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| author | Christophe Leroy <christophe.leroy@c-s.fr> | 2018-04-24 18:04:25 +0200 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2018-06-04 00:39:18 +1000 |
| commit | 56b04d568f880a48d892e840cfaf4efc0f0ce39b (patch) | |
| tree | 8ac4e93758f05f3d9a6c7c37ae44c6569bff7e8c /arch | |
| parent | d04f11d2713e736a3740361f8b5bb42c7147c5a2 (diff) | |
| download | linux-0-day-56b04d568f880a48d892e840cfaf4efc0f0ce39b.tar.gz linux-0-day-56b04d568f880a48d892e840cfaf4efc0f0ce39b.tar.xz | |
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: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Mathieu Malaterre <malat@debian.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/powerpc/kernel/signal_32.c | 13 |
1 files changed, 5 insertions, 8 deletions
diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c index 342ac78f620f5..5eedbb282d42f 100644 --- a/arch/powerpc/kernel/signal_32.c +++ b/arch/powerpc/kernel/signal_32.c @@ -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; /* |