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powerpc: Add ppc_inst_as_u64()

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The code patching code wants to get the value of a struct ppc_inst as
a u64 when the instruction is prefixed, so we can pass the u64 down to
__put_user_asm() and write it with a single store.

The optprobes code wants to load a struct ppc_inst as an immediate
into a register so it is useful to have it as a u64 to use the
existing helper function.

Currently this is a bit awkward because the value differs based on the
CPU endianness, so add a helper to do the conversion.

This fixes the usage in arch_prepare_optimized_kprobe() which was
previously incorrect on big endian.

Fixes: 650b55b707 ("powerpc: Add prefixed instructions to instruction data type")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Tested-by: Jordan Niethe <jniethe5@gmail.com>
Link: https://lore.kernel.org/r/20200526072630.2487363-1-mpe@ellerman.id.au
This commit is contained in:
Michael Ellerman
2020-05-26 17:26:30 +10:00
parent c5ff46d69c
commit 16ef9767e4
3 changed files with 11 additions and 9 deletions
Download Patch File Download Diff File Expand all files Collapse all files

8
arch/powerpc/lib/code-patching.c
View File

@@ -27,13 +27,7 @@ static int __patch_instruction(struct ppc_inst *exec_addr, struct ppc_inst instr
if (!ppc_inst_prefixed(instr)) {
__put_user_asm(ppc_inst_val(instr), patch_addr, err, "stw");
} else {
#ifdef CONFIG_CPU_LITTLE_ENDIAN
__put_user_asm((u64)ppc_inst_suffix(instr) << 32 |
ppc_inst_val(instr), patch_addr, err, "std");
#else
__put_user_asm((u64)ppc_inst_val(instr) << 32 |
ppc_inst_suffix(instr), patch_addr, err, "std");
#endif
__put_user_asm(ppc_inst_as_u64(instr), patch_addr, err, "std");
}
if (err)