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Commit 56b04d56 authored by Christophe Leroy's avatar Christophe Leroy Committed by Michael Ellerman
Browse files

powerpc/signal32: Use fault_in_pages_readable() to prefault user context 



Use fault_in_pages_readable() to prefault user context
instead of open coding

Signed-off-by: default avatarChristophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: default avatarMathieu Malaterre <malat@debian.org>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent d04f11d2

arch/powerpc/kernel/signal_32.c

+5 −8
Original line number Diff line number Diff line
@@ -25,6 +25,7 @@ 
#include <linux/errno.h>

#include <linux/elf.h>

#include <linux/ptrace.h>

#include <linux/pagemap.h>

#include <linux/ratelimit.h>

#include <linux/syscalls.h>

#ifdef CONFIG_PPC64
@@ -1049,7 +1050,6 @@ SYSCALL_DEFINE3(swapcontext, struct ucontext __user *, old_ctx, 
#endif

{

	struct pt_regs *regs = current_pt_regs();

	unsigned char tmp __maybe_unused;

	int ctx_has_vsx_region = 0;



#ifdef CONFIG_PPC64
@@ -1113,9 +1113,8 @@ SYSCALL_DEFINE3(swapcontext, struct ucontext __user *, old_ctx, 
	}

	if (new_ctx == NULL)

		return 0;

	if (!access_ok(VERIFY_READ, new_ctx, ctx_size)

	    || __get_user(tmp, (u8 __user *) new_ctx)

	    || __get_user(tmp, (u8 __user *) new_ctx + ctx_size - 1))

	if (!access_ok(VERIFY_READ, new_ctx, ctx_size) ||

	    fault_in_pages_readable((u8 __user *)new_ctx, ctx_size))

		return -EFAULT;



	/*
@@ -1242,7 +1241,6 @@ SYSCALL_DEFINE3(debug_setcontext, struct ucontext __user *, ctx, 
	struct pt_regs *regs = current_pt_regs();

	struct sig_dbg_op op;

	int i;

	unsigned char tmp __maybe_unused;

	unsigned long new_msr = regs->msr;

#ifdef CONFIG_PPC_ADV_DEBUG_REGS

	unsigned long new_dbcr0 = current->thread.debug.dbcr0;
@@ -1298,9 +1296,8 @@ SYSCALL_DEFINE3(debug_setcontext, struct ucontext __user *, ctx, 
	current->thread.debug.dbcr0 = new_dbcr0;

#endif



	if (!access_ok(VERIFY_READ, ctx, sizeof(*ctx))

	    || __get_user(tmp, (u8 __user *) ctx)

	    || __get_user(tmp, (u8 __user *) (ctx + 1) - 1))

	if (!access_ok(VERIFY_READ, ctx, sizeof(*ctx)) ||

	    fault_in_pages_readable((u8 __user *)ctx, sizeof(*ctx)))

		return -EFAULT;



	/*