cregit-Linux how code gets into the kernel

Release 4.16 arch/tile/kernel/compat_signal.c

Directory: arch/tile/kernel
/*
 * Copyright 2010 Tilera Corporation. All Rights Reserved.
 *
 *   This program is free software; you can redistribute it and/or
 *   modify it under the terms of the GNU General Public License
 *   as published by the Free Software Foundation, version 2.
 *
 *   This program is distributed in the hope that it will be useful, but
 *   WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
 *   NON INFRINGEMENT.  See the GNU General Public License for
 *   more details.
 */

#include <linux/sched.h>
#include <linux/sched/task_stack.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/kernel.h>
#include <linux/signal.h>
#include <linux/errno.h>
#include <linux/wait.h>
#include <linux/unistd.h>
#include <linux/stddef.h>
#include <linux/personality.h>
#include <linux/suspend.h>
#include <linux/ptrace.h>
#include <linux/elf.h>
#include <linux/compat.h>
#include <linux/syscalls.h>
#include <linux/uaccess.h>
#include <asm/processor.h>
#include <asm/ucontext.h>
#include <asm/sigframe.h>
#include <asm/syscalls.h>
#include <asm/vdso.h>
#include <arch/interrupts.h>


struct compat_ucontext {
	
compat_ulong_t	  uc_flags;
	
compat_uptr_t     uc_link;
	
struct compat_sigaltstack	  uc_stack;
	
struct sigcontext uc_mcontext;
	
sigset_t	  uc_sigmask;	/* mask last for extensibility */
};


struct compat_rt_sigframe {
	
unsigned char save_area[C_ABI_SAVE_AREA_SIZE]; /* caller save area */
	
struct compat_siginfo info;
	
struct compat_ucontext uc;
};

/* The assembly shim for this function arranges to ignore the return value. */

long compat_sys_rt_sigreturn(void) { struct pt_regs *regs = current_pt_regs(); struct compat_rt_sigframe __user *frame = (struct compat_rt_sigframe __user *) compat_ptr(regs->sp); sigset_t set; if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) goto badframe; if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set))) goto badframe; set_current_blocked(&set); if (restore_sigcontext(regs, &frame->uc.uc_mcontext)) goto badframe; if (compat_restore_altstack(&frame->uc.uc_stack)) goto badframe; return 0; badframe: signal_fault("bad sigreturn frame", regs, frame, 0); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Chris Metcalf13498.53%571.43%
Matt Fleming10.74%114.29%
Al Viro10.74%114.29%
Total136100.00%7100.00%

/* * Determine which stack to use.. */
static inline void __user *compat_get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size) { unsigned long sp; /* Default to using normal stack */ sp = (unsigned long)compat_ptr(regs->sp); /* * If we are on the alternate signal stack and would overflow * it, don't. Return an always-bogus address instead so we * will die with SIGSEGV. */ if (on_sig_stack(sp) && !likely(on_sig_stack(sp - frame_size))) return (void __user __force *)-1UL; /* This is the X/Open sanctioned signal stack switching. */ if (ka->sa.sa_flags & SA_ONSTACK) { if (sas_ss_flags(sp) == 0) sp = current->sas_ss_sp + current->sas_ss_size; } sp -= frame_size; /* * Align the stack pointer according to the TILE ABI, * i.e. so that on function entry (sp & 15) == 0. */ sp &= -16UL; return (void __user *) sp; }

Contributors

PersonTokensPropCommitsCommitProp
Chris Metcalf119100.00%2100.00%
Total119100.00%2100.00%


int compat_setup_rt_frame(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs) { unsigned long restorer; struct compat_rt_sigframe __user *frame; int err = 0, sig = ksig->sig; frame = compat_get_sigframe(&ksig->ka, regs, sizeof(*frame)); if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) goto err; /* Always write at least the signal number for the stack backtracer. */ if (ksig->ka.sa.sa_flags & SA_SIGINFO) { /* At sigreturn time, restore the callee-save registers too. */ err |= copy_siginfo_to_user32(&frame->info, &ksig->info); regs->flags |= PT_FLAGS_RESTORE_REGS; } else { err |= __put_user(ksig->info.si_signo, &frame->info.si_signo); } /* Create the ucontext. */ err |= __clear_user(&frame->save_area, sizeof(frame->save_area)); err |= __put_user(0, &frame->uc.uc_flags); err |= __put_user(0, &frame->uc.uc_link); err |= __compat_save_altstack(&frame->uc.uc_stack, regs->sp); err |= setup_sigcontext(&frame->uc.uc_mcontext, regs); err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); if (err) goto err; restorer = VDSO_SYM(&__vdso_rt_sigreturn); if (ksig->ka.sa.sa_flags & SA_RESTORER) restorer = ptr_to_compat_reg(ksig->ka.sa.sa_restorer); /* * Set up registers for signal handler. * Registers that we don't modify keep the value they had from * user-space at the time we took the signal. * We always pass siginfo and mcontext, regardless of SA_SIGINFO, * since some things rely on this (e.g. glibc's debug/segfault.c). */ regs->pc = ptr_to_compat_reg(ksig->ka.sa.sa_handler); regs->ex1 = PL_ICS_EX1(USER_PL, 1); /* set crit sec in handler */ regs->sp = ptr_to_compat_reg(frame); regs->lr = restorer; regs->regs[0] = (unsigned long) sig; regs->regs[1] = ptr_to_compat_reg(&frame->info); regs->regs[2] = ptr_to_compat_reg(&frame->uc); regs->flags |= PT_FLAGS_CALLER_SAVES; return 0; err: trace_unhandled_signal("bad sigreturn frame", regs, (unsigned long)frame, SIGSEGV); return -EFAULT; }

Contributors

PersonTokensPropCommitsCommitProp
Chris Metcalf34589.15%457.14%
Richard Weinberger4010.34%228.57%
Al Viro20.52%114.29%
Total387100.00%7100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
Chris Metcalf71193.80%861.54%
Richard Weinberger405.28%215.38%
Al Viro30.40%17.69%
Ingo Molnar30.40%17.69%
Matt Fleming10.13%17.69%
Total758100.00%13100.00%
Directory: arch/tile/kernel
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