diff options
| author | Andy Lutomirski <luto@kernel.org> | 2020-06-26 20:21:13 +0300 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2020-07-01 11:00:26 +0300 |
| commit | ffae641f57476369b4d503402b37ebe489d23395 (patch) | |
| tree | 66ad35049b3c31cf7256e2aa29ddbb1a420d2c8d /arch/x86/entry | |
| parent | d1721250f3ffed9afba3e1fb729947cec64c5a8a (diff) | |
| download | linux-ffae641f57476369b4d503402b37ebe489d23395.tar.xz | |
x86/entry/64/compat: Fix Xen PV SYSENTER frame setup
The SYSENTER frame setup was nonsense. It worked by accident because the
normal code into which the Xen asm jumped (entry_SYSENTER_32/compat) threw
away SP without touching the stack. entry_SYSENTER_compat was recently
modified such that it relied on having a valid stack pointer, so now the
Xen asm needs to invoke it with a valid stack.
Fix it up like SYSCALL: use the Xen-provided frame and skip the bare
metal prologue.
Fixes: 1c3e5d3f60e2 ("x86/entry: Make entry_64_compat.S objtool clean")
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Link: https://lkml.kernel.org/r/947880c41ade688ff4836f665d0c9fcaa9bd1201.1593191971.git.luto@kernel.org
Diffstat (limited to 'arch/x86/entry')
| -rw-r--r-- | arch/x86/entry/entry_64_compat.S | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/x86/entry/entry_64_compat.S b/arch/x86/entry/entry_64_compat.S index 7b9d8150f652..381a6de7de9c 100644 --- a/arch/x86/entry/entry_64_compat.S +++ b/arch/x86/entry/entry_64_compat.S @@ -79,6 +79,7 @@ SYM_CODE_START(entry_SYSENTER_compat) pushfq /* pt_regs->flags (except IF = 0) */ pushq $__USER32_CS /* pt_regs->cs */ pushq $0 /* pt_regs->ip = 0 (placeholder) */ +SYM_INNER_LABEL(entry_SYSENTER_compat_after_hwframe, SYM_L_GLOBAL) pushq %rax /* pt_regs->orig_ax */ pushq %rdi /* pt_regs->di */ pushq %rsi /* pt_regs->si */ |