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| author | Rohan McLure <rmclure@linux.ibm.com> | 2022-12-01 10:10:16 +0300 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2022-12-02 12:46:01 +0300 |
| commit | 2487fd2e6d61b5293eed8ecd25add3cc78593d38 (patch) | |
| tree | 3ca10a866717b367b2ffa9f0f6da580d86e3b52a /arch/powerpc/kernel | |
| parent | 75c5d6b1e194c341371639469fcb8691afa0e254 (diff) | |
| download | linux-2487fd2e6d61b5293eed8ecd25add3cc78593d38.tar.xz | |
powerpc/64s: IOption for MSR stored in r12
Interrupt handlers in asm/exceptions-64s.S contain a great deal of common
code produced by the GEN_COMMON macros. Currently, at the exit point of
the macro, r12 will contain the contents of the MSR. A future patch will
cause these macros to zeroise architected registers to avoid potential
speculation influence of user data.
Provide an IOption that signals that r12 must be retained, as the
interrupt handler assumes it to hold the contents of the MSR.
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Rohan McLure <rmclure@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20221201071019.1953023-4-rmclure@linux.ibm.com
Diffstat (limited to 'arch/powerpc/kernel')
| -rw-r--r-- | arch/powerpc/kernel/exceptions-64s.S | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S index ac3b0580224e..42b7c3212f29 100644 --- a/arch/powerpc/kernel/exceptions-64s.S +++ b/arch/powerpc/kernel/exceptions-64s.S @@ -111,6 +111,7 @@ name: #define ISTACK .L_ISTACK_\name\() /* Set regular kernel stack */ #define __ISTACK(name) .L_ISTACK_ ## name #define IKUAP .L_IKUAP_\name\() /* Do KUAP lock */ +#define IMSR_R12 .L_IMSR_R12_\name\() /* Assumes MSR saved to r12 */ #define INT_DEFINE_BEGIN(n) \ .macro int_define_ ## n name @@ -176,6 +177,9 @@ do_define_int n .ifndef IKUAP IKUAP=1 .endif + .ifndef IMSR_R12 + IMSR_R12=0 + .endif .endm /* @@ -1751,6 +1755,7 @@ INT_DEFINE_BEGIN(fp_unavailable) #ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE IKVM_REAL=1 #endif + IMSR_R12=1 INT_DEFINE_END(fp_unavailable) EXC_REAL_BEGIN(fp_unavailable, 0x800, 0x100) @@ -2384,6 +2389,7 @@ INT_DEFINE_BEGIN(altivec_unavailable) #ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE IKVM_REAL=1 #endif + IMSR_R12=1 INT_DEFINE_END(altivec_unavailable) EXC_REAL_BEGIN(altivec_unavailable, 0xf20, 0x20) @@ -2433,6 +2439,7 @@ INT_DEFINE_BEGIN(vsx_unavailable) #ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE IKVM_REAL=1 #endif + IMSR_R12=1 INT_DEFINE_END(vsx_unavailable) EXC_REAL_BEGIN(vsx_unavailable, 0xf40, 0x20) |