May 2024 - Linux-stable-mirror

[PATCH v2] arm64/mm: pmd_mkinvalid() must handle swap pmds

by Ryan Roberts

__split_huge_pmd_locked() can be called for a present THP, devmap or (non-present) migration entry. It calls pmdp_invalidate() unconditionally on the pmdp and only determines if it is present or not based on the returned old pmd. But arm64's pmd_mkinvalid(), called by pmdp_invalidate(), unconditionally sets the PMD_PRESENT_INVALID flag, which causes future pmd_present() calls to return true - even for a swap pmd. Therefore any lockless pgtable walker could see the migration entry pmd in this state and start interpretting the fields (e.g. pmd_pfn()) as if it were present, leading to BadThings (TM). GUP-fast appears to be one such lockless pgtable walker. While the obvious fix is for core-mm to avoid such calls for non-present pmds (pmdp_invalidate() will also issue TLBI which is not necessary for this case either), all other arches that implement pmd_mkinvalid() do it in such a way that it is robust to being called with a non-present pmd. So it is simpler and safer to make arm64 robust too. This approach means we can even add tests to debug_vm_pgtable.c to validate the required behaviour. This is a theoretical bug found during code review. I don't have any test case to trigger it in practice. Cc: stable(a)vger.kernel.org Fixes: 53fa117bb33c ("arm64/mm: Enable THP migration") Signed-off-by: Ryan Roberts <ryan.roberts(a)arm.com> --- Hi all, v1 of this fix [1] took the approach of fixing core-mm to never call pmdp_invalidate() on a non-present pmd. But Zi Yan highlighted that only arm64 suffers this problem; all other arches are robust. So his suggestion was to instead make arm64 robust in the same way and add tests to validate it. Despite my stated reservations in the context of the v1 discussion, having thought on it for a bit, I now agree with Zi Yan. Hence this post. Andrew has v1 in mm-unstable at the moment, so probably the best thing to do is remove it from there and have this go in through the arm64 tree? Assuming there is agreement that this approach is right one. This applies on top of v6.9-rc5. Passes all the mm selftests on arm64. [1] https://lore.kernel.org/linux-mm/20240425170704.3379492-1-ryan.roberts@arm.… Thanks, Ryan arch/arm64/include/asm/pgtable.h | 12 +++++-- mm/debug_vm_pgtable.c | 61 ++++++++++++++++++++++++++++++++ 2 files changed, 71 insertions(+), 2 deletions(-) diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index afdd56d26ad7..7d580271a46d 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -511,8 +511,16 @@ static inline int pmd_trans_huge(pmd_t pmd) static inline pmd_t pmd_mkinvalid(pmd_t pmd) { - pmd = set_pmd_bit(pmd, __pgprot(PMD_PRESENT_INVALID)); - pmd = clear_pmd_bit(pmd, __pgprot(PMD_SECT_VALID)); + /* + * If not valid then either we are already present-invalid or we are + * not-present (i.e. none or swap entry). We must not convert + * not-present to present-invalid. Unbelievably, the core-mm may call + * pmd_mkinvalid() for a swap entry and all other arches can handle it. + */ + if (pmd_valid(pmd)) { + pmd = set_pmd_bit(pmd, __pgprot(PMD_PRESENT_INVALID)); + pmd = clear_pmd_bit(pmd, __pgprot(PMD_SECT_VALID)); + } return pmd; } diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c index 65c19025da3d..7e9c387d06b0 100644 --- a/mm/debug_vm_pgtable.c +++ b/mm/debug_vm_pgtable.c @@ -956,6 +956,65 @@ static void __init hugetlb_basic_tests(struct pgtable_debug_args *args) { } #endif /* CONFIG_HUGETLB_PAGE */ #ifdef CONFIG_TRANSPARENT_HUGEPAGE +#if !defined(__HAVE_ARCH_PMDP_INVALIDATE) && defined(CONFIG_ARCH_ENABLE_THP_MIGRATION) +static void __init swp_pmd_mkinvalid_tests(struct pgtable_debug_args *args) +{ + unsigned long max_swap_offset; + swp_entry_t swp_set, swp_clear, swp_convert; + pmd_t pmd_set, pmd_clear; + + /* + * See generic_max_swapfile_size(): probe the maximum offset, then + * create swap entry will all possible bits set and a swap entry will + * all bits clear. + */ + max_swap_offset = swp_offset(pmd_to_swp_entry(swp_entry_to_pmd(swp_entry(0, ~0UL)))); + swp_set = swp_entry((1 << MAX_SWAPFILES_SHIFT) - 1, max_swap_offset); + swp_clear = swp_entry(0, 0); + + /* Convert to pmd. */ + pmd_set = swp_entry_to_pmd(swp_set); + pmd_clear = swp_entry_to_pmd(swp_clear); + + /* + * Sanity check that the pmds are not-present, not-huge and swap entry + * is recoverable without corruption. + */ + WARN_ON(pmd_present(pmd_set)); + WARN_ON(pmd_trans_huge(pmd_set)); + swp_convert = pmd_to_swp_entry(pmd_set); + WARN_ON(swp_type(swp_set) != swp_type(swp_convert)); + WARN_ON(swp_offset(swp_set) != swp_offset(swp_convert)); + WARN_ON(pmd_present(pmd_clear)); + WARN_ON(pmd_trans_huge(pmd_clear)); + swp_convert = pmd_to_swp_entry(pmd_clear); + WARN_ON(swp_type(swp_clear) != swp_type(swp_convert)); + WARN_ON(swp_offset(swp_clear) != swp_offset(swp_convert)); + + /* Now invalidate the pmd. */ + pmd_set = pmd_mkinvalid(pmd_set); + pmd_clear = pmd_mkinvalid(pmd_clear); + + /* + * Since its a swap pmd, invalidation should effectively be a noop and + * the checks we already did should give the same answer. Check the + * invalidation didn't corrupt any fields. + */ + WARN_ON(pmd_present(pmd_set)); + WARN_ON(pmd_trans_huge(pmd_set)); + swp_convert = pmd_to_swp_entry(pmd_set); + WARN_ON(swp_type(swp_set) != swp_type(swp_convert)); + WARN_ON(swp_offset(swp_set) != swp_offset(swp_convert)); + WARN_ON(pmd_present(pmd_clear)); + WARN_ON(pmd_trans_huge(pmd_clear)); + swp_convert = pmd_to_swp_entry(pmd_clear); + WARN_ON(swp_type(swp_clear) != swp_type(swp_convert)); + WARN_ON(swp_offset(swp_clear) != swp_offset(swp_convert)); +} +#else +static void __init swp_pmd_mkinvalid_tests(struct pgtable_debug_args *args) { } +#endif /* !__HAVE_ARCH_PMDP_INVALIDATE && CONFIG_ARCH_ENABLE_THP_MIGRATION */ + static void __init pmd_thp_tests(struct pgtable_debug_args *args) { pmd_t pmd; @@ -982,6 +1041,8 @@ static void __init pmd_thp_tests(struct pgtable_debug_args *args) WARN_ON(!pmd_trans_huge(pmd_mkinvalid(pmd_mkhuge(pmd)))); WARN_ON(!pmd_present(pmd_mkinvalid(pmd_mkhuge(pmd)))); #endif /* __HAVE_ARCH_PMDP_INVALIDATE */ + + swp_pmd_mkinvalid_tests(args); } #ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD -- 2.25.1

5 months, 2 weeks

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[PATCH] docs: stable-kernel-rules: fix typo sent->send

by Bird, Tim

Change 'sent' to 'send' Signed-off-by: Tim Bird <tim.bird(a)sony.com> --- Documentation/process/stable-kernel-rules.rst | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/Documentation/process/stable-kernel-rules.rst b/Documentation/process/stable-kernel-rules.rst index 1704f1c686d0..3178bef6fca3 100644 --- a/Documentation/process/stable-kernel-rules.rst +++ b/Documentation/process/stable-kernel-rules.rst @@ -78,7 +78,7 @@ in the sign-off area. Once the patch is mainlined it will be applied to the stable tree without anything else needing to be done by the author or subsystem maintainer. -To sent additional instructions to the stable team, use a shell-style inline +To send additional instructions to the stable team, use a shell-style inline comment: * To specify any additional patch prerequisites for cherry picking use the -- 2.25.1

5 months, 2 weeks

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[PATCH v2 0/5] docs: stable-kernel-rules: fine-tuning and 'no stable backport' tag

by Thorsten Leemhuis

After a recent discussion regarding "do we need a 'nobackport' tag" I set out to create one change for stable-kernel-rules.rst. This is now the last patch in the series, which links to that discussion with all the details; the other stuff is fine-tuning that happened along the way. Ciao, Thorsten --- v1->v2: * Add reviewed-by tag from Greg to the first patch. * Change the backport example in 2 as suggested by Greg. * Improve description of patch 3 while also making the change remove a level of indenting. * Add patch explaining stable(a)kernel.org (w/o @vger.) * Move the patch adding a 'make AUTOSEL et. al. ignore a change' flag to the end of the series and use stable+noautosel(a)kernel.org as suggested my Konstantin and ACKed by Greg. v1: https://lore.kernel.org/all/cover.1712812895.git.linux@leemhuis.info/ Thorsten Leemhuis (5): docs: stable-kernel-rules: reduce redundancy docs: stable-kernel-rules: call mainline by its name and change example docs: stable-kernel-rules: remove code-labels tags and a indention level docs: stable-kernel-rules: explain use of stable(a)kernel.org (w/o @vger.) docs: stable-kernel-rules: create special tag to flag 'no backporting' Documentation/process/stable-kernel-rules.rst | 234 ++++++++---------- 1 file changed, 110 insertions(+), 124 deletions(-) base-commit: 5eb4573ea63d0c83bf58fb7c243fc2c2b6966c02 -- 2.44.0

5 months, 2 weeks

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+ mm-fix-race-between-__split_huge_pmd_locked-and-gup-fast.patch added to mm-unstable branch

by Andrew Morton

The patch titled Subject: mm: fix race between __split_huge_pmd_locked() and GUP-fast has been added to the -mm mm-unstable branch. Its filename is mm-fix-race-between-__split_huge_pmd_locked-and-gup-fast.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patche… This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Ryan Roberts <ryan.roberts(a)arm.com> Subject: mm: fix race between __split_huge_pmd_locked() and GUP-fast Date: Wed, 1 May 2024 15:33:10 +0100 __split_huge_pmd_locked() can be called for a present THP, devmap or (non-present) migration entry. It calls pmdp_invalidate() unconditionally on the pmdp and only determines if it is present or not based on the returned old pmd. This is a problem for the migration entry case because pmd_mkinvalid(), called by pmdp_invalidate() must only be called for a present pmd. On arm64 at least, pmd_mkinvalid() will mark the pmd such that any future call to pmd_present() will return true. And therefore any lockless pgtable walker could see the migration entry pmd in this state and start interpretting the fields as if it were present, leading to BadThings (TM). GUP-fast appears to be one such lockless pgtable walker. x86 does not suffer the above problem, but instead pmd_mkinvalid() will corrupt the offset field of the swap entry within the swap pte. See link below for discussion of that problem. Fix all of this by only calling pmdp_invalidate() for a present pmd. And for good measure let's add a warning to all implementations of pmdp_invalidate[_ad](). I've manually reviewed all other pmdp_invalidate[_ad]() call sites and believe all others to be conformant. This is a theoretical bug found during code review. I don't have any test case to trigger it in practice. Link: https://lkml.kernel.org/r/20240501143310.1381675-1-ryan.roberts@arm.com Link: https://lore.kernel.org/all/0dd7827a-6334-439a-8fd0-43c98e6af22b@arm.com/ Fixes: 84c3fc4e9c56 ("mm: thp: check pmd migration entry in common path") Signed-off-by: Ryan Roberts <ryan.roberts(a)arm.com> Reviewed-by: Zi Yan <ziy(a)nvidia.com> Reviewed-by: Anshuman Khandual <anshuman.khandual(a)arm.com> Acked-by: David Hildenbrand <david(a)redhat.com> Cc: Andreas Larsson <andreas(a)gaisler.com> Cc: Andy Lutomirski <luto(a)kernel.org> Cc: Aneesh Kumar K.V <aneesh.kumar(a)kernel.org> Cc: Borislav Petkov (AMD) <bp(a)alien8.de> Cc: Catalin Marinas <catalin.marinas(a)arm.com> Cc: Christian Borntraeger <borntraeger(a)linux.ibm.com> Cc: Christophe Leroy <christophe.leroy(a)csgroup.eu> Cc: Dave Hansen <dave.hansen(a)linux.intel.com> Cc: "David S. Miller" <davem(a)davemloft.net> Cc: Ingo Molnar <mingo(a)redhat.com> Cc: Jonathan Corbet <corbet(a)lwn.net> Cc: Mark Rutland <mark.rutland(a)arm.com> Cc: Naveen N. Rao <naveen.n.rao(a)linux.ibm.com> Cc: Nicholas Piggin <npiggin(a)gmail.com> Cc: Peter Zijlstra <peterz(a)infradead.org> Cc: Sven Schnelle <svens(a)linux.ibm.com> Cc: Thomas Gleixner <tglx(a)linutronix.de> Cc: Will Deacon <will(a)kernel.org> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- Documentation/mm/arch_pgtable_helpers.rst | 6 +- arch/powerpc/mm/book3s64/pgtable.c | 1 arch/s390/include/asm/pgtable.h | 4 + arch/sparc/mm/tlb.c | 1 arch/x86/mm/pgtable.c | 2 mm/huge_memory.c | 49 ++++++++++---------- mm/pgtable-generic.c | 2 7 files changed, 39 insertions(+), 26 deletions(-) --- a/arch/powerpc/mm/book3s64/pgtable.c~mm-fix-race-between-__split_huge_pmd_locked-and-gup-fast +++ a/arch/powerpc/mm/book3s64/pgtable.c @@ -170,6 +170,7 @@ pmd_t pmdp_invalidate(struct vm_area_str { unsigned long old_pmd; + VM_WARN_ON_ONCE(!pmd_present(*pmdp)); old_pmd = pmd_hugepage_update(vma->vm_mm, address, pmdp, _PAGE_PRESENT, _PAGE_INVALID); flush_pmd_tlb_range(vma, address, address + HPAGE_PMD_SIZE); return __pmd(old_pmd); --- a/arch/s390/include/asm/pgtable.h~mm-fix-race-between-__split_huge_pmd_locked-and-gup-fast +++ a/arch/s390/include/asm/pgtable.h @@ -1769,8 +1769,10 @@ static inline pmd_t pmdp_huge_clear_flus static inline pmd_t pmdp_invalidate(struct vm_area_struct *vma, unsigned long addr, pmd_t *pmdp) { - pmd_t pmd = __pmd(pmd_val(*pmdp) | _SEGMENT_ENTRY_INVALID); + pmd_t pmd; + VM_WARN_ON_ONCE(!pmd_present(*pmdp)); + pmd = __pmd(pmd_val(*pmdp) | _SEGMENT_ENTRY_INVALID); return pmdp_xchg_direct(vma->vm_mm, addr, pmdp, pmd); } --- a/arch/sparc/mm/tlb.c~mm-fix-race-between-__split_huge_pmd_locked-and-gup-fast +++ a/arch/sparc/mm/tlb.c @@ -249,6 +249,7 @@ pmd_t pmdp_invalidate(struct vm_area_str { pmd_t old, entry; + VM_WARN_ON_ONCE(!pmd_present(*pmdp)); entry = __pmd(pmd_val(*pmdp) & ~_PAGE_VALID); old = pmdp_establish(vma, address, pmdp, entry); flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE); --- a/arch/x86/mm/pgtable.c~mm-fix-race-between-__split_huge_pmd_locked-and-gup-fast +++ a/arch/x86/mm/pgtable.c @@ -631,6 +631,8 @@ int pmdp_clear_flush_young(struct vm_are pmd_t pmdp_invalidate_ad(struct vm_area_struct *vma, unsigned long address, pmd_t *pmdp) { + VM_WARN_ON_ONCE(!pmd_present(*pmdp)); + /* * No flush is necessary. Once an invalid PTE is established, the PTE's * access and dirty bits cannot be updated. --- a/Documentation/mm/arch_pgtable_helpers.rst~mm-fix-race-between-__split_huge_pmd_locked-and-gup-fast +++ a/Documentation/mm/arch_pgtable_helpers.rst @@ -140,7 +140,8 @@ PMD Page Table Helpers +---------------------------+--------------------------------------------------+ | pmd_swp_clear_soft_dirty | Clears a soft dirty swapped PMD | +---------------------------+--------------------------------------------------+ -| pmd_mkinvalid | Invalidates a mapped PMD [1] | +| pmd_mkinvalid | Invalidates a present PMD; do not call for | +| | non-present PMD [1] | +---------------------------+--------------------------------------------------+ | pmd_set_huge | Creates a PMD huge mapping | +---------------------------+--------------------------------------------------+ @@ -196,7 +197,8 @@ PUD Page Table Helpers +---------------------------+--------------------------------------------------+ | pud_mkdevmap | Creates a ZONE_DEVICE mapped PUD | +---------------------------+--------------------------------------------------+ -| pud_mkinvalid | Invalidates a mapped PUD [1] | +| pud_mkinvalid | Invalidates a present PUD; do not call for | +| | non-present PUD [1] | +---------------------------+--------------------------------------------------+ | pud_set_huge | Creates a PUD huge mapping | +---------------------------+--------------------------------------------------+ --- a/mm/huge_memory.c~mm-fix-race-between-__split_huge_pmd_locked-and-gup-fast +++ a/mm/huge_memory.c @@ -2430,32 +2430,11 @@ static void __split_huge_pmd_locked(stru return __split_huge_zero_page_pmd(vma, haddr, pmd); } - /* - * Up to this point the pmd is present and huge and userland has the - * whole access to the hugepage during the split (which happens in - * place). If we overwrite the pmd with the not-huge version pointing - * to the pte here (which of course we could if all CPUs were bug - * free), userland could trigger a small page size TLB miss on the - * small sized TLB while the hugepage TLB entry is still established in - * the huge TLB. Some CPU doesn't like that. - * See http://support.amd.com/TechDocs/41322_10h_Rev_Gd.pdf, Erratum - * 383 on page 105. Intel should be safe but is also warns that it's - * only safe if the permission and cache attributes of the two entries - * loaded in the two TLB is identical (which should be the case here). - * But it is generally safer to never allow small and huge TLB entries - * for the same virtual address to be loaded simultaneously. So instead - * of doing "pmd_populate(); flush_pmd_tlb_range();" we first mark the - * current pmd notpresent (atomically because here the pmd_trans_huge - * must remain set at all times on the pmd until the split is complete - * for this pmd), then we flush the SMP TLB and finally we write the - * non-huge version of the pmd entry with pmd_populate. - */ - old_pmd = pmdp_invalidate(vma, haddr, pmd); - - pmd_migration = is_pmd_migration_entry(old_pmd); + pmd_migration = is_pmd_migration_entry(*pmd); if (unlikely(pmd_migration)) { swp_entry_t entry; + old_pmd = *pmd; entry = pmd_to_swp_entry(old_pmd); page = pfn_swap_entry_to_page(entry); write = is_writable_migration_entry(entry); @@ -2466,6 +2445,30 @@ static void __split_huge_pmd_locked(stru soft_dirty = pmd_swp_soft_dirty(old_pmd); uffd_wp = pmd_swp_uffd_wp(old_pmd); } else { + /* + * Up to this point the pmd is present and huge and userland has + * the whole access to the hugepage during the split (which + * happens in place). If we overwrite the pmd with the not-huge + * version pointing to the pte here (which of course we could if + * all CPUs were bug free), userland could trigger a small page + * size TLB miss on the small sized TLB while the hugepage TLB + * entry is still established in the huge TLB. Some CPU doesn't + * like that. See + * http://support.amd.com/TechDocs/41322_10h_Rev_Gd.pdf, Erratum + * 383 on page 105. Intel should be safe but is also warns that + * it's only safe if the permission and cache attributes of the + * two entries loaded in the two TLB is identical (which should + * be the case here). But it is generally safer to never allow + * small and huge TLB entries for the same virtual address to be + * loaded simultaneously. So instead of doing "pmd_populate(); + * flush_pmd_tlb_range();" we first mark the current pmd + * notpresent (atomically because here the pmd_trans_huge must + * remain set at all times on the pmd until the split is + * complete for this pmd), then we flush the SMP TLB and finally + * we write the non-huge version of the pmd entry with + * pmd_populate. + */ + old_pmd = pmdp_invalidate(vma, haddr, pmd); page = pmd_page(old_pmd); folio = page_folio(page); if (pmd_dirty(old_pmd)) { --- a/mm/pgtable-generic.c~mm-fix-race-between-__split_huge_pmd_locked-and-gup-fast +++ a/mm/pgtable-generic.c @@ -198,6 +198,7 @@ pgtable_t pgtable_trans_huge_withdraw(st pmd_t pmdp_invalidate(struct vm_area_struct *vma, unsigned long address, pmd_t *pmdp) { + VM_WARN_ON_ONCE(!pmd_present(*pmdp)); pmd_t old = pmdp_establish(vma, address, pmdp, pmd_mkinvalid(*pmdp)); flush_pmd_tlb_range(vma, address, address + HPAGE_PMD_SIZE); return old; @@ -208,6 +209,7 @@ pmd_t pmdp_invalidate(struct vm_area_str pmd_t pmdp_invalidate_ad(struct vm_area_struct *vma, unsigned long address, pmd_t *pmdp) { + VM_WARN_ON_ONCE(!pmd_present(*pmdp)); return pmdp_invalidate(vma, address, pmdp); } #endif _ Patches currently in -mm which might be from ryan.roberts(a)arm.com are fs-proc-task_mmu-fix-loss-of-young-dirty-bits-during-pagemap-scan.patch fs-proc-task_mmu-fix-uffd-wp-confusion-in-pagemap_scan_pmd_entry.patch selftests-mm-soft-dirty-should-fail-if-a-testcase-fails.patch mm-debug_vm_pgtable-test-pmd_leaf-behavior-with-pmd_mkinvalid.patch mm-fix-race-between-__split_huge_pmd_locked-and-gup-fast.patch

5 months, 2 weeks

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[PATCH] drm/i915/audio: Fix audio time stamp programming for DP

by Chaitanya Kumar Borah

Intel hardware is capable of programming the Maud/Naud SDPs on its own based on real-time clocks. While doing so, it takes care of any deviations from the theoretical values. Programming the registers explicitly with static values can interfere with this logic. Therefore, let the HW decide the Maud and Naud SDPs on it's own. Cc: stable(a)vger.kernel.org # v5.17 Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/8097 Co-developed-by: Kai Vehmanen <kai.vehmanen(a)intel.com> Signed-off-by: Kai Vehmanen <kai.vehmanen(a)intel.com> Signed-off-by: Chaitanya Kumar Borah <chaitanya.kumar.borah(a)intel.com> --- drivers/gpu/drm/i915/display/intel_audio.c | 113 ++------------------- 1 file changed, 8 insertions(+), 105 deletions(-) diff --git a/drivers/gpu/drm/i915/display/intel_audio.c b/drivers/gpu/drm/i915/display/intel_audio.c index 07e0c73204f3..ed81e1466c4b 100644 --- a/drivers/gpu/drm/i915/display/intel_audio.c +++ b/drivers/gpu/drm/i915/display/intel_audio.c @@ -76,19 +76,6 @@ struct intel_audio_funcs { struct intel_crtc_state *crtc_state); }; -/* DP N/M table */ -#define LC_810M 810000 -#define LC_540M 540000 -#define LC_270M 270000 -#define LC_162M 162000 - -struct dp_aud_n_m { - int sample_rate; - int clock; - u16 m; - u16 n; -}; - struct hdmi_aud_ncts { int sample_rate; int clock; @@ -96,60 +83,6 @@ struct hdmi_aud_ncts { int cts; }; -/* Values according to DP 1.4 Table 2-104 */ -static const struct dp_aud_n_m dp_aud_n_m[] = { - { 32000, LC_162M, 1024, 10125 }, - { 44100, LC_162M, 784, 5625 }, - { 48000, LC_162M, 512, 3375 }, - { 64000, LC_162M, 2048, 10125 }, - { 88200, LC_162M, 1568, 5625 }, - { 96000, LC_162M, 1024, 3375 }, - { 128000, LC_162M, 4096, 10125 }, - { 176400, LC_162M, 3136, 5625 }, - { 192000, LC_162M, 2048, 3375 }, - { 32000, LC_270M, 1024, 16875 }, - { 44100, LC_270M, 784, 9375 }, - { 48000, LC_270M, 512, 5625 }, - { 64000, LC_270M, 2048, 16875 }, - { 88200, LC_270M, 1568, 9375 }, - { 96000, LC_270M, 1024, 5625 }, - { 128000, LC_270M, 4096, 16875 }, - { 176400, LC_270M, 3136, 9375 }, - { 192000, LC_270M, 2048, 5625 }, - { 32000, LC_540M, 1024, 33750 }, - { 44100, LC_540M, 784, 18750 }, - { 48000, LC_540M, 512, 11250 }, - { 64000, LC_540M, 2048, 33750 }, - { 88200, LC_540M, 1568, 18750 }, - { 96000, LC_540M, 1024, 11250 }, - { 128000, LC_540M, 4096, 33750 }, - { 176400, LC_540M, 3136, 18750 }, - { 192000, LC_540M, 2048, 11250 }, - { 32000, LC_810M, 1024, 50625 }, - { 44100, LC_810M, 784, 28125 }, - { 48000, LC_810M, 512, 16875 }, - { 64000, LC_810M, 2048, 50625 }, - { 88200, LC_810M, 1568, 28125 }, - { 96000, LC_810M, 1024, 16875 }, - { 128000, LC_810M, 4096, 50625 }, - { 176400, LC_810M, 3136, 28125 }, - { 192000, LC_810M, 2048, 16875 }, -}; - -static const struct dp_aud_n_m * -audio_config_dp_get_n_m(const struct intel_crtc_state *crtc_state, int rate) -{ - int i; - - for (i = 0; i < ARRAY_SIZE(dp_aud_n_m); i++) { - if (rate == dp_aud_n_m[i].sample_rate && - crtc_state->port_clock == dp_aud_n_m[i].clock) - return &dp_aud_n_m[i]; - } - - return NULL; -} - static const struct { int clock; u32 config; @@ -387,47 +320,17 @@ hsw_dp_audio_config_update(struct intel_encoder *encoder, const struct intel_crtc_state *crtc_state) { struct drm_i915_private *i915 = to_i915(encoder->base.dev); - struct i915_audio_component *acomp = i915->display.audio.component; enum transcoder cpu_transcoder = crtc_state->cpu_transcoder; - enum port port = encoder->port; - const struct dp_aud_n_m *nm; - int rate; - u32 tmp; - - rate = acomp ? acomp->aud_sample_rate[port] : 0; - nm = audio_config_dp_get_n_m(crtc_state, rate); - if (nm) - drm_dbg_kms(&i915->drm, "using Maud %u, Naud %u\n", nm->m, - nm->n); - else - drm_dbg_kms(&i915->drm, "using automatic Maud, Naud\n"); - - tmp = intel_de_read(i915, HSW_AUD_CFG(cpu_transcoder)); - tmp &= ~AUD_CONFIG_N_VALUE_INDEX; - tmp &= ~AUD_CONFIG_PIXEL_CLOCK_HDMI_MASK; - tmp &= ~AUD_CONFIG_N_PROG_ENABLE; - tmp |= AUD_CONFIG_N_VALUE_INDEX; - if (nm) { - tmp &= ~AUD_CONFIG_N_MASK; - tmp |= AUD_CONFIG_N(nm->n); - tmp |= AUD_CONFIG_N_PROG_ENABLE; - } - - intel_de_write(i915, HSW_AUD_CFG(cpu_transcoder), tmp); - - tmp = intel_de_read(i915, HSW_AUD_M_CTS_ENABLE(cpu_transcoder)); - tmp &= ~AUD_CONFIG_M_MASK; - tmp &= ~AUD_M_CTS_M_VALUE_INDEX; - tmp &= ~AUD_M_CTS_M_PROG_ENABLE; - - if (nm) { - tmp |= nm->m; - tmp |= AUD_M_CTS_M_VALUE_INDEX; - tmp |= AUD_M_CTS_M_PROG_ENABLE; - } + /* Enable time stamps. Let HW calculate Maud/Naud values */ + intel_de_rmw(i915, HSW_AUD_CFG(cpu_transcoder), + AUD_CONFIG_N_VALUE_INDEX | + AUD_CONFIG_PIXEL_CLOCK_HDMI_MASK | + AUD_CONFIG_UPPER_N_MASK | + AUD_CONFIG_LOWER_N_MASK | + AUD_CONFIG_N_PROG_ENABLE, + AUD_CONFIG_N_VALUE_INDEX); - intel_de_write(i915, HSW_AUD_M_CTS_ENABLE(cpu_transcoder), tmp); } static void -- 2.25.1

5 months, 2 weeks

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[PATCH v2 1/5] tracefs: Reset permissions on remount if permissions are options

by Steven Rostedt

From: "Steven Rostedt (Google)" <rostedt(a)goodmis.org> There's an inconsistency with the way permissions are handled in tracefs. Because the permissions are generated when accessed, they default to the root inode's permission if they were never set by the user. If the user sets the permissions, then a flag is set and the permissions are saved via the inode (for tracefs files) or an internal attribute field (for eventfs). But if a remount happens that specify the permissions, all the files that were not changed by the user gets updated, but the ones that were are not. If the user were to remount the file system with a given permission, then all files and directories within that file system should be updated. This can cause security issues if a file's permission was updated but the admin forgot about it. They could incorrectly think that remounting with permissions set would update all files, but miss some. For example: # cd /sys/kernel/tracing # chgrp 1002 current_tracer # ls -l [..] -rw-r----- 1 root root 0 May 1 21:25 buffer_size_kb -rw-r----- 1 root root 0 May 1 21:25 buffer_subbuf_size_kb -r--r----- 1 root root 0 May 1 21:25 buffer_total_size_kb -rw-r----- 1 root lkp 0 May 1 21:25 current_tracer -rw-r----- 1 root root 0 May 1 21:25 dynamic_events -r--r----- 1 root root 0 May 1 21:25 dyn_ftrace_total_info -r--r----- 1 root root 0 May 1 21:25 enabled_functions Where current_tracer now has group "lkp". # mount -o remount,gid=1001 . # ls -l -rw-r----- 1 root tracing 0 May 1 21:25 buffer_size_kb -rw-r----- 1 root tracing 0 May 1 21:25 buffer_subbuf_size_kb -r--r----- 1 root tracing 0 May 1 21:25 buffer_total_size_kb -rw-r----- 1 root lkp 0 May 1 21:25 current_tracer -rw-r----- 1 root tracing 0 May 1 21:25 dynamic_events -r--r----- 1 root tracing 0 May 1 21:25 dyn_ftrace_total_info -r--r----- 1 root tracing 0 May 1 21:25 enabled_functions Everything changed but the "current_tracer". Add a new link list that keeps track of all the tracefs_inodes which has the permission flags that tell if the file/dir should use the root inode's permission or not. Then on remount, clear all the flags so that the default behavior of using the root inode's permission is done for all files and directories. Cc: stable(a)vger.kernel.org Fixes: 8186fff7ab649 ("tracefs/eventfs: Use root and instance inodes as default ownership") Signed-off-by: Steven Rostedt (Google) <rostedt(a)goodmis.org> --- fs/tracefs/event_inode.c | 29 +++++++++++++++++++++++ fs/tracefs/inode.c | 50 +++++++++++++++++++++++++++++++++++++++- fs/tracefs/internal.h | 7 +++++- 3 files changed, 84 insertions(+), 2 deletions(-) diff --git a/fs/tracefs/event_inode.c b/fs/tracefs/event_inode.c index f5510e26f0f6..a754c6725a52 100644 --- a/fs/tracefs/event_inode.c +++ b/fs/tracefs/event_inode.c @@ -301,6 +301,35 @@ static const struct file_operations eventfs_file_operations = { .llseek = generic_file_llseek, }; +/* + * On a remount of tracefs, if UID or GID options are set, then + * the mount point inode permissions should be used. + * Reset the saved permission flags appropriately. + */ +void eventfs_remount(struct tracefs_inode *ti, bool update_uid, bool update_gid) +{ + struct eventfs_inode *ei = ti->private; + + if (!ei) + return; + + if (update_uid) + ei->attr.mode &= ~EVENTFS_SAVE_UID; + + if (update_gid) + ei->attr.mode &= ~EVENTFS_SAVE_GID; + + if (!ei->entry_attrs) + return; + + for (int i = 0; i < ei->nr_entries; i++) { + if (update_uid) + ei->entry_attrs[i].mode &= ~EVENTFS_SAVE_UID; + if (update_gid) + ei->entry_attrs[i].mode &= ~EVENTFS_SAVE_GID; + } +} + /* Return the evenfs_inode of the "events" directory */ static struct eventfs_inode *eventfs_find_events(struct dentry *dentry) { diff --git a/fs/tracefs/inode.c b/fs/tracefs/inode.c index 5545e6bf7d26..5f2417df1c43 100644 --- a/fs/tracefs/inode.c +++ b/fs/tracefs/inode.c @@ -30,20 +30,47 @@ static struct vfsmount *tracefs_mount; static int tracefs_mount_count; static bool tracefs_registered; +/* + * Keep track of all tracefs_inodes in order to update their + * flags if necessary on a remount. + */ +static DEFINE_SPINLOCK(tracefs_inode_lock); +static LIST_HEAD(tracefs_inodes); + static struct inode *tracefs_alloc_inode(struct super_block *sb) { struct tracefs_inode *ti; + unsigned long flags; ti = kmem_cache_alloc(tracefs_inode_cachep, GFP_KERNEL); if (!ti) return NULL; + spin_lock_irqsave(&tracefs_inode_lock, flags); + list_add_rcu(&ti->list, &tracefs_inodes); + spin_unlock_irqrestore(&tracefs_inode_lock, flags); + return &ti->vfs_inode; } +static void tracefs_free_inode_rcu(struct rcu_head *rcu) +{ + struct tracefs_inode *ti; + + ti = container_of(rcu, struct tracefs_inode, rcu); + kmem_cache_free(tracefs_inode_cachep, ti); +} + static void tracefs_free_inode(struct inode *inode) { - kmem_cache_free(tracefs_inode_cachep, get_tracefs(inode)); + struct tracefs_inode *ti = get_tracefs(inode); + unsigned long flags; + + spin_lock_irqsave(&tracefs_inode_lock, flags); + list_del_rcu(&ti->list); + spin_unlock_irqrestore(&tracefs_inode_lock, flags); + + call_rcu(&ti->rcu, tracefs_free_inode_rcu); } static ssize_t default_read_file(struct file *file, char __user *buf, @@ -313,6 +340,8 @@ static int tracefs_apply_options(struct super_block *sb, bool remount) struct tracefs_fs_info *fsi = sb->s_fs_info; struct inode *inode = d_inode(sb->s_root); struct tracefs_mount_opts *opts = &fsi->mount_opts; + struct tracefs_inode *ti; + bool update_uid, update_gid; umode_t tmp_mode; /* @@ -332,6 +361,25 @@ static int tracefs_apply_options(struct super_block *sb, bool remount) if (!remount || opts->opts & BIT(Opt_gid)) inode->i_gid = opts->gid; + if (remount && (opts->opts & BIT(Opt_uid) || opts->opts & BIT(Opt_gid))) { + + update_uid = opts->opts & BIT(Opt_uid); + update_gid = opts->opts & BIT(Opt_gid); + + rcu_read_lock(); + list_for_each_entry_rcu(ti, &tracefs_inodes, list) { + if (update_uid) + ti->flags &= ~TRACEFS_UID_PERM_SET; + + if (update_gid) + ti->flags &= ~TRACEFS_GID_PERM_SET; + + if (ti->flags & TRACEFS_EVENT_INODE) + eventfs_remount(ti, update_uid, update_gid); + } + rcu_read_unlock(); + } + return 0; } diff --git a/fs/tracefs/internal.h b/fs/tracefs/internal.h index 15c26f9aaad4..29f0c999975b 100644 --- a/fs/tracefs/internal.h +++ b/fs/tracefs/internal.h @@ -11,8 +11,12 @@ enum { }; struct tracefs_inode { - struct inode vfs_inode; + union { + struct inode vfs_inode; + struct rcu_head rcu; + }; /* The below gets initialized with memset_after(ti, 0, vfs_inode) */ + struct list_head list; unsigned long flags; void *private; }; @@ -73,6 +77,7 @@ struct dentry *tracefs_end_creating(struct dentry *dentry); struct dentry *tracefs_failed_creating(struct dentry *dentry); struct inode *tracefs_get_inode(struct super_block *sb); +void eventfs_remount(struct tracefs_inode *ti, bool update_uid, bool update_gid); void eventfs_d_release(struct dentry *dentry); #endif /* _TRACEFS_INTERNAL_H */ -- 2.43.0

5 months, 2 weeks

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[PATCH v2 5/5] eventfs: Have "events" directory get permissions from its parent

by Steven Rostedt

From: "Steven Rostedt (Google)" <rostedt(a)goodmis.org> The events directory gets its permissions from the root inode. But this can cause an inconsistency if the instances directory changes its permissions, as the permissions of the created directories under it should inherit the permissions of the instances directory when directories under it are created. Currently the behavior is: # cd /sys/kernel/tracing # chgrp 1002 instances # mkdir instances/foo # ls -l instances/foo [..] -r--r----- 1 root lkp 0 May 1 18:55 buffer_total_size_kb -rw-r----- 1 root lkp 0 May 1 18:55 current_tracer -rw-r----- 1 root lkp 0 May 1 18:55 error_log drwxr-xr-x 1 root root 0 May 1 18:55 events --w------- 1 root lkp 0 May 1 18:55 free_buffer drwxr-x--- 2 root lkp 0 May 1 18:55 options drwxr-x--- 10 root lkp 0 May 1 18:55 per_cpu -rw-r----- 1 root lkp 0 May 1 18:55 set_event All the files and directories under "foo" has the "lkp" group except the "events" directory. That's because its getting its default value from the mount point instead of its parent. Have the "events" directory make its default value based on its parent's permissions. That now gives: # ls -l instances/foo [..] -rw-r----- 1 root lkp 0 May 1 21:16 buffer_subbuf_size_kb -r--r----- 1 root lkp 0 May 1 21:16 buffer_total_size_kb -rw-r----- 1 root lkp 0 May 1 21:16 current_tracer -rw-r----- 1 root lkp 0 May 1 21:16 error_log drwxr-xr-x 1 root lkp 0 May 1 21:16 events --w------- 1 root lkp 0 May 1 21:16 free_buffer drwxr-x--- 2 root lkp 0 May 1 21:16 options drwxr-x--- 10 root lkp 0 May 1 21:16 per_cpu -rw-r----- 1 root lkp 0 May 1 21:16 set_event Cc: stable(a)vger.kernel.org Fixes: 8186fff7ab649 ("tracefs/eventfs: Use root and instance inodes as default ownership") Signed-off-by: Steven Rostedt (Google) <rostedt(a)goodmis.org> --- fs/tracefs/event_inode.c | 30 ++++++++++++++++++++++++------ 1 file changed, 24 insertions(+), 6 deletions(-) diff --git a/fs/tracefs/event_inode.c b/fs/tracefs/event_inode.c index ff4ee3dad56a..3ea32159d556 100644 --- a/fs/tracefs/event_inode.c +++ b/fs/tracefs/event_inode.c @@ -37,6 +37,7 @@ static DEFINE_MUTEX(eventfs_mutex); struct eventfs_root_inode { struct eventfs_inode ei; + struct inode *parent_inode; struct dentry *events_dir; }; @@ -219,12 +220,23 @@ static int eventfs_set_attr(struct mnt_idmap *idmap, struct dentry *dentry, static void update_events_attr(struct eventfs_inode *ei, struct super_block *sb) { - struct inode *root; + struct eventfs_root_inode *rei; + struct inode *parent; + + rei = get_root_inode(ei); + + /* Use the parent inode permissions unless root set its permissions */ + parent = rei->parent_inode; - /* Get the tracefs root inode. */ - root = d_inode(sb->s_root); - ei->attr.uid = root->i_uid; - ei->attr.gid = root->i_gid; + if (rei->ei.attr.mode & EVENTFS_SAVE_UID) + ei->attr.uid = rei->ei.attr.uid; + else + ei->attr.uid = parent->i_uid; + + if (rei->ei.attr.mode & EVENTFS_SAVE_GID) + ei->attr.gid = rei->ei.attr.gid; + else + ei->attr.gid = parent->i_gid; } static void set_top_events_ownership(struct inode *inode) @@ -810,6 +822,7 @@ struct eventfs_inode *eventfs_create_events_dir(const char *name, struct dentry // Note: we have a ref to the dentry from tracefs_start_creating() rei = get_root_inode(ei); rei->events_dir = dentry; + rei->parent_inode = d_inode(dentry->d_sb->s_root); ei->entries = entries; ei->nr_entries = size; @@ -819,10 +832,15 @@ struct eventfs_inode *eventfs_create_events_dir(const char *name, struct dentry uid = d_inode(dentry->d_parent)->i_uid; gid = d_inode(dentry->d_parent)->i_gid; - /* This is used as the default ownership of the files and directories */ ei->attr.uid = uid; ei->attr.gid = gid; + /* + * When the "events" directory is created, it takes on the + * permissions of its parent. But can be reset on remount. + */ + ei->attr.mode |= EVENTFS_SAVE_UID | EVENTFS_SAVE_GID; + INIT_LIST_HEAD(&ei->children); INIT_LIST_HEAD(&ei->list); -- 2.43.0

5 months, 2 weeks

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[PATCH v2 4/5] eventfs: Do not treat events directory different than other directories

by Steven Rostedt

From: "Steven Rostedt (Google)" <rostedt(a)goodmis.org> Treat the events directory the same as other directories when it comes to permissions. The events directory was considered different because it's dentry is persistent, whereas the other directory dentries are created when accessed. But the way tracefs now does its ownership by using the root dentry's permissions as the default permissions, the events directory can get out of sync when a remount is performed setting the group and user permissions. Remove the special case for the events directory on setting the attributes. This allows the updates caused by remount to work properly as well as simplifies the code. Cc: stable(a)vger.kernel.org Fixes: 8186fff7ab649 ("tracefs/eventfs: Use root and instance inodes as default ownership") Signed-off-by: Steven Rostedt (Google) <rostedt(a)goodmis.org> --- fs/tracefs/event_inode.c | 16 +--------------- 1 file changed, 1 insertion(+), 15 deletions(-) diff --git a/fs/tracefs/event_inode.c b/fs/tracefs/event_inode.c index 2971609946e5..ff4ee3dad56a 100644 --- a/fs/tracefs/event_inode.c +++ b/fs/tracefs/event_inode.c @@ -199,21 +199,7 @@ static int eventfs_set_attr(struct mnt_idmap *idmap, struct dentry *dentry, * determined by the parent directory. */ if (dentry->d_inode->i_mode & S_IFDIR) { - /* - * The events directory dentry is never freed, unless its - * part of an instance that is deleted. It's attr is the - * default for its child files and directories. - * Do not update it. It's not used for its own mode or ownership. - */ - if (ei->is_events) { - /* But it still needs to know if it was modified */ - if (iattr->ia_valid & ATTR_UID) - ei->attr.mode |= EVENTFS_SAVE_UID; - if (iattr->ia_valid & ATTR_GID) - ei->attr.mode |= EVENTFS_SAVE_GID; - } else { - update_attr(&ei->attr, iattr); - } + update_attr(&ei->attr, iattr); } else { name = dentry->d_name.name; -- 2.43.0

5 months, 2 weeks

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[PATCH v2 3/5] eventfs: Do not differentiate the toplevel events directory

by Steven Rostedt

From: "Steven Rostedt (Google)" <rostedt(a)goodmis.org> The toplevel events directory is really no different than the events directory of instances. Having the two be different caused inconsistencies and made it harder to fix the permissions bugs. Make all events directories act the same. Cc: stable(a)vger.kernel.org Fixes: 8186fff7ab649 ("tracefs/eventfs: Use root and instance inodes as default ownership") Signed-off-by: Steven Rostedt (Google) <rostedt(a)goodmis.org> --- fs/tracefs/event_inode.c | 29 ++++++++--------------------- fs/tracefs/internal.h | 7 +++---- 2 files changed, 11 insertions(+), 25 deletions(-) diff --git a/fs/tracefs/event_inode.c b/fs/tracefs/event_inode.c index a754c6725a52..2971609946e5 100644 --- a/fs/tracefs/event_inode.c +++ b/fs/tracefs/event_inode.c @@ -68,7 +68,6 @@ enum { EVENTFS_SAVE_MODE = BIT(16), EVENTFS_SAVE_UID = BIT(17), EVENTFS_SAVE_GID = BIT(18), - EVENTFS_TOPLEVEL = BIT(19), }; #define EVENTFS_MODE_MASK (EVENTFS_SAVE_MODE - 1) @@ -232,14 +231,10 @@ static int eventfs_set_attr(struct mnt_idmap *idmap, struct dentry *dentry, return ret; } -static void update_top_events_attr(struct eventfs_inode *ei, struct super_block *sb) +static void update_events_attr(struct eventfs_inode *ei, struct super_block *sb) { struct inode *root; - /* Only update if the "events" was on the top level */ - if (!ei || !(ei->attr.mode & EVENTFS_TOPLEVEL)) - return; - /* Get the tracefs root inode. */ root = d_inode(sb->s_root); ei->attr.uid = root->i_uid; @@ -252,10 +247,10 @@ static void set_top_events_ownership(struct inode *inode) struct eventfs_inode *ei = ti->private; /* The top events directory doesn't get automatically updated */ - if (!ei || !ei->is_events || !(ei->attr.mode & EVENTFS_TOPLEVEL)) + if (!ei || !ei->is_events) return; - update_top_events_attr(ei, inode->i_sb); + update_events_attr(ei, inode->i_sb); if (!(ei->attr.mode & EVENTFS_SAVE_UID)) inode->i_uid = ei->attr.uid; @@ -284,7 +279,7 @@ static int eventfs_permission(struct mnt_idmap *idmap, return generic_permission(idmap, inode, mask); } -static const struct inode_operations eventfs_root_dir_inode_operations = { +static const struct inode_operations eventfs_dir_inode_operations = { .lookup = eventfs_root_lookup, .setattr = eventfs_set_attr, .getattr = eventfs_get_attr, @@ -352,7 +347,7 @@ static struct eventfs_inode *eventfs_find_events(struct dentry *dentry) // Walk upwards until you find the events inode } while (!ei->is_events); - update_top_events_attr(ei, dentry->d_sb); + update_events_attr(ei, dentry->d_sb); return ei; } @@ -458,7 +453,7 @@ static struct dentry *lookup_dir_entry(struct dentry *dentry, update_inode_attr(dentry, inode, &ei->attr, S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO); - inode->i_op = &eventfs_root_dir_inode_operations; + inode->i_op = &eventfs_dir_inode_operations; inode->i_fop = &eventfs_file_operations; /* All directories will have the same inode number */ @@ -838,14 +833,6 @@ struct eventfs_inode *eventfs_create_events_dir(const char *name, struct dentry uid = d_inode(dentry->d_parent)->i_uid; gid = d_inode(dentry->d_parent)->i_gid; - /* - * If the events directory is of the top instance, then parent - * is NULL. Set the attr.mode to reflect this and its permissions will - * default to the tracefs root dentry. - */ - if (!parent) - ei->attr.mode = EVENTFS_TOPLEVEL; - /* This is used as the default ownership of the files and directories */ ei->attr.uid = uid; ei->attr.gid = gid; @@ -854,13 +841,13 @@ struct eventfs_inode *eventfs_create_events_dir(const char *name, struct dentry INIT_LIST_HEAD(&ei->list); ti = get_tracefs(inode); - ti->flags |= TRACEFS_EVENT_INODE | TRACEFS_EVENT_TOP_INODE; + ti->flags |= TRACEFS_EVENT_INODE; ti->private = ei; inode->i_mode = S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO; inode->i_uid = uid; inode->i_gid = gid; - inode->i_op = &eventfs_root_dir_inode_operations; + inode->i_op = &eventfs_dir_inode_operations; inode->i_fop = &eventfs_file_operations; dentry->d_fsdata = get_ei(ei); diff --git a/fs/tracefs/internal.h b/fs/tracefs/internal.h index 29f0c999975b..f704d8348357 100644 --- a/fs/tracefs/internal.h +++ b/fs/tracefs/internal.h @@ -4,10 +4,9 @@ enum { TRACEFS_EVENT_INODE = BIT(1), - TRACEFS_EVENT_TOP_INODE = BIT(2), - TRACEFS_GID_PERM_SET = BIT(3), - TRACEFS_UID_PERM_SET = BIT(4), - TRACEFS_INSTANCE_INODE = BIT(5), + TRACEFS_GID_PERM_SET = BIT(2), + TRACEFS_UID_PERM_SET = BIT(3), + TRACEFS_INSTANCE_INODE = BIT(4), }; struct tracefs_inode { -- 2.43.0

5 months, 2 weeks

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[PATCH v2 2/5] tracefs: Still use mount point as default permissions for instances

by Steven Rostedt

From: "Steven Rostedt (Google)" <rostedt(a)goodmis.org> If the instances directory's permissions were never change, then have it and its children use the mount point permissions as the default. Currently, the permissions of instance directories are determined by the instance directory's permissions itself. But if the tracefs file system is remounted and changes the permissions, the instance directory and its children should use the new permission. But because both the instance directory and its children use the instance directory's inode for permissions, it misses the update. To demonstrate this: # cd /sys/kernel/tracing/ # mkdir instances/foo # ls -ld instances/foo drwxr-x--- 5 root root 0 May 1 19:07 instances/foo # ls -ld instances drwxr-x--- 3 root root 0 May 1 18:57 instances # ls -ld current_tracer -rw-r----- 1 root root 0 May 1 18:57 current_tracer # mount -o remount,gid=1002 . # ls -ld instances drwxr-x--- 3 root root 0 May 1 18:57 instances # ls -ld instances/foo/ drwxr-x--- 5 root root 0 May 1 19:07 instances/foo/ # ls -ld current_tracer -rw-r----- 1 root lkp 0 May 1 18:57 current_tracer Notice that changing the group id to that of "lkp" did not affect the instances directory nor its children. It should have been: # ls -ld current_tracer -rw-r----- 1 root root 0 May 1 19:19 current_tracer # ls -ld instances/foo/ drwxr-x--- 5 root root 0 May 1 19:25 instances/foo/ # ls -ld instances drwxr-x--- 3 root root 0 May 1 19:19 instances # mount -o remount,gid=1002 . # ls -ld current_tracer -rw-r----- 1 root lkp 0 May 1 19:19 current_tracer # ls -ld instances drwxr-x--- 3 root lkp 0 May 1 19:19 instances # ls -ld instances/foo/ drwxr-x--- 5 root lkp 0 May 1 19:25 instances/foo/ Where all files were updated by the remount gid update. Cc: stable(a)vger.kernel.org Fixes: 8186fff7ab649 ("tracefs/eventfs: Use root and instance inodes as default ownership") Signed-off-by: Steven Rostedt (Google) <rostedt(a)goodmis.org> --- fs/tracefs/inode.c | 27 +++++++++++++++++++++++++-- 1 file changed, 25 insertions(+), 2 deletions(-) diff --git a/fs/tracefs/inode.c b/fs/tracefs/inode.c index 5f2417df1c43..e1bf65efdbb3 100644 --- a/fs/tracefs/inode.c +++ b/fs/tracefs/inode.c @@ -180,16 +180,39 @@ static void set_tracefs_inode_owner(struct inode *inode) { struct tracefs_inode *ti = get_tracefs(inode); struct inode *root_inode = ti->private; + kuid_t uid; + kgid_t gid; + + uid = root_inode->i_uid; + gid = root_inode->i_gid; + + /* + * If the root is not the mount point, then check the root's + * permissions. If it was never set, then default to the + * mount point. + */ + if (root_inode != d_inode(root_inode->i_sb->s_root)) { + struct tracefs_inode *rti; + + rti = get_tracefs(root_inode); + root_inode = d_inode(root_inode->i_sb->s_root); + + if (!(rti->flags & TRACEFS_UID_PERM_SET)) + uid = root_inode->i_uid; + + if (!(rti->flags & TRACEFS_GID_PERM_SET)) + gid = root_inode->i_gid; + } /* * If this inode has never been referenced, then update * the permissions to the superblock. */ if (!(ti->flags & TRACEFS_UID_PERM_SET)) - inode->i_uid = root_inode->i_uid; + inode->i_uid = uid; if (!(ti->flags & TRACEFS_GID_PERM_SET)) - inode->i_gid = root_inode->i_gid; + inode->i_gid = gid; } static int tracefs_permission(struct mnt_idmap *idmap, -- 2.43.0

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Linux-stable-mirror May 2024