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author | Victor Kamensky <kamensky@cisco.com> | 2017-04-04 05:51:01 (GMT) |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-04-12 10:41:11 (GMT) |
commit | 3715dbf77f3bcbd82f447b50e3310f5139028cde (patch) | |
tree | 4af41fbf8985cd10cfb54766c81bf8eeeeb041b2 /arch/arm64 | |
parent | 71b44ef83d2a74e1be9053f80455f62086fae822 (diff) | |
download | linux-3715dbf77f3bcbd82f447b50e3310f5139028cde.tar.xz |
arm64: mm: unaligned access by user-land should be received as SIGBUS
commit 09a6adf53d42ca3088fa3fb41f40b768efc711ed upstream.
After 52d7523 (arm64: mm: allow the kernel to handle alignment faults on
user accesses) commit user-land accesses that produce unaligned exceptions
like in case of aarch32 ldm/stm/ldrd/strd instructions operating on
unaligned memory received by user-land as SIGSEGV. It is wrong, it should
be reported as SIGBUS as it was before 52d7523 commit.
Changed do_bad_area function to take signal and code parameters out of esr
value using fault_info table, so in case of do_alignment_fault fault
user-land will receive SIGBUS. Wrapped access to fault_info table into
esr_to_fault_info function.
Fixes: 52d7523 (arm64: mm: allow the kernel to handle alignment faults on user accesses)
Signed-off-by: Victor Kamensky <kamensky@cisco.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/arm64')
-rw-r--r-- | arch/arm64/mm/fault.c | 42 |
1 files changed, 24 insertions, 18 deletions
diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c index 0f87883..8b8ac3d 100644 --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c @@ -41,7 +41,20 @@ #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) @@ -196,10 +209,12 @@ 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); @@ -218,14 +233,16 @@ 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); } @@ -481,12 +498,7 @@ 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" }, @@ -553,19 +565,13 @@ 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)) |