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/m68k/kernel/traps.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'arch/m68k') diff --git a/arch/m68k/kernel/traps.c b/arch/m68k/kernel/traps.c index c1cc4e99aa94..0a00b476236d 100644 --- a/arch/m68k/kernel/traps.c +++ b/arch/m68k/kernel/traps.c @@ -1011,6 +1011,7 @@ asmlinkage void trap_c(struct frame *fp) int vector = (fp->ptregs.vector >> 2) & 0xff; siginfo_t info; + clear_siginfo(&info); if (fp->ptregs.sr & PS_S) { if (vector == VEC_TRACE) { /* traced a trapping instruction on a 68020/30, @@ -1163,6 +1164,7 @@ asmlinkage void fpemu_signal(int signal, int code, void *addr) { siginfo_t info; + clear_siginfo(&info); info.si_signo = signal; info.si_errno = 0; info.si_code = code; -- cgit v1.2.3 From 3c67075d5df21f6bdb1dade1f2ab7e82ef0c0f6a Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Mon, 16 Apr 2018 11:25:17 -0500 Subject: signal/m68k: 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: Geert Uytterhoeven Cc: linux-m68k@lists.linux-m68k.org Signed-off-by: "Eric W. Biederman" --- arch/m68k/kernel/traps.c | 60 ++++++++++++++++++++---------------------------- arch/m68k/mm/fault.c | 25 +++++++++----------- 2 files changed, 36 insertions(+), 49 deletions(-) (limited to 'arch/m68k') diff --git a/arch/m68k/kernel/traps.c b/arch/m68k/kernel/traps.c index 0a00b476236d..b2fd000b9285 100644 --- a/arch/m68k/kernel/traps.c +++ b/arch/m68k/kernel/traps.c @@ -1007,11 +1007,10 @@ void bad_super_trap (struct frame *fp) asmlinkage void trap_c(struct frame *fp) { - int sig; + int sig, si_code; + void __user *addr; int vector = (fp->ptregs.vector >> 2) & 0xff; - siginfo_t info; - clear_siginfo(&info); if (fp->ptregs.sr & PS_S) { if (vector == VEC_TRACE) { /* traced a trapping instruction on a 68020/30, @@ -1030,21 +1029,21 @@ asmlinkage void trap_c(struct frame *fp) /* send the appropriate signal to the user program */ switch (vector) { case VEC_ADDRERR: - info.si_code = BUS_ADRALN; + si_code = BUS_ADRALN; sig = SIGBUS; break; case VEC_ILLEGAL: case VEC_LINE10: case VEC_LINE11: - info.si_code = ILL_ILLOPC; + si_code = ILL_ILLOPC; sig = SIGILL; break; case VEC_PRIV: - info.si_code = ILL_PRVOPC; + si_code = ILL_PRVOPC; sig = SIGILL; break; case VEC_COPROC: - info.si_code = ILL_COPROC; + si_code = ILL_COPROC; sig = SIGILL; break; case VEC_TRAP1: @@ -1061,76 +1060,74 @@ asmlinkage void trap_c(struct frame *fp) case VEC_TRAP12: case VEC_TRAP13: case VEC_TRAP14: - info.si_code = ILL_ILLTRP; + si_code = ILL_ILLTRP; sig = SIGILL; break; case VEC_FPBRUC: case VEC_FPOE: case VEC_FPNAN: - info.si_code = FPE_FLTINV; + si_code = FPE_FLTINV; sig = SIGFPE; break; case VEC_FPIR: - info.si_code = FPE_FLTRES; + si_code = FPE_FLTRES; sig = SIGFPE; break; case VEC_FPDIVZ: - info.si_code = FPE_FLTDIV; + si_code = FPE_FLTDIV; sig = SIGFPE; break; case VEC_FPUNDER: - info.si_code = FPE_FLTUND; + si_code = FPE_FLTUND; sig = SIGFPE; break; case VEC_FPOVER: - info.si_code = FPE_FLTOVF; + si_code = FPE_FLTOVF; sig = SIGFPE; break; case VEC_ZERODIV: - info.si_code = FPE_INTDIV; + si_code = FPE_INTDIV; sig = SIGFPE; break; case VEC_CHK: case VEC_TRAP: - info.si_code = FPE_INTOVF; + si_code = FPE_INTOVF; sig = SIGFPE; break; case VEC_TRACE: /* ptrace single step */ - info.si_code = TRAP_TRACE; + si_code = TRAP_TRACE; sig = SIGTRAP; break; case VEC_TRAP15: /* breakpoint */ - info.si_code = TRAP_BRKPT; + si_code = TRAP_BRKPT; sig = SIGTRAP; break; default: - info.si_code = ILL_ILLOPC; + si_code = ILL_ILLOPC; sig = SIGILL; break; } - info.si_signo = sig; - info.si_errno = 0; switch (fp->ptregs.format) { default: - info.si_addr = (void *) fp->ptregs.pc; + addr = (void __user *) fp->ptregs.pc; break; case 2: - info.si_addr = (void *) fp->un.fmt2.iaddr; + addr = (void __user *) fp->un.fmt2.iaddr; break; case 7: - info.si_addr = (void *) fp->un.fmt7.effaddr; + addr = (void __user *) fp->un.fmt7.effaddr; break; case 9: - info.si_addr = (void *) fp->un.fmt9.iaddr; + addr = (void __user *) fp->un.fmt9.iaddr; break; case 10: - info.si_addr = (void *) fp->un.fmta.daddr; + addr = (void __user *) fp->un.fmta.daddr; break; case 11: - info.si_addr = (void *) fp->un.fmtb.daddr; + addr = (void __user*) fp->un.fmtb.daddr; break; } - force_sig_info (sig, &info, current); + force_sig_fault(sig, si_code, addr, current); } void die_if_kernel (char *str, struct pt_regs *fp, int nr) @@ -1162,13 +1159,6 @@ asmlinkage void fpsp040_die(void) #ifdef CONFIG_M68KFPU_EMU asmlinkage void fpemu_signal(int signal, int code, void *addr) { - siginfo_t info; - - clear_siginfo(&info); - info.si_signo = signal; - info.si_errno = 0; - info.si_code = code; - info.si_addr = addr; - force_sig_info(signal, &info, current); + force_sig_fault(signal, code, addr, current); } #endif diff --git a/arch/m68k/mm/fault.c b/arch/m68k/mm/fault.c index 03253c4f8e6a..f2ff3779875a 100644 --- a/arch/m68k/mm/fault.c +++ b/arch/m68k/mm/fault.c @@ -21,35 +21,32 @@ extern void die_if_kernel(char *, struct pt_regs *, long); int send_fault_sig(struct pt_regs *regs) { - siginfo_t siginfo; + int signo, si_code; + void __user *addr; - clear_siginfo(&siginfo); - siginfo.si_signo = current->thread.signo; - siginfo.si_code = current->thread.code; - siginfo.si_addr = (void *)current->thread.faddr; - pr_debug("send_fault_sig: %p,%d,%d\n", siginfo.si_addr, - siginfo.si_signo, siginfo.si_code); + signo = current->thread.signo; + si_code = current->thread.code; + addr = (void __user *)current->thread.faddr; + pr_debug("send_fault_sig: %p,%d,%d\n", addr, signo, si_code); if (user_mode(regs)) { - force_sig_info(siginfo.si_signo, - &siginfo, current); + force_sig_fault(signo, si_code, addr, current); } else { if (fixup_exception(regs)) return -1; - //if (siginfo.si_signo == SIGBUS) - // force_sig_info(siginfo.si_signo, - // &siginfo, current); + //if (signo == SIGBUS) + // force_sig_fault(si_signo, si_code, addr, current); /* * Oops. The kernel tried to access some bad page. We'll have to * terminate things with extreme prejudice. */ - if ((unsigned long)siginfo.si_addr < PAGE_SIZE) + if ((unsigned long)addr < PAGE_SIZE) pr_alert("Unable to handle kernel NULL pointer dereference"); else pr_alert("Unable to handle kernel access"); - pr_cont(" at virtual address %p\n", siginfo.si_addr); + pr_cont(" at virtual address %p\n", addr); die_if_kernel("Oops", regs, 0 /*error_code*/); do_exit(SIGKILL); } -- cgit v1.2.3