Merge tag 'for-linus-6.13-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull xen updates from Juergen Gross:
- a series for booting as a PVH guest, doing some cleanups after the
previous work to make PVH boot code position independent
- a fix of the xenbus driver avoiding a leak in an error case
* tag 'for-linus-6.13-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
xen: Fix the issue of resource not being properly released in xenbus_dev_probe()
x86/pvh: Avoid absolute symbol references in .head.text
x86/xen: Avoid relocatable quantities in Xen ELF notes
x86/pvh: Omit needless clearing of phys_base
x86/pvh: Use correct size value in GDT descriptor
x86/pvh: Call C code via the kernel virtual mapping
diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S
index feb8102..6519984 100644
--- a/arch/x86/kernel/vmlinux.lds.S
+++ b/arch/x86/kernel/vmlinux.lds.S
@@ -531,3 +531,22 @@
#endif
#endif /* CONFIG_X86_64 */
+
+/*
+ * The symbols below are referenced using relative relocations in the
+ * respective ELF notes. This produces build time constants that the
+ * linker will never mark as relocatable. (Using just ABSOLUTE() is not
+ * sufficient for that).
+ */
+#ifdef CONFIG_XEN
+#ifdef CONFIG_XEN_PV
+xen_elfnote_entry_value =
+ ABSOLUTE(xen_elfnote_entry) + ABSOLUTE(startup_xen);
+#endif
+xen_elfnote_hypercall_page_value =
+ ABSOLUTE(xen_elfnote_hypercall_page) + ABSOLUTE(hypercall_page);
+#endif
+#ifdef CONFIG_PVH
+xen_elfnote_phys32_entry_value =
+ ABSOLUTE(xen_elfnote_phys32_entry) + ABSOLUTE(pvh_start_xen - LOAD_OFFSET);
+#endif
diff --git a/arch/x86/platform/pvh/head.S b/arch/x86/platform/pvh/head.S
index 64fca49..4733a5f 100644
--- a/arch/x86/platform/pvh/head.S
+++ b/arch/x86/platform/pvh/head.S
@@ -6,7 +6,9 @@
.code32
.text
+#ifdef CONFIG_X86_32
#define _pa(x) ((x) - __START_KERNEL_map)
+#endif
#define rva(x) ((x) - pvh_start_xen)
#include <linux/elfnote.h>
@@ -52,7 +54,7 @@
#define PVH_CS_SEL (PVH_GDT_ENTRY_CS * 8)
#define PVH_DS_SEL (PVH_GDT_ENTRY_DS * 8)
-SYM_CODE_START_LOCAL(pvh_start_xen)
+SYM_CODE_START(pvh_start_xen)
UNWIND_HINT_END_OF_STACK
cld
@@ -72,8 +74,7 @@
movl $0, %esp
leal rva(gdt)(%ebp), %eax
- leal rva(gdt_start)(%ebp), %ecx
- movl %ecx, 2(%eax)
+ addl %eax, 2(%eax)
lgdt (%eax)
mov $PVH_DS_SEL,%eax
@@ -103,10 +104,23 @@
btsl $_EFER_LME, %eax
wrmsr
+ /*
+ * Reuse the non-relocatable symbol emitted for the ELF note to
+ * subtract the build time physical address of pvh_start_xen() from
+ * its actual runtime address, without relying on absolute 32-bit ELF
+ * relocations, as these are not supported by the linker when running
+ * in -pie mode, and should be avoided in .head.text in general.
+ */
mov %ebp, %ebx
- subl $_pa(pvh_start_xen), %ebx /* offset */
+ subl rva(xen_elfnote_phys32_entry)(%ebp), %ebx
jz .Lpagetable_done
+ /*
+ * Store the resulting load offset in phys_base. __pa() needs
+ * phys_base set to calculate the hypercall page in xen_pvh_init().
+ */
+ movl %ebx, rva(phys_base)(%ebp)
+
/* Fixup page-tables for relocation. */
leal rva(pvh_init_top_pgt)(%ebp), %edi
movl $PTRS_PER_PGD, %ecx
@@ -165,20 +179,12 @@
xor %edx, %edx
wrmsr
- /*
- * Calculate load offset and store in phys_base. __pa() needs
- * phys_base set to calculate the hypercall page in xen_pvh_init().
- */
- movq %rbp, %rbx
- subq $_pa(pvh_start_xen), %rbx
- movq %rbx, phys_base(%rip)
- call xen_prepare_pvh
- /*
- * Clear phys_base. __startup_64 will *add* to its value,
- * so reset to 0.
- */
- xor %rbx, %rbx
- movq %rbx, phys_base(%rip)
+ /* Call xen_prepare_pvh() via the kernel virtual mapping */
+ leaq xen_prepare_pvh(%rip), %rax
+ subq phys_base(%rip), %rax
+ addq $__START_KERNEL_map, %rax
+ ANNOTATE_RETPOLINE_SAFE
+ call *%rax
/* startup_64 expects boot_params in %rsi. */
lea pvh_bootparams(%rip), %rsi
@@ -217,8 +223,8 @@
.section ".init.data","aw"
.balign 8
SYM_DATA_START_LOCAL(gdt)
- .word gdt_end - gdt_start
- .long _pa(gdt_start) /* x86-64 will overwrite if relocated. */
+ .word gdt_end - gdt_start - 1
+ .long gdt_start - gdt
.word 0
SYM_DATA_END(gdt)
SYM_DATA_START_LOCAL(gdt_start)
@@ -300,5 +306,5 @@
.long KERNEL_IMAGE_SIZE - 1)
#endif
- ELFNOTE(Xen, XEN_ELFNOTE_PHYS32_ENTRY,
- _ASM_PTR (pvh_start_xen - __START_KERNEL_map))
+ ELFNOTE(Xen, XEN_ELFNOTE_PHYS32_ENTRY, .global xen_elfnote_phys32_entry;
+ xen_elfnote_phys32_entry: _ASM_PTR xen_elfnote_phys32_entry_value - .)
diff --git a/arch/x86/tools/relocs.c b/arch/x86/tools/relocs.c
index c101bed..3ede19c 100644
--- a/arch/x86/tools/relocs.c
+++ b/arch/x86/tools/relocs.c
@@ -56,6 +56,7 @@ static const char * const sym_regex_kernel[S_NSYMTYPES] = {
[S_ABS] =
"^(xen_irq_disable_direct_reloc$|"
"xen_save_fl_direct_reloc$|"
+ "xen_elfnote_.+_offset$|"
"VDSO|"
"__kcfi_typeid_|"
"__crc_)",
diff --git a/arch/x86/xen/xen-head.S b/arch/x86/xen/xen-head.S
index 758bcd4..7f6c69db 100644
--- a/arch/x86/xen/xen-head.S
+++ b/arch/x86/xen/xen-head.S
@@ -94,7 +94,8 @@
ELFNOTE(Xen, XEN_ELFNOTE_VIRT_BASE, _ASM_PTR __START_KERNEL_map)
/* Map the p2m table to a 512GB-aligned user address. */
ELFNOTE(Xen, XEN_ELFNOTE_INIT_P2M, .quad (PUD_SIZE * PTRS_PER_PUD))
- ELFNOTE(Xen, XEN_ELFNOTE_ENTRY, _ASM_PTR startup_xen)
+ ELFNOTE(Xen, XEN_ELFNOTE_ENTRY, .globl xen_elfnote_entry;
+ xen_elfnote_entry: _ASM_PTR xen_elfnote_entry_value - .)
ELFNOTE(Xen, XEN_ELFNOTE_FEATURES, .ascii "!writable_page_tables")
ELFNOTE(Xen, XEN_ELFNOTE_PAE_MODE, .asciz "yes")
ELFNOTE(Xen, XEN_ELFNOTE_L1_MFN_VALID,
@@ -115,7 +116,8 @@
#else
# define FEATURES_DOM0 0
#endif
- ELFNOTE(Xen, XEN_ELFNOTE_HYPERCALL_PAGE, _ASM_PTR hypercall_page)
+ ELFNOTE(Xen, XEN_ELFNOTE_HYPERCALL_PAGE, .globl xen_elfnote_hypercall_page;
+ xen_elfnote_hypercall_page: _ASM_PTR xen_elfnote_hypercall_page_value - .)
ELFNOTE(Xen, XEN_ELFNOTE_SUPPORTED_FEATURES,
.long FEATURES_PV | FEATURES_PVH | FEATURES_DOM0)
ELFNOTE(Xen, XEN_ELFNOTE_LOADER, .asciz "generic")
diff --git a/drivers/xen/xenbus/xenbus_probe.c b/drivers/xen/xenbus/xenbus_probe.c
index 9f097f1..6d32ffb 100644
--- a/drivers/xen/xenbus/xenbus_probe.c
+++ b/drivers/xen/xenbus/xenbus_probe.c
@@ -313,7 +313,7 @@ int xenbus_dev_probe(struct device *_dev)
if (err) {
dev_warn(&dev->dev, "watch_otherend on %s failed.\n",
dev->nodename);
- return err;
+ goto fail_remove;
}
dev->spurious_threshold = 1;
@@ -322,6 +322,12 @@ int xenbus_dev_probe(struct device *_dev)
dev->nodename);
return 0;
+fail_remove:
+ if (drv->remove) {
+ down(&dev->reclaim_sem);
+ drv->remove(dev);
+ up(&dev->reclaim_sem);
+ }
fail_put:
module_put(drv->driver.owner);
fail:
