From 10348f5976830e5d8f74e8abb04a9a057a5e8478 Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt Date: Mon, 13 Jan 2014 09:49:17 +1100 Subject: powerpc: Check return value of instance-to-package OF call On PA-Semi firmware, the instance-to-package callback doesn't seem to be implemented. We didn't check for error, however, thus subsequently passed the -1 value returned into stdout_node to thins like prom_getprop etc... Thus caused the firmware to load values around 0 (physical) internally as node structures. It somewhat "worked" as long as we had a NULL in the right place (address 8) at the beginning of the kernel, we didn't "see" the bug. But commit 5c0484e25ec03243d4c2f2d4416d4a13efc77f6a "powerpc: Endian safe trampoline" changed the kernel entry point causing that old bug to now cause a crash early during boot. This fixes booting on PA-Semi board by properly checking the return value from instance-to-package. Signed-off-by: Benjamin Herrenschmidt Tested-by: Olof Johansson --- --- arch/powerpc/kernel/prom_init.c | 22 +++++++++++++--------- 1 file changed, 13 insertions(+), 9 deletions(-) (limited to 'arch/powerpc') diff --git a/arch/powerpc/kernel/prom_init.c b/arch/powerpc/kernel/prom_init.c index cb64a6e1dc51..078145acf7fb 100644 --- a/arch/powerpc/kernel/prom_init.c +++ b/arch/powerpc/kernel/prom_init.c @@ -1986,19 +1986,23 @@ static void __init prom_init_stdout(void) /* Get the full OF pathname of the stdout device */ memset(path, 0, 256); call_prom("instance-to-path", 3, 1, prom.stdout, path, 255); - stdout_node = call_prom("instance-to-package", 1, 1, prom.stdout); - val = cpu_to_be32(stdout_node); - prom_setprop(prom.chosen, "/chosen", "linux,stdout-package", - &val, sizeof(val)); prom_printf("OF stdout device is: %s\n", of_stdout_device); prom_setprop(prom.chosen, "/chosen", "linux,stdout-path", path, strlen(path) + 1); - /* If it's a display, note it */ - memset(type, 0, sizeof(type)); - prom_getprop(stdout_node, "device_type", type, sizeof(type)); - if (strcmp(type, "display") == 0) - prom_setprop(stdout_node, path, "linux,boot-display", NULL, 0); + /* instance-to-package fails on PA-Semi */ + stdout_node = call_prom("instance-to-package", 1, 1, prom.stdout); + if (stdout_node != PROM_ERROR) { + val = cpu_to_be32(stdout_node); + prom_setprop(prom.chosen, "/chosen", "linux,stdout-package", + &val, sizeof(val)); + + /* If it's a display, note it */ + memset(type, 0, sizeof(type)); + prom_getprop(stdout_node, "device_type", type, sizeof(type)); + if (strcmp(type, "display") == 0) + prom_setprop(stdout_node, path, "linux,boot-display", NULL, 0); + } } static int __init prom_find_machine_type(void) -- cgit v1.2.2 From aee636c4809fa54848ff07a899b326eb1f9987a2 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Wed, 15 Jan 2014 06:50:07 -0800 Subject: bpf: do not use reciprocal divide At first Jakub Zawadzki noticed that some divisions by reciprocal_divide were not correct. (off by one in some cases) http://www.wireshark.org/~darkjames/reciprocal-buggy.c He could also show this with BPF: http://www.wireshark.org/~darkjames/set-and-dump-filter-k-bug.c The reciprocal divide in linux kernel is not generic enough, lets remove its use in BPF, as it is not worth the pain with current cpus. Signed-off-by: Eric Dumazet Reported-by: Jakub Zawadzki Cc: Mircea Gherzan Cc: Daniel Borkmann Cc: Hannes Frederic Sowa Cc: Matt Evans Cc: Martin Schwidefsky Cc: Heiko Carstens Cc: David S. Miller Signed-off-by: David S. Miller --- arch/powerpc/net/bpf_jit_comp.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) (limited to 'arch/powerpc') diff --git a/arch/powerpc/net/bpf_jit_comp.c b/arch/powerpc/net/bpf_jit_comp.c index ac3c2a10dafd..555034f8505e 100644 --- a/arch/powerpc/net/bpf_jit_comp.c +++ b/arch/powerpc/net/bpf_jit_comp.c @@ -223,10 +223,11 @@ static int bpf_jit_build_body(struct sk_filter *fp, u32 *image, } PPC_DIVWU(r_A, r_A, r_X); break; - case BPF_S_ALU_DIV_K: /* A = reciprocal_divide(A, K); */ + case BPF_S_ALU_DIV_K: /* A /= K */ + if (K == 1) + break; PPC_LI32(r_scratch1, K); - /* Top 32 bits of 64bit result -> A */ - PPC_MULHWU(r_A, r_A, r_scratch1); + PPC_DIVWU(r_A, r_A, r_scratch1); break; case BPF_S_ALU_AND_X: ctx->seen |= SEEN_XREG; -- cgit v1.2.2