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authorNicholas Piggin <npiggin@gmail.com>2021-08-20 12:34:31 +0200
committerMichael Ellerman <mpe@ellerman.id.au>2021-08-20 14:35:18 +0200
commit787c70f2f9990b5a197320152d2fc32cd8a6ad1a (patch)
treea8103d3b32d9f20c026530ccf0f2a4eedfa73722
parentpowerpc: Re-enable ARCH_ENABLE_SPLIT_PMD_PTLOCK (diff)
downloadlinux-787c70f2f9990b5a197320152d2fc32cd8a6ad1a.tar.xz
linux-787c70f2f9990b5a197320152d2fc32cd8a6ad1a.zip
powerpc/64s: Fix scv implicit soft-mask table for relocated kernels
The implict soft-mask table addresses get relocated if they use a relative symbol like a label. This is right for code that runs relocated but not for unrelocated. The scv interrupt vectors run unrelocated, so absolute addresses are required for their soft-mask table entry. This fixes crashing with relocated kernels, usually an asynchronous interrupt hitting in the scv handler, then hitting the trap that checks whether r1 is in userspace. Fixes: 325678fd0522 ("powerpc/64s: add a table of implicit soft-masked addresses") Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210820103431.1701240-1-npiggin@gmail.com
-rw-r--r--arch/powerpc/kernel/exceptions-64s.S7
1 files changed, 4 insertions, 3 deletions
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 4aec59a77d4c..37859e62a8dc 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -812,7 +812,6 @@ __start_interrupts:
* syscall register convention is in Documentation/powerpc/syscall64-abi.rst
*/
EXC_VIRT_BEGIN(system_call_vectored, 0x3000, 0x1000)
-1:
/* SCV 0 */
mr r9,r13
GET_PACA(r13)
@@ -842,10 +841,12 @@ EXC_VIRT_BEGIN(system_call_vectored, 0x3000, 0x1000)
b system_call_vectored_sigill
#endif
.endr
-2:
EXC_VIRT_END(system_call_vectored, 0x3000, 0x1000)
-SOFT_MASK_TABLE(1b, 2b) // Treat scv vectors as soft-masked, see comment above.
+// Treat scv vectors as soft-masked, see comment above.
+// Use absolute values rather than labels here, so they don't get relocated,
+// because this code runs unrelocated.
+SOFT_MASK_TABLE(0xc000000000003000, 0xc000000000004000)
#ifdef CONFIG_RELOCATABLE
TRAMP_VIRT_BEGIN(system_call_vectored_tramp)