocks(1);
if (is_el1_permission_fault(esr, regs, addr)) {
if (esr & ESR_ELx_WNR)
msg = "write to read-only memory";
@ -280,15 +294,7 @@ static void __do_kernel_fault(unsigned long addr, unsigned int esr,
msg = "paging request";
}
pr_alert("Unable to handle kernel %s at virtual address %08lx\n", msg,
addr);
mem_abort_decode(esr);
show_pte(addr);
die("Oops", regs, esr);
bust_spinlocks(0);
do_exit(SIGKILL);
die_kernel_fault(msg, addr, esr, regs);
}
static void __do_user_fault(struct siginfo *info, unsigned int esr)
@ -399,13 +405,16 @@ static int __kprobes do_page_fault(unsigned long addr, unsigned int esr,
if (addr < TASK_SIZE && is_el1_permission_fault(esr, regs, addr)) {
/* regs->orig_addr_limit may be 0 if we entered from EL0 */
if (regs->orig_addr_limit == KERNEL_DS)
die("Accessing user space memory with fs=KERNEL_DS", regs, esr);
die_kernel_fault("access to user memory with fs=KERNEL_DS",
addr, esr, regs);
if (is_el1_instruction_abort(esr))
die("Attempting to execute userspace memory", regs, esr);
die_kernel_fault("execution of user memory",
addr, esr, regs);
if (!search_exception_tables(regs->pc))
die("Accessing user space memory outside uaccess.h routines", regs, esr);
die_kernel_fault("access to user memory outside uaccess routines",
addr, esr, regs);
}
perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, addr);