diff options
| author | Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | 2024-02-27 14:09:58 -0500 |
|---|---|---|
| committer | Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | 2024-02-27 17:28:07 -0500 |
| commit | 94f43fc905cd7097e54a3e7d27cf2f486fa58724 (patch) | |
| tree | 78da82ba45b54aeb7c87b07699dded42c8ec804e | |
| parent | 71884a4b1f9167e6698cf4875943af2795cfa4c7 (diff) | |
| download | librseq-94f43fc905cd7097e54a3e7d27cf2f486fa58724.tar.gz | |
x86-32: Remove support for old IDT WinChip and PPRO
The rseq system call first appeared in Linux v4.18, which did not
support the old IDT WinChip Intel clones and PentiumPro CPUs anymore.
Therefore, remove CPU barrier instructions from the smp_rmb() and
smp_wmb() macros given that librseq will realistically never be used on
such hardware.
Expect all x86-32 hardware to be TSO.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I07a03006e2eb8ec0928c63f16df94ad42d440b10
| -rw-r--r-- | include/rseq/rseq-x86.h | 30 |
1 files changed, 4 insertions, 26 deletions
diff --git a/include/rseq/rseq-x86.h b/include/rseq/rseq-x86.h index 9d38628..eb5cc19 100644 --- a/include/rseq/rseq-x86.h +++ b/include/rseq/rseq-x86.h @@ -31,10 +31,6 @@ #define RSEQ_CS_OFFSET 8 #define RSEQ_MM_CID_OFFSET 24 -#ifdef __x86_64__ - -#define RSEQ_ASM_TP_SEGMENT %%fs - #define rseq_smp_mb() \ __asm__ __volatile__ ("lock; addl $0,-128(%%rsp)" ::: "memory", "cc") #define rseq_smp_rmb() rseq_barrier() @@ -55,6 +51,10 @@ do { \ RSEQ_WRITE_ONCE(*(p), v); \ } while (0) +#ifdef __x86_64__ + +#define RSEQ_ASM_TP_SEGMENT %%fs + #define __RSEQ_ASM_DEFINE_TABLE(label, version, flags, \ start_ip, post_commit_offset, abort_ip) \ ".pushsection __rseq_cs, \"aw\"\n\t" \ @@ -117,28 +117,6 @@ do { \ #define RSEQ_ASM_TP_SEGMENT %%gs -#define rseq_smp_mb() \ - __asm__ __volatile__ ("lock; addl $0,-128(%%esp)" ::: "memory", "cc") -#define rseq_smp_rmb() \ - __asm__ __volatile__ ("lock; addl $0,-128(%%esp)" ::: "memory", "cc") -#define rseq_smp_wmb() \ - __asm__ __volatile__ ("lock; addl $0,-128(%%esp)" ::: "memory", "cc") - -#define rseq_smp_load_acquire(p) \ -__extension__ ({ \ - rseq_unqual_scalar_typeof(*(p)) ____p1 = RSEQ_READ_ONCE(*(p)); \ - rseq_smp_mb(); \ - ____p1; \ -}) - -#define rseq_smp_acquire__after_ctrl_dep() rseq_smp_rmb() - -#define rseq_smp_store_release(p, v) \ -do { \ - rseq_smp_mb(); \ - RSEQ_WRITE_ONCE(*p, v); \ -} while (0) - /* * Use eax as scratch register and take memory operands as input to * lessen register pressure. Especially needed when compiling in O0. |