[PATCH 3/4] arm64: hwpoison: add VM_FAULT_HWPOISON[_LARGE] handling
From: Punit Agrawal <hidden>
Date: 2017-03-30 16:39:52
Also in:
linux-mm, lkml
Subsystem:
arm64 port (aarch64 architecture), the rest · Maintainers:
Catalin Marinas, Will Deacon, Linus Torvalds
From: "Jonathan (Zhixiong) Zhang" <redacted> Add VM_FAULT_HWPOISON[_LARGE] handling to the arm64 page fault handler. Handling of VM_FAULT_HWPOISON[_LARGE] is very similar to VM_FAULT_OOM, the only difference is that a different si_code (BUS_MCEERR_AR) is passed to user space and si_addr_lsb field is initialized. Signed-off-by: Jonathan (Zhixiong) Zhang <redacted> Signed-off-by: Tyler Baicar <redacted> Signed-off-by: Punit Agrawal <redacted> --- arch/arm64/mm/fault.c | 22 +++++++++++++++++++--- 1 file changed, 19 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
index 4bf899fb451b..212c862b2fd0 100644
--- a/arch/arm64/mm/fault.c
+++ b/arch/arm64/mm/fault.c@@ -31,6 +31,7 @@ #include <linux/highmem.h> #include <linux/perf_event.h> #include <linux/preempt.h> +#include <linux/hugetlb.h> #include <asm/bug.h> #include <asm/cpufeature.h>
@@ -194,9 +195,10 @@ static void __do_kernel_fault(struct mm_struct *mm, unsigned long addr, */ static void __do_user_fault(struct task_struct *tsk, unsigned long addr, unsigned int esr, unsigned int sig, int code, - struct pt_regs *regs) + struct pt_regs *regs, int fault) { struct siginfo si; + unsigned int lsb = 0; if (unhandled_signal(tsk, sig) && show_unhandled_signals_ratelimited()) { pr_info("%s[%d]: unhandled %s (%d) at 0x%08lx, esr 0x%03x\n",
@@ -212,6 +214,17 @@ static void __do_user_fault(struct task_struct *tsk, unsigned long addr, si.si_errno = 0; si.si_code = code; si.si_addr = (void __user *)addr; + /* + * Either small page or large page may be poisoned. + * In other words, VM_FAULT_HWPOISON_LARGE and + * VM_FAULT_HWPOISON are mutually exclusive. + */ + if (fault & VM_FAULT_HWPOISON_LARGE) + lsb = hstate_index_to_shift(VM_FAULT_GET_HINDEX(fault)); + else if (fault & VM_FAULT_HWPOISON) + lsb = PAGE_SHIFT; + si.si_addr_lsb = lsb; + force_sig_info(sig, &si, tsk); }
@@ -225,7 +238,7 @@ static void do_bad_area(unsigned long addr, unsigned int esr, struct pt_regs *re * handle this fault with. */ if (user_mode(regs)) - __do_user_fault(tsk, addr, esr, SIGSEGV, SEGV_MAPERR, regs); + __do_user_fault(tsk, addr, esr, SIGSEGV, SEGV_MAPERR, regs, 0); else __do_kernel_fault(mm, addr, esr, regs); }
@@ -427,6 +440,9 @@ static int __kprobes do_page_fault(unsigned long addr, unsigned int esr, */ sig = SIGBUS; code = BUS_ADRERR; + } else if (fault & (VM_FAULT_HWPOISON | VM_FAULT_HWPOISON_LARGE)) { + sig = SIGBUS; + code = BUS_MCEERR_AR; } else { /* * Something tried to access memory that isn't in our memory
@@ -437,7 +453,7 @@ static int __kprobes do_page_fault(unsigned long addr, unsigned int esr, SEGV_ACCERR : SEGV_MAPERR; } - __do_user_fault(tsk, addr, esr, sig, code, regs); + __do_user_fault(tsk, addr, esr, sig, code, regs, fault); return 0; no_context:
--
2.11.0