[PATCH AUTOSEL 4.4 35/43] ARM: mvebu: declare asm symbols as character arrays in pmsu.c

From: Sasha Levin
Date: Sun Sep 16 2018 - 23:12:03 EST

From: Ethan Tuttle <ethan@xxxxxxxxxxxxxxx>

[ Upstream commit d0d378ff451a66e486488eec842e507d28145813 ]

With CONFIG_FORTIFY_SOURCE, memcpy uses the declared size of operands to
detect buffer overflows. If src or dest is declared as a char, attempts to
copy more than byte will result in a fortify_panic().

Address this problem in mvebu_setup_boot_addr_wa() by declaring
mvebu_boot_wa_start and mvebu_boot_wa_end as character arrays. Also remove
a couple addressof operators to avoid "arithmetic on pointer to an
incomplete type" compiler error.

See commit 54a7d50b9205 ("x86: mark kprobe templates as character arrays,
not single characters") for a similar fix.

Fixes "detected buffer overflow in memcpy" error during init on some mvebu
systems (armada-370-xp, armada-375):

(fortify_panic) from (mvebu_setup_boot_addr_wa+0xb0/0xb4)
(mvebu_setup_boot_addr_wa) from (mvebu_v7_cpu_pm_init+0x154/0x204)
(mvebu_v7_cpu_pm_init) from (do_one_initcall+0x7c/0x1a8)
(do_one_initcall) from (kernel_init_freeable+0x1bc/0x254)
(kernel_init_freeable) from (kernel_init+0x8/0x114)
(kernel_init) from (ret_from_fork+0x14/0x2c)

Signed-off-by: Ethan Tuttle <ethan@xxxxxxxxxxxxxxx>
Tested-by: Ethan Tuttle <ethan@xxxxxxxxxxxxxxx>
Signed-off-by: Gregory CLEMENT <gregory.clement@xxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
arch/arm/mach-mvebu/pmsu.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/arm/mach-mvebu/pmsu.c b/arch/arm/mach-mvebu/pmsu.c
index ed8fda4cd055..45fd4b173dac 100644
--- a/arch/arm/mach-mvebu/pmsu.c
+++ b/arch/arm/mach-mvebu/pmsu.c
@@ -117,8 +117,8 @@ void mvebu_pmsu_set_cpu_boot_addr(int hw_cpu, void *boot_addr)

-extern unsigned char mvebu_boot_wa_start;
-extern unsigned char mvebu_boot_wa_end;
+extern unsigned char mvebu_boot_wa_start[];
+extern unsigned char mvebu_boot_wa_end[];

* This function sets up the boot address workaround needed for SMP
@@ -131,7 +131,7 @@ int mvebu_setup_boot_addr_wa(unsigned int crypto_eng_target,
phys_addr_t resume_addr_reg)
void __iomem *sram_virt_base;
- u32 code_len = &mvebu_boot_wa_end - &mvebu_boot_wa_start;
+ u32 code_len = mvebu_boot_wa_end - mvebu_boot_wa_start;

mvebu_mbus_del_window(BOOTROM_BASE, BOOTROM_SIZE);
mvebu_mbus_add_window_by_id(crypto_eng_target, crypto_eng_attribute,