summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
-rw-r--r--arch/Kconfig9
-rw-r--r--arch/powerpc/Kconfig1
-rw-r--r--arch/powerpc/include/asm/elf.h2
-rw-r--r--fs/binfmt_elf.c10
-rw-r--r--fs/binfmt_elf_fdpic.c85
-rw-r--r--fs/coredump.c17
-rw-r--r--fs/exec.c8
-rw-r--r--include/linux/coredump.h2
-rw-r--r--include/linux/elf.h2
-rw-r--r--include/trace/events/sched.h35
10 files changed, 120 insertions, 51 deletions
diff --git a/arch/Kconfig b/arch/Kconfig
index 9f2f3060a6ab..93404c802d29 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -510,6 +510,15 @@ config MMU_LAZY_TLB_SHOOTDOWN
config ARCH_HAVE_NMI_SAFE_CMPXCHG
bool
+config ARCH_HAVE_EXTRA_ELF_NOTES
+ bool
+ help
+ An architecture should select this in order to enable adding an
+ arch-specific ELF note section to core files. It must provide two
+ functions: elf_coredump_extra_notes_size() and
+ elf_coredump_extra_notes_write() which are invoked by the ELF core
+ dumper.
+
config ARCH_HAS_NMI_SAFE_THIS_CPU_OPS
bool
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 1c4be3373686..c45fa9d7fb76 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -156,6 +156,7 @@ config PPC
select ARCH_HAS_UACCESS_FLUSHCACHE
select ARCH_HAS_UBSAN
select ARCH_HAVE_NMI_SAFE_CMPXCHG
+ select ARCH_HAVE_EXTRA_ELF_NOTES if SPU_BASE
select ARCH_KEEP_MEMBLOCK
select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE if PPC_RADIX_MMU
select ARCH_MIGHT_HAVE_PC_PARPORT
diff --git a/arch/powerpc/include/asm/elf.h b/arch/powerpc/include/asm/elf.h
index 79f1c480b5eb..bb4b94444d3e 100644
--- a/arch/powerpc/include/asm/elf.h
+++ b/arch/powerpc/include/asm/elf.h
@@ -127,8 +127,6 @@ extern int arch_setup_additional_pages(struct linux_binprm *bprm,
/* Notes used in ET_CORE. Note name is "SPU/<fd>/<filename>". */
#define NT_SPU 1
-#define ARCH_HAVE_EXTRA_ELF_NOTES
-
#endif /* CONFIG_SPU_BASE */
#ifdef CONFIG_PPC64
diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index 5397b552fbeb..b5a25ee49eea 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -1262,6 +1262,9 @@ out_free_interp:
if (IS_ENABLED(CONFIG_ARCH_HAS_ELF_RANDOMIZE) &&
elf_ex->e_type == ET_DYN && !interpreter) {
mm->brk = mm->start_brk = ELF_ET_DYN_BASE;
+ } else {
+ /* Otherwise leave a gap between .bss and brk. */
+ mm->brk = mm->start_brk = mm->brk + PAGE_SIZE;
}
mm->brk = mm->start_brk = arch_randomize_brk(mm);
@@ -1564,7 +1567,6 @@ static void fill_siginfo_note(struct memelfnote *note, user_siginfo_t *csigdata,
fill_note(note, "CORE", NT_SIGINFO, sizeof(*csigdata), csigdata);
}
-#define MAX_FILE_NOTE_SIZE (4*1024*1024)
/*
* Format of NT_FILE note:
*
@@ -1592,8 +1594,12 @@ static int fill_files_note(struct memelfnote *note, struct coredump_params *cprm
names_ofs = (2 + 3 * count) * sizeof(data[0]);
alloc:
- if (size >= MAX_FILE_NOTE_SIZE) /* paranoia check */
+ /* paranoia check */
+ if (size >= core_file_note_size_limit) {
+ pr_warn_once("coredump Note size too large: %u (does kernel.core_file_note_size_limit sysctl need adjustment?\n",
+ size);
return -EINVAL;
+ }
size = round_up(size, PAGE_SIZE);
/*
* "size" can be 0 here legitimately.
diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c
index 3314249e8674..b799701454a9 100644
--- a/fs/binfmt_elf_fdpic.c
+++ b/fs/binfmt_elf_fdpic.c
@@ -505,8 +505,9 @@ static int create_elf_fdpic_tables(struct linux_binprm *bprm,
char *k_platform, *k_base_platform;
char __user *u_platform, *u_base_platform, *p;
int loop;
- int nr; /* reset for each csp adjustment */
unsigned long flags = 0;
+ int ei_index;
+ elf_addr_t *elf_info;
#ifdef CONFIG_MMU
/* In some cases (e.g. Hyper-Threading), we want to avoid L1 evictions
@@ -601,44 +602,24 @@ static int create_elf_fdpic_tables(struct linux_binprm *bprm,
csp -= sp & 15UL;
sp -= sp & 15UL;
- /* put the ELF interpreter info on the stack */
-#define NEW_AUX_ENT(id, val) \
- do { \
- struct { unsigned long _id, _val; } __user *ent, v; \
- \
- ent = (void __user *) csp; \
- v._id = (id); \
- v._val = (val); \
- if (copy_to_user(ent + nr, &v, sizeof(v))) \
- return -EFAULT; \
- nr++; \
+ /* Create the ELF interpreter info */
+ elf_info = (elf_addr_t *)mm->saved_auxv;
+ /* update AT_VECTOR_SIZE_BASE if the number of NEW_AUX_ENT() changes */
+#define NEW_AUX_ENT(id, val) \
+ do { \
+ *elf_info++ = id; \
+ *elf_info++ = val; \
} while (0)
- nr = 0;
- csp -= 2 * sizeof(unsigned long);
- NEW_AUX_ENT(AT_NULL, 0);
- if (k_platform) {
- nr = 0;
- csp -= 2 * sizeof(unsigned long);
- NEW_AUX_ENT(AT_PLATFORM,
- (elf_addr_t) (unsigned long) u_platform);
- }
-
- if (k_base_platform) {
- nr = 0;
- csp -= 2 * sizeof(unsigned long);
- NEW_AUX_ENT(AT_BASE_PLATFORM,
- (elf_addr_t) (unsigned long) u_base_platform);
- }
-
- if (bprm->have_execfd) {
- nr = 0;
- csp -= 2 * sizeof(unsigned long);
- NEW_AUX_ENT(AT_EXECFD, bprm->execfd);
- }
-
- nr = 0;
- csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long);
+#ifdef ARCH_DLINFO
+ /*
+ * ARCH_DLINFO must come first so PPC can do its special alignment of
+ * AUXV.
+ * update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT() in
+ * ARCH_DLINFO changes
+ */
+ ARCH_DLINFO;
+#endif
NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP);
#ifdef ELF_HWCAP2
NEW_AUX_ENT(AT_HWCAP2, ELF_HWCAP2);
@@ -659,17 +640,29 @@ static int create_elf_fdpic_tables(struct linux_binprm *bprm,
NEW_AUX_ENT(AT_EGID, (elf_addr_t) from_kgid_munged(cred->user_ns, cred->egid));
NEW_AUX_ENT(AT_SECURE, bprm->secureexec);
NEW_AUX_ENT(AT_EXECFN, bprm->exec);
+ if (k_platform)
+ NEW_AUX_ENT(AT_PLATFORM,
+ (elf_addr_t)(unsigned long)u_platform);
+ if (k_base_platform)
+ NEW_AUX_ENT(AT_BASE_PLATFORM,
+ (elf_addr_t)(unsigned long)u_base_platform);
+ if (bprm->have_execfd)
+ NEW_AUX_ENT(AT_EXECFD, bprm->execfd);
+#undef NEW_AUX_ENT
+ /* AT_NULL is zero; clear the rest too */
+ memset(elf_info, 0, (char *)mm->saved_auxv +
+ sizeof(mm->saved_auxv) - (char *)elf_info);
-#ifdef ARCH_DLINFO
- nr = 0;
- csp -= AT_VECTOR_SIZE_ARCH * 2 * sizeof(unsigned long);
+ /* And advance past the AT_NULL entry. */
+ elf_info += 2;
- /* ARCH_DLINFO must come last so platform specific code can enforce
- * special alignment requirements on the AUXV if necessary (eg. PPC).
- */
- ARCH_DLINFO;
-#endif
-#undef NEW_AUX_ENT
+ ei_index = elf_info - (elf_addr_t *)mm->saved_auxv;
+ csp -= ei_index * sizeof(elf_addr_t);
+
+ /* Put the elf_info on the stack in the right place. */
+ if (copy_to_user((void __user *)csp, mm->saved_auxv,
+ ei_index * sizeof(elf_addr_t)))
+ return -EFAULT;
/* allocate room for argv[] and envv[] */
csp -= (bprm->envc + 1) * sizeof(elf_caddr_t);
diff --git a/fs/coredump.c b/fs/coredump.c
index be6403b4b14b..317065e3eb9b 100644
--- a/fs/coredump.c
+++ b/fs/coredump.c
@@ -56,10 +56,15 @@
static bool dump_vma_snapshot(struct coredump_params *cprm);
static void free_vma_snapshot(struct coredump_params *cprm);
+#define CORE_FILE_NOTE_SIZE_DEFAULT (4*1024*1024)
+/* Define a reasonable max cap */
+#define CORE_FILE_NOTE_SIZE_MAX (16*1024*1024)
+
static int core_uses_pid;
static unsigned int core_pipe_limit;
static char core_pattern[CORENAME_MAX_SIZE] = "core";
static int core_name_size = CORENAME_MAX_SIZE;
+unsigned int core_file_note_size_limit = CORE_FILE_NOTE_SIZE_DEFAULT;
struct core_name {
char *corename;
@@ -998,6 +1003,9 @@ static int proc_dostring_coredump(struct ctl_table *table, int write,
return error;
}
+static const unsigned int core_file_note_size_min = CORE_FILE_NOTE_SIZE_DEFAULT;
+static const unsigned int core_file_note_size_max = CORE_FILE_NOTE_SIZE_MAX;
+
static struct ctl_table coredump_sysctls[] = {
{
.procname = "core_uses_pid",
@@ -1020,6 +1028,15 @@ static struct ctl_table coredump_sysctls[] = {
.mode = 0644,
.proc_handler = proc_dointvec,
},
+ {
+ .procname = "core_file_note_size_limit",
+ .data = &core_file_note_size_limit,
+ .maxlen = sizeof(unsigned int),
+ .mode = 0644,
+ .proc_handler = proc_douintvec_minmax,
+ .extra1 = (unsigned int *)&core_file_note_size_min,
+ .extra2 = (unsigned int *)&core_file_note_size_max,
+ },
};
static int __init init_fs_coredump_sysctls(void)
diff --git a/fs/exec.c b/fs/exec.c
index cf1df7f16e55..b3c40fbb325f 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -1268,6 +1268,14 @@ int begin_new_exec(struct linux_binprm * bprm)
return retval;
/*
+ * This tracepoint marks the point before flushing the old exec where
+ * the current task is still unchanged, but errors are fatal (point of
+ * no return). The later "sched_process_exec" tracepoint is called after
+ * the current task has successfully switched to the new exec.
+ */
+ trace_sched_prepare_exec(current, bprm);
+
+ /*
* Ensure all future errors are fatal.
*/
bprm->point_of_no_return = true;
diff --git a/include/linux/coredump.h b/include/linux/coredump.h
index d3eba4360150..0904ba010341 100644
--- a/include/linux/coredump.h
+++ b/include/linux/coredump.h
@@ -30,6 +30,8 @@ struct coredump_params {
struct core_vma_metadata *vma_meta;
};
+extern unsigned int core_file_note_size_limit;
+
/*
* These are the only things you should do on a core-file: use only these
* functions to write out all the necessary info.
diff --git a/include/linux/elf.h b/include/linux/elf.h
index c9a46c4e183b..5c402788da19 100644
--- a/include/linux/elf.h
+++ b/include/linux/elf.h
@@ -65,7 +65,7 @@ extern Elf64_Dyn _DYNAMIC [];
struct file;
struct coredump_params;
-#ifndef ARCH_HAVE_EXTRA_ELF_NOTES
+#ifndef CONFIG_ARCH_HAVE_EXTRA_ELF_NOTES
static inline int elf_coredump_extra_notes_size(void) { return 0; }
static inline int elf_coredump_extra_notes_write(struct coredump_params *cprm) { return 0; }
#else
diff --git a/include/trace/events/sched.h b/include/trace/events/sched.h
index dbb01b4b7451..226f47c6939c 100644
--- a/include/trace/events/sched.h
+++ b/include/trace/events/sched.h
@@ -420,6 +420,41 @@ TRACE_EVENT(sched_process_exec,
__entry->pid, __entry->old_pid)
);
+/**
+ * sched_prepare_exec - called before setting up new exec
+ * @task: pointer to the current task
+ * @bprm: pointer to linux_binprm used for new exec
+ *
+ * Called before flushing the old exec, where @task is still unchanged, but at
+ * the point of no return during switching to the new exec. At the point it is
+ * called the exec will either succeed, or on failure terminate the task. Also
+ * see the "sched_process_exec" tracepoint, which is called right after @task
+ * has successfully switched to the new exec.
+ */
+TRACE_EVENT(sched_prepare_exec,
+
+ TP_PROTO(struct task_struct *task, struct linux_binprm *bprm),
+
+ TP_ARGS(task, bprm),
+
+ TP_STRUCT__entry(
+ __string( interp, bprm->interp )
+ __string( filename, bprm->filename )
+ __field( pid_t, pid )
+ __string( comm, task->comm )
+ ),
+
+ TP_fast_assign(
+ __assign_str(interp, bprm->interp);
+ __assign_str(filename, bprm->filename);
+ __entry->pid = task->pid;
+ __assign_str(comm, task->comm);
+ ),
+
+ TP_printk("interp=%s filename=%s pid=%d comm=%s",
+ __get_str(interp), __get_str(filename),
+ __entry->pid, __get_str(comm))
+);
#ifdef CONFIG_SCHEDSTATS
#define DEFINE_EVENT_SCHEDSTAT DEFINE_EVENT