Bin Yang 831b624df1 pstore: Fix incorrect persistent ram buffer mapping ... persistent_ram_vmap() returns the page start vaddr. persistent_ram_iomap() supports non-page-aligned mapping. persistent_ram_buffer_map() always adds offset-in-page to the vaddr returned from these two functions, which causes incorrect mapping of non-page-aligned persistent ram buffer. By default ftrace_size is 4096 and max_ftrace_cnt is nr_cpu_ids. Without this patch, the zone_sz in ramoops_init_przs() is 4096/nr_cpu_ids which might not be page aligned. If the offset-in-page > 2048, the vaddr will be in next page. If the next page is not mapped, it will cause kernel panic: [ 0.074231] BUG: unable to handle kernel paging request at ffffa19e0081b000 ... [ 0.075000] RIP: 0010:persistent_ram_new+0x1f8/0x39f ... [ 0.075000] Call Trace: [ 0.075000] ramoops_init_przs.part.10.constprop.15+0x105/0x260 [ 0.075000] ramoops_probe+0x232/0x3a0 [ 0.075000] platform_drv_probe+0x3e/0xa0 [ 0.075000] driver_probe_device+0x2cd/0x400 [ 0.075000] __driver_attach+0xe4/0x110 [ 0.075000] ? driver_probe_device+0x400/0x400 [ 0.075000] bus_for_each_dev+0x70/0xa0 [ 0.075000] driver_attach+0x1e/0x20 [ 0.075000] bus_add_driver+0x159/0x230 [ 0.075000] ? do_early_param+0x95/0x95 [ 0.075000] driver_register+0x70/0xc0 [ 0.075000] ? init_pstore_fs+0x4d/0x4d [ 0.075000] __platform_driver_register+0x36/0x40 [ 0.075000] ramoops_init+0x12f/0x131 [ 0.075000] do_one_initcall+0x4d/0x12c [ 0.075000] ? do_early_param+0x95/0x95 [ 0.075000] kernel_init_freeable+0x19b/0x222 [ 0.075000] ? rest_init+0xbb/0xbb [ 0.075000] kernel_init+0xe/0xfc [ 0.075000] ret_from_fork+0x3a/0x50 Signed-off-by: Bin Yang <bin.yang@intel.com> [kees: add comments describing the mapping differences, updated commit log] Fixes: 24c3d2f342 ("staging: android: persistent_ram: Make it possible to use memory outside of bootmem") Cc: stable@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org>		2018-09-13 09:14:57 -07:00
..
ftrace.c
inode.c
internal.h
Kconfig	pstore: add zstd compression support	2018-08-03 18:12:18 -07:00
Makefile
platform.c	pstore: add zstd compression support	2018-08-03 18:12:18 -07:00
pmsg.c
ram_core.c	pstore: Fix incorrect persistent ram buffer mapping	2018-09-13 09:14:57 -07:00
ram.c	pstore: Remove bogus format string definition	2018-06-14 14:57:24 +02:00