From: Josh Poimboeuf Associate an .sframe section with its mm by adding it to a per-mm maple tree which is indexed by the corresponding text address range. A single .sframe section can be associated with multiple text ranges. [ Jens Remus: Minor cleanups. Reword commit subject/message. ] Cc: Thomas Gleixner Cc: Masami Hiramatsu Cc: Mathieu Desnoyers Cc: Peter Zijlstra Cc: Ingo Molnar Cc: Jiri Olsa Cc: Arnaldo Carvalho de Melo Cc: Namhyung Kim Cc: Andrii Nakryiko Cc: Indu Bhagat Cc: "Jose E. Marchesi" Cc: Beau Belgrave Cc: Jens Remus Cc: Linus Torvalds Cc: Florian Weimer Cc: Sam James Cc: Kees Cook Cc: "Carlos O'Donell" Cc: Borislav Petkov Cc: Dave Hansen Cc: "H. Peter Anvin" Cc: Andrew Morton Cc: David Hildenbrand Cc: Lorenzo Stoakes Cc: "Liam R. Howlett" Cc: Vlastimil Babka Cc: Mike Rapoport Cc: Suren Baghdasaryan Cc: Michal Hocko Cc: x86@kernel.org Cc: linux-mm@kvack.org Signed-off-by: Josh Poimboeuf Signed-off-by: Steven Rostedt (Google) Signed-off-by: Jens Remus --- Notes (jremus): Changes in v12: - Add include of linux/mm_types.h and variable sframe_mt from "unwind_user/sframe: Add support for reading .sframe headers". - Reword commit subject/message to consistently use ".sframe" when referring to the section. arch/x86/include/asm/mmu.h | 2 +- include/linux/mm_types.h | 3 ++ include/linux/sframe.h | 15 ++++++++++ kernel/fork.c | 10 +++++++ kernel/unwind/sframe.c | 56 ++++++++++++++++++++++++++++++++++++-- mm/init-mm.c | 2 ++ 6 files changed, 84 insertions(+), 4 deletions(-) diff --git a/arch/x86/include/asm/mmu.h b/arch/x86/include/asm/mmu.h index 0fe9c569d171..227a32899a59 100644 --- a/arch/x86/include/asm/mmu.h +++ b/arch/x86/include/asm/mmu.h @@ -87,7 +87,7 @@ typedef struct { .context = { \ .ctx_id = 1, \ .lock = __MUTEX_INITIALIZER(mm.context.lock), \ - } + }, void leave_mm(void); #define leave_mm leave_mm diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index 90e5790c318f..01e2cffbd84e 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -1227,6 +1227,9 @@ struct mm_struct { #ifdef CONFIG_MM_ID mm_id_t mm_id; #endif /* CONFIG_MM_ID */ +#ifdef CONFIG_HAVE_UNWIND_USER_SFRAME + struct maple_tree sframe_mt; +#endif } __randomize_layout; /* diff --git a/include/linux/sframe.h b/include/linux/sframe.h index 0642595534f9..7ea6a97ed8af 100644 --- a/include/linux/sframe.h +++ b/include/linux/sframe.h @@ -2,6 +2,8 @@ #ifndef _LINUX_SFRAME_H #define _LINUX_SFRAME_H +#include + #ifdef CONFIG_HAVE_UNWIND_USER_SFRAME struct sframe_section { @@ -19,18 +21,31 @@ struct sframe_section { signed char fp_off; }; +#define INIT_MM_SFRAME .sframe_mt = MTREE_INIT(sframe_mt, 0), +extern void sframe_free_mm(struct mm_struct *mm); + extern int sframe_add_section(unsigned long sframe_start, unsigned long sframe_end, unsigned long text_start, unsigned long text_end); extern int sframe_remove_section(unsigned long sframe_addr); +static inline bool current_has_sframe(void) +{ + struct mm_struct *mm = current->mm; + + return mm && !mtree_empty(&mm->sframe_mt); +} + #else /* !CONFIG_HAVE_UNWIND_USER_SFRAME */ +#define INIT_MM_SFRAME +static inline void sframe_free_mm(struct mm_struct *mm) {} static inline int sframe_add_section(unsigned long sframe_start, unsigned long sframe_end, unsigned long text_start, unsigned long text_end) { return -ENOSYS; } static inline int sframe_remove_section(unsigned long sframe_addr) { return -ENOSYS; } +static inline bool current_has_sframe(void) { return false; } #endif /* CONFIG_HAVE_UNWIND_USER_SFRAME */ diff --git a/kernel/fork.c b/kernel/fork.c index 3da0f08615a9..15c24411dd7d 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -106,6 +106,7 @@ #include #include #include +#include #include #include @@ -689,6 +690,7 @@ void __mmdrop(struct mm_struct *mm) mm_pasid_drop(mm); mm_destroy_cid(mm); percpu_counter_destroy_many(mm->rss_stat, NR_MM_COUNTERS); + sframe_free_mm(mm); free_mm(mm); } @@ -1027,6 +1029,13 @@ static void mmap_init_lock(struct mm_struct *mm) #endif } +static void mm_init_sframe(struct mm_struct *mm) +{ +#ifdef CONFIG_HAVE_UNWIND_USER_SFRAME + mt_init(&mm->sframe_mt); +#endif +} + static struct mm_struct *mm_init(struct mm_struct *mm, struct task_struct *p, struct user_namespace *user_ns) { @@ -1055,6 +1064,7 @@ static struct mm_struct *mm_init(struct mm_struct *mm, struct task_struct *p, mm->pmd_huge_pte = NULL; #endif mm_init_uprobes_state(mm); + mm_init_sframe(mm); hugetlb_count_init(mm); mm_flags_clear_all(mm); diff --git a/kernel/unwind/sframe.c b/kernel/unwind/sframe.c index 26bb16f76a8d..149ce70e4229 100644 --- a/kernel/unwind/sframe.c +++ b/kernel/unwind/sframe.c @@ -81,6 +81,7 @@ static int sframe_read_header(struct sframe_section *sec) int sframe_add_section(unsigned long sframe_start, unsigned long sframe_end, unsigned long text_start, unsigned long text_end) { + struct maple_tree *sframe_mt = ¤t->mm->sframe_mt; struct vm_area_struct *sframe_vma, *text_vma; struct mm_struct *mm = current->mm; struct sframe_section *sec; @@ -122,15 +123,64 @@ int sframe_add_section(unsigned long sframe_start, unsigned long sframe_end, if (ret) goto err_free; - /* TODO nowhere to store it yet - just free it and return an error */ - ret = -ENOSYS; + ret = mtree_insert_range(sframe_mt, sec->text_start, sec->text_end, sec, GFP_KERNEL); + if (ret) { + dbg("mtree_insert_range failed: text=%lx-%lx\n", + sec->text_start, sec->text_end); + goto err_free; + } + + return 0; err_free: free_section(sec); return ret; } +static int __sframe_remove_section(struct mm_struct *mm, + struct sframe_section *sec) +{ + if (!mtree_erase(&mm->sframe_mt, sec->text_start)) { + dbg("mtree_erase failed: text=%lx\n", sec->text_start); + return -EINVAL; + } + + free_section(sec); + + return 0; +} + int sframe_remove_section(unsigned long sframe_start) { - return -ENOSYS; + struct mm_struct *mm = current->mm; + struct sframe_section *sec; + unsigned long index = 0; + bool found = false; + int ret = 0; + + mt_for_each(&mm->sframe_mt, sec, index, ULONG_MAX) { + if (sec->sframe_start == sframe_start) { + found = true; + ret |= __sframe_remove_section(mm, sec); + } + } + + if (!found || ret) + return -EINVAL; + + return 0; +} + +void sframe_free_mm(struct mm_struct *mm) +{ + struct sframe_section *sec; + unsigned long index = 0; + + if (!mm) + return; + + mt_for_each(&mm->sframe_mt, sec, index, ULONG_MAX) + free_section(sec); + + mtree_destroy(&mm->sframe_mt); } diff --git a/mm/init-mm.c b/mm/init-mm.c index 4600e7605cab..b32fcf167cc2 100644 --- a/mm/init-mm.c +++ b/mm/init-mm.c @@ -11,6 +11,7 @@ #include #include #include +#include #include #ifndef INIT_MM_CONTEXT @@ -46,6 +47,7 @@ struct mm_struct init_mm = { .user_ns = &init_user_ns, .cpu_bitmap = CPU_BITS_NONE, INIT_MM_CONTEXT(init_mm) + INIT_MM_SFRAME }; void setup_initial_init_mm(void *start_code, void *end_code, -- 2.48.1