From 3eb0f5193b497083391aa05d35210d5645211eef Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Tue, 17 Apr 2018 15:26:37 -0500 Subject: signal: Ensure every siginfo we send has all bits initialized Call clear_siginfo to ensure every stack allocated siginfo is properly initialized before being passed to the signal sending functions. Note: It is not safe to depend on C initializers to initialize struct siginfo on the stack because C is allowed to skip holes when initializing a structure. The initialization of struct siginfo in tracehook_report_syscall_exit was moved from the helper user_single_step_siginfo into tracehook_report_syscall_exit itself, to make it clear that the local variable siginfo gets fully initialized. In a few cases the scope of struct siginfo has been reduced to make it clear that siginfo siginfo is not used on other paths in the function in which it is declared. Instances of using memset to initialize siginfo have been replaced with calls clear_siginfo for clarity. Signed-off-by: "Eric W. Biederman" --- arch/nds32/mm/fault.c | 1 + 1 file changed, 1 insertion(+) (limited to 'arch/nds32/mm') diff --git a/arch/nds32/mm/fault.c b/arch/nds32/mm/fault.c index 3a246fb8098c..876ee01ff80a 100644 --- a/arch/nds32/mm/fault.c +++ b/arch/nds32/mm/fault.c @@ -77,6 +77,7 @@ void do_page_fault(unsigned long entry, unsigned long addr, unsigned int mask = VM_READ | VM_WRITE | VM_EXEC; unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE; + clear_siginfo(&info); error_code = error_code & (ITYPE_mskINST | ITYPE_mskETYPE); tsk = current; mm = tsk->mm; -- cgit v1.2.3 From d808e918ed1533132c3124be52dfcfcda16a0bf0 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Mon, 16 Apr 2018 14:58:34 -0500 Subject: signal/nds32: Use force_sig_fault where appropriate Filling in struct siginfo before calling force_sig_info a tedious and error prone process, where once in a great while the wrong fields are filled out, and siginfo has been inconsistently cleared. Simplify this process by using the helper force_sig_fault. Which takes as a parameters all of the information it needs, ensures all of the fiddly bits of filling in struct siginfo are done properly and then calls force_sig_info. In short about a 5 line reduction in code for every time force_sig_info is called, which makes the calling function clearer. Cc: Greentime Hu Cc: Vincent Chen Acked-by: Vincent Chen Signed-off-by: "Eric W. Biederman" --- arch/nds32/kernel/traps.c | 20 ++++---------------- arch/nds32/mm/fault.c | 19 +++++-------------- 2 files changed, 9 insertions(+), 30 deletions(-) (limited to 'arch/nds32/mm') diff --git a/arch/nds32/kernel/traps.c b/arch/nds32/kernel/traps.c index 46911768f4b5..a6205fd4db52 100644 --- a/arch/nds32/kernel/traps.c +++ b/arch/nds32/kernel/traps.c @@ -222,20 +222,13 @@ void die_if_kernel(const char *str, struct pt_regs *regs, int err) int bad_syscall(int n, struct pt_regs *regs) { - siginfo_t info; - if (current->personality != PER_LINUX) { send_sig(SIGSEGV, current, 1); return regs->uregs[0]; } - clear_siginfo(&info); - info.si_signo = SIGILL; - info.si_errno = 0; - info.si_code = ILL_ILLTRP; - info.si_addr = (void __user *)instruction_pointer(regs) - 4; - - force_sig_info(SIGILL, &info, current); + force_sig_fault(SIGILL, ILL_ILLTRP, + (void __user *)instruction_pointer(regs) - 4, current); die_if_kernel("Oops - bad syscall", regs, n); return regs->uregs[0]; } @@ -288,16 +281,11 @@ void __init early_trap_init(void) void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs, int error_code, int si_code) { - struct siginfo info; - tsk->thread.trap_no = ENTRY_DEBUG_RELATED; tsk->thread.error_code = error_code; - clear_siginfo(&info); - info.si_signo = SIGTRAP; - info.si_code = si_code; - info.si_addr = (void __user *)instruction_pointer(regs); - force_sig_info(SIGTRAP, &info, tsk); + force_sig_fault(SIGTRAP, si_code, + (void __user *)instruction_pointer(regs), tsk); } void do_debug_trap(unsigned long entry, unsigned long addr, diff --git a/arch/nds32/mm/fault.c b/arch/nds32/mm/fault.c index 876ee01ff80a..9bdb7c3ecbb6 100644 --- a/arch/nds32/mm/fault.c +++ b/arch/nds32/mm/fault.c @@ -72,16 +72,15 @@ void do_page_fault(unsigned long entry, unsigned long addr, struct task_struct *tsk; struct mm_struct *mm; struct vm_area_struct *vma; - siginfo_t info; + int si_code; int fault; unsigned int mask = VM_READ | VM_WRITE | VM_EXEC; unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE; - clear_siginfo(&info); error_code = error_code & (ITYPE_mskINST | ITYPE_mskETYPE); tsk = current; mm = tsk->mm; - info.si_code = SEGV_MAPERR; + si_code = SEGV_MAPERR; /* * We fault-in kernel-space virtual memory on-demand. The * 'reference' page table is init_mm.pgd. @@ -162,7 +161,7 @@ retry: */ good_area: - info.si_code = SEGV_ACCERR; + si_code = SEGV_ACCERR; /* first do some preliminary protection checks */ if (entry == ENTRY_PTE_NOT_PRESENT) { @@ -267,11 +266,7 @@ bad_area_nosemaphore: tsk->thread.address = addr; tsk->thread.error_code = error_code; tsk->thread.trap_no = entry; - info.si_signo = SIGSEGV; - info.si_errno = 0; - /* info.si_code has been set above */ - info.si_addr = (void *)addr; - force_sig_info(SIGSEGV, &info, tsk); + force_sig_fault(SIGSEGV, si_code, (void __user *)addr, tsk); return; } @@ -340,11 +335,7 @@ do_sigbus: tsk->thread.address = addr; tsk->thread.error_code = error_code; tsk->thread.trap_no = entry; - info.si_signo = SIGBUS; - info.si_errno = 0; - info.si_code = BUS_ADRERR; - info.si_addr = (void *)addr; - force_sig_info(SIGBUS, &info, tsk); + force_sig_fault(SIGBUS, BUS_ADRERR, (void __user *)addr, tsk); return; -- cgit v1.2.3