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[tip: perf/urgent] perf/core: Fix MMAP2 event device with backing files

by tip-bot2 for Adrian Hunter

The following commit has been merged into the perf/urgent branch of tip: Commit-ID: fa4f4bae893fbce8a3edfff1ab7ece0c01dc1328 Gitweb: https://git.kernel.org/tip/fa4f4bae893fbce8a3edfff1ab7ece0c01dc1328 Author: Adrian Hunter <adrian.hunter(a)intel.com> AuthorDate: Mon, 13 Oct 2025 10:22:44 +03:00 Committer: Peter Zijlstra <peterz(a)infradead.org> CommitterDate: Tue, 14 Oct 2025 10:38:10 +02:00 perf/core: Fix MMAP2 event device with backing files Some file systems like FUSE-based ones or overlayfs may record the backing file in struct vm_area_struct vm_file, instead of the user file that the user mmapped. That causes perf to misreport the device major/minor numbers of the file system of the file, and the generation of the file, and potentially other inode details. There is an existing helper file_user_inode() for that situation. Use file_user_inode() instead of file_inode() to get the inode for MMAP2 events. Example: Setup: # cd /root # mkdir test ; cd test ; mkdir lower upper work merged # cp `which cat` lower # mount -t overlay overlay -olowerdir=lower,upperdir=upper,workdir=work merged # perf record -e cycles:u -- /root/test/merged/cat /proc/self/maps ... 55b2c91d0000-55b2c926b000 r-xp 00018000 00:1a 3419 /root/test/merged/cat ... [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.004 MB perf.data (5 samples) ] # # stat /root/test/merged/cat File: /root/test/merged/cat Size: 1127792 Blocks: 2208 IO Block: 4096 regular file Device: 0,26 Inode: 3419 Links: 1 Access: (0755/-rwxr-xr-x) Uid: ( 0/ root) Gid: ( 0/ root) Access: 2025-09-08 12:23:59.453309624 +0000 Modify: 2025-09-08 12:23:59.454309624 +0000 Change: 2025-09-08 12:23:59.454309624 +0000 Birth: 2025-09-08 12:23:59.453309624 +0000 Before: Device reported 00:02 differs from stat output and /proc/self/maps # perf script --show-mmap-events | grep /root/test/merged/cat cat 377 [-01] 243.078558: PERF_RECORD_MMAP2 377/377: [0x55b2c91d0000(0x9b000) @ 0x18000 00:02 3419 2068525940]: r-xp /root/test/merged/cat After: Device reported 00:1a is the same as stat output and /proc/self/maps # perf script --show-mmap-events | grep /root/test/merged/cat cat 362 [-01] 127.755167: PERF_RECORD_MMAP2 362/362: [0x55ba6e781000(0x9b000) @ 0x18000 00:1a 3419 0]: r-xp /root/test/merged/cat With respect to stable kernels, overlayfs mmap function ovl_mmap() was added in v4.19 but file_user_inode() was not added until v6.8 and never back-ported to stable kernels. FMODE_BACKING that it depends on was added in v6.5. This issue has gone largely unnoticed, so back-porting before v6.8 is probably not worth it, so put 6.8 as the stable kernel prerequisite version, although in practice the next long term kernel is 6.12. Signed-off-by: Adrian Hunter <adrian.hunter(a)intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz(a)infradead.org> Acked-by: Amir Goldstein <amir73il(a)gmail.com> Cc: stable(a)vger.kernel.org # 6.8 --- kernel/events/core.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/events/core.c b/kernel/events/core.c index 7b5c237..177e57c 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -9403,7 +9403,7 @@ static void perf_event_mmap_event(struct perf_mmap_event *mmap_event) flags |= MAP_HUGETLB; if (file) { - struct inode *inode; + const struct inode *inode; dev_t dev; buf = kmalloc(PATH_MAX, GFP_KERNEL); @@ -9421,7 +9421,7 @@ static void perf_event_mmap_event(struct perf_mmap_event *mmap_event) name = "//toolong"; goto cpy_name; } - inode = file_inode(vma->vm_file); + inode = file_user_inode(vma->vm_file); dev = inode->i_sb->s_dev; ino = inode->i_ino; gen = inode->i_generation;

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[PATCH] [PATCH v3] perf/x86/amd: check event before enable to avoid GPF

by George Kennedy

On AMD machines cpuc->events[idx] can become NULL in a subtle race condition with NMI->throttle->x86_pmu_stop(). Check event for NULL in amd_pmu_enable_all() before enable to avoid a GPF. This appears to be an AMD only issue. Syzkaller reported a GPF in amd_pmu_enable_all. INFO: NMI handler (perf_event_nmi_handler) took too long to run: 13.143 msecs Oops: general protection fault, probably for non-canonical address 0xdffffc0000000034: 0000 PREEMPT SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x00000000000001a0-0x00000000000001a7] CPU: 0 UID: 0 PID: 328415 Comm: repro_36674776 Not tainted 6.12.0-rc1-syzk RIP: 0010:x86_pmu_enable_event (arch/x86/events/perf_event.h:1195 arch/x86/events/core.c:1430) RSP: 0018:ffff888118009d60 EFLAGS: 00010012 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000034 RSI: 0000000000000000 RDI: 00000000000001a0 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000002 R13: ffff88811802a440 R14: ffff88811802a240 R15: ffff8881132d8601 FS: 00007f097dfaa700(0000) GS:ffff888118000000(0000) GS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000200001c0 CR3: 0000000103d56000 CR4: 00000000000006f0 Call Trace: <IRQ> amd_pmu_enable_all (arch/x86/events/amd/core.c:760 (discriminator 2)) x86_pmu_enable (arch/x86/events/core.c:1360) event_sched_out (kernel/events/core.c:1191 kernel/events/core.c:1186 kernel/events/core.c:2346) __perf_remove_from_context (kernel/events/core.c:2435) event_function (kernel/events/core.c:259) remote_function (kernel/events/core.c:92 (discriminator 1) kernel/events/core.c:72 (discriminator 1)) __flush_smp_call_function_queue (./arch/x86/include/asm/jump_label.h:27 ./include/linux/jump_label.h:207 ./include/trace/events/csd.h:64 kernel/smp.c:135 kernel/smp.c:540) __sysvec_call_function_single (./arch/x86/include/asm/jump_label.h:27 ./include/linux/jump_label.h:207 ./arch/x86/include/asm/trace/irq_vectors.h:99 arch/x86/kernel/smp.c:272) sysvec_call_function_single (arch/x86/kernel/smp.c:266 (discriminator 47) arch/x86/kernel/smp.c:266 (discriminator 47)) </IRQ> Reported-by: syzkaller <syzkaller(a)googlegroups.com> Signed-off-by: George Kennedy <george.kennedy(a)oracle.com> --- Suggested comment now with the code. arch/x86/events/amd/core.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/arch/x86/events/amd/core.c b/arch/x86/events/amd/core.c index 920e3a640cad..6615ace15f5d 100644 --- a/arch/x86/events/amd/core.c +++ b/arch/x86/events/amd/core.c @@ -762,7 +762,12 @@ static void amd_pmu_enable_all(int added) if (!test_bit(idx, cpuc->active_mask)) continue; - amd_pmu_enable_event(cpuc->events[idx]); + /* + * FIXME: cpuc->events[idx] can become NULL in a subtle race + * condition with NMI->throttle->x86_pmu_stop(). + */ + if (cpuc->events[idx]) + amd_pmu_enable_event(cpuc->events[idx]); } } -- 2.39.3

3 weeks

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[PATCH] drm/ast: Blank with VGACR17 sync enable, always clear VGACRB6 sync off

by Thomas Zimmermann

Blank the display by disabling sync pulses with VGACR17<7>. Unblank by reenabling them. This VGA setting should be supported by all Aspeed hardware. Ast currently blanks via sync-off bits in VGACRB6. Not all BMCs handle VGACRB6 correctly. After disabling sync during a reboot, some BMCs do not reenable it after the soft reset. The display output remains dark. When the display is off during boot, some BMCs set the sync-off bits in VGACRB6, so the display remains dark. Observed with Blackbird AST2500 BMC. Clearing the sync-off bits unconditionally fixes these issues. Also do not modify VGASR1's SD bit for blanking, as it only disables GPU access to video memory. Signed-off-by: Thomas Zimmermann <tzimmermann(a)suse.de> Fixes: ce3d99c83495 ("drm: Call drm_atomic_helper_shutdown() at shutdown time for misc drivers") Tested-by: Nick Bowler <nbowler(a)draconx.ca> Reported-by: Nick Bowler <nbowler(a)draconx.ca> Closes: https://lore.kernel.org/dri-devel/wpwd7rit6t4mnu6kdqbtsnk5bhftgslio6e2jgkz6… Cc: Douglas Anderson <dianders(a)chromium.org> Cc: Dave Airlie <airlied(a)redhat.com> Cc: Thomas Zimmermann <tzimmermann(a)suse.de> Cc: Jocelyn Falempe <jfalempe(a)redhat.com> Cc: dri-devel(a)lists.freedesktop.org Cc: <stable(a)vger.kernel.org> # v6.7+ --- drivers/gpu/drm/ast/ast_mode.c | 18 ++++++++++-------- drivers/gpu/drm/ast/ast_reg.h | 1 + 2 files changed, 11 insertions(+), 8 deletions(-) diff --git a/drivers/gpu/drm/ast/ast_mode.c b/drivers/gpu/drm/ast/ast_mode.c index 6b9d510c509d..fe8089266db5 100644 --- a/drivers/gpu/drm/ast/ast_mode.c +++ b/drivers/gpu/drm/ast/ast_mode.c @@ -836,22 +836,24 @@ ast_crtc_helper_atomic_flush(struct drm_crtc *crtc, static void ast_crtc_helper_atomic_enable(struct drm_crtc *crtc, struct drm_atomic_state *state) { struct ast_device *ast = to_ast_device(crtc->dev); + u8 vgacr17 = 0x00; + u8 vgacrb6 = 0x00; - ast_set_index_reg_mask(ast, AST_IO_VGACRI, 0xb6, 0xfc, 0x00); - ast_set_index_reg_mask(ast, AST_IO_VGASRI, 0x01, 0xdf, 0x00); + vgacr17 |= AST_IO_VGACR17_SYNC_ENABLE; + vgacrb6 &= ~(AST_IO_VGACRB6_VSYNC_OFF | AST_IO_VGACRB6_HSYNC_OFF); + + ast_set_index_reg_mask(ast, AST_IO_VGACRI, 0x17, 0x7f, vgacr17); + ast_set_index_reg_mask(ast, AST_IO_VGACRI, 0xb6, 0xfc, vgacrb6); } static void ast_crtc_helper_atomic_disable(struct drm_crtc *crtc, struct drm_atomic_state *state) { struct drm_crtc_state *old_crtc_state = drm_atomic_get_old_crtc_state(state, crtc); struct ast_device *ast = to_ast_device(crtc->dev); - u8 vgacrb6; + u8 vgacr17 = 0xff; - ast_set_index_reg_mask(ast, AST_IO_VGASRI, 0x01, 0xdf, AST_IO_VGASR1_SD); - - vgacrb6 = AST_IO_VGACRB6_VSYNC_OFF | - AST_IO_VGACRB6_HSYNC_OFF; - ast_set_index_reg_mask(ast, AST_IO_VGACRI, 0xb6, 0xfc, vgacrb6); + vgacr17 &= ~AST_IO_VGACR17_SYNC_ENABLE; + ast_set_index_reg_mask(ast, AST_IO_VGACRI, 0x17, 0x7f, vgacr17); /* * HW cursors require the underlying primary plane and CRTC to diff --git a/drivers/gpu/drm/ast/ast_reg.h b/drivers/gpu/drm/ast/ast_reg.h index e15adaf3a80e..30578e3b07e4 100644 --- a/drivers/gpu/drm/ast/ast_reg.h +++ b/drivers/gpu/drm/ast/ast_reg.h @@ -29,6 +29,7 @@ #define AST_IO_VGAGRI (0x4E) #define AST_IO_VGACRI (0x54) +#define AST_IO_VGACR17_SYNC_ENABLE BIT(7) /* called "Hardware reset" in docs */ #define AST_IO_VGACR80_PASSWORD (0xa8) #define AST_IO_VGACR99_VGAMEM_RSRV_MASK GENMASK(1, 0) #define AST_IO_VGACRA1_VGAIO_DISABLED BIT(1) -- 2.51.0

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[PATCH 03/15] PCI: Limit islolated function probing on bus 0 for LoongArch

by Huacai Chen

We found some discrete AMD graphics devices hide funtion 0 and the whole is not supposed to be probed. Since our original purpose is to allow integrated devices (on bus 0) to be probed without function 0, we can limit the islolated function probing only on bus 0. Cc: stable(a)vger.kernel.org Fixes: a02fd05661d73a8 ("PCI: Extend isolated function probing to LoongArch") Signed-off-by: Huacai Chen <chenhuacai(a)loongson.cn> --- drivers/pci/probe.c | 2 +- include/linux/hypervisor.h | 8 +++++--- 2 files changed, 6 insertions(+), 4 deletions(-) diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index c83e75a0ec12..da6a2aef823a 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -2883,7 +2883,7 @@ int pci_scan_slot(struct pci_bus *bus, int devfn) * a hypervisor that passes through individual PCI * functions. */ - if (!hypervisor_isolated_pci_functions()) + if (!hypervisor_isolated_pci_functions(bus->number)) break; } fn = next_fn(bus, dev, fn); diff --git a/include/linux/hypervisor.h b/include/linux/hypervisor.h index be5417303ecf..30ece04a16d9 100644 --- a/include/linux/hypervisor.h +++ b/include/linux/hypervisor.h @@ -32,13 +32,15 @@ static inline bool jailhouse_paravirt(void) #endif /* !CONFIG_X86 */ -static inline bool hypervisor_isolated_pci_functions(void) +static inline bool hypervisor_isolated_pci_functions(int bus) { if (IS_ENABLED(CONFIG_S390)) return true; - if (IS_ENABLED(CONFIG_LOONGARCH)) - return true; + if (IS_ENABLED(CONFIG_LOONGARCH)) { + if (bus == 0) + return true; + } return jailhouse_paravirt(); } -- 2.47.3

3 weeks

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[PATCH v3] exfat: fix out-of-bounds in exfat_nls_to_ucs2()

by Jeongjun Park

Since the len argument value passed to exfat_ioctl_set_volume_label() from exfat_nls_to_utf16() is passed 1 too large, an out-of-bounds read occurs when dereferencing p_cstring in exfat_nls_to_ucs2() later. And because of the NLS_NAME_OVERLEN macro, another error occurs when creating a file with a period at the end using utf8 and other iocharsets, so the NLS_NAME_OVERLEN macro should be removed and the len argument value should be passed as FSLABEL_MAX - 1. Cc: <stable(a)vger.kernel.org> Reported-by: syzbot+98cc76a76de46b3714d4(a)syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=98cc76a76de46b3714d4 Fixes: 370e812b3ec1 ("exfat: add nls operations") Signed-off-by: Jeongjun Park <aha310510(a)gmail.com> --- fs/exfat/file.c | 2 +- fs/exfat/nls.c | 3 --- 2 files changed, 1 insertion(+), 4 deletions(-) diff --git a/fs/exfat/file.c b/fs/exfat/file.c index f246cf439588..7ce0fb6f2564 100644 --- a/fs/exfat/file.c +++ b/fs/exfat/file.c @@ -521,7 +521,7 @@ static int exfat_ioctl_set_volume_label(struct super_block *sb, memset(&uniname, 0, sizeof(uniname)); if (label[0]) { - ret = exfat_nls_to_utf16(sb, label, FSLABEL_MAX, + ret = exfat_nls_to_utf16(sb, label, FSLABEL_MAX - 1, &uniname, &lossy); if (ret < 0) return ret; diff --git a/fs/exfat/nls.c b/fs/exfat/nls.c index 8243d94ceaf4..57db08a5271c 100644 --- a/fs/exfat/nls.c +++ b/fs/exfat/nls.c @@ -616,9 +616,6 @@ static int exfat_nls_to_ucs2(struct super_block *sb, unilen++; } - if (p_cstring[i] != '\0') - lossy |= NLS_NAME_OVERLEN; - *uniname = '\0'; p_uniname->name_len = unilen; p_uniname->name_hash = exfat_calc_chksum16(upname, unilen << 1, 0, --

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FAILED: patch "[PATCH] selftests/mm: skip soft-dirty tests when" failed to apply to 6.1-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.1-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y git checkout FETCH_HEAD git cherry-pick -x 0389c305ef56cbadca4cbef44affc0ec3213ed30 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025101330-hemstitch-crimson-1681@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 0389c305ef56cbadca4cbef44affc0ec3213ed30 Mon Sep 17 00:00:00 2001 From: Lance Yang <lance.yang(a)linux.dev> Date: Wed, 17 Sep 2025 21:31:37 +0800 Subject: [PATCH] selftests/mm: skip soft-dirty tests when CONFIG_MEM_SOFT_DIRTY is disabled The madv_populate and soft-dirty kselftests currently fail on systems where CONFIG_MEM_SOFT_DIRTY is disabled. Introduce a new helper softdirty_supported() into vm_util.c/h to ensure tests are properly skipped when the feature is not enabled. Link: https://lkml.kernel.org/r/20250917133137.62802-1-lance.yang@linux.dev Fixes: 9f3265db6ae8 ("selftests: vm: add test for Soft-Dirty PTE bit") Signed-off-by: Lance Yang <lance.yang(a)linux.dev> Acked-by: David Hildenbrand <david(a)redhat.com> Suggested-by: David Hildenbrand <david(a)redhat.com> Cc: Lorenzo Stoakes <lorenzo.stoakes(a)oracle.com> Cc: Shuah Khan <shuah(a)kernel.org> Cc: Gabriel Krisman Bertazi <krisman(a)collabora.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> diff --git a/tools/testing/selftests/mm/madv_populate.c b/tools/testing/selftests/mm/madv_populate.c index b6fabd5c27ed..d8d11bc67ddc 100644 --- a/tools/testing/selftests/mm/madv_populate.c +++ b/tools/testing/selftests/mm/madv_populate.c @@ -264,23 +264,6 @@ static void test_softdirty(void) munmap(addr, SIZE); } -static int system_has_softdirty(void) -{ - /* - * There is no way to check if the kernel supports soft-dirty, other - * than by writing to a page and seeing if the bit was set. But the - * tests are intended to check that the bit gets set when it should, so - * doing that check would turn a potentially legitimate fail into a - * skip. Fortunately, we know for sure that arm64 does not support - * soft-dirty. So for now, let's just use the arch as a corse guide. - */ -#if defined(__aarch64__) - return 0; -#else - return 1; -#endif -} - int main(int argc, char **argv) { int nr_tests = 16; @@ -288,7 +271,7 @@ int main(int argc, char **argv) pagesize = getpagesize(); - if (system_has_softdirty()) + if (softdirty_supported()) nr_tests += 5; ksft_print_header(); @@ -300,7 +283,7 @@ int main(int argc, char **argv) test_holes(); test_populate_read(); test_populate_write(); - if (system_has_softdirty()) + if (softdirty_supported()) test_softdirty(); err = ksft_get_fail_cnt(); diff --git a/tools/testing/selftests/mm/soft-dirty.c b/tools/testing/selftests/mm/soft-dirty.c index 8a3f2b4b2186..4ee4db3750c1 100644 --- a/tools/testing/selftests/mm/soft-dirty.c +++ b/tools/testing/selftests/mm/soft-dirty.c @@ -200,8 +200,11 @@ int main(int argc, char **argv) int pagesize; ksft_print_header(); - ksft_set_plan(15); + if (!softdirty_supported()) + ksft_exit_skip("soft-dirty is not support\n"); + + ksft_set_plan(15); pagemap_fd = open(PAGEMAP_FILE_PATH, O_RDONLY); if (pagemap_fd < 0) ksft_exit_fail_msg("Failed to open %s\n", PAGEMAP_FILE_PATH); diff --git a/tools/testing/selftests/mm/vm_util.c b/tools/testing/selftests/mm/vm_util.c index 56e9bd541edd..e33cda301dad 100644 --- a/tools/testing/selftests/mm/vm_util.c +++ b/tools/testing/selftests/mm/vm_util.c @@ -449,6 +449,23 @@ bool check_vmflag_pfnmap(void *addr) return check_vmflag(addr, "pf"); } +bool softdirty_supported(void) +{ + char *addr; + bool supported = false; + const size_t pagesize = getpagesize(); + + /* New mappings are expected to be marked with VM_SOFTDIRTY (sd). */ + addr = mmap(0, pagesize, PROT_READ | PROT_WRITE, + MAP_ANONYMOUS | MAP_PRIVATE, 0, 0); + if (!addr) + ksft_exit_fail_msg("mmap failed\n"); + + supported = check_vmflag(addr, "sd"); + munmap(addr, pagesize); + return supported; +} + /* * Open an fd at /proc/$pid/maps and configure procmap_out ready for * PROCMAP_QUERY query. Returns 0 on success, or an error code otherwise. diff --git a/tools/testing/selftests/mm/vm_util.h b/tools/testing/selftests/mm/vm_util.h index 07c4acfd84b6..26c30fdc0241 100644 --- a/tools/testing/selftests/mm/vm_util.h +++ b/tools/testing/selftests/mm/vm_util.h @@ -104,6 +104,7 @@ bool find_vma_procmap(struct procmap_fd *procmap, void *address); int close_procmap(struct procmap_fd *procmap); int write_sysfs(const char *file_path, unsigned long val); int read_sysfs(const char *file_path, unsigned long *val); +bool softdirty_supported(void); static inline int open_self_procmap(struct procmap_fd *procmap_out) {

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[Patch v2] mm/huge_memory: add pmd folio to ds_queue in do_huge_zero_wp_pmd()

by Wei Yang

We add pmd folio into ds_queue on the first page fault in __do_huge_pmd_anonymous_page(), so that we can split it in case of memory pressure. This should be the same for a pmd folio during wp page fault. Commit 1ced09e0331f ("mm: allocate THP on hugezeropage wp-fault") miss to add it to ds_queue, which means system may not reclaim enough memory in case of memory pressure even the pmd folio is under used. Move deferred_split_folio() into map_anon_folio_pmd() to make the pmd folio installation consistent. Fixes: 1ced09e0331f ("mm: allocate THP on hugezeropage wp-fault") Signed-off-by: Wei Yang <richard.weiyang(a)gmail.com> Cc: David Hildenbrand <david(a)redhat.com> Cc: Lance Yang <lance.yang(a)linux.dev> Cc: Dev Jain <dev.jain(a)arm.com> Cc: <stable(a)vger.kernel.org> --- v2: * add fix, cc stable and put description about the flow of current code * move deferred_split_folio() into map_anon_folio_pmd() --- mm/huge_memory.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 1b81680b4225..f13de93637bf 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -1232,6 +1232,7 @@ static void map_anon_folio_pmd(struct folio *folio, pmd_t *pmd, count_vm_event(THP_FAULT_ALLOC); count_mthp_stat(HPAGE_PMD_ORDER, MTHP_STAT_ANON_FAULT_ALLOC); count_memcg_event_mm(vma->vm_mm, THP_FAULT_ALLOC); + deferred_split_folio(folio, false); } static vm_fault_t __do_huge_pmd_anonymous_page(struct vm_fault *vmf) @@ -1272,7 +1273,6 @@ static vm_fault_t __do_huge_pmd_anonymous_page(struct vm_fault *vmf) pgtable_trans_huge_deposit(vma->vm_mm, vmf->pmd, pgtable); map_anon_folio_pmd(folio, vmf->pmd, vma, haddr); mm_inc_nr_ptes(vma->vm_mm); - deferred_split_folio(folio, false); spin_unlock(vmf->ptl); } -- 2.34.1

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FAILED: patch "[PATCH] tracing: Fix race condition in kprobe initialization causing" failed to apply to 6.1-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.1-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y git checkout FETCH_HEAD git cherry-pick -x 9cf9aa7b0acfde7545c1a1d912576e9bab28dc6f # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025101322-quickstep-lanky-3be6@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 9cf9aa7b0acfde7545c1a1d912576e9bab28dc6f Mon Sep 17 00:00:00 2001 From: Yuan Chen <chenyuan(a)kylinos.cn> Date: Wed, 1 Oct 2025 03:20:25 +0100 Subject: [PATCH] tracing: Fix race condition in kprobe initialization causing NULL pointer dereference MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit There is a critical race condition in kprobe initialization that can lead to NULL pointer dereference and kernel crash. [1135630.084782] Unable to handle kernel paging request at virtual address 0000710a04630000 ... [1135630.260314] pstate: 404003c9 (nZcv DAIF +PAN -UAO) [1135630.269239] pc : kprobe_perf_func+0x30/0x260 [1135630.277643] lr : kprobe_dispatcher+0x44/0x60 [1135630.286041] sp : ffffaeff4977fa40 [1135630.293441] x29: ffffaeff4977fa40 x28: ffffaf015340e400 [1135630.302837] x27: 0000000000000000 x26: 0000000000000000 [1135630.312257] x25: ffffaf029ed108a8 x24: ffffaf015340e528 [1135630.321705] x23: ffffaeff4977fc50 x22: ffffaeff4977fc50 [1135630.331154] x21: 0000000000000000 x20: ffffaeff4977fc50 [1135630.340586] x19: ffffaf015340e400 x18: 0000000000000000 [1135630.349985] x17: 0000000000000000 x16: 0000000000000000 [1135630.359285] x15: 0000000000000000 x14: 0000000000000000 [1135630.368445] x13: 0000000000000000 x12: 0000000000000000 [1135630.377473] x11: 0000000000000000 x10: 0000000000000000 [1135630.386411] x9 : 0000000000000000 x8 : 0000000000000000 [1135630.395252] x7 : 0000000000000000 x6 : 0000000000000000 [1135630.403963] x5 : 0000000000000000 x4 : 0000000000000000 [1135630.412545] x3 : 0000710a04630000 x2 : 0000000000000006 [1135630.421021] x1 : ffffaeff4977fc50 x0 : 0000710a04630000 [1135630.429410] Call trace: [1135630.434828] kprobe_perf_func+0x30/0x260 [1135630.441661] kprobe_dispatcher+0x44/0x60 [1135630.448396] aggr_pre_handler+0x70/0xc8 [1135630.454959] kprobe_breakpoint_handler+0x140/0x1e0 [1135630.462435] brk_handler+0xbc/0xd8 [1135630.468437] do_debug_exception+0x84/0x138 [1135630.475074] el1_dbg+0x18/0x8c [1135630.480582] security_file_permission+0x0/0xd0 [1135630.487426] vfs_write+0x70/0x1c0 [1135630.493059] ksys_write+0x5c/0xc8 [1135630.498638] __arm64_sys_write+0x24/0x30 [1135630.504821] el0_svc_common+0x78/0x130 [1135630.510838] el0_svc_handler+0x38/0x78 [1135630.516834] el0_svc+0x8/0x1b0 kernel/trace/trace_kprobe.c: 1308 0xffff3df8995039ec <kprobe_perf_func+0x2c>: ldr x21, [x24,#120] include/linux/compiler.h: 294 0xffff3df8995039f0 <kprobe_perf_func+0x30>: ldr x1, [x21,x0] kernel/trace/trace_kprobe.c 1308: head = this_cpu_ptr(call->perf_events); 1309: if (hlist_empty(head)) 1310: return 0; crash> struct trace_event_call -o struct trace_event_call { ... [120] struct hlist_head *perf_events; //(call->perf_event) ... } crash> struct trace_event_call ffffaf015340e528 struct trace_event_call { ... perf_events = 0xffff0ad5fa89f088, //this value is correct, but x21 = 0 ... } Race Condition Analysis: The race occurs between kprobe activation and perf_events initialization: CPU0 CPU1 ==== ==== perf_kprobe_init perf_trace_event_init tp_event->perf_events = list;(1) tp_event->class->reg (2)← KPROBE ACTIVE Debug exception triggers ... kprobe_dispatcher kprobe_perf_func (tk->tp.flags & TP_FLAG_PROFILE) head = this_cpu_ptr(call->perf_events)(3) (perf_events is still NULL) Problem: 1. CPU0 executes (1) assigning tp_event->perf_events = list 2. CPU0 executes (2) enabling kprobe functionality via class->reg() 3. CPU1 triggers and reaches kprobe_dispatcher 4. CPU1 checks TP_FLAG_PROFILE - condition passes (step 2 completed) 5. CPU1 calls kprobe_perf_func() and crashes at (3) because call->perf_events is still NULL CPU1 sees that kprobe functionality is enabled but does not see that perf_events has been assigned. Add pairing read and write memory barriers to guarantee that if CPU1 sees that kprobe functionality is enabled, it must also see that perf_events has been assigned. Link: https://lore.kernel.org/all/20251001022025.44626-1-chenyuan_fl@163.com/ Fixes: 50d780560785 ("tracing/kprobes: Add probe handler dispatcher to support perf and ftrace concurrent use") Cc: stable(a)vger.kernel.org Signed-off-by: Yuan Chen <chenyuan(a)kylinos.cn> Signed-off-by: Masami Hiramatsu (Google) <mhiramat(a)kernel.org> diff --git a/kernel/trace/trace_fprobe.c b/kernel/trace/trace_fprobe.c index b36ade43d4b3..ad9d6347b5fa 100644 --- a/kernel/trace/trace_fprobe.c +++ b/kernel/trace/trace_fprobe.c @@ -522,13 +522,14 @@ static int fentry_dispatcher(struct fprobe *fp, unsigned long entry_ip, void *entry_data) { struct trace_fprobe *tf = container_of(fp, struct trace_fprobe, fp); + unsigned int flags = trace_probe_load_flag(&tf->tp); int ret = 0; - if (trace_probe_test_flag(&tf->tp, TP_FLAG_TRACE)) + if (flags & TP_FLAG_TRACE) fentry_trace_func(tf, entry_ip, fregs); #ifdef CONFIG_PERF_EVENTS - if (trace_probe_test_flag(&tf->tp, TP_FLAG_PROFILE)) + if (flags & TP_FLAG_PROFILE) ret = fentry_perf_func(tf, entry_ip, fregs); #endif return ret; @@ -540,11 +541,12 @@ static void fexit_dispatcher(struct fprobe *fp, unsigned long entry_ip, void *entry_data) { struct trace_fprobe *tf = container_of(fp, struct trace_fprobe, fp); + unsigned int flags = trace_probe_load_flag(&tf->tp); - if (trace_probe_test_flag(&tf->tp, TP_FLAG_TRACE)) + if (flags & TP_FLAG_TRACE) fexit_trace_func(tf, entry_ip, ret_ip, fregs, entry_data); #ifdef CONFIG_PERF_EVENTS - if (trace_probe_test_flag(&tf->tp, TP_FLAG_PROFILE)) + if (flags & TP_FLAG_PROFILE) fexit_perf_func(tf, entry_ip, ret_ip, fregs, entry_data); #endif } diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index fa60362a3f31..ee8171b19bee 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -1815,14 +1815,15 @@ static int kprobe_register(struct trace_event_call *event, static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs) { struct trace_kprobe *tk = container_of(kp, struct trace_kprobe, rp.kp); + unsigned int flags = trace_probe_load_flag(&tk->tp); int ret = 0; raw_cpu_inc(*tk->nhit); - if (trace_probe_test_flag(&tk->tp, TP_FLAG_TRACE)) + if (flags & TP_FLAG_TRACE) kprobe_trace_func(tk, regs); #ifdef CONFIG_PERF_EVENTS - if (trace_probe_test_flag(&tk->tp, TP_FLAG_PROFILE)) + if (flags & TP_FLAG_PROFILE) ret = kprobe_perf_func(tk, regs); #endif return ret; @@ -1834,6 +1835,7 @@ kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs) { struct kretprobe *rp = get_kretprobe(ri); struct trace_kprobe *tk; + unsigned int flags; /* * There is a small chance that get_kretprobe(ri) returns NULL when @@ -1846,10 +1848,11 @@ kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs) tk = container_of(rp, struct trace_kprobe, rp); raw_cpu_inc(*tk->nhit); - if (trace_probe_test_flag(&tk->tp, TP_FLAG_TRACE)) + flags = trace_probe_load_flag(&tk->tp); + if (flags & TP_FLAG_TRACE) kretprobe_trace_func(tk, ri, regs); #ifdef CONFIG_PERF_EVENTS - if (trace_probe_test_flag(&tk->tp, TP_FLAG_PROFILE)) + if (flags & TP_FLAG_PROFILE) kretprobe_perf_func(tk, ri, regs); #endif return 0; /* We don't tweak kernel, so just return 0 */ diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h index 842383fbc03b..08b5bda24da2 100644 --- a/kernel/trace/trace_probe.h +++ b/kernel/trace/trace_probe.h @@ -271,16 +271,21 @@ struct event_file_link { struct list_head list; }; +static inline unsigned int trace_probe_load_flag(struct trace_probe *tp) +{ + return smp_load_acquire(&tp->event->flags); +} + static inline bool trace_probe_test_flag(struct trace_probe *tp, unsigned int flag) { - return !!(tp->event->flags & flag); + return !!(trace_probe_load_flag(tp) & flag); } static inline void trace_probe_set_flag(struct trace_probe *tp, unsigned int flag) { - tp->event->flags |= flag; + smp_store_release(&tp->event->flags, tp->event->flags | flag); } static inline void trace_probe_clear_flag(struct trace_probe *tp, diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c index 8b0bcc0d8f41..430d09c49462 100644 --- a/kernel/trace/trace_uprobe.c +++ b/kernel/trace/trace_uprobe.c @@ -1547,6 +1547,7 @@ static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs, struct trace_uprobe *tu; struct uprobe_dispatch_data udd; struct uprobe_cpu_buffer *ucb = NULL; + unsigned int flags; int ret = 0; tu = container_of(con, struct trace_uprobe, consumer); @@ -1561,11 +1562,12 @@ static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs, if (WARN_ON_ONCE(!uprobe_cpu_buffer)) return 0; - if (trace_probe_test_flag(&tu->tp, TP_FLAG_TRACE)) + flags = trace_probe_load_flag(&tu->tp); + if (flags & TP_FLAG_TRACE) ret |= uprobe_trace_func(tu, regs, &ucb); #ifdef CONFIG_PERF_EVENTS - if (trace_probe_test_flag(&tu->tp, TP_FLAG_PROFILE)) + if (flags & TP_FLAG_PROFILE) ret |= uprobe_perf_func(tu, regs, &ucb); #endif uprobe_buffer_put(ucb); @@ -1579,6 +1581,7 @@ static int uretprobe_dispatcher(struct uprobe_consumer *con, struct trace_uprobe *tu; struct uprobe_dispatch_data udd; struct uprobe_cpu_buffer *ucb = NULL; + unsigned int flags; tu = container_of(con, struct trace_uprobe, consumer); @@ -1590,11 +1593,12 @@ static int uretprobe_dispatcher(struct uprobe_consumer *con, if (WARN_ON_ONCE(!uprobe_cpu_buffer)) return 0; - if (trace_probe_test_flag(&tu->tp, TP_FLAG_TRACE)) + flags = trace_probe_load_flag(&tu->tp); + if (flags & TP_FLAG_TRACE) uretprobe_trace_func(tu, func, regs, &ucb); #ifdef CONFIG_PERF_EVENTS - if (trace_probe_test_flag(&tu->tp, TP_FLAG_PROFILE)) + if (flags & TP_FLAG_PROFILE) uretprobe_perf_func(tu, func, regs, &ucb); #endif uprobe_buffer_put(ucb);

3 weeks

2
1
0 0

FAILED: patch "[PATCH] selftests/mm: skip soft-dirty tests when" failed to apply to 6.6-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.6-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y git checkout FETCH_HEAD git cherry-pick -x 0389c305ef56cbadca4cbef44affc0ec3213ed30 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025101329-unplanted-language-2cc7@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 0389c305ef56cbadca4cbef44affc0ec3213ed30 Mon Sep 17 00:00:00 2001 From: Lance Yang <lance.yang(a)linux.dev> Date: Wed, 17 Sep 2025 21:31:37 +0800 Subject: [PATCH] selftests/mm: skip soft-dirty tests when CONFIG_MEM_SOFT_DIRTY is disabled The madv_populate and soft-dirty kselftests currently fail on systems where CONFIG_MEM_SOFT_DIRTY is disabled. Introduce a new helper softdirty_supported() into vm_util.c/h to ensure tests are properly skipped when the feature is not enabled. Link: https://lkml.kernel.org/r/20250917133137.62802-1-lance.yang@linux.dev Fixes: 9f3265db6ae8 ("selftests: vm: add test for Soft-Dirty PTE bit") Signed-off-by: Lance Yang <lance.yang(a)linux.dev> Acked-by: David Hildenbrand <david(a)redhat.com> Suggested-by: David Hildenbrand <david(a)redhat.com> Cc: Lorenzo Stoakes <lorenzo.stoakes(a)oracle.com> Cc: Shuah Khan <shuah(a)kernel.org> Cc: Gabriel Krisman Bertazi <krisman(a)collabora.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> diff --git a/tools/testing/selftests/mm/madv_populate.c b/tools/testing/selftests/mm/madv_populate.c index b6fabd5c27ed..d8d11bc67ddc 100644 --- a/tools/testing/selftests/mm/madv_populate.c +++ b/tools/testing/selftests/mm/madv_populate.c @@ -264,23 +264,6 @@ static void test_softdirty(void) munmap(addr, SIZE); } -static int system_has_softdirty(void) -{ - /* - * There is no way to check if the kernel supports soft-dirty, other - * than by writing to a page and seeing if the bit was set. But the - * tests are intended to check that the bit gets set when it should, so - * doing that check would turn a potentially legitimate fail into a - * skip. Fortunately, we know for sure that arm64 does not support - * soft-dirty. So for now, let's just use the arch as a corse guide. - */ -#if defined(__aarch64__) - return 0; -#else - return 1; -#endif -} - int main(int argc, char **argv) { int nr_tests = 16; @@ -288,7 +271,7 @@ int main(int argc, char **argv) pagesize = getpagesize(); - if (system_has_softdirty()) + if (softdirty_supported()) nr_tests += 5; ksft_print_header(); @@ -300,7 +283,7 @@ int main(int argc, char **argv) test_holes(); test_populate_read(); test_populate_write(); - if (system_has_softdirty()) + if (softdirty_supported()) test_softdirty(); err = ksft_get_fail_cnt(); diff --git a/tools/testing/selftests/mm/soft-dirty.c b/tools/testing/selftests/mm/soft-dirty.c index 8a3f2b4b2186..4ee4db3750c1 100644 --- a/tools/testing/selftests/mm/soft-dirty.c +++ b/tools/testing/selftests/mm/soft-dirty.c @@ -200,8 +200,11 @@ int main(int argc, char **argv) int pagesize; ksft_print_header(); - ksft_set_plan(15); + if (!softdirty_supported()) + ksft_exit_skip("soft-dirty is not support\n"); + + ksft_set_plan(15); pagemap_fd = open(PAGEMAP_FILE_PATH, O_RDONLY); if (pagemap_fd < 0) ksft_exit_fail_msg("Failed to open %s\n", PAGEMAP_FILE_PATH); diff --git a/tools/testing/selftests/mm/vm_util.c b/tools/testing/selftests/mm/vm_util.c index 56e9bd541edd..e33cda301dad 100644 --- a/tools/testing/selftests/mm/vm_util.c +++ b/tools/testing/selftests/mm/vm_util.c @@ -449,6 +449,23 @@ bool check_vmflag_pfnmap(void *addr) return check_vmflag(addr, "pf"); } +bool softdirty_supported(void) +{ + char *addr; + bool supported = false; + const size_t pagesize = getpagesize(); + + /* New mappings are expected to be marked with VM_SOFTDIRTY (sd). */ + addr = mmap(0, pagesize, PROT_READ | PROT_WRITE, + MAP_ANONYMOUS | MAP_PRIVATE, 0, 0); + if (!addr) + ksft_exit_fail_msg("mmap failed\n"); + + supported = check_vmflag(addr, "sd"); + munmap(addr, pagesize); + return supported; +} + /* * Open an fd at /proc/$pid/maps and configure procmap_out ready for * PROCMAP_QUERY query. Returns 0 on success, or an error code otherwise. diff --git a/tools/testing/selftests/mm/vm_util.h b/tools/testing/selftests/mm/vm_util.h index 07c4acfd84b6..26c30fdc0241 100644 --- a/tools/testing/selftests/mm/vm_util.h +++ b/tools/testing/selftests/mm/vm_util.h @@ -104,6 +104,7 @@ bool find_vma_procmap(struct procmap_fd *procmap, void *address); int close_procmap(struct procmap_fd *procmap); int write_sysfs(const char *file_path, unsigned long val); int read_sysfs(const char *file_path, unsigned long *val); +bool softdirty_supported(void); static inline int open_self_procmap(struct procmap_fd *procmap_out) {

3 weeks

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[PATCH] dmaengine: fsl-edma: Fix clk leak on alloc_chan_resources failure

by Zhen Ni

When fsl_edma_alloc_chan_resources() fails after clk_prepare_enable(), the error paths only free IRQs and destroy the TCD pool, but forget to call clk_disable_unprepare(). This causes the channel clock to remain enabled, leaking power and resources. Fix it by disabling the channel clock in the error unwind path. Fixes: d8d4355861d8 ("dmaengine: fsl-edma: add i.MX8ULP edma support") Cc: stable(a)vger.kernel.org Signed-off-by: Zhen Ni <zhen.ni(a)easystack.cn> --- drivers/dma/fsl-edma-common.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/dma/fsl-edma-common.c b/drivers/dma/fsl-edma-common.c index 4976d7dde080..bd673f08f610 100644 --- a/drivers/dma/fsl-edma-common.c +++ b/drivers/dma/fsl-edma-common.c @@ -852,6 +852,8 @@ int fsl_edma_alloc_chan_resources(struct dma_chan *chan) free_irq(fsl_chan->txirq, fsl_chan); err_txirq: dma_pool_destroy(fsl_chan->tcd_pool); + if (fsl_edma_drvflags(fsl_chan) & FSL_EDMA_DRV_HAS_CHCLK) + clk_disable_unprepare(fsl_chan->clk); return ret; } -- 2.20.1

3 weeks

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