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/openrisc/kernel/traps.c | 5 ++++- arch/openrisc/mm/fault.c | 1 + 2 files changed, 5 insertions(+), 1 deletion(-) (limited to 'arch/openrisc') diff --git a/arch/openrisc/kernel/traps.c b/arch/openrisc/kernel/traps.c index 113c175fe469..1610b1d65a11 100644 --- a/arch/openrisc/kernel/traps.c +++ b/arch/openrisc/kernel/traps.c @@ -251,7 +251,7 @@ void __init trap_init(void) asmlinkage void do_trap(struct pt_regs *regs, unsigned long address) { siginfo_t info; - memset(&info, 0, sizeof(info)); + clear_siginfo(&info); info.si_signo = SIGTRAP; info.si_code = TRAP_TRACE; info.si_addr = (void *)address; @@ -266,6 +266,7 @@ asmlinkage void do_unaligned_access(struct pt_regs *regs, unsigned long address) if (user_mode(regs)) { /* Send a SIGBUS */ + clear_siginfo(&info); info.si_signo = SIGBUS; info.si_errno = 0; info.si_code = BUS_ADRALN; @@ -285,6 +286,7 @@ asmlinkage void do_bus_fault(struct pt_regs *regs, unsigned long address) if (user_mode(regs)) { /* Send a SIGBUS */ + clear_siginfo(&info); info.si_signo = SIGBUS; info.si_errno = 0; info.si_code = BUS_ADRERR; @@ -485,6 +487,7 @@ asmlinkage void do_illegal_instruction(struct pt_regs *regs, if (user_mode(regs)) { /* Send a SIGILL */ + clear_siginfo(&info); info.si_signo = SIGILL; info.si_errno = 0; info.si_code = ILL_ILLOPC; diff --git a/arch/openrisc/mm/fault.c b/arch/openrisc/mm/fault.c index d0021dfae20a..68be33e4ae17 100644 --- a/arch/openrisc/mm/fault.c +++ b/arch/openrisc/mm/fault.c @@ -56,6 +56,7 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long address, int fault; unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE; + clear_siginfo(&info); tsk = current; /* -- cgit From 75bfb9a1c89ae1f28cd09f7ae0d236ebde9b97ec Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Sun, 15 Apr 2018 20:14:10 -0500 Subject: signal/openrisc: 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: Jonas Bonn Cc: Stefan Kristiansson Cc: Stafford Horne Cc: openrisc@lists.librecores.org Signed-off-by: "Eric W. Biederman" --- arch/openrisc/kernel/traps.c | 33 ++++----------------------------- arch/openrisc/mm/fault.c | 19 +++++-------------- 2 files changed, 9 insertions(+), 43 deletions(-) (limited to 'arch/openrisc') diff --git a/arch/openrisc/kernel/traps.c b/arch/openrisc/kernel/traps.c index 1610b1d65a11..fac246e6f37a 100644 --- a/arch/openrisc/kernel/traps.c +++ b/arch/openrisc/kernel/traps.c @@ -250,28 +250,16 @@ void __init trap_init(void) asmlinkage void do_trap(struct pt_regs *regs, unsigned long address) { - siginfo_t info; - clear_siginfo(&info); - info.si_signo = SIGTRAP; - info.si_code = TRAP_TRACE; - info.si_addr = (void *)address; - force_sig_info(SIGTRAP, &info, current); + force_sig_fault(SIGTRAP, TRAP_TRACE, (void __user *)address, current); regs->pc += 4; } asmlinkage void do_unaligned_access(struct pt_regs *regs, unsigned long address) { - siginfo_t info; - if (user_mode(regs)) { /* Send a SIGBUS */ - clear_siginfo(&info); - info.si_signo = SIGBUS; - info.si_errno = 0; - info.si_code = BUS_ADRALN; - info.si_addr = (void __user *)address; - force_sig_info(SIGBUS, &info, current); + force_sig_fault(SIGBUS, BUS_ADRALN, (void __user *)address, current); } else { printk("KERNEL: Unaligned Access 0x%.8lx\n", address); show_registers(regs); @@ -282,16 +270,9 @@ asmlinkage void do_unaligned_access(struct pt_regs *regs, unsigned long address) asmlinkage void do_bus_fault(struct pt_regs *regs, unsigned long address) { - siginfo_t info; - if (user_mode(regs)) { /* Send a SIGBUS */ - clear_siginfo(&info); - info.si_signo = SIGBUS; - info.si_errno = 0; - info.si_code = BUS_ADRERR; - info.si_addr = (void *)address; - force_sig_info(SIGBUS, &info, current); + force_sig_fault(SIGBUS, BUS_ADRERR, (void __user *)address, current); } else { /* Kernel mode */ printk("KERNEL: Bus error (SIGBUS) 0x%.8lx\n", address); show_registers(regs); @@ -466,7 +447,6 @@ static inline void simulate_swa(struct pt_regs *regs, unsigned long address, asmlinkage void do_illegal_instruction(struct pt_regs *regs, unsigned long address) { - siginfo_t info; unsigned int op; unsigned int insn = *((unsigned int *)address); @@ -487,12 +467,7 @@ asmlinkage void do_illegal_instruction(struct pt_regs *regs, if (user_mode(regs)) { /* Send a SIGILL */ - clear_siginfo(&info); - info.si_signo = SIGILL; - info.si_errno = 0; - info.si_code = ILL_ILLOPC; - info.si_addr = (void *)address; - force_sig_info(SIGBUS, &info, current); + force_sig_fault(SIGILL, ILL_ILLOPC, (void __user *)address, current); } else { /* Kernel mode */ printk("KERNEL: Illegal instruction (SIGILL) 0x%.8lx\n", address); diff --git a/arch/openrisc/mm/fault.c b/arch/openrisc/mm/fault.c index 68be33e4ae17..9f011d16cc46 100644 --- a/arch/openrisc/mm/fault.c +++ b/arch/openrisc/mm/fault.c @@ -52,11 +52,10 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long address, struct task_struct *tsk; struct mm_struct *mm; struct vm_area_struct *vma; - siginfo_t info; + int si_code; int fault; unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE; - clear_siginfo(&info); tsk = current; /* @@ -98,7 +97,7 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long address, } mm = tsk->mm; - info.si_code = SEGV_MAPERR; + si_code = SEGV_MAPERR; /* * If we're in an interrupt or have no user @@ -140,7 +139,7 @@ retry: */ good_area: - info.si_code = SEGV_ACCERR; + si_code = SEGV_ACCERR; /* first do some preliminary protection checks */ @@ -214,11 +213,7 @@ bad_area_nosemaphore: /* User mode accesses just cause a SIGSEGV */ if (user_mode(regs)) { - info.si_signo = SIGSEGV; - info.si_errno = 0; - /* info.si_code has been set above */ - info.si_addr = (void *)address; - force_sig_info(SIGSEGV, &info, tsk); + force_sig_fault(SIGSEGV, si_code, (void __user *)address, tsk); return; } @@ -283,11 +278,7 @@ do_sigbus: * Send a sigbus, regardless of whether we were in kernel * or user mode. */ - info.si_signo = SIGBUS; - info.si_errno = 0; - info.si_code = BUS_ADRERR; - info.si_addr = (void *)address; - force_sig_info(SIGBUS, &info, tsk); + force_sig_fault(SIGBUS, BUS_ADRERR, (void __user *)address, tsk); /* Kernel mode? Handle exceptions or die */ if (!user_mode(regs)) -- cgit