From: Michael Holzheu For s390 we first want to check if kdump checksums are valid before we start the kdump kernel. With this patch on s390 the purgatory entry point is called with a parameter. If the parameter is "0", only the checksum test is done and the result (0 = ok, 1 = invalid) is passed as return code back to the caller (kernel). If the parameter is "1", the complete purgatory code is executed and kdump is started. Signed-off-by: Michael Holzheu --- purgatory/arch/s390/setup-s390.S | 14 ++++++++++++++ purgatory/purgatory.c | 13 ++++++++----- 2 files changed, 22 insertions(+), 5 deletions(-) --- a/purgatory/arch/s390/setup-s390.S +++ b/purgatory/arch/s390/setup-s390.S @@ -11,12 +11,23 @@ .balign 16 purgatory_start: #ifdef __s390x__ + larl %r5,gprs_save_area + stmg %r6,%r15,0(%r5) larl %r15,lstack_end aghi %r15,-160 + + clgfi %r2,0 + je verify_checksums + brasl %r14,purgatory larl %r14,kdump_psw lpswe 0(%r14) +verify_checksums: + brasl %r14,verify_sha256_digest + larl %r5,gprs_save_area + lmg %r6,%r15,0(%r5) + br %r14 .section ".data" .balign 16 kdump_psw: @@ -24,6 +35,9 @@ kdump_psw: .quad 0x0000000000010010 .bss +gprs_save_area: + .fill 80 + .balign 4096 lstack: .skip 4096 --- a/purgatory/purgatory.c +++ b/purgatory/purgatory.c @@ -9,7 +9,7 @@ struct sha256_region sha256_regions[SHA256_REGIONS] = {}; sha256_digest_t sha256_digest = { }; -void verify_sha256_digest(void) +int verify_sha256_digest(void) { struct sha256_region *ptr, *end; sha256_digest_t digest; @@ -34,16 +34,19 @@ void verify_sha256_digest(void) printf("%hhx ", sha256_digest[i]); } printf("\n"); - for(;;) { - /* loop forever */ - } + return 1; } + return 0; } void purgatory(void) { printf("I'm in purgatory\n"); setup_arch(); - verify_sha256_digest(); + if (verify_sha256_digest()) { + for(;;) { + /* loop forever */ + } + } post_verification_setup_arch(); } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/