diff options
| author |   Juergen Gross <jgross@suse.com> | 2022-06-30 09:14:39 +0200 |
|---|---|---|
| committer |   Borislav Petkov <bp@suse.de> | 2022-07-01 10:57:52 +0200 |
| commit | 96e8fc5818686d4a1591bb6907e7fdb64ef29884 (patch) | |
| tree | 52cac6393567e532ed0bf7aa5ceafbeebe5b1b52 /arch/x86 | |
| parent | Linux 5.19-rc4 (diff) | |
| download | linux-dev-96e8fc5818686d4a1591bb6907e7fdb64ef29884.tar.xz linux-dev-96e8fc5818686d4a1591bb6907e7fdb64ef29884.zip | |
x86/xen: Use clear_bss() for Xen PV guests
Instead of clearing the bss area in assembly code, use the clear_bss()
function.
This requires to pass the start_info address as parameter to
xen_start_kernel() in order to avoid the xen_start_info being zeroed
again.
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Link: https://lore.kernel.org/r/20220630071441.28576-2-jgross@suse.com
Diffstat (limited to '')
| -rw-r--r-- | arch/x86/include/asm/setup.h | 3 | ||||
| -rw-r--r-- | arch/x86/kernel/head64.c | 2 | ||||
| -rw-r--r-- | arch/x86/xen/enlighten_pv.c | 8 | ||||
| -rw-r--r-- | arch/x86/xen/xen-head.S | 10 |
4 files changed, 11 insertions, 12 deletions
diff --git a/arch/x86/include/asm/setup.h b/arch/x86/include/asm/setup.h index f8b9ee97a891..f37cbff7354c 100644 --- a/arch/x86/include/asm/setup.h +++ b/arch/x86/include/asm/setup.h @@ -120,6 +120,9 @@ void *extend_brk(size_t size, size_t align); static char __brk_##name[size] extern void probe_roms(void); + +void clear_bss(void); + #ifdef __i386__ asmlinkage void __init i386_start_kernel(void); diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c index bd4a34100ed0..e7e233209a8c 100644 --- a/arch/x86/kernel/head64.c +++ b/arch/x86/kernel/head64.c @@ -426,7 +426,7 @@ void __init do_early_exception(struct pt_regs *regs, int trapnr) /* Don't add a printk in there. printk relies on the PDA which is not initialized yet. */ -static void __init clear_bss(void) +void __init clear_bss(void) { memset(__bss_start, 0, (unsigned long) __bss_stop - (unsigned long) __bss_start); diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c index e3297b15701c..70fb2ea85e90 100644 --- a/arch/x86/xen/enlighten_pv.c +++ b/arch/x86/xen/enlighten_pv.c @@ -1183,15 +1183,19 @@ static void __init xen_domu_set_legacy_features(void) extern void early_xen_iret_patch(void); /* First C function to be called on Xen boot */ -asmlinkage __visible void __init xen_start_kernel(void) +asmlinkage __visible void __init xen_start_kernel(struct start_info *si) { struct physdev_set_iopl set_iopl; unsigned long initrd_start = 0; int rc; - if (!xen_start_info) + if (!si) return; + clear_bss(); + + xen_start_info = si; + __text_gen_insn(&early_xen_iret_patch, JMP32_INSN_OPCODE, &early_xen_iret_patch, &xen_iret, JMP32_INSN_SIZE); diff --git a/arch/x86/xen/xen-head.S b/arch/x86/xen/xen-head.S index 3a2cd93bf059..13af6fe453e3 100644 --- a/arch/x86/xen/xen-head.S +++ b/arch/x86/xen/xen-head.S @@ -48,15 +48,6 @@ SYM_CODE_START(startup_xen) ANNOTATE_NOENDBR cld - /* Clear .bss */ - xor %eax,%eax - mov $__bss_start, %rdi - mov $__bss_stop, %rcx - sub %rdi, %rcx - shr $3, %rcx - rep stosq - - mov %rsi, xen_start_info mov initial_stack(%rip), %rsp /* Set up %gs. @@ -71,6 +62,7 @@ SYM_CODE_START(startup_xen) cdq wrmsr + mov %rsi, %rdi call xen_start_kernel SYM_CODE_END(startup_xen) __FINIT |