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authorLinus Torvalds <torvalds@linux-foundation.org>2017-09-17 08:16:36 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2017-09-17 08:16:36 -0700
commit0666f560b71b899cd11a7caf39fd45129e9030fd (patch)
tree24c537b475c6237e99af316d34605a9ad52f3a12
parente77d3b0c4a6a973872652601aae35d4ab1785fb4 (diff)
parentfd7d56270b526ca3ed0c224362e3c64a0f86687a (diff)
downloadlinux-stericsson-0666f560b71b899cd11a7caf39fd45129e9030fd.tar.gz
Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull misc fixes from Thomas Gleixner: - A fix for a user space regression in /proc/$PID/stat - A couple of objtool fixes: ~ Plug a memory leak ~ Avoid accessing empty sections which upsets certain binutil versions ~ Prevent corrupting the obj file when section sizes did not change * 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: fs/proc: Report eip/esp in /prod/PID/stat for coredumping objtool: Fix object file corruption objtool: Do not retrieve data from empty sections objtool: Fix memory leak in elf_create_rela_section()
-rw-r--r--fs/proc/array.c9
-rw-r--r--tools/objtool/elf.c33
2 files changed, 29 insertions, 13 deletions
diff --git a/fs/proc/array.c b/fs/proc/array.c
index 88c355574aa0..525157ca25cb 100644
--- a/fs/proc/array.c
+++ b/fs/proc/array.c
@@ -62,6 +62,7 @@
#include <linux/mman.h>
#include <linux/sched/mm.h>
#include <linux/sched/numa_balancing.h>
+#include <linux/sched/task_stack.h>
#include <linux/sched/task.h>
#include <linux/sched/cputime.h>
#include <linux/proc_fs.h>
@@ -421,7 +422,15 @@ static int do_task_stat(struct seq_file *m, struct pid_namespace *ns,
* esp and eip are intentionally zeroed out. There is no
* non-racy way to read them without freezing the task.
* Programs that need reliable values can use ptrace(2).
+ *
+ * The only exception is if the task is core dumping because
+ * a program is not able to use ptrace(2) in that case. It is
+ * safe because the task has stopped executing permanently.
*/
+ if (permitted && (task->flags & PF_DUMPCORE)) {
+ eip = KSTK_EIP(task);
+ esp = KSTK_ESP(task);
+ }
}
get_task_comm(tcomm, task);
diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c
index 6e9f980a7d26..24460155c82c 100644
--- a/tools/objtool/elf.c
+++ b/tools/objtool/elf.c
@@ -175,19 +175,20 @@ static int read_sections(struct elf *elf)
return -1;
}
- sec->data = elf_getdata(s, NULL);
- if (!sec->data) {
- WARN_ELF("elf_getdata");
- return -1;
- }
-
- if (sec->data->d_off != 0 ||
- sec->data->d_size != sec->sh.sh_size) {
- WARN("unexpected data attributes for %s", sec->name);
- return -1;
+ if (sec->sh.sh_size != 0) {
+ sec->data = elf_getdata(s, NULL);
+ if (!sec->data) {
+ WARN_ELF("elf_getdata");
+ return -1;
+ }
+ if (sec->data->d_off != 0 ||
+ sec->data->d_size != sec->sh.sh_size) {
+ WARN("unexpected data attributes for %s",
+ sec->name);
+ return -1;
+ }
}
-
- sec->len = sec->data->d_size;
+ sec->len = sec->sh.sh_size;
}
/* sanity check, one more call to elf_nextscn() should return NULL */
@@ -508,6 +509,7 @@ struct section *elf_create_rela_section(struct elf *elf, struct section *base)
strcat(relaname, base->name);
sec = elf_create_section(elf, relaname, sizeof(GElf_Rela), 0);
+ free(relaname);
if (!sec)
return NULL;
@@ -561,6 +563,7 @@ int elf_write(struct elf *elf)
struct section *sec;
Elf_Scn *s;
+ /* Update section headers for changed sections: */
list_for_each_entry(sec, &elf->sections, list) {
if (sec->changed) {
s = elf_getscn(elf->elf, sec->idx);
@@ -568,13 +571,17 @@ int elf_write(struct elf *elf)
WARN_ELF("elf_getscn");
return -1;
}
- if (!gelf_update_shdr (s, &sec->sh)) {
+ if (!gelf_update_shdr(s, &sec->sh)) {
WARN_ELF("gelf_update_shdr");
return -1;
}
}
}
+ /* Make sure the new section header entries get updated properly. */
+ elf_flagelf(elf->elf, ELF_C_SET, ELF_F_DIRTY);
+
+ /* Write all changes to the file. */
if (elf_update(elf->elf, ELF_C_WRITE) < 0) {
WARN_ELF("elf_update");
return -1;