| Message ID | 1403190809-8413-1-git-send-email-rahul.sharma@samsung.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Inki, What do you think about the following fix? I need your inputs for this. Regards, Rahul Sharma On 19 June 2014 20:43, Rahul Sharma <rahul.sharma@samsung.com> wrote: > This situation arises when userspace remove the frambuffer object > and call setmode ioctl. > > drm_mode_rmfb --> drm_plane_force_disable --> plane->crtc = NULL; > and > drm_mode_setcrtc --> exynos_plane_commit --> passes plane->crtc to > exynos_drm_crtc_plane_commit which is NULL. > > This crashes the system. > > Signed-off-by: Rahul Sharma <rahul.sharma@samsung.com> > --- > This works fine but I am not confident on the correctness of the > solution. > > drivers/gpu/drm/exynos/exynos_drm_crtc.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/drivers/gpu/drm/exynos/exynos_drm_crtc.c b/drivers/gpu/drm/exynos/exynos_drm_crtc.c > index 95c9435..da4efe4 100644 > --- a/drivers/gpu/drm/exynos/exynos_drm_crtc.c > +++ b/drivers/gpu/drm/exynos/exynos_drm_crtc.c > @@ -165,6 +165,12 @@ static int exynos_drm_crtc_mode_set_commit(struct drm_crtc *crtc, int x, int y, > return -EPERM; > } > > + /* when framebuffer is removed, commit should not proceed. */ > + if(!plane->fb){ > + DRM_ERROR("framebuffer has been removed from plane.\n"); > + return -EFAULT; > + } > + > crtc_w = crtc->primary->fb->width - x; > crtc_h = crtc->primary->fb->height - y; > > -- > 1.7.9.5 >
2014-06-20 0:13 GMT+09:00 Rahul Sharma <rahul.sharma@samsung.com>: > This situation arises when userspace remove the frambuffer object > and call setmode ioctl. > > drm_mode_rmfb --> drm_plane_force_disable --> plane->crtc = NULL; > and > drm_mode_setcrtc --> exynos_plane_commit --> passes plane->crtc to > exynos_drm_crtc_plane_commit which is NULL. If user process requested drm_mode_rmfb with a fb_id, fb object to the fb_id must be removed from crtc_idr table. So drm_mode_setcrtc should be failed because there is no the fb object in the crtc_idr table anymore. I cannot understand how exynos_drm_crtc_plane_commit function could be called. Can you give me more details? Thanks, Inki Dae > > This crashes the system. > > Signed-off-by: Rahul Sharma <rahul.sharma@samsung.com> > --- > This works fine but I am not confident on the correctness of the > solution. > > drivers/gpu/drm/exynos/exynos_drm_crtc.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/drivers/gpu/drm/exynos/exynos_drm_crtc.c b/drivers/gpu/drm/exynos/exynos_drm_crtc.c > index 95c9435..da4efe4 100644 > --- a/drivers/gpu/drm/exynos/exynos_drm_crtc.c > +++ b/drivers/gpu/drm/exynos/exynos_drm_crtc.c > @@ -165,6 +165,12 @@ static int exynos_drm_crtc_mode_set_commit(struct drm_crtc *crtc, int x, int y, > return -EPERM; > } > > + /* when framebuffer is removed, commit should not proceed. */ > + if(!plane->fb){ > + DRM_ERROR("framebuffer has been removed from plane.\n"); > + return -EFAULT; > + } > + > crtc_w = crtc->primary->fb->width - x; > crtc_h = crtc->primary->fb->height - y; > > -- > 1.7.9.5 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html
On 8 July 2014 21:25, Inki Dae <inki.dae@samsung.com> wrote: > 2014-06-20 0:13 GMT+09:00 Rahul Sharma <rahul.sharma@samsung.com>: >> This situation arises when userspace remove the frambuffer object >> and call setmode ioctl. >> >> drm_mode_rmfb --> drm_plane_force_disable --> plane->crtc = NULL; >> and >> drm_mode_setcrtc --> exynos_plane_commit --> passes plane->crtc to >> exynos_drm_crtc_plane_commit which is NULL. > > If user process requested drm_mode_rmfb with a fb_id, fb object to the > fb_id must be removed from crtc_idr table. So drm_mode_setcrtc should > be failed because there is no the fb object in the crtc_idr table > anymore. > I cannot understand how exynos_drm_crtc_plane_commit function could be > called. Can you give me more details? Inki, These logs should clarify more about the problem: localhost ~ # halt localhost ~ # [ 130.570309] init: debugd main process (781) killed by TERM signal [ 130.602453] init: lid_touchpad_helper main process (2100) killed by TERM signal [ 131.374955] CPU: 2 PID: 834 Comm: X Tainted: G W 3.16.0-rc1+ #623 [ 131.380558] [<c00155b8>] (unwind_backtrace) from [<c001213c>] (show_stack+0x20/0x24) [ 131.388327] [<c001213c>] (show_stack) from [<c05217d4>] (dump_stack+0x7c/0x98) [ 131.395522] [<c05217d4>] (dump_stack) from [<c02ab7e4>] (exynos_drm_crtc_plane_commit+0x20/0x40) [ 131.404263] [<c02ab7e4>] (exynos_drm_crtc_plane_commit) from [<c02ae28c>] (exynos_plane_commit+0x24/0x28) [ 131.413779] [<c02ae28c>] (exynos_plane_commit) from [<c02ab1c8>] (exynos_drm_crtc_commit+0x2c/0x54) [ 131.422802] [<c02ab1c8>] (exynos_drm_crtc_commit) from [<c02ab2c0>] (exynos_drm_crtc_mode_set_commit.isra.1+0x8c/0xa0) [ 131.433468] [<c02ab2c0>] (exynos_drm_crtc_mode_set_commit.isra.1) from [<c02ab3f0>] (exynos_drm_crtc_page_flip+0x100/0x174) [ 131.444587] [<c02ab3f0>] (exynos_drm_crtc_page_flip) from [<c02a1ab4>] (drm_mode_page_flip_ioctl+0x1f0/0x2b0) -->> [ 131.454460] [<c02a1ab4>] (drm_mode_page_flip_ioctl) from [<c0292cb4>] (drm_ioctl+0x270/0x44c) [ 131.462966] [<c0292cb4>] (drm_ioctl) from [<c011302c>] (do_vfs_ioctl+0x4e4/0x5a0) [ 131.470397] [<c011302c>] (do_vfs_ioctl) from [<c0113144>] (SyS_ioctl+0x5c/0x84) [ 131.477728] [<c0113144>] (SyS_ioctl) from [<c000e380>] (ret_fast_syscall+0x0/0x30) [ 131.762797] CPU: 1 PID: 834 Comm: X Tainted: G W 3.16.0-rc1+ #623 [ 131.768378] [<c00155b8>] (unwind_backtrace) from [<c001213c>] (show_stack+0x20/0x24) [ 131.776151] [<c001213c>] (show_stack) from [<c05217d4>] (dump_stack+0x7c/0x98) [ 131.783315] [<c05217d4>] (dump_stack) from [<c029c130>] (drm_plane_force_disable+0x5c/0x68) [ 131.791658] [<c029c130>] (drm_plane_force_disable) from [<c029cf68>] (drm_framebuffer_remove+0xe4/0x110) [ 131.801070] [<c029cf68>] (drm_framebuffer_remove) from [<c02a09c0>] (drm_mode_rmfb+0xd4/0xfc) -->> [ 131.809597] [<c02a09c0>] (drm_mode_rmfb) from [<c0292cb4>] (drm_ioctl+0x270/0x44c) [ 131.817135] [<c0292cb4>] (drm_ioctl) from [<c011302c>] (do_vfs_ioctl+0x4e4/0x5a0) [ 131.824609] [<c011302c>] (do_vfs_ioctl) from [<c0113144>] (SyS_ioctl+0x5c/0x84) [ 131.831884] [<c0113144>] (SyS_ioctl) from [<c000e380>] (ret_fast_syscall+0x0/0x30) [ 132.077803] CPU: 0 PID: 834 Comm: X Tainted: G W 3.16.0-rc1+ #623 [ 132.083413] [<c00155b8>] (unwind_backtrace) from [<c001213c>] (show_stack+0x20/0x24) [ 132.091111] [<c001213c>] (show_stack) from [<c05217d4>] (dump_stack+0x7c/0x98) [ 132.098343] [<c05217d4>] (dump_stack) from [<c02ab7e4>] (exynos_drm_crtc_plane_commit+0x20/0x40) [ 132.107098] [<c02ab7e4>] (exynos_drm_crtc_plane_commit) from [<c02ae28c>] (exynos_plane_commit+0x24/0x28) [ 132.116631] [<c02ae28c>] (exynos_plane_commit) from [<c02ab1c8>] (exynos_drm_crtc_commit+0x2c/0x54) [ 132.125660] [<c02ab1c8>] (exynos_drm_crtc_commit) from [<c02ab2c0>] (exynos_drm_crtc_mode_set_commit.isra.1+0x8c/0xa0) [ 132.136330] [<c02ab2c0>] (exynos_drm_crtc_mode_set_commit.isra.1) from [<c02ab2ec>] (exynos_drm_crtc_mode_set_base+0x18/0x1c) [ 132.147605] [<c02ab2ec>] (exynos_drm_crtc_mode_set_base) from [<c028c148>] (drm_crtc_helper_set_config+0x828/0x8a4) [ 132.158029] [<c028c148>] (drm_crtc_helper_set_config) from [<c029ce1c>] (drm_mode_set_config_internal+0x58/0xc0) [ 132.168155] [<c029ce1c>] (drm_mode_set_config_internal) from [<c029fe64>] (drm_mode_setcrtc+0x388/0x4ac) -->> [ 132.177630] [<c029fe64>] (drm_mode_setcrtc) from [<c0292cb4>] (drm_ioctl+0x270/0x44c) [ 132.185417] [<c0292cb4>] (drm_ioctl) from [<c011302c>] (do_vfs_ioctl+0x4e4/0x5a0) [ 132.192897] [<c011302c>] (do_vfs_ioctl) from [<c0113144>] (SyS_ioctl+0x5c/0x84) [ 132.200138] [<c0113144>] (SyS_ioctl) from [<c000e380>] (ret_fast_syscall+0x0/0x30) [ 132.207735] Unable to handle kernel NULL pointer dereference at virtual address 0000032c .. .. [ 132.510786] ff80: b6ebdeb8 bee1d5e8 c06864a2 00000036 c000e5a4 ecf0e000 00000000 ecf0ffa8 [ 132.518941] ffa0: c000e380 c01130f4 b6ebdeb8 bee1d5e8 00000005 c06864a2 bee1d5e8 00000001 [ 132.527095] ffc0: b6ebdeb8 bee1d5e8 c06864a2 00000036 b85d4a74 b8702a60 00000000 bee1d688 [ 132.535250] ffe0: b6a82f30 bee1d5cc b6a75cff b6bce50c 00000010 00000005 e1a0c00d e92dd800 [ 132.543408] [<c02ab7e4>] (exynos_drm_crtc_plane_commit) from [<c02ae28c>] (exynos_plane_commit+0x24/0x28) [ 132.552949] [<c02ae28c>] (exynos_plane_commit) from [<c02ab1c8>] (exynos_drm_crtc_commit+0x2c/0x54) [ 132.561971] [<c02ab1c8>] (exynos_drm_crtc_commit) from [<c02ab2c0>] (exynos_drm_crtc_mode_set_commit.isra.1+0x8c/0xa0) [ 132.572641] [<c02ab2c0>] (exynos_drm_crtc_mode_set_commit.isra.1) from [<c02ab2ec>] (exynos_drm_crtc_mode_set_base+0x18/0x1c) [ 132.583919] [<c02ab2ec>] (exynos_drm_crtc_mode_set_base) from [<c028c148>] (drm_crtc_helper_set_config+0x828/0x8a4) [ 132.594329] [<c028c148>] (drm_crtc_helper_set_config) from [<c029ce1c>] (drm_mode_set_config_internal+0x58/0xc0) [ 132.604478] [<c029ce1c>] (drm_mode_set_config_internal) from [<c029fe64>] (drm_mode_setcrtc+0x388/0x4ac) [ 132.613933] [<c029fe64>] (drm_mode_setcrtc) from [<c0292cb4>] (drm_ioctl+0x270/0x44c) [ 132.621741] [<c0292cb4>] (drm_ioctl) from [<c011302c>] (do_vfs_ioctl+0x4e4/0x5a0) [ 132.629201] [<c011302c>] (do_vfs_ioctl) from [<c0113144>] (SyS_ioctl+0x5c/0x84) [ 132.636489] [<c0113144>] (SyS_ioctl) from [<c000e380>] (ret_fast_syscall+0x0/0x30) [ 132.644035] Code: e8bd4000 e1a05000 e1a04001 eb09d7dc (e595032c) [ 132.650164] ---[ end trace 4bc5b9657975a179 ]--- [ 132.654749] Kernel panic - not syncing: Fatal exception [ 132.659912] CPU3: stopping [ 132.662600] CPU: 3 PID: 478 Comm: rs:main Q:Reg Tainted: G D W 3.16.0-rc1+ #623 [ 132.670673] [<c00155b8>] (unwind_backtrace) from [<c001213c>] (show_stack+0x20/0x24) [ 132.678392] [<c001213c>] (show_stack) from [<c05217d4>] (dump_stack+0x7c/0x98) [ 132.685590] [<c05217d4>] (dump_stack) from [<c001409c>] (handle_IPI+0xd8/0x160) [ 132.692876] [<c001409c>] (handle_IPI) from [<c0008688>] (gic_handle_irq+0x68/0x70) [ 132.700423] [<c0008688>] (gic_handle_irq) from [<c0012cc0>] (__irq_svc+0x40/0x50) Regards, Rahul Sharma. > > Thanks, > Inki Dae > >> >> This crashes the system. >> >> Signed-off-by: Rahul Sharma <rahul.sharma@samsung.com> >> --- >> This works fine but I am not confident on the correctness of the >> solution. >> >> drivers/gpu/drm/exynos/exynos_drm_crtc.c | 6 ++++++ >> 1 file changed, 6 insertions(+) >> >> diff --git a/drivers/gpu/drm/exynos/exynos_drm_crtc.c b/drivers/gpu/drm/exynos/exynos_drm_crtc.c >> index 95c9435..da4efe4 100644 >> --- a/drivers/gpu/drm/exynos/exynos_drm_crtc.c >> +++ b/drivers/gpu/drm/exynos/exynos_drm_crtc.c >> @@ -165,6 +165,12 @@ static int exynos_drm_crtc_mode_set_commit(struct drm_crtc *crtc, int x, int y, >> return -EPERM; >> } >> >> + /* when framebuffer is removed, commit should not proceed. */ >> + if(!plane->fb){ >> + DRM_ERROR("framebuffer has been removed from plane.\n"); >> + return -EFAULT; >> + } >> + >> crtc_w = crtc->primary->fb->width - x; >> crtc_h = crtc->primary->fb->height - y; >> >> -- >> 1.7.9.5 >> >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html
On 2014? 07? 09? 20:06, Rahul Sharma wrote: > On 8 July 2014 21:25, Inki Dae <inki.dae@samsung.com> wrote: >> 2014-06-20 0:13 GMT+09:00 Rahul Sharma <rahul.sharma@samsung.com>: >>> This situation arises when userspace remove the frambuffer object >>> and call setmode ioctl. >>> >>> drm_mode_rmfb --> drm_plane_force_disable --> plane->crtc = NULL; >>> and >>> drm_mode_setcrtc --> exynos_plane_commit --> passes plane->crtc to >>> exynos_drm_crtc_plane_commit which is NULL. >> >> If user process requested drm_mode_rmfb with a fb_id, fb object to the >> fb_id must be removed from crtc_idr table. So drm_mode_setcrtc should >> be failed because there is no the fb object in the crtc_idr table >> anymore. >> I cannot understand how exynos_drm_crtc_plane_commit function could be >> called. Can you give me more details? > > Inki, > > These logs should clarify more about the problem: Thanks. And how can I reenact below problem? if we could reenact this problem, we may find out fundamental problem and resolve it in more generic. Can I get example code? Thanks, Inki Dae > > localhost ~ # halt > localhost ~ # [ 130.570309] init: debugd main process (781) killed by > TERM signal > [ 130.602453] init: lid_touchpad_helper main process (2100) killed by > TERM signal > [ 131.374955] CPU: 2 PID: 834 Comm: X Tainted: G W 3.16.0-rc1+ #623 > [ 131.380558] [<c00155b8>] (unwind_backtrace) from [<c001213c>] > (show_stack+0x20/0x24) > [ 131.388327] [<c001213c>] (show_stack) from [<c05217d4>] > (dump_stack+0x7c/0x98) > [ 131.395522] [<c05217d4>] (dump_stack) from [<c02ab7e4>] > (exynos_drm_crtc_plane_commit+0x20/0x40) > [ 131.404263] [<c02ab7e4>] (exynos_drm_crtc_plane_commit) from > [<c02ae28c>] (exynos_plane_commit+0x24/0x28) > [ 131.413779] [<c02ae28c>] (exynos_plane_commit) from [<c02ab1c8>] > (exynos_drm_crtc_commit+0x2c/0x54) > [ 131.422802] [<c02ab1c8>] (exynos_drm_crtc_commit) from [<c02ab2c0>] > (exynos_drm_crtc_mode_set_commit.isra.1+0x8c/0xa0) > [ 131.433468] [<c02ab2c0>] (exynos_drm_crtc_mode_set_commit.isra.1) > from [<c02ab3f0>] (exynos_drm_crtc_page_flip+0x100/0x174) > [ 131.444587] [<c02ab3f0>] (exynos_drm_crtc_page_flip) from > [<c02a1ab4>] (drm_mode_page_flip_ioctl+0x1f0/0x2b0) > -->> [ 131.454460] [<c02a1ab4>] (drm_mode_page_flip_ioctl) from > [<c0292cb4>] (drm_ioctl+0x270/0x44c) > [ 131.462966] [<c0292cb4>] (drm_ioctl) from [<c011302c>] > (do_vfs_ioctl+0x4e4/0x5a0) > [ 131.470397] [<c011302c>] (do_vfs_ioctl) from [<c0113144>] > (SyS_ioctl+0x5c/0x84) > [ 131.477728] [<c0113144>] (SyS_ioctl) from [<c000e380>] > (ret_fast_syscall+0x0/0x30) > [ 131.762797] CPU: 1 PID: 834 Comm: X Tainted: G W 3.16.0-rc1+ #623 > [ 131.768378] [<c00155b8>] (unwind_backtrace) from [<c001213c>] > (show_stack+0x20/0x24) > [ 131.776151] [<c001213c>] (show_stack) from [<c05217d4>] > (dump_stack+0x7c/0x98) > [ 131.783315] [<c05217d4>] (dump_stack) from [<c029c130>] > (drm_plane_force_disable+0x5c/0x68) > [ 131.791658] [<c029c130>] (drm_plane_force_disable) from > [<c029cf68>] (drm_framebuffer_remove+0xe4/0x110) > [ 131.801070] [<c029cf68>] (drm_framebuffer_remove) from [<c02a09c0>] > (drm_mode_rmfb+0xd4/0xfc) > -->> [ 131.809597] [<c02a09c0>] (drm_mode_rmfb) from [<c0292cb4>] > (drm_ioctl+0x270/0x44c) > [ 131.817135] [<c0292cb4>] (drm_ioctl) from [<c011302c>] > (do_vfs_ioctl+0x4e4/0x5a0) > [ 131.824609] [<c011302c>] (do_vfs_ioctl) from [<c0113144>] > (SyS_ioctl+0x5c/0x84) > [ 131.831884] [<c0113144>] (SyS_ioctl) from [<c000e380>] > (ret_fast_syscall+0x0/0x30) > [ 132.077803] CPU: 0 PID: 834 Comm: X Tainted: G W 3.16.0-rc1+ #623 > [ 132.083413] [<c00155b8>] (unwind_backtrace) from [<c001213c>] > (show_stack+0x20/0x24) > [ 132.091111] [<c001213c>] (show_stack) from [<c05217d4>] > (dump_stack+0x7c/0x98) > [ 132.098343] [<c05217d4>] (dump_stack) from [<c02ab7e4>] > (exynos_drm_crtc_plane_commit+0x20/0x40) > [ 132.107098] [<c02ab7e4>] (exynos_drm_crtc_plane_commit) from > [<c02ae28c>] (exynos_plane_commit+0x24/0x28) > [ 132.116631] [<c02ae28c>] (exynos_plane_commit) from [<c02ab1c8>] > (exynos_drm_crtc_commit+0x2c/0x54) > [ 132.125660] [<c02ab1c8>] (exynos_drm_crtc_commit) from [<c02ab2c0>] > (exynos_drm_crtc_mode_set_commit.isra.1+0x8c/0xa0) > [ 132.136330] [<c02ab2c0>] (exynos_drm_crtc_mode_set_commit.isra.1) > from [<c02ab2ec>] (exynos_drm_crtc_mode_set_base+0x18/0x1c) > [ 132.147605] [<c02ab2ec>] (exynos_drm_crtc_mode_set_base) from > [<c028c148>] (drm_crtc_helper_set_config+0x828/0x8a4) > [ 132.158029] [<c028c148>] (drm_crtc_helper_set_config) from > [<c029ce1c>] (drm_mode_set_config_internal+0x58/0xc0) > [ 132.168155] [<c029ce1c>] (drm_mode_set_config_internal) from > [<c029fe64>] (drm_mode_setcrtc+0x388/0x4ac) > -->> [ 132.177630] [<c029fe64>] (drm_mode_setcrtc) from [<c0292cb4>] > (drm_ioctl+0x270/0x44c) > [ 132.185417] [<c0292cb4>] (drm_ioctl) from [<c011302c>] > (do_vfs_ioctl+0x4e4/0x5a0) > [ 132.192897] [<c011302c>] (do_vfs_ioctl) from [<c0113144>] > (SyS_ioctl+0x5c/0x84) > [ 132.200138] [<c0113144>] (SyS_ioctl) from [<c000e380>] > (ret_fast_syscall+0x0/0x30) > [ 132.207735] Unable to handle kernel NULL pointer dereference at > virtual address 0000032c > .. > .. > [ 132.510786] ff80: b6ebdeb8 bee1d5e8 c06864a2 00000036 c000e5a4 > ecf0e000 00000000 ecf0ffa8 > [ 132.518941] ffa0: c000e380 c01130f4 b6ebdeb8 bee1d5e8 00000005 > c06864a2 bee1d5e8 00000001 > [ 132.527095] ffc0: b6ebdeb8 bee1d5e8 c06864a2 00000036 b85d4a74 > b8702a60 00000000 bee1d688 > [ 132.535250] ffe0: b6a82f30 bee1d5cc b6a75cff b6bce50c 00000010 > 00000005 e1a0c00d e92dd800 > [ 132.543408] [<c02ab7e4>] (exynos_drm_crtc_plane_commit) from > [<c02ae28c>] (exynos_plane_commit+0x24/0x28) > [ 132.552949] [<c02ae28c>] (exynos_plane_commit) from [<c02ab1c8>] > (exynos_drm_crtc_commit+0x2c/0x54) > [ 132.561971] [<c02ab1c8>] (exynos_drm_crtc_commit) from [<c02ab2c0>] > (exynos_drm_crtc_mode_set_commit.isra.1+0x8c/0xa0) > [ 132.572641] [<c02ab2c0>] (exynos_drm_crtc_mode_set_commit.isra.1) > from [<c02ab2ec>] (exynos_drm_crtc_mode_set_base+0x18/0x1c) > [ 132.583919] [<c02ab2ec>] (exynos_drm_crtc_mode_set_base) from > [<c028c148>] (drm_crtc_helper_set_config+0x828/0x8a4) > [ 132.594329] [<c028c148>] (drm_crtc_helper_set_config) from > [<c029ce1c>] (drm_mode_set_config_internal+0x58/0xc0) > [ 132.604478] [<c029ce1c>] (drm_mode_set_config_internal) from > [<c029fe64>] (drm_mode_setcrtc+0x388/0x4ac) > [ 132.613933] [<c029fe64>] (drm_mode_setcrtc) from [<c0292cb4>] > (drm_ioctl+0x270/0x44c) > [ 132.621741] [<c0292cb4>] (drm_ioctl) from [<c011302c>] > (do_vfs_ioctl+0x4e4/0x5a0) > [ 132.629201] [<c011302c>] (do_vfs_ioctl) from [<c0113144>] > (SyS_ioctl+0x5c/0x84) > [ 132.636489] [<c0113144>] (SyS_ioctl) from [<c000e380>] > (ret_fast_syscall+0x0/0x30) > [ 132.644035] Code: e8bd4000 e1a05000 e1a04001 eb09d7dc (e595032c) > [ 132.650164] ---[ end trace 4bc5b9657975a179 ]--- > [ 132.654749] Kernel panic - not syncing: Fatal exception > [ 132.659912] CPU3: stopping > [ 132.662600] CPU: 3 PID: 478 Comm: rs:main Q:Reg Tainted: G D W > 3.16.0-rc1+ #623 > [ 132.670673] [<c00155b8>] (unwind_backtrace) from [<c001213c>] > (show_stack+0x20/0x24) > [ 132.678392] [<c001213c>] (show_stack) from [<c05217d4>] > (dump_stack+0x7c/0x98) > [ 132.685590] [<c05217d4>] (dump_stack) from [<c001409c>] > (handle_IPI+0xd8/0x160) > [ 132.692876] [<c001409c>] (handle_IPI) from [<c0008688>] > (gic_handle_irq+0x68/0x70) > [ 132.700423] [<c0008688>] (gic_handle_irq) from [<c0012cc0>] > (__irq_svc+0x40/0x50) > > Regards, > Rahul Sharma. > >> >> Thanks, >> Inki Dae >> >>> >>> This crashes the system. >>> >>> Signed-off-by: Rahul Sharma <rahul.sharma@samsung.com> >>> --- >>> This works fine but I am not confident on the correctness of the >>> solution. >>> >>> drivers/gpu/drm/exynos/exynos_drm_crtc.c | 6 ++++++ >>> 1 file changed, 6 insertions(+) >>> >>> diff --git a/drivers/gpu/drm/exynos/exynos_drm_crtc.c b/drivers/gpu/drm/exynos/exynos_drm_crtc.c >>> index 95c9435..da4efe4 100644 >>> --- a/drivers/gpu/drm/exynos/exynos_drm_crtc.c >>> +++ b/drivers/gpu/drm/exynos/exynos_drm_crtc.c >>> @@ -165,6 +165,12 @@ static int exynos_drm_crtc_mode_set_commit(struct drm_crtc *crtc, int x, int y, >>> return -EPERM; >>> } >>> >>> + /* when framebuffer is removed, commit should not proceed. */ >>> + if(!plane->fb){ >>> + DRM_ERROR("framebuffer has been removed from plane.\n"); >>> + return -EFAULT; >>> + } >>> + >>> crtc_w = crtc->primary->fb->width - x; >>> crtc_h = crtc->primary->fb->height - y; >>> >>> -- >>> 1.7.9.5 >>> >>> -- >>> To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in >>> the body of a message to majordomo@vger.kernel.org >>> More majordomo info at http://vger.kernel.org/majordomo-info.html >
diff --git a/drivers/gpu/drm/exynos/exynos_drm_crtc.c b/drivers/gpu/drm/exynos/exynos_drm_crtc.c index 95c9435..da4efe4 100644 --- a/drivers/gpu/drm/exynos/exynos_drm_crtc.c +++ b/drivers/gpu/drm/exynos/exynos_drm_crtc.c @@ -165,6 +165,12 @@ static int exynos_drm_crtc_mode_set_commit(struct drm_crtc *crtc, int x, int y, return -EPERM; } + /* when framebuffer is removed, commit should not proceed. */ + if(!plane->fb){ + DRM_ERROR("framebuffer has been removed from plane.\n"); + return -EFAULT; + } + crtc_w = crtc->primary->fb->width - x; crtc_h = crtc->primary->fb->height - y;
This situation arises when userspace remove the frambuffer object and call setmode ioctl. drm_mode_rmfb --> drm_plane_force_disable --> plane->crtc = NULL; and drm_mode_setcrtc --> exynos_plane_commit --> passes plane->crtc to exynos_drm_crtc_plane_commit which is NULL. This crashes the system. Signed-off-by: Rahul Sharma <rahul.sharma@samsung.com> --- This works fine but I am not confident on the correctness of the solution. drivers/gpu/drm/exynos/exynos_drm_crtc.c | 6 ++++++ 1 file changed, 6 insertions(+)