The following commit has been merged into the x86/asm branch of tip: Commit-ID: 183ef7adf4ed638ac0fb0c3c9a71fc00e8512b61 Gitweb: https://git.kernel.org/tip/183ef7adf4ed638ac0fb0c3c9a71fc00e8512b61 Author: Arvind Sankar <nivedita@xxxxxxxxxxxx> AuthorDate: Tue, 07 Jan 2020 14:44:34 -05:00 Committer: Borislav Petkov <bp@xxxxxxx> CommitterDate: Thu, 23 Jan 2020 11:58:43 +01:00 x86/boot: Simplify calculation of output address Condense the calculation of decompressed kernel start a little. Committer notes: before: ebp = ebx - (init_size - _end) after: eax = (ebx + _end) - init_size where in both ebx contains the temporary address the kernel is moved to for in-place decompression. The before and after difference in register state is %eax and %ebp but that is immaterial because the compressed image is not built with -mregparm, i.e., all arguments of the following extract_kernel() call are passed on the stack. Signed-off-by: Arvind Sankar <nivedita@xxxxxxxxxxxx> Signed-off-by: Borislav Petkov <bp@xxxxxxx> Link: https://lkml.kernel.org/r/20200107194436.2166846-1-nivedita@xxxxxxxxxxxx --- arch/x86/boot/compressed/head_32.S | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) diff --git a/arch/x86/boot/compressed/head_32.S b/arch/x86/boot/compressed/head_32.S index f2dfd6d..1cc55c7 100644 --- a/arch/x86/boot/compressed/head_32.S +++ b/arch/x86/boot/compressed/head_32.S @@ -240,11 +240,9 @@ SYM_FUNC_START_LOCAL_NOALIGN(.Lrelocated) /* push arguments for extract_kernel: */ pushl $z_output_len /* decompressed length, end of relocs */ - movl BP_init_size(%esi), %eax - subl $_end, %eax - movl %ebx, %ebp - subl %eax, %ebp - pushl %ebp /* output address */ + leal _end(%ebx), %eax + subl BP_init_size(%esi), %eax + pushl %eax /* output address */ pushl $z_input_len /* input_len */ leal input_data(%ebx), %eax
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