From 09c033b66596a9c38f61875c80c674c4fed61b86 Mon Sep 17 00:00:00 2001 From: Mauro Carvalho Chehab Date: Tue, 17 Apr 2018 09:01:46 -0400 Subject: [PATCH] media: v4l2-compat-ioctl32: simplify casts Making the cast right for get_user/put_user is not trivial, as it needs to ensure that the types are the correct ones. Improve it by using macros. Tested with vivid with: $ sudo modprobe vivid no_error_inj=1 $ v4l2-compliance-32bits -a -s10 >32bits && v4l2-compliance-64bits -a -s10 > 64bits && diff -U0 32bits 64bits --- 32bits 2018-04-17 11:18:29.141240772 -0300 +++ 64bits 2018-04-17 11:18:40.635282341 -0300 @@ -1 +1 @@ -v4l2-compliance SHA : bc71e4a67c6fbc5940062843bc41e7c8679634ce, 32 bits +v4l2-compliance SHA : bc71e4a67c6fbc5940062843bc41e7c8679634ce, 64 bits Using the latest version of v4l-utils with this patch applied: https://patchwork.linuxtv.org/patch/48746/ Reviewed-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab --- drivers/media/v4l2-core/v4l2-compat-ioctl32.c | 36 +++++++++++++++++++-------- 1 file changed, 25 insertions(+), 11 deletions(-) diff --git a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c index 543dab6..a7ed123 100644 --- a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c +++ b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c @@ -30,6 +30,24 @@ get_user(__assign_tmp, from) || put_user(__assign_tmp, to); \ }) +#define get_user_cast(__x, __ptr) \ +({ \ + get_user(__x, (typeof(*__ptr) __user *)(__ptr)); \ +}) + +#define put_user_force(__x, __ptr) \ +({ \ + put_user((typeof(*__x) __force *)(__x), __ptr); \ +}) + +#define assign_in_user_cast(to, from) \ +({ \ + typeof(*from) __assign_tmp; \ + \ + get_user_cast(__assign_tmp, from) || put_user(__assign_tmp, to);\ +}) + + static long native_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { long ret = -ENOIOCTLCMD; @@ -543,8 +561,7 @@ static int get_v4l2_buffer32(struct v4l2_buffer __user *p64, return -EFAULT; uplane = aux_buf; - if (put_user((__force struct v4l2_plane *)uplane, - &p64->m.planes)) + if (put_user_force(uplane, &p64->m.planes)) return -EFAULT; while (num_planes--) { @@ -683,7 +700,7 @@ static int get_v4l2_framebuffer32(struct v4l2_framebuffer __user *p64, if (!access_ok(VERIFY_READ, p32, sizeof(*p32)) || get_user(tmp, &p32->base) || - put_user((void __force *)compat_ptr(tmp), &p64->base) || + put_user_force(compat_ptr(tmp), &p64->base) || assign_in_user(&p64->capability, &p32->capability) || assign_in_user(&p64->flags, &p32->flags) || copy_in_user(&p64->fmt, &p32->fmt, sizeof(p64->fmt))) @@ -832,8 +849,7 @@ static int get_v4l2_ext_controls32(struct file *file, if (aux_space < count * sizeof(*kcontrols)) return -EFAULT; kcontrols = aux_buf; - if (put_user((__force struct v4l2_ext_control *)kcontrols, - &p64->controls)) + if (put_user_force(kcontrols, &p64->controls)) return -EFAULT; for (n = 0; n < count; n++) { @@ -899,10 +915,9 @@ static int put_v4l2_ext_controls32(struct file *file, unsigned int size = sizeof(*ucontrols); u32 id; - if (get_user(id, (unsigned int __user *)&kcontrols->id) || + if (get_user_cast(id, &kcontrols->id) || put_user(id, &ucontrols->id) || - assign_in_user(&ucontrols->size, - (unsigned int __user *)&kcontrols->size) || + assign_in_user_cast(&ucontrols->size, &kcontrols->size) || copy_in_user(&ucontrols->reserved2, (void __user *)&kcontrols->reserved2, sizeof(ucontrols->reserved2))) @@ -971,10 +986,9 @@ static int get_v4l2_edid32(struct v4l2_edid __user *p64, if (!access_ok(VERIFY_READ, p32, sizeof(*p32)) || assign_in_user(&p64->pad, &p32->pad) || assign_in_user(&p64->start_block, &p32->start_block) || - assign_in_user(&p64->blocks, - (u32 __user *)&p32->blocks) || + assign_in_user_cast(&p64->blocks, &p32->blocks) || get_user(tmp, &p32->edid) || - put_user((void __force *)compat_ptr(tmp), &p64->edid) || + put_user_force(compat_ptr(tmp), &p64->edid) || copy_in_user(p64->reserved, p32->reserved, sizeof(p64->reserved))) return -EFAULT; return 0; -- 2.7.4