@@ -236,12 +236,19 @@ static efi_status_t __init phys_efi_set_virtual_address_map(
efi_memory_desc_t *virtual_map)
{
efi_status_t status;
+ unsigned long flags;
efi_call_phys_prelog();
+
+ /* Disable interrupts around EFI calls: */
+ local_irq_save(flags);
status = efi_call_phys(efi_phys.set_virtual_address_map,
memory_map_size, descriptor_size,
descriptor_version, virtual_map);
+ local_irq_restore(flags);
+
efi_call_phys_epilog();
+
return status;
}
@@ -33,11 +33,10 @@
/*
* To make EFI call EFI runtime service in physical addressing mode we need
- * prelog/epilog before/after the invocation to disable interrupt, to
- * claim EFI runtime service handler exclusively and to duplicate a memory in
- * low memory space say 0 - 3G.
+ * prolog/epilog before/after the invocation to claim the EFI runtime service
+ * handler exclusively and to duplicate a memory mapping in low memory space,
+ * say 0 - 3G.
*/
-static unsigned long efi_rt_eflags;
void efi_sync_low_kernel_mappings(void) {}
void __init efi_dump_pagetable(void) {}
@@ -59,8 +58,6 @@ void efi_call_phys_prelog(void)
{
struct desc_ptr gdt_descr;
- local_irq_save(efi_rt_eflags);
-
load_cr3(initial_page_table);
__flush_tlb_all();
@@ -79,8 +76,6 @@ void efi_call_phys_epilog(void)
load_cr3(swapper_pg_dir);
__flush_tlb_all();
-
- local_irq_restore(efi_rt_eflags);
}
void __init efi_runtime_mkexec(void)
@@ -42,7 +42,6 @@
#include <asm/time.h>
static pgd_t *save_pgd __initdata;
-static unsigned long efi_flags __initdata;
/*
* We allocate runtime services regions bottom-up, starting from -4G, i.e.
@@ -89,7 +88,6 @@ void __init efi_call_phys_prelog(void)
return;
early_code_mapping_set_exec(1);
- local_irq_save(efi_flags);
n_pgds = DIV_ROUND_UP((max_pfn << PAGE_SHIFT), PGDIR_SIZE);
save_pgd = kmalloc(n_pgds * sizeof(pgd_t), GFP_KERNEL);
@@ -117,7 +115,6 @@ void __init efi_call_phys_epilog(void)
set_pgd(pgd_offset_k(pgd * PGDIR_SIZE), save_pgd[pgd]);
kfree(save_pgd);
__flush_tlb_all();
- local_irq_restore(efi_flags);
early_code_mapping_set_exec(0);
}
This is a note to let you know that I have just added a patch titled efi: Disable interrupts around EFI calls, not in the epilog/prolog calls to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree which can be found at: http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.16.y-queue This patch is scheduled to be released in version 3.16.7-ckt23. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.16.y-ckt tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Luis ---8<------------------------------------------------------------ From 3fc550e9e44b3b82adf983f0a40f1be288230439 Mon Sep 17 00:00:00 2001 From: Ingo Molnar <mingo@kernel.org> Date: Tue, 3 Mar 2015 07:34:33 +0100 Subject: efi: Disable interrupts around EFI calls, not in the epilog/prolog calls commit 23a0d4e8fa6d3a1d7fb819f79bcc0a3739c30ba9 upstream. Tapasweni Pathak reported that we do a kmalloc() in efi_call_phys_prolog() on x86-64 while having interrupts disabled, which is a big no-no, as kmalloc() can sleep. Solve this by removing the irq disabling from the prolog/epilog calls around EFI calls: it's unnecessary, as in this stage we are single threaded in the boot thread, and we don't ever execute this from interrupt contexts. Reported-by: Tapasweni Pathak <tapaswenipathak@gmail.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Matt Fleming <matt.fleming@intel.com> [ luis: backported to 3.16: adjusted context ] Signed-off-by: Luis Henriques <luis.henriques@canonical.com> --- arch/x86/platform/efi/efi.c | 7 +++++++ arch/x86/platform/efi/efi_32.c | 11 +++-------- arch/x86/platform/efi/efi_64.c | 3 --- 3 files changed, 10 insertions(+), 11 deletions(-)