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/sh/mm/fault.c | 1 + 1 file changed, 1 insertion(+) (limited to 'arch/sh/mm') diff --git a/arch/sh/mm/fault.c b/arch/sh/mm/fault.c index 6fd1bf7481c7d..4c98b6f20e022 100644 --- a/arch/sh/mm/fault.c +++ b/arch/sh/mm/fault.c @@ -44,6 +44,7 @@ force_sig_info_fault(int si_signo, int si_code, unsigned long address, { siginfo_t info; + clear_siginfo(&info); info.si_signo = si_signo; info.si_errno = 0; info.si_code = si_code; -- cgit v1.2.3 From c65626c0cd4d3e2f43a5f62fcde4fcd594959938 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Sun, 15 Apr 2018 19:56:33 -0500 Subject: signal/sh: 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: Yoshinori Sato Cc: Rich Felker Cc: linux-sh@vger.kernel.org Acked-by: Rich Felker Signed-off-by: "Eric W. Biederman" --- arch/sh/kernel/traps_32.c | 19 +++++-------------- arch/sh/math-emu/math.c | 9 ++------- arch/sh/mm/fault.c | 10 +--------- 3 files changed, 8 insertions(+), 30 deletions(-) (limited to 'arch/sh/mm') diff --git a/arch/sh/kernel/traps_32.c b/arch/sh/kernel/traps_32.c index e85e59c3d6dff..660a4bc17698a 100644 --- a/arch/sh/kernel/traps_32.c +++ b/arch/sh/kernel/traps_32.c @@ -477,7 +477,6 @@ asmlinkage void do_address_error(struct pt_regs *regs, { unsigned long error_code = 0; mm_segment_t oldfs; - siginfo_t info; insn_size_t instruction; int tmp; @@ -537,12 +536,7 @@ uspace_segv: "access (PC %lx PR %lx)\n", current->comm, regs->pc, regs->pr); - clear_siginfo(&info); - info.si_signo = SIGBUS; - info.si_errno = 0; - info.si_code = si_code; - info.si_addr = (void __user *)address; - force_sig_info(SIGBUS, &info, current); + force_sig_fault(SIGBUS, si_code, (void __user *)address, current); } else { inc_unaligned_kernel_access(); @@ -599,20 +593,17 @@ int is_dsp_inst(struct pt_regs *regs) #ifdef CONFIG_CPU_SH2A asmlinkage void do_divide_error(unsigned long r4) { - siginfo_t info; + int code; - clear_siginfo(&info); switch (r4) { case TRAP_DIVZERO_ERROR: - info.si_code = FPE_INTDIV; + code = FPE_INTDIV; break; case TRAP_DIVOVF_ERROR: - info.si_code = FPE_INTOVF; + code = FPE_INTOVF; break; } - - info.si_signo = SIGFPE; - force_sig_info(info.si_signo, &info, current); + force_sig_fault(SIGFPE, code, NULL, current); } #endif diff --git a/arch/sh/math-emu/math.c b/arch/sh/math-emu/math.c index d6d2213df0787..a0fa8fc887399 100644 --- a/arch/sh/math-emu/math.c +++ b/arch/sh/math-emu/math.c @@ -507,7 +507,6 @@ static int ieee_fpe_handler(struct pt_regs *regs) unsigned short insn = *(unsigned short *)regs->pc; unsigned short finsn; unsigned long nextpc; - siginfo_t info; int nib[4] = { (insn >> 12) & 0xf, (insn >> 8) & 0xf, @@ -560,12 +559,8 @@ static int ieee_fpe_handler(struct pt_regs *regs) ~(FPSCR_CAUSE_MASK | FPSCR_FLAG_MASK); task_thread_info(tsk)->status |= TS_USEDFPU; } else { - clear_siginfo(&info); - info.si_signo = SIGFPE; - info.si_errno = 0; - info.si_code = FPE_FLTINV; - info.si_addr = (void __user *)regs->pc; - force_sig_info(SIGFPE, &info, tsk); + force_sig_fault(SIGFPE, FPE_FLTINV, + (void __user *)regs->pc, tsk); } regs->pc = nextpc; diff --git a/arch/sh/mm/fault.c b/arch/sh/mm/fault.c index 4c98b6f20e022..b8e7bb84b6b1c 100644 --- a/arch/sh/mm/fault.c +++ b/arch/sh/mm/fault.c @@ -42,15 +42,7 @@ static void force_sig_info_fault(int si_signo, int si_code, unsigned long address, struct task_struct *tsk) { - siginfo_t info; - - clear_siginfo(&info); - info.si_signo = si_signo; - info.si_errno = 0; - info.si_code = si_code; - info.si_addr = (void __user *)address; - - force_sig_info(si_signo, &info, tsk); + force_sig_fault(si_signo, si_code, (void __user *)address, tsk); } /* -- cgit v1.2.3