#ifndef __GENELF_H__
#define __GENELF_H__
/* genelf.c */
int jit_write_elf(int fd, uint64_t code_addr, const char *sym,
const void *code, int csize, void *debug, int nr_debug_entries,
void *unwinding, uint64_t unwinding_header_size, uint64_t unwinding_size);
#ifdef HAVE_DWARF_SUPPORT
/* genelf_debug.c */
int jit_add_debug_info(Elf *e, uint64_t code_addr, void *debug, int nr_debug_entries);
#endif
#if defined(__arm__)
#define GEN_ELF_ARCH EM_ARM
#define GEN_ELF_CLASS ELFCLASS32
#elif defined(__aarch64__)
#define GEN_ELF_ARCH EM_AARCH64
#define GEN_ELF_CLASS ELFCLASS64
#elif defined(__x86_64__)
#define GEN_ELF_ARCH EM_X86_64
#define GEN_ELF_CLASS ELFCLASS64
#elif defined(__i386__)
#define GEN_ELF_ARCH EM_386
#define GEN_ELF_CLASS ELFCLASS32
#elif defined(__powerpc64__)
#define GEN_ELF_ARCH EM_PPC64
#define GEN_ELF_CLASS ELFCLASS64
#elif defined(__powerpc__)
#define GEN_ELF_ARCH EM_PPC
#define GEN_ELF_CLASS ELFCLASS32
#else
#error "unsupported architecture"
#endif
#if __BYTE_ORDER == __BIG_ENDIAN
#define GEN_ELF_ENDIAN ELFDATA2MSB
#else
#define GEN_ELF_ENDIAN ELFDATA2LSB
#endif
#if GEN_ELF_CLASS == ELFCLASS64
#define elf_newehdr elf64_newehdr
#define elf_getshdr elf64_getshdr
#define Elf_Ehdr Elf64_Ehdr
#define Elf_Shdr Elf64_Shdr
#define Elf_Sym Elf64_Sym
#define ELF_ST_TYPE(a) ELF64_ST_TYPE(a)
#define ELF_ST_BIND(a) ELF64_ST_BIND(a)
#define ELF_ST_VIS(a) ELF64_ST_VISIBILITY(a)
#else
#define elf_newehdr elf32_newehdr
#define elf_getshdr elf32_getshdr
#define Elf_Ehdr Elf32_Ehdr
#define Elf_Shdr Elf32_Shdr
#define Elf_Sym Elf32_Sym
#define ELF_ST_TYPE(a) ELF32_ST_TYPE(a)
#define ELF_ST_BIND(a) ELF32_ST_BIND(a)
#define ELF_ST_VIS(a) ELF32_ST_VISIBILITY(a)
#endif
/* The .text section is directly after the ELF header */
#define GEN_ELF_TEXT_OFFSET sizeof(Elf_Ehdr)
#endif
7f6dfba96c543e55b6672d5a37e'>treecommitdiff
drm/i915: Check for NULL i915_vma in intel_unpin_fb_obj()
I've seen this trigger twice now, where the i915_gem_object_to_ggtt()
call in intel_unpin_fb_obj() returns NULL, resulting in an oops
immediately afterwards as the (inlined) call to i915_vma_unpin_fence()
tries to dereference it.
It seems to be some race condition where the object is going away at
shutdown time, since both times happened when shutting down the X
server. The call chains were different:
- VT ioctl(KDSETMODE, KD_TEXT):
intel_cleanup_plane_fb+0x5b/0xa0 [i915]
drm_atomic_helper_cleanup_planes+0x6f/0x90 [drm_kms_helper]
intel_atomic_commit_tail+0x749/0xfe0 [i915]
intel_atomic_commit+0x3cb/0x4f0 [i915]
drm_atomic_commit+0x4b/0x50 [drm]
restore_fbdev_mode+0x14c/0x2a0 [drm_kms_helper]
drm_fb_helper_restore_fbdev_mode_unlocked+0x34/0x80 [drm_kms_helper]
drm_fb_helper_set_par+0x2d/0x60 [drm_kms_helper]
intel_fbdev_set_par+0x18/0x70 [i915]
fb_set_var+0x236/0x460
fbcon_blank+0x30f/0x350
do_unblank_screen+0xd2/0x1a0
vt_ioctl+0x507/0x12a0
tty_ioctl+0x355/0xc30
do_vfs_ioctl+0xa3/0x5e0
SyS_ioctl+0x79/0x90
entry_SYSCALL_64_fastpath+0x13/0x94
- i915 unpin_work workqueue:
intel_unpin_work_fn+0x58/0x140 [i915]
process_one_work+0x1f1/0x480
worker_thread+0x48/0x4d0
kthread+0x101/0x140
and this patch purely papers over the issue by adding a NULL pointer
check and a WARN_ON_ONCE() to avoid the oops that would then generally
make the machine unresponsive.
Other callers of i915_gem_object_to_ggtt() seem to also check for the
returned pointer being NULL and warn about it, so this clearly has
happened before in other places.
[ Reported it originally to the i915 developers on Jan 8, applying the
ugly workaround on my own now after triggering the problem for the
second time with no feedback.
This is likely to be the same bug reported as
https://bugs.freedesktop.org/show_bug.cgi?id=98829
https://bugs.freedesktop.org/show_bug.cgi?id=99134
which has a patch for the underlying problem, but it hasn't gotten to
me, so I'm applying the workaround. ]
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>