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| author |  Willy Tarreau <w@1wt.eu>
| 2023-01-10 08:24:27 +0100 |
|---|---|---|
| committer |  Paul E. McKenney <paulmck@kernel.org>
| 2023-01-10 13:33:56 -0800 |
| commit | 2a39a53245d2b5eae83c10a67581e8dc6b629b85 (patch) | |
| tree | ea023096042992420de926e042b54d7644638dda /tools/include | |
| parent | tools/nolibc: add auxiliary vector retrieval for x86_64 (diff) | |
| download | linux-2a39a53245d2b5eae83c10a67581e8dc6b629b85.tar.gz linux-2a39a53245d2b5eae83c10a67581e8dc6b629b85.tar.bz2 linux-2a39a53245d2b5eae83c10a67581e8dc6b629b85.zip | |
tools/nolibc: add auxiliary vector retrieval for arm64
In the _start block we now iterate over envp to find the auxiliary
vector after the NULL. The pointer is saved into an _auxv variable
that is marked as weak so that it's accessible from multiple units.
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Diffstat (limited to 'tools/include')
| -rw-r--r-- | tools/include/nolibc/arch-aarch64.h | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/tools/include/nolibc/arch-aarch64.h b/tools/include/nolibc/arch-aarch64.h index 2e3d9adc4c4c..383baddef701 100644 --- a/tools/include/nolibc/arch-aarch64.h +++ b/tools/include/nolibc/arch-aarch64.h @@ -170,6 +170,7 @@ struct sys_stat_struct { }) char **environ __attribute__((weak)); +const unsigned long *_auxv __attribute__((weak)); /* startup code */ void __attribute__((weak,noreturn,optimize("omit-frame-pointer"))) _start(void) @@ -182,6 +183,12 @@ void __attribute__((weak,noreturn,optimize("omit-frame-pointer"))) _start(void) "add x2, x2, x1\n" // + argv "adrp x3, environ\n" // x3 = &environ (high bits) "str x2, [x3, #:lo12:environ]\n" // store envp into environ + "mov x4, x2\n" // search for auxv (follows NULL after last env) + "0:\n" + "ldr x5, [x4], 8\n" // x5 = *x4; x4 += 8 + "cbnz x5, 0b\n" // and stop at NULL after last env + "adrp x3, _auxv\n" // x3 = &_auxv (high bits) + "str x4, [x3, #:lo12:_auxv]\n" // store x4 into _auxv "and sp, x1, -16\n" // sp must be 16-byte aligned in the callee "bl main\n" // main() returns the status code, we'll exit with it. "mov x8, 93\n" // NR_exit == 93 |