| Message ID | 20180424160425.DB9946C5A7@po15720vm.idsi0.si.c-s.fr (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 56b04d568f880a48d892e840cfaf4efc0f0ce39b |
| Headers | show |
| Series | [v2] powerpc/signal32: Use fault_in_pages_readable() to prefault user context | expand |
On Tue, Apr 24, 2018 at 6:04 PM, Christophe Leroy <christophe.leroy@c-s.fr> wrote: > Use fault_in_pages_readable() to prefault user context > instead of open coding > > Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> > --- > v2: using sizeof(*ctx) as size of ctx instead of 1 > > arch/powerpc/kernel/signal_32.c | 13 +++++-------- > 1 file changed, 5 insertions(+), 8 deletions(-) > > diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c > index 492f03451877..4a9e4d6d555b 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> > #ifdef CONFIG_PPC64 > #include <linux/syscalls.h> > @@ -1045,7 +1046,6 @@ long sys_swapcontext(struct ucontext __user *old_ctx, > struct ucontext __user *new_ctx, > int ctx_size, int r6, int r7, int r8, struct pt_regs *regs) > { > - unsigned char tmp __maybe_unused; > int ctx_has_vsx_region = 0; > > #ifdef CONFIG_PPC64 > @@ -1109,9 +1109,8 @@ long sys_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; > > /* > @@ -1231,7 +1230,6 @@ int sys_debug_setcontext(struct ucontext __user *ctx, > { > 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; > @@ -1287,9 +1285,8 @@ int sys_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; > > /* > -- > 2.13.3 > Looks good: Reviewed-by: Mathieu Malaterre <malat@debian.org> Thanks for fixing my previous attempt !
On Tue, 2018-04-24 at 16:04:25 UTC, Christophe Leroy wrote: > 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> Applied to powerpc next, thanks. https://git.kernel.org/powerpc/c/56b04d568f880a48d892e840cfaf4e cheers
diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c index 492f03451877..4a9e4d6d555b 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> #ifdef CONFIG_PPC64 #include <linux/syscalls.h> @@ -1045,7 +1046,6 @@ long sys_swapcontext(struct ucontext __user *old_ctx, struct ucontext __user *new_ctx, int ctx_size, int r6, int r7, int r8, struct pt_regs *regs) { - unsigned char tmp __maybe_unused; int ctx_has_vsx_region = 0; #ifdef CONFIG_PPC64 @@ -1109,9 +1109,8 @@ long sys_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; /* @@ -1231,7 +1230,6 @@ int sys_debug_setcontext(struct ucontext __user *ctx, { 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; @@ -1287,9 +1285,8 @@ int sys_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; /*
Use fault_in_pages_readable() to prefault user context instead of open coding Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> --- v2: using sizeof(*ctx) as size of ctx instead of 1 arch/powerpc/kernel/signal_32.c | 13 +++++-------- 1 file changed, 5 insertions(+), 8 deletions(-)