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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2023-07-22 19:32:00 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2023-07-22 19:32:00 -0700 |
| commit | c2782531397f5cb19ca3f8f9c17727f1cdf5bee8 (patch) | |
| tree | 49ba5ab7407f662e700cf43ef933ed7edfda4caa /arch/powerpc/platforms/pseries/vas.c | |
| parent | 295e1388de2d5c0c354adbd65d0319c5d636c222 (diff) | |
| parent | 106ea7ffd56b0f9454cd4f625474967f12ac4dbd (diff) | |
Merge tag 'powerpc-6.5-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc fixes from Michael Ellerman:
- Reinstate support for little endian ELFv1 binaries, which it turns
out still exist in the wild.
- Revert a change which used asm goto for WARN_ON/__WARN_FLAGS, as it
lead to dead code generation and seemed to trigger compiler bugs in
some edge cases.
- Fix a deadlock in the pseries VAS code, between live migration and
the driver's mmap handler.
- Disable KCOV instrumentation in the powerpc KASAN code.
Thanks to Andrew Donnellan, Benjamin Gray, Christophe Leroy, Haren
Myneni, Russell Currey, and Uwe Kleine-König.
* tag 'powerpc-6.5-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
Revert "powerpc/64s: Remove support for ELFv1 little endian userspace"
powerpc/kasan: Disable KCOV in KASAN code
powerpc/512x: lpbfifo: Convert to platform remove callback returning void
powerpc/crypto: Add gitignore for generated P10 AES/GCM .S files
Revert "powerpc/bug: Provide better flexibility to WARN_ON/__WARN_FLAGS() with asm goto"
powerpc/pseries/vas: Hold mmap_mutex after mmap lock during window close
Diffstat (limited to 'arch/powerpc/platforms/pseries/vas.c')
| -rw-r--r-- | arch/powerpc/platforms/pseries/vas.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/arch/powerpc/platforms/pseries/vas.c b/arch/powerpc/platforms/pseries/vas.c index 9a44a98ba342..3fbc2a6aa319 100644 --- a/arch/powerpc/platforms/pseries/vas.c +++ b/arch/powerpc/platforms/pseries/vas.c @@ -744,6 +744,12 @@ static int reconfig_close_windows(struct vas_caps *vcap, int excess_creds, } task_ref = &win->vas_win.task_ref; + /* + * VAS mmap (coproc_mmap()) and its fault handler + * (vas_mmap_fault()) are called after holding mmap lock. + * So hold mmap mutex after mmap_lock to avoid deadlock. + */ + mmap_write_lock(task_ref->mm); mutex_lock(&task_ref->mmap_mutex); vma = task_ref->vma; /* @@ -752,7 +758,6 @@ static int reconfig_close_windows(struct vas_caps *vcap, int excess_creds, */ win->vas_win.status |= flag; - mmap_write_lock(task_ref->mm); /* * vma is set in the original mapping. But this mapping * is done with mmap() after the window is opened with ioctl. @@ -762,8 +767,8 @@ static int reconfig_close_windows(struct vas_caps *vcap, int excess_creds, if (vma) zap_vma_pages(vma); - mmap_write_unlock(task_ref->mm); mutex_unlock(&task_ref->mmap_mutex); + mmap_write_unlock(task_ref->mm); /* * Close VAS window in the hypervisor, but do not * free vas_window struct since it may be reused |