1e68b7ce6b
[ Upstream commit 5af757124792817f8eb1bd0c80ad60fab519586b ] When users run the command: cat /sys/kernel/debug/dri/0/amdgpu_dm_dtn_log The following NULL pointer dereference happens: [ +0.000003] BUG: kernel NULL pointer dereference, address: NULL [ +0.000005] #PF: supervisor instruction fetch in kernel mode [ +0.000002] #PF: error_code(0x0010) - not-present page [ +0.000002] PGD 0 P4D 0 [ +0.000004] Oops: 0010 [#1] PREEMPT SMP NOPTI [ +0.000003] RIP: 0010:0x0 [ +0.000008] Code: Unable to access opcode bytes at 0xffffffffffffffd6. [...] [ +0.000002] PKRU: 55555554 [ +0.000002] Call Trace: [ +0.000002] <TASK> [ +0.000003] ? show_regs+0x65/0x70 [ +0.000006] ? __die+0x24/0x70 [ +0.000004] ? page_fault_oops+0x160/0x470 [ +0.000006] ? do_user_addr_fault+0x2b5/0x690 [ +0.000003] ? prb_read_valid+0x1c/0x30 [ +0.000005] ? exc_page_fault+0x8c/0x1a0 [ +0.000005] ? asm_exc_page_fault+0x27/0x30 [ +0.000012] dcn10_log_color_state+0xf9/0x510 [amdgpu] [ +0.000306] ? srso_alias_return_thunk+0x5/0xfbef5 [ +0.000003] ? vsnprintf+0x2fb/0x600 [ +0.000009] dcn10_log_hw_state+0xfd0/0xfe0 [amdgpu] [ +0.000218] ? __mod_memcg_lruvec_state+0xe8/0x170 [ +0.000008] ? srso_alias_return_thunk+0x5/0xfbef5 [ +0.000002] ? debug_smp_processor_id+0x17/0x20 [ +0.000003] ? srso_alias_return_thunk+0x5/0xfbef5 [ +0.000002] ? srso_alias_return_thunk+0x5/0xfbef5 [ +0.000002] ? set_ptes.isra.0+0x2b/0x90 [ +0.000004] ? srso_alias_return_thunk+0x5/0xfbef5 [ +0.000002] ? _raw_spin_unlock+0x19/0x40 [ +0.000004] ? srso_alias_return_thunk+0x5/0xfbef5 [ +0.000002] ? do_anonymous_page+0x337/0x700 [ +0.000004] dtn_log_read+0x82/0x120 [amdgpu] [ +0.000207] full_proxy_read+0x66/0x90 [ +0.000007] vfs_read+0xb0/0x340 [ +0.000005] ? __count_memcg_events+0x79/0xe0 [ +0.000002] ? srso_alias_return_thunk+0x5/0xfbef5 [ +0.000003] ? count_memcg_events.constprop.0+0x1e/0x40 [ +0.000003] ? handle_mm_fault+0xb2/0x370 [ +0.000003] ksys_read+0x6b/0xf0 [ +0.000004] __x64_sys_read+0x19/0x20 [ +0.000003] do_syscall_64+0x60/0x130 [ +0.000004] entry_SYSCALL_64_after_hwframe+0x6e/0x76 [ +0.000003] RIP: 0033:0x7fdf32f147e2 [...] This error happens when the color log tries to read the gamut remap information from DCN401 which is not initialized in the dcn401_dpp_funcs which leads to a null pointer dereference. This commit addresses this issue by adding a proper guard to access the gamut_remap callback in case the specific ASIC did not implement this function. Reviewed-by: Aurabindo Pillai <aurabindo.pillai@amd.com> Acked-by: Hamza Mahfooz <hamza.mahfooz@amd.com> Signed-off-by: Rodrigo Siqueira <rodrigo.siqueira@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.