Date: Sat, 4 Aug 2012 05:30:20 +0000 (UTC) From: Andrew Turner <andrew@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r239031 - head/libexec/rtld-elf/arm Message-ID: <201208040530.q745UKpP013972@svn.freebsd.org>
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Author: andrew Date: Sat Aug 4 05:30:20 2012 New Revision: 239031 URL: http://svn.freebsd.org/changeset/base/239031 Log: Ensure we align the stack to 8 bytes in rtld. This is not strictly required with the current ABI but will be when we switch to the ARM EABI. The aapcs requires the stack to be 4 byte aligned at all times and 8 byte aligned when calling a public subroutine where the current ABI only requires sp to be a multiple of 4. Modified: head/libexec/rtld-elf/arm/rtld_start.S Modified: head/libexec/rtld-elf/arm/rtld_start.S ============================================================================== --- head/libexec/rtld-elf/arm/rtld_start.S Sat Aug 4 04:30:26 2012 (r239030) +++ head/libexec/rtld-elf/arm/rtld_start.S Sat Aug 4 05:30:20 2012 (r239031) @@ -37,6 +37,8 @@ __FBSDID("$FreeBSD$"); .globl .rtld_start .type .rtld_start,%function .rtld_start: + mov r6, sp /* save the stack pointer */ + bic sp, sp, #7 /* align the stack pointer */ sub sp, sp, #8 /* make room for obj_main & exit proc */ mov r4, r0 /* save ps_strings */ ldr sl, .L2 @@ -52,13 +54,13 @@ __FBSDID("$FreeBSD$"); bl _rtld_relocate_nonplt_self mov r1, sp add r2, sp, #4 - add r0, sp, #8 + mov r0, r6 /* load the sp the kernel gave us */ bl _rtld /* call the shared loader */ mov r3, r0 /* save entry point */ ldr r2, [sp, #0] /* r2 = cleanup */ ldr r1, [sp, #4] /* r1 = obj_main */ - add sp, sp, #8 /* restore stack */ + mov sp, r6 /* restore stack */ mov r0, r4 /* restore ps_strings */ mov pc, r3 /* jump to the entry point */ .L2:
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