diff options
| author | Jinglin Wen <jinglin.wen@shingroup.cn> | 2024-06-20 04:41:50 +0200 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2024-06-23 03:54:13 +0200 |
| commit | 13fc6c175924eaa953cf597ce28ffa4edc4554a6 (patch) | |
| tree | 7e9733c6ea65b0d11268abef1c4b76a0606e1853 | |
| parent | KVM: PPC: Book3S HV: Prevent UAF in kvm_spapr_tce_attach_iommu_group() (diff) | |
| download | linux-13fc6c175924eaa953cf597ce28ffa4edc4554a6.tar.xz linux-13fc6c175924eaa953cf597ce28ffa4edc4554a6.zip | |
powerpc/64s: Fix unnecessary copy to 0 when kernel is booted at address 0
According to the code logic, when the kernel is loaded at address 0, no
copying operation should be performed, but it is currently being done.
This patch fixes the issue where the kernel code was incorrectly
duplicated to address 0 when booting from address 0.
Fixes: b270bebd34e3 ("powerpc/64s: Run at the kernel virtual address earlier in boot")
Cc: stable@vger.kernel.org # v6.4+
Signed-off-by: Jinglin Wen <jinglin.wen@shingroup.cn>
Suggested-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240620024150.14857-1-jinglin.wen@shingroup.cn
| -rw-r--r-- | arch/powerpc/kernel/head_64.S | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S index 4690c219bfa4..63432a33ec49 100644 --- a/arch/powerpc/kernel/head_64.S +++ b/arch/powerpc/kernel/head_64.S @@ -647,8 +647,9 @@ __after_prom_start: * Note: This process overwrites the OF exception vectors. */ LOAD_REG_IMMEDIATE(r3, PAGE_OFFSET) - mr. r4,r26 /* In some cases the loader may */ - beq 9f /* have already put us at zero */ + mr r4,r26 /* Load the virtual source address into r4 */ + cmpld r3,r4 /* Check if source == dest */ + beq 9f /* If so skip the copy */ li r6,0x100 /* Start offset, the first 0x100 */ /* bytes were copied earlier. */ |