6.1-stable review patch. If anyone has any objections, please let me know.
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From: Christophe Leroy christophe.leroy@csgroup.eu
[ Upstream commit 65a82e117ffeeab0baf6f871a1cab11a28ace183 ]
Since commit 9132a2e82adc ("powerpc/8xx: Define a MODULE area below kernel text"), module exec space is below PAGE_OFFSET so not only space above PAGE_OFFSET, but space above TASK_SIZE need to be seen as kernel space.
Until now the problem went undetected because by default TASK_SIZE is 0x8000000 which means address space is determined by just checking upper address bit. But when TASK_SIZE is over 0x80000000, PAGE_OFFSET is used for comparison, leading to thinking module addresses are part of user space.
Fix it by using TASK_SIZE instead of PAGE_OFFSET for address comparison.
Fixes: 9132a2e82adc ("powerpc/8xx: Define a MODULE area below kernel text") Signed-off-by: Christophe Leroy christophe.leroy@csgroup.eu Signed-off-by: Michael Ellerman mpe@ellerman.id.au Link: https://msgid.link/3f574c9845ff0a023b46cb4f38d2c45aecd769bd.1724173828.git.c... Signed-off-by: Sasha Levin sashal@kernel.org --- arch/powerpc/kernel/head_8xx.S | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S index 0b05f2be66b9f..f267e1587a9ba 100644 --- a/arch/powerpc/kernel/head_8xx.S +++ b/arch/powerpc/kernel/head_8xx.S @@ -40,12 +40,12 @@ #include "head_32.h"
.macro compare_to_kernel_boundary scratch, addr -#if CONFIG_TASK_SIZE <= 0x80000000 && CONFIG_PAGE_OFFSET >= 0x80000000 +#if CONFIG_TASK_SIZE <= 0x80000000 && MODULES_VADDR >= 0x80000000 /* By simply checking Address >= 0x80000000, we know if its a kernel address */ not. \scratch, \addr #else rlwinm \scratch, \addr, 16, 0xfff8 - cmpli cr0, \scratch, PAGE_OFFSET@h + cmpli cr0, \scratch, TASK_SIZE@h #endif .endm
@@ -403,7 +403,7 @@ FixupDAR:/* Entry point for dcbx workaround. */ mfspr r10, SPRN_SRR0 mtspr SPRN_MD_EPN, r10 rlwinm r11, r10, 16, 0xfff8 - cmpli cr1, r11, PAGE_OFFSET@h + cmpli cr1, r11, TASK_SIZE@h mfspr r11, SPRN_M_TWB /* Get level 1 table */ blt+ cr1, 3f