| Subject | [PATCH 50 of 55] xen64: save lots of registers | Date | Tue, 08 Jul 2008 15:07:12 -0700 | From | Jeremy Fitzhardinge <> |
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The Xen hypercall interface is allowed to trash any or all of the argument registers, so we need to be careful that the kernel state isn't damaged. On 32-bit kernels, the hypercall parameter registers same as a regparm function call, so we've got away without explicit clobbering so far. The 64-bit ABI defines lots of caller-save registers, so save them all for safety. We can trim this set later by re-distributing the responsibility for saving all these registers.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> --- include/asm-x86/paravirt.h | 26 ++++++++++++++++++++++---- 1 file changed, 22 insertions(+), 4 deletions(-)
diff --git a/include/asm-x86/paravirt.h b/include/asm-x86/paravirt.h --- a/include/asm-x86/paravirt.h +++ b/include/asm-x86/paravirt.h @@ -1396,8 +1396,8 @@ * caller saved registers but the argument parameter */ #define PV_SAVE_REGS "pushq %%rdi;" #define PV_RESTORE_REGS "popq %%rdi;" -#define PV_EXTRA_CLOBBERS EXTRA_CLOBBERS, "rcx" , "rdx" -#define PV_VEXTRA_CLOBBERS EXTRA_CLOBBERS, "rdi", "rcx" , "rdx" +#define PV_EXTRA_CLOBBERS EXTRA_CLOBBERS, "rcx" , "rdx", "rsi" +#define PV_VEXTRA_CLOBBERS EXTRA_CLOBBERS, "rdi", "rcx" , "rdx", "rsi" #define PV_FLAGS_ARG "D" #endif @@ -1489,8 +1489,26 @@ #ifdef CONFIG_X86_64 -#define PV_SAVE_REGS pushq %rax; pushq %rdi; pushq %rcx; pushq %rdx -#define PV_RESTORE_REGS popq %rdx; popq %rcx; popq %rdi; popq %rax +#define PV_SAVE_REGS \ + push %rax; \ + push %rcx; \ + push %rdx; \ + push %rsi; \ + push %rdi; \ + push %r8; \ + push %r9; \ + push %r10; \ + push %r11 +#define PV_RESTORE_REGS \ + pop %r11; \ + pop %r10; \ + pop %r9; \ + pop %r8; \ + pop %rdi; \ + pop %rsi; \ + pop %rdx; \ + pop %rcx; \ + pop %rax #define PARA_PATCH(struct, off) ((PARAVIRT_PATCH_##struct + (off)) / 8) #define PARA_SITE(ptype, clobbers, ops) _PVSITE(ptype, clobbers, ops, .quad, 8) #define PARA_INDIRECT(addr) *addr(%rip)
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