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| author |   Arvind Sankar <nivedita@alum.mit.edu> | 2020-02-02 12:13:47 -0500 |
|---|---|---|
| committer |   Ard Biesheuvel <ardb@kernel.org> | 2020-02-22 23:37:37 +0100 |
| commit | 67a6af7ad1d161dbc9c139e868d5549e632923f7 (patch) | |
| tree | 8de615eaa7de8d0a465c5738418ef6eb3f42ec4d | |
| parent | efi/libstub/arm: Make efi_entry() an ordinary PE/COFF entrypoint (diff) | |
| download | wireguard-linux-67a6af7ad1d161dbc9c139e868d5549e632923f7.tar.xz wireguard-linux-67a6af7ad1d161dbc9c139e868d5549e632923f7.zip | |
x86/boot: Remove KEEP_SEGMENTS support
Commit a24e785111a3 ("i386: paravirt boot sequence") added this flag for
use by paravirtualized environments such as Xen. However, Xen never made
use of this flag [1], and it was only ever used by lguest [2].
Commit ecda85e70277 ("x86/lguest: Remove lguest support") removed
lguest, so KEEP_SEGMENTS has lost its last user.
[1] https://lore.kernel.org/lkml/4D4B097C.5050405@goop.org
[2] https://www.mail-archive.com/lguest@lists.ozlabs.org/msg00469.html
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Link: https://lore.kernel.org/r/20200202171353.3736319-2-nivedita@alum.mit.edu
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
| -rw-r--r-- | Documentation/x86/boot.rst | 8 | ||||
| -rw-r--r-- | arch/x86/boot/compressed/head_32.S | 8 | ||||
| -rw-r--r-- | arch/x86/boot/compressed/head_64.S | 8 | ||||
| -rw-r--r-- | arch/x86/kernel/head_32.S | 6 |
4 files changed, 2 insertions, 28 deletions
diff --git a/Documentation/x86/boot.rst b/Documentation/x86/boot.rst index c9c201596c3e..fa7ddc0428c8 100644 --- a/Documentation/x86/boot.rst +++ b/Documentation/x86/boot.rst @@ -490,15 +490,11 @@ Protocol: 2.00+ kernel) to not write early messages that require accessing the display hardware directly. - Bit 6 (write): KEEP_SEGMENTS + Bit 6 (obsolete): KEEP_SEGMENTS Protocol: 2.07+ - - If 0, reload the segment registers in the 32bit entry point. - - If 1, do not reload the segment registers in the 32bit entry point. - - Assume that %cs %ds %ss %es are all set to flat segments with - a base of 0 (or the equivalent for their environment). + - This flag is obsolete. Bit 7 (write): CAN_USE_HEAP diff --git a/arch/x86/boot/compressed/head_32.S b/arch/x86/boot/compressed/head_32.S index 73f17d0544dd..cb2cb91fce45 100644 --- a/arch/x86/boot/compressed/head_32.S +++ b/arch/x86/boot/compressed/head_32.S @@ -63,13 +63,6 @@ __HEAD SYM_FUNC_START(startup_32) cld - /* - * Test KEEP_SEGMENTS flag to see if the bootloader is asking - * us to not reload segments - */ - testb $KEEP_SEGMENTS, BP_loadflags(%esi) - jnz 1f - cli movl $__BOOT_DS, %eax movl %eax, %ds @@ -77,7 +70,6 @@ SYM_FUNC_START(startup_32) movl %eax, %fs movl %eax, %gs movl %eax, %ss -1: /* * Calculate the delta between where we were compiled to run diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S index 1f1f6c8139b3..bd44d89540d3 100644 --- a/arch/x86/boot/compressed/head_64.S +++ b/arch/x86/boot/compressed/head_64.S @@ -53,19 +53,11 @@ SYM_FUNC_START(startup_32) * all need to be under the 4G limit. */ cld - /* - * Test KEEP_SEGMENTS flag to see if the bootloader is asking - * us to not reload segments - */ - testb $KEEP_SEGMENTS, BP_loadflags(%esi) - jnz 1f - cli movl $(__BOOT_DS), %eax movl %eax, %ds movl %eax, %es movl %eax, %ss -1: /* * Calculate the delta between where we were compiled to run diff --git a/arch/x86/kernel/head_32.S b/arch/x86/kernel/head_32.S index 3923ab4630d7..f66a6b90f954 100644 --- a/arch/x86/kernel/head_32.S +++ b/arch/x86/kernel/head_32.S @@ -67,11 +67,6 @@ __HEAD SYM_CODE_START(startup_32) movl pa(initial_stack),%ecx - /* test KEEP_SEGMENTS flag to see if the bootloader is asking - us to not reload segments */ - testb $KEEP_SEGMENTS, BP_loadflags(%esi) - jnz 2f - /* * Set segments to known values. */ @@ -82,7 +77,6 @@ SYM_CODE_START(startup_32) movl %eax,%fs movl %eax,%gs movl %eax,%ss -2: leal -__PAGE_OFFSET(%ecx),%esp /* |