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author | Linus Torvalds <torvalds@linux-foundation.org> | 2021-08-29 19:26:00 +0200 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-08-29 19:26:00 +0200 |
commit | 072a276745da10620c9b84a08519620670ba7496 (patch) | |
tree | e0118d29a40a6a0352c348a61a8c0b9ee0855fb5 | |
parent | Revert "parisc: Add assembly implementations for memset, strlen, strcpy, strn... (diff) | |
parent | x86/resctrl: Fix a maybe-uninitialized build warning treated as error (diff) | |
download | linux-072a276745da10620c9b84a08519620670ba7496.tar.xz linux-072a276745da10620c9b84a08519620670ba7496.zip |
Merge tag 'x86_urgent_for_v5.14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Borislav Petkov:
- Fix build error on RHEL where -Werror=maybe-uninitialized is set.
- Restore the firmware's IDT when calling EFI boot services and before
ExitBootServices() has been called. This fixes a boot failure on what
appears to be a tablet with 32-bit UEFI running a 64-bit kernel.
* tag 'x86_urgent_for_v5.14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/resctrl: Fix a maybe-uninitialized build warning treated as error
x86/efi: Restore Firmware IDT before calling ExitBootServices()
-rw-r--r-- | arch/x86/boot/compressed/efi_thunk_64.S | 30 | ||||
-rw-r--r-- | arch/x86/boot/compressed/head_64.S | 3 | ||||
-rw-r--r-- | arch/x86/kernel/cpu/resctrl/monitor.c | 6 |
3 files changed, 30 insertions, 9 deletions
diff --git a/arch/x86/boot/compressed/efi_thunk_64.S b/arch/x86/boot/compressed/efi_thunk_64.S index 95a223b3e56a..8bb92e9f4e97 100644 --- a/arch/x86/boot/compressed/efi_thunk_64.S +++ b/arch/x86/boot/compressed/efi_thunk_64.S @@ -5,9 +5,8 @@ * Early support for invoking 32-bit EFI services from a 64-bit kernel. * * Because this thunking occurs before ExitBootServices() we have to - * restore the firmware's 32-bit GDT before we make EFI service calls, - * since the firmware's 32-bit IDT is still currently installed and it - * needs to be able to service interrupts. + * restore the firmware's 32-bit GDT and IDT before we make EFI service + * calls. * * On the plus side, we don't have to worry about mangling 64-bit * addresses into 32-bits because we're executing with an identity @@ -39,7 +38,7 @@ SYM_FUNC_START(__efi64_thunk) /* * Convert x86-64 ABI params to i386 ABI */ - subq $32, %rsp + subq $64, %rsp movl %esi, 0x0(%rsp) movl %edx, 0x4(%rsp) movl %ecx, 0x8(%rsp) @@ -49,14 +48,19 @@ SYM_FUNC_START(__efi64_thunk) leaq 0x14(%rsp), %rbx sgdt (%rbx) + addq $16, %rbx + sidt (%rbx) + /* - * Switch to gdt with 32-bit segments. This is the firmware GDT - * that was installed when the kernel started executing. This - * pointer was saved at the EFI stub entry point in head_64.S. + * Switch to IDT and GDT with 32-bit segments. This is the firmware GDT + * and IDT that was installed when the kernel started executing. The + * pointers were saved at the EFI stub entry point in head_64.S. * * Pass the saved DS selector to the 32-bit code, and use far return to * restore the saved CS selector. */ + leaq efi32_boot_idt(%rip), %rax + lidt (%rax) leaq efi32_boot_gdt(%rip), %rax lgdt (%rax) @@ -67,7 +71,7 @@ SYM_FUNC_START(__efi64_thunk) pushq %rax lretq -1: addq $32, %rsp +1: addq $64, %rsp movq %rdi, %rax pop %rbx @@ -128,10 +132,13 @@ SYM_FUNC_START_LOCAL(efi_enter32) /* * Some firmware will return with interrupts enabled. Be sure to - * disable them before we switch GDTs. + * disable them before we switch GDTs and IDTs. */ cli + lidtl (%ebx) + subl $16, %ebx + lgdtl (%ebx) movl %cr4, %eax @@ -166,6 +173,11 @@ SYM_DATA_START(efi32_boot_gdt) .quad 0 SYM_DATA_END(efi32_boot_gdt) +SYM_DATA_START(efi32_boot_idt) + .word 0 + .quad 0 +SYM_DATA_END(efi32_boot_idt) + SYM_DATA_START(efi32_boot_cs) .word 0 SYM_DATA_END(efi32_boot_cs) diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S index a2347ded77ea..572c535cf45b 100644 --- a/arch/x86/boot/compressed/head_64.S +++ b/arch/x86/boot/compressed/head_64.S @@ -319,6 +319,9 @@ SYM_INNER_LABEL(efi32_pe_stub_entry, SYM_L_LOCAL) movw %cs, rva(efi32_boot_cs)(%ebp) movw %ds, rva(efi32_boot_ds)(%ebp) + /* Store firmware IDT descriptor */ + sidtl rva(efi32_boot_idt)(%ebp) + /* Disable paging */ movl %cr0, %eax btrl $X86_CR0_PG_BIT, %eax diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c index 57e4bb695ff9..8caf871b796f 100644 --- a/arch/x86/kernel/cpu/resctrl/monitor.c +++ b/arch/x86/kernel/cpu/resctrl/monitor.c @@ -304,6 +304,12 @@ static u64 __mon_event_count(u32 rmid, struct rmid_read *rr) case QOS_L3_MBM_LOCAL_EVENT_ID: m = &rr->d->mbm_local[rmid]; break; + default: + /* + * Code would never reach here because an invalid + * event id would fail the __rmid_read. + */ + return RMID_VAL_ERROR; } if (rr->first) { |