[Resend PATCH] fs: use kvmalloc for big coredump file

[zhaoyang.huang]

From: Zhaoyang Huang <zhaoyang.huang@xxxxxxxxxx>

High order page allocation observed which even introduce kernel panic when generating
coredump file, use kvmalloc_array instead of kmalloc_array

[68058.982108] init: Untracked pid 3847 exited with status 0
[68058.982343] init: Untracked pid 3847 did not have an associated service entry and will not be reaped
[68059.038127] warn_alloc: 29 callbacks suppressed
[68059.038132] TimerThread: page allocation failure: order:7, mode:0x40dc0(GFP_KERNEL|__GFP_COMP|__GFP_ZERO), nodemask=(null),cpuset=foreground,mems_allowed=0
[68059.038155] CPU: 6 PID: 3597 Comm: TimerThread Tainted: G        W  OE     5.15.41-android13-8-01198-g03458ee9a090-ab000039 #1
[68059.038159] Hardware name: Unisoc UMS9620-base Board (DT)
[68059.038161] Call trace:
[68059.038163]  dump_backtrace.cfi_jt+0x0/0x8
[68059.038169]  dump_stack_lvl+0x98/0xe8
[68059.038174]  warn_alloc+0x164/0x200
[68059.038180]  __alloc_pages_slowpath+0x9d4/0xb64
[68059.038183]  __alloc_pages+0x21c/0x39c
[68059.038186]  kmalloc_order+0x4c/0x13c
[68059.038189]  kmalloc_order_trace+0x34/0x154
[68059.038192]  __kmalloc+0x600/0x8a8
[68059.038196]  elf_core_dump+0x7c4/0x15d8
[68059.038201]  do_coredump+0x680/0xe54
[68059.038203]  get_signal+0x610/0x988
[68059.038209]  do_signal+0xd4/0x2bc
[68059.038213]  do_notify_resume+0xa0/0x1c8
[68059.038216]  el0_svc+0x68/0x90
[68059.038219]  el0t_64_sync_handler+0x88/0xec
[68059.038222]  el0t_64_sync+0x1b4/0x1b8

Reported-by: Guanglu Xu <guanglu.xu@xxxxxxxxxx>
Signed-off-by: Zhaoyang Huang <zhaoyang.huang@xxxxxxxxxx>
---
 fs/coredump.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/coredump.c b/fs/coredump.c
index ebc43f9..52e9177 100644
--- a/fs/coredump.c
+++ b/fs/coredump.c
@@ -612,7 +612,7 @@ void do_coredump(const kernel_siginfo_t *siginfo)
 			goto fail_dropcount;
 		}
 
-		helper_argv = kmalloc_array(argc + 1, sizeof(*helper_argv),
+		helper_argv = kvmalloc_array(argc + 1, sizeof(*helper_argv),
 					    GFP_KERNEL);
 		if (!helper_argv) {
 			printk(KERN_WARNING "%s failed to allocate memory\n",
@@ -631,7 +631,7 @@ void do_coredump(const kernel_siginfo_t *siginfo)
 			retval = call_usermodehelper_exec(sub_info,
 							  UMH_WAIT_EXEC);
 
-		kfree(helper_argv);
+		kvfree(helper_argv);
 		if (retval) {
 			printk(KERN_INFO "Core dump to |%s pipe failed\n",
 			       cn.corename);
-- 
1.9.1